Methods

Study design: parallel‐group RCT

Number randomized: 135 eyes of 96 participants in total; 45 eyes of 32 participants in each of the 3 groups

Exclusions after randomization: none reported

Number analyzed: not reported, assumed to be: 135 eyes of 96 participants in total; 45 eyes of 32 participants in each of the 3 groups

Unit of analysis: unclear as trial investigators did not report how 39 participants with both eyes included were analyzed

Unit of randomization: unclear as trial investigators did not report whether 39 participants were assigned to the same or different groups

Losses to follow‐up: none reported

How were missing data handled? no missing data reported

Reported power calculation: no

Participants

Country: Turkey

Mean age (SD): 64.5(NR) overall:

61.5 (8.1) for the B‐MICS with 1.2 to 1.4 trapezoidal/1.8‐millimeter incision group

65.8 (13.2) for the larger C‐MICS group

66.2 (12.6) for the standard phacoemulsification with 2.8‐millimeter incision group

Gender: 50 men and 46 women overall:

14 men (44%) and 18 women (56%) in the B‐MICS with 1.2 to 1.4 trapezoidal/1.8‐millimeter incision group

17 men (55%) and 14 women (45%) in the larger C‐MICS group

19 men (58%) and 14 women (42%) in the standard phacoemulsification with 2.8‐millimeter incision group

Inclusion criteria: not reported

Exclusion criteria: previous ocular surgery or eye disease that might affect the final visual acuity (amblyopia, corneal scar, glaucoma, retinal or macular disorders, etc.)

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: B‐MICS with 1.2 to 1.4 trapezoidal/1.8‐millimeter incision group

Intervention 2: larger C‐MICS group

Intervention 3: standard phacoemulsification with 2.8‐millimeter incision group

The type of IOL inserted was not reported.

Length of follow‐up:

Planned: not reported
Actual: 90 days

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: VA, pachymetric differences, SIA, phacoemulsification time, CDE (i.e. average ultrasound power), and effective phaco time (time required had 100% power been used throughout), complications
Adverse events reported: yes, 1 eye with capsule rupture in 2.8‐millimeter group

Intervals at which outcomes assessed: 1 day, 7 days, 30 days, and 90 days

Notes

Full study name: Coaxial, microcoaxial, and biaxial microincision cataract surgery prospective comparative study

Type of study: published

Funding sources: not reported

Disclosures of interest: No author has a financial or proprietary interest in any material or method mentioned.

Study period: November 2006 to September 2008

Trial registration: not reported

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

The study did not report whether participants were masked.

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

The study did not report how many participants were followed at each time point.

Selective reporting (reporting bias)

Unclear risk

Protocol was not available. Trial registration not reported.

Other bias

Low risk

Source of funding not reported. Study investigators declared "no author has a financial or proprietary interest in any material or method mentioned" (p740).

Methods

Study design: paired‐eye RCT

Number randomized: 74 eyes of 37 participants; 37 eyes of 37 participants per group

Exclusions after randomization: none reported

Number analyzed: 72 eyes of 36 participants at 3 months; 36 eyes of 36 participants per group

Unit of analysis: 1 eye of each participant

Unit of randomization: both eyes of each participant included; 1 eye is randomized to smaller C‐MICS and the other eye to standard phacoemulsification

Losses to follow‐up: 1 participant at 3 months

How were missing data handled? excluded from analysis

Reported power calculation: no

Unusual study design: the study used paired‐eye design, but did not used paired analysis.

Participants

Country: Spain

Mean age (SD): 72.97 (NR) years overall; age not reported by group

Age range: 52 to 84 years

Gender: 12 men (32%) and 25 women (68%) overall; number per group not reported

Inclusion criteria: over 50 years of age, bilateral senile cataracts intervened for cataract surgery in both eyes between September 2008 and April 2010

Exclusion criteria: corneal pathology, previous ocular trauma or surgery, infectious and/or inflammatory ocular pathology, and astigmatism exceeding 3 diopters

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: smaller C‐MICS

Intervention 2: standard phacoemulsification with 2.8‐millimeter incision

Akreos MI60 IOL (Bausch & Lomb) was inserted for both groups.

Length of follow‐up:

Planned: 3 months
Actual: 3 months

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined by the study report: SIA, ECL, CCT, and foveal thickness
Adverse events reported: no

Intervals at which outcomes assessed: preoperatively and day 1, 1 week, 1 month, and 3 months after surgery

Notes

Full study name: Comparative study of coaxial microincision cataract surgery and standard phacoemulsification

Type of study: published

Funding sources: not reported

Disclosures of interest: not reported

Study period: September 2008 to April 2010

Trial registration: not reported

We emailed the authors and included data provided through email correspondence.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

High risk

The published reported stated that it was a prospective randomized study, but through email correspondence on 24 January 2017, the authors reported assigning treatment by "alternating one‐by‐one."

From the published reported: "prospective and randomised study" (p269)

Allocation concealment (selection bias)

High risk

The published reported stated that it was a prospective randomized study, but through email correspondence the authors reported assigning treatment by "alternating one‐by‐one."

Masking of participants and personnel (performance bias)

High risk

We were informed through email correspondence that participants and personnel were not masked.

Masking of outcome assessment (detection bias)

High risk

We were informed through email correspondence that outcome assessors were not masked.

Incomplete outcome data (attrition bias)
All outcomes

Low risk

1 out of 37 participants (less than 3%) lost to follow‐up.

Selective reporting (reporting bias)

Unclear risk

The protocol was not available. Trial registration not reported. We were informed through email correspondence that the protocol was not published and the trial was not registered.

Other bias

Unclear risk

Source of funding and conflicts of interest not reported.

Methods

Study design: parallel‐group RCT
Number randomized: 50 eyes of 50 participants total; 25 eyes of 25 participants in each group
Exclusions after randomization: none reported
Number analyzed: not reported, assumed to be 50 eyes of 50 participants total and 25 eyes of 25 participants in each group
Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant
Losses to follow‐up: none reported
How were missing data handled? no missing data reported
Reported power calculation: no

Participants

Country: Switzerland
Mean age: 75 years overall:

75 years for the C‐MICS group

75 years for the standard phacoemulsification group

Gender: 22 men (41%) and 28 women (59%) in total:

8 men (32%) and 17 women (68%) in the smaller C‐MICS group

14 men (53%) and 11 women (47%) in the standard phacoemulsification group
Inclusion criteria: people who had nuclear or corticonuclear cataract of grade 2 to 4 according to the Lens Opacities Classification System III scale
Exclusion criteria: people who had corneal pathology, inflammatory eye disease, glaucoma, previous ocular surgery or trauma, and endothelial cell density less than 1500 cells/mm²
Equivalence of baseline characteristics: yes

Interventions

Intervention 1: smaller C‐MICS with 1.6‐millimeter incision; enlarged to 1.8 mm
Intervention 2: standard phacoemulsification with 2.8‐millimeter incision
Lentis L‐303 IOL (WaveLight GmbH) was inserted for both groups.

Length of follow‐up:
Planned: not reported
Actual: 8 weeks

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: BCVA, CCT, and ECL
Adverse events reported: no
Intervals at which outcomes assessed: preoperatively and postoperatively at 1 and 8 weeks

Notes

Full study name: Outcomes of coaxial microincision cataract surgery versus conventional coaxial cataract surgery
Type of study: published
Funding sources: not reported
Disclosures of interest: Dr Di Nardo is an employee of Oertli Instrumente. No other author has a financial or proprietary interest in any material or method mentioned.
Study period: January 2007 to March 2007

Trial registration: not reported

We attempted to contact the authors but the email was returned undeliverable.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

“The participants were randomly assigned to have coaxial MICS or conventional coaxial phacoemulsification.”; but sequence generation was not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

Not reported. Protocol not available. Trial registration not reported.

Other bias

Unclear risk

Source of funding and conflicts of interest not reported.

Methods

Study design: parallel‐group RCT

Number randomized: 190 eyes of 151 participants in total:

63 eyes of 52 participants in the smaller C‐MICS group

66 eyes of 52 participants in the larger C‐MICS group

61 eyes of 47 participants in the standard phacoemulsification group

Exclusions after randomization: none reported

Number analyzed: 190 eyes of 151 participants in total:

63 eyes of 52 participants in the smaller C‐MICS group

66 eyes of 52 participants in the larger C‐MICS group

61 eyes of 47 participants in the standard phacoemulsification group

Unit of analysis: mixed

"As the original dataset included both unilateral and bilateral cases, we reported for each comparison the estimates obtained considering all evaluated eyes (unilateral and bilateral cases) and then repeated the analysis after restricting the data set to one eye per patient by choosing one eye randomly (via a computer‐generated algorithm) in bilateral cases (data not shown)." (p262)

Unit of randomization: 1 or both eyes per participant were assigned to the same treatment group.

Losses to follow‐up: none reported

How were missing data handled? no missing data reported

Reported power calculation: no

Participants

Country: not reported, assumed to be in France (all surgeries were performed by the same surgeon (JLF))
Mean age: 75.1 (9.2) overall:

76.6 (7.6) in the smaller C‐MICS group

73.9 (8.4) in the larger C‐MICS group

74.7 (11.3) in the standard phacoemulsification group

Age range: not reported
Gender: 93 women (62%) and 58 men (38%) overall:

35 women (67%) and 17 men (33%) in the smaller C‐MICS group

37 women (71%) and 15 men (29%) in the larger C‐MICS group

21 women (47%) and 26 men (53%) in the standard phacoemulsification group

Inclusion criteria: people undergoing cataract surgery
Exclusion criteria: "eyes with associated corneal, vitreous, or retinal pathologies" (p262)

Interventions

Intervention 1: smaller C‐MICS with MI 60 IOL (Bausch & Lomb, Rochester, NY, USA) inserted

Intervention 2: larger C‐MICS with AcrySof Natural SN60WF IOL (Alcon, Fort Worth, TX, USA) inserted

Intervention 3: standard phacoemulsification (3.2‐millimeter incision) with Adapt AO IOL (Bausch & Lomb, Rochester, NY, USA) inserted

We considered standard phacoemulsification with incisions ranging from 2.75 to 3.2 mm to be about 3.0 mm.

Length of follow‐up:

Planned: not reported

Actual: 1 month

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: keratometric astigmatism (using the same autokeratometer (Tonoref II; Nidek, Aichi, Japan); the Tonoref II measures the corneal curvature based on the projection onto the cornea of 4 near‐infrared rays, scalar comparison of astigmatism, with‐the‐wound change, and against‐the‐wound change
Adverse events reported: no
Intervals at which outcomes assessed: 1 month

Notes

Full study name: Astigmatic equivalence of 2.2‐mm and 1.8‐mm superior clear corneal cataract incision
Type of study: published full text
Funding sources: not reported
Disclosures of interest: not reported
Study period: not reported

Trial registration: not reported

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

None of the participants were reported to have been lost to follow‐up.

Selective reporting (reporting bias)

Unclear risk

Trial registry number and protocol were not reported, therefore we could not compare outcomes reported in the published full text and the trial registry/protocol.

Other bias

Unclear risk

Trial register number and funding sources were not reported.

Methods

Study design: parallel‐group RCT
Number randomized: 117 eyes of 85 participants in total:

59 eyes of 43 participants in the smaller C‐MICS group

58 eyes of 42 participants in the standard phacoemulsification group
Exclusions after randomization: none reported
Number analyzed: 85 participants with 117 eyes in total:

59 eyes of 43 participants in the smaller C‐MICS group

58 eyes of 42 participants in the standard phacoemulsification group
Unit of analysis: unclear as trial investigators did not report how 32 participants with both eyes included were analyzed

Unit of randomization: unclear whether both eyes of the 32 participants were assigned to the same or different groups
Losses to follow‐up: none reported
How were missing data handled? no missing data reported
Reported power calculation: no

Participants

Country: China
Mean age (SD): 64.1 (8.6) overall:

64.8 (8.5) in the smaller C‐MICS group

63.3 (8.8) in the standard phacoemulsification group
Gender: 40 men (47%) and 45 women (53%) overall:

21 men (49%) and 22 women (51%) in the smaller C‐MICS group

19 men (45%) and 23 women (55%) in the standard phacoemulsification group
Inclusion criteria: “(1)根据LOCSIII分级标准,晶状体核硬度为II˜III级;(2)角膜屈光度<1.0 diopters;(3)眼轴22 ˜ 24.5mm;(4)角膜内皮细胞密度>1500 个/mm2。” (p1829)

(1) people with cataract nucleus graded II‐III, according to the Emery‐Little classification; (2) corneal diopter less than 1.0 diopters; (3) axial lengths 22 to 24.5 mm; (4) endothelial cell density more than 1500 cells/mm²
Exclusion criteria: “(1)角膜变性、葡萄膜炎、青光眼、高度近视眼、视神经 病变、视网膜病变、年龄相关性黄斑变性、眼外伤病史、准分子激光手术和其他内眼手术史;(2) 全身严重疾病史不能耐受手术者。” (p1829)

(1) corneal degeneration, uveitis, glaucoma, high myopia, optic neuropathy, retinopathy, age‐related macular degeneration, history of eye injury, history of LASIK; (2) history of systemic disorders that could not tolerate operation
Equivalence of baseline characteristics: yes

Interventions

Intervention 1: smaller C‐MICS with Akreos MI60 IOL inserted

Intervention 2: standard phacoemulsification with 3.2‐millimeter incision with Adapt‐AO IOL inserted

Planned: not reported
Actual: 90 days

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: uncorrected VA, average ultrasound energy, effective phacoemulsification time, ECL, and corneal topography

Adverse events reported: yes, temporary increase in intraocular pressure
Intervals at which outcomes assessed: 1 day, 7 days, 30 days, 90 days for uncorrected VA, 90 days for other outcomes

Notes

Full study name: 同轴 1. 8mm 微切口白内障超声乳化吸除术的临床研究

[Clinical effects of coaxial 1.8 mm microincision phacoemulsification]

Type of study: published full text

Funding sources: 陕西省科学技术研究发展计划项目 [Shaanxi Province Science and Technology Research and Development Project (No. 2012K16‐11(5))]

Disclosures of interest: not reported

Trial registry number: not reported

Study period: December 2012 to March 2015

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

“将患者按数字表法随机分为两组" [Participants were randomized into 2 groups using random number tables.] (p1829)

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

No missing data were reported.

Selective reporting (reporting bias)

Unclear risk

No protocol available for comparison.

Other bias

Unclear risk

No disclosures of interest, no trial registry number, no protocol

Methods

Study design: parallel‐group RCT

Number randomized: 60 eyes of 55 participants overall:

30 eyes of 28 participants in the larger C‐MICS group

30 eyes of 27 participants in the standard phacoemulsification group

Number randomized: 55 participants of 60 eyes overall:

30 eyes of 28 participants in the larger C‐MICS group

30 eyes of 27 participants in the standard phacoemulsification group

Exclusions after randomization: none reported

Number analyzed: unclear, assumed to be:

60 eyes of 55 participants overall:

30 eyes of 28 participants in the larger C‐MICS group

30 eyes of 27 participants in the standard phacoemulsification group

Unit of analysis: unclear, as trial investigators did not report how 5 participants with both eyes included were analyzed

Unit of randomization: unclear whether both eyes of the 5 participants were assigned to the same or different groups

Losses to follow‐up: none reported

How were missing data handled? no missing data reported

Reported power calculation: no

Participants

Country: South Korea

Overall mean age: not reported

Mean age (SD): 69.7 (NR) overall:

70.6 (9.2) in the larger C‐MICS group

68.8 (7.6) in the standard phacoemulsification group

Age range: not reported

Gender: 13 men and 15 women in the larger C‐MICS group; 11 men and 16 women in the standard phacoemulsification group

Inclusion criteria: not reported

Exclusion criteria: "patients with corneal disease, intraocular inflammation, glaucoma, and those who had previously undergone corneal surgery or surgery that could affect high‐order aberrations were excluded" (p1598)

Interventions

Intervention 1: larger C‐MICS

Intervention 2: standard phacoemulsification (2.8 mm)

We considered standard phacoemulsification with incisions ranging from 2.75 to 3.2 mm to be about 3.0 mm.

SA60AT IOL (AcrySof; Alcon, USA) was inserted for both groups.

Length of follow‐up:

Planned: protocol not available
Actual: 3 months

Outcomes

Primary outcome, as defined in study reports: SIA
Secondary outcomes, as defined in study reports:

Postoperative change of corneal higher‐order aberrations in each group at 1 month or 3 months after surgery

Corneal higher‐order aberrations between the 2 groups preoperatively, at 1 month or 3 months

after surgery
Adverse events reported: not reported

Intervals at which outcomes assessed: baseline, 1 month and 3 months

Notes

Type of study: published full text

Funding sources: Inje University

Disclosures of interest: not reported

Trial registry number: not reported

Study period: July 2006 to December 2006

We attempted to contact the authors but the email was returned undeliverable.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

The protocol was not available. Trial registration not reported.

Other bias

Unclear risk

Source of funding and conflicts of interest not reported.

Methods

Study design: paired‐eye RCT
Number randomized: 42 participants with 42 eyes in total:

42 eyes of 42 participants in the larger C‐MICS group

42 eyes of 42 participants in the standard phacoemulsification group
Exclusions after randomization: none reported
Number analyzed: 42 participants with 42 eyes in total:

42 eyes of 42 participants in the larger C‐MICS group

42 eyes of 42 participants in the standard phacoemulsification group
Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant
Losses to follow‐up: none reported
How were missing data handled? not reported
Reported power calculation: none reported
Unusual study design: the study randomized participants and included both eyes of the same participant in the same intervention, but they did not account for intraperson correlation.

Participants

Country: Korea
Mean age (SD): 65.20 (NR) overall:

64.52 (10.65) in the larger C‐MICS group

65.87 (12.91) in the standard phacoemulsification group
Gender: not reported
Inclusion criteria: “patients with nuclear density from Grade 3–4, a dilated pupil of 7.0 mm or larger, and a corneal endothelial cell count (ECC) >2000 cells/mm².” (p190)
Exclusion criteria: “patients with history of uveitis or other intra‐ocular inflammation diseases, topical prostaglandin users, and intraoperative complications such as posterior lens capsule rupture and lens dislocation” (p190)
Equivalence of baseline characteristics: yes

Interventions

Intervention 1: larger C‐MICS group
Intervention 2: standard phacoemulsification (2.75 mm) group

MI60 IOL (Bausch & Lomb, Rochester, NY, USA) was inserted for both groups.
Length of follow‐up:
Planned: not reported
Actual: 2 months

Outcomes

Primary outcome, as defined in study reports:

"1. Intraoperative measurements included:

1.1. Ultrasound time (UST)

1.2. Mean cumulative dissipated ultrasound energy (CDE)

1.3. Total balanced salt solution (BSS) use

2. Clinical measurements included preoperative, 1­week postoperative, 1­month postoperative and 2­month postoperative:

2.1. Best corrected visual acuity (BCVA)

2.2. Central corneal thickness (CCT)

2.3. Endothelial cell count (ECC)"
Secondary outcomes, as defined in study reports: enzyme­linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT­PCR) were performed for IL‐1alpha, IL‐6, VEGF, and PGE2 preoperatively and at 1 week postoperatively.
Adverse events reported: not reported

Intervals at which outcomes assessed: 1 day, 1 week, 1 month, and 2 months

Notes

Full study name: Comparison of macular thickness and inflammatory cytokine levels after microincision versus small incision coaxial cataract surgery

Type of study: published full text

Funding sources: "Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (No. 2012R1A1A1038648) and the Institute of Clinical Medicine Research of Bucheon St. Mary’s Hospital, Research Fund, BCMC14AA07" (p194)

Disclosures of interest: not reported

Trial registry number: ISRCTN 69290731

Study period: not reported

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Low risk

“One examiner was masked as to whether the images were from the microincision group or the small incision group.” (p191)

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

None of the participants were reported to have been lost to follow‐up.

Selective reporting (reporting bias)

Low risk

All the outcomes in the registry have been reported.

Other bias

Unclear risk

Disclosures of interest were not reported.

Methods

Study design: parallel‐group RCT

Number randomized: 144 eyes of 96 participants overall:

72 eyes of NR participants in the larger C‐MICS group

72 eyes of NR participants in the standard phacoemulsification group

Exclusions after randomization: none reported, assumed to be none

Number analyzed: 144 eyes of 96 participants overall:

72 eyes of NR participants in the larger C‐MICS group

72 eyes of NR participants in the standard phacoemulsification group

Unit of analysis: unclear as trial investigators did not report how 48 participants with both eyes included were analyzed

Unit of randomization: unclear whether both eyes of the 48 participants were assigned to the same or different groups

Losses to follow‐up: none reported

How were missing data handled?: no missing data reported

Reported power calculation: no

Participants

Country: South Korea

Mean age (SD): 71.49 (NR) overall:

72.30 (10.85) in C‐MICS group

70.67 (8.27) in standard phacoemulsification group

Age range: not reported

Gender: not reported

Inclusion criteria: people with cataract; no specific description

Exclusion criteria: "patients with a history of preoperative corneal surgery, patients with diabetic retinopathy or iritis, and those who were previously diagnosed with keratopathy were excluded. The posterior capsular rupture or vitreous loss was excluded from the study." (p709)

Interventions

Intervention 1: larger C‐MICS

Intervention 2: standard phacoemulsification with 2.8‐millimeter incision

We considered standard phacoemulsification with incisions ranging from 2.75 to 3.2 mm to be about 3.0 mm.

MI‐60 IOL (Bausch & Lomb, Rochester, NY, USA) was inserted for both groups.

Length of follow‐up:

Planned: not available
Actual: 1 month

Outcomes

Primary outcome, as defined in study reports: total UST, CDE, average torsional amplitude, fluid amount, case time, CCT increase
Secondary outcomes, as defined in study reports: ultrasound dynamic parameters measured during surgery and edema

Adverse events reported: yes, burning of the cornea, no postoperative infection or persistent inflammation

Intervals at which outcomes assessed: baseline, 1 day, and 1 month

Notes

Type of study: published full text

Funding sources: not reported

Disclosures of interest: not reported

Trial registry number: not reported

Study period: not reported

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

Authors may have not reported an outcome due to difficulty assigning it.

"To assess corneal stress after surgery, it may be helpful to measure the density of endothelial cells and measure the thickness and recovery pattern of the corneal incision site. In the present study, it was difficult to measure endothelial cells in the presence of central corneal edema 1 day after surgery. Therefore, there is a limitation that it is excluded."

Other bias

Unclear risk

Source of funding and conflicts of interest not reported.

Methods

Study design: parallel‐group RCT

Number randomized: 76 eyes of 71 participants in total:

37 eyes of NR participants in the larger C‐MICS group

39 eyes of NR participants in the standard phacoemulsification group

Exclusions after randomization: none reported

Number analyzed: not reported, assumed to be:

76 eyes of 71 participants total; 37 eyes in the larger C‐MICS group

39 eyes in the standard phacoemulsification group

Unit of analysis: unclear as trial investigators did not report how 5 participants with both eyes included were analyzed

Unit of randomization: unclear whether both eyes of the 5 participants were assigned to the same or different groups

Losses to follow‐up: none reported

How were missing data handled? no missing data reported

Reported power calculation: no

Participants

Country: Korea

Mean age: overall 68.53 years:

66.83 years in the larger C‐MICS group

69.25 years in the standard phacoemulsification group

Age range: 57 to 85 overall

Gender: 39 men (55%) and 32 women (45%) overall; number per group not reported

Inclusion criteria: age‐related cataracts included eyes with grade II‐IV nuclear cataracts (Lens Opacities Classification System (LOCS) III)

Exclusion criteria: “presence of pre‐existing corneal disease or degeneration, an incision that required enlarging to insert an IOL, and complicated or excessively prolonged surgery”

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: larger C‐MICS

Intervention 2: standard phacoemulsification with 2.8‐millimeter incision

They type of IOL was not reported; "in both the 2.2 and 2.8 mm groups, the IOL type and the IOL injector system were matched, except for the incision size, to minimize bias." (p201)

Length of follow‐up:

Planned: 1 month
Actual: 1 month

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: CDE, UST, ECL, and CCT

Adverse events reported: not reported

Intervals at which outcomes assessed: 1 day before surgery, and postoperatively at 1 day, 1 week, and 1 month

Notes

Full study name: Early changes in corneal edema following torsional phacoemulsification using anterior segment optical coherence tomography and Scheimpflug photography

Type of study: published

Funding sources: Korea Healthcare Technology R&D Project, Ministry for Health Welfare & Family Affairs, Republic of Korea (A 090573)

Disclosures of interest: not reported

Study period: May to July 2009

Trial registration: not reported

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

The study mentioned that participants were randomized, but did not specify methods for random sequence generation.

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

Protocol not reported. Trial registration not reported.

Other bias

Low risk

Source of funding reported, conflicts of interest not reported. "This work was supported by the Korea Healthcare Technology R&D Project, Ministry for Health Welfare & Family Affairs, Republic of Korea (A 090573)." (p203)

Methods

Study design: parallel‐group RCT
Number randomized: 90 eyes of 90 participants in total; 45 eyes of 45 participants in each group
Exclusions after randomization: none reported
Number analyzed: 90 eyes of 90 participants in total; 45 eyes of 45 participants in each group

Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant
Losses to follow‐up: none reported
How were missing data handled? no missing data reported
Reported power calculation: no
Unusual study design: none

Participants

Country: China
Mean age (SD): 64.1 (8.6) overall:

51.5 (4.2) in C‐MICS 2.2 mm and IOL implantation group

50.2 (3.9) in standard phacoemulsification 3.0 mm and IOL implantation group

Age range: 45 to 62 overall:

45 to 62 in coaxial C‐MICS 2.2 mm and IOL implantation group

46 to 61 in standard phacoemulsification 3.0 mm and IOL implantation group
Gender: 49 men and 41 women overall:

25 men (56%) and 20 women (44%) in C‐MICS 2.2 mm and IOL implantation group

24 men (53%) and 21 women (47%) in standard phacoemulsification 3.0 mm and IOL implantation group
Inclusion criteria: "patients receiving phacoemulsification cataract extraction surgeries" (p81)
Exclusion criteria: "other eye diseases, severe autoimmune system diseases, and systemic connective tissue diseases" (p81)
Equivalence of baseline characteristics: yes

Interventions

Intervention 1: C‐MICS 2.2 mm and IOL implantation

Intervention 2: standard phacoemulsification 3.0 mm and IOL implantation

Akreos MI60 IOL was inserted for both groups.

Length of follow‐up:

Planned: not reported

Actual: 30 days

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: dry eye symptom score, break‐up time, Schirmer's 1 test, and corneal fluorescein staining score

Adverse events reported: yes, temporary increase in intraocular pressure
Intervals at which outcomes assessed: 10, 20, 30 days

Notes

Full study name: Changes of the ocular surface and tear film after clear corneal incision phacoemulsification with different incision sizes

Type of study: published full text

Funding sources: "海南省卫生厅科研项目(No.琼卫2012PT‐28)作者单位:(570102)中国海南省海口市,海南医学院附属医院眼科" (p80)

Research of Hainan Provincial Health Department (No.琼卫2012PT‐28)

Disclosures of interest: not reported

Study period: May 2013 to May 2014

Trial registration: not reported

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

Protocol not reported. Trial registration not reported.

Other bias

Low risk

Source of funding reported, conflicts of interest not reported

"海南省卫生厅科研项目(No. 琼卫2012PT‐28)
作者单位:(570102)中国海南省海口市,海南医学院附属医院
眼科" (p80)

Methods

Study design: parallel‐group RCT
Number randomized: 78 eyes of 56 participants in total:

38 eyes of NR participants in the larger C‐MICS group

40 eyes of NR participants in the standard phacoemulsification (3.0‐millimeter incision) group
Exclusions after randomization: none reported
Number analyzed: not reported, assumed to be:

78 eyes of 56 participants in total:

38 eyes of NR participants in the larger C‐MICS group

40 eyes of NR participants in the standard phacoemulsification (3.0‐millimeter incision) group

Unit of analysis: unclear as trial investigators did not report how 22 participants with both eyes included were analyzed

Unit of randomization: unclear whether both eyes of the 22 participants were assigned to the same or different groups
Losses to follow‐up: not reported
How were missing data handled? not reported
Reported power calculation: no
Unusual study design: the study randomized participants and included both eyes of the same participant in the same intervention, but they did not account for intraperson correlation.

Participants

Country: China
Mean age: 71.3 years overall: not reported by group
Gender: not reported
Inclusion criteria: “诊断为老年性白内 障，患者年龄大于50 岁,裂隙灯下观察见患眼晶状体混浊。 术前检查角膜内皮 细胞计数大于1200 个/mm2。” (p1465)

age‐related cataract with age over 50 with preoperation endothelial cell count larger than 1200/mm²
Exclusion criteria: “排除增殖期糖尿病视网膜病变、青光眼、老年性黄斑变性等眼部疾病及既 往有内眼手术史的患者。 术中出现后囊膜破裂、玻璃体溢 出等并发症者、不能完成 3mo 随访者予以剔除。 ” (p1465)

diabetic retinopathy, glaucoma, age‐related macular degeneration, previous operation, posterior capsule rupture during surgery, vitreous loss in the surgery
Equivalence of baseline characteristics: yes

Interventions

Intervention 1: C‐MICS (2.2‐millimeter incision)

Intervention 2: standard phacoemulsification (3.0‐millimeter incision)

SN60WF IOL (Alcon) was inserted for both groups.

Length of follow‐up:

Planned: not reported

Actual: 3 months

Outcomes

Primary and secondary outcomes were not differentiated.

Outcomes, as defined in the study reports: uncorrected VA, BCVA, corneal astigmatism, SIA

Notes

Full study name: 同轴微切口白内障超声乳化术后角膜散光的临床观察

Observation of corneal astigmatism induced by 2.2‐millimeter microincision coaxial phacoemulsification

Type of study: published full text

Funding sources: 佛山市卫生局医学科研立项课题 (No. 2011162)

Medical scientific research program of Foshan board of health (No. 2011162)

Disclosures of interest: not reported

Trial registry number: not reported

Study period: January to September 2011

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

High risk

“将患者按就诊顺序登记并按随机表法分成两组,分别施行 2郾 2mm 同轴微切口白内障超声乳化联合 IOL 植入术及 3.0mm 常规白内障超声乳化联合 IOL 植入术,其中 2.2mm 组 38 眼,3. 0mm 组 40 眼。

“排除增殖期糖尿病视网膜病变、青光眼、老年性黄斑变性等眼部疾病及既 往有内眼手术史的患者。 术中出现后囊膜破裂、玻璃体溢 出等并发症者、不能完成 3mo 随访者予以剔除。 ” (p1465)

Randomized table was used to distribute the participants into different groups. Diabetic retinopathy, glaucoma, age‐related macular degeneration, previous operation, posterior capsule rupture during surgery, vitreous loss in the surgery. Postrandomization exclusions exist.

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

High risk

Participants were excluded postrandomization.

Selective reporting (reporting bias)

Unclear risk

Trial registry number and protocol were not available for comparison.

Other bias

Unclear risk

Funding sources and disclosures of interests were not reported.

Methods

Study design: parallel‐group RCT

Number randomized: 120 eyes of 120 participants total; 40 eyes of 40 participants per group

Exclusions after randomization: none

Number analyzed: 120 eyes of 120 participants total; 40 eyes of 40 participants per group

Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant

Losses to follow‐up: none reported

How were missing data handled? no missing data

Reported power calculation: no

Unusual study design: no

Participants

Country: China

Mean age: overall mean age not reported; 73.95 years for 1.8 mm; 71.37 years for 2.2 mm; 72.48 years for 3.0 mm

Gender: 58 men and 62 women overall;

21 men (53%) and 19 women (47%) in the smaller C‐MICS group

18 men (45%) and 22 women (55%) in the C‐MICS (2.2‐millimeter incision) group

19 men (47%) and 21 women (53%) in the standard phacoemulsification (3.0‐millimeter incision) group

Inclusion criteria: age between 55 and 85 years, the presence of nuclear or corticonuclear cataract of grades 2.0 to 4.0 (Lens Opacities Classification System III), a transparent central cornea, pupil dilation 7 mm at the time of preoperative examination, and a preoperative central endothelial cell count of 1500 cells/mm²

Exclusion criteria: previous intraocular surgery, glaucoma, pseudoexfoliation, uveitis, high myopia, and diabetes mellitus

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: smaller C‐MICS group with Akreos MI 60 IOL (Bausch & Lomb) inserted

Intervention 2: C‐MICS (2.2‐millimeter incision) group with SN60WF IOL (Alcon) inserted

Intervention 3: standard phacoemulsification (3.0‐millimeter incision) group with SA60AT IOL (Alcon) inserted

We considered standard phacoemulsification with incisions ranging from 2.75 to 3.2 mm to be about 3.0 mm.

Length of follow‐up:

Planned: 3 months
Actual: 3 months

Outcomes

Primary outcome, as defined in study reports: UST, surgical time, CDE and the total BSS volume, intraoperative measurements of corneal incision size during surgery, change in maximal clear corneal incision thickness as evaluated by AS‐OCT, BCVA, central cornea ECL, and SIA
Secondary outcomes, as defined in study reports: primary and secondary outcomes not differentiated
Adverse events reported: no

Intervals at which outcomes assessed: postoperatively at 1 day, 1 week, 1 month, 3 months

Notes

Full study name: Clinical evaluation of three incision size–dependent phacoemulsification systems

Type of study: published

Funding sources: Natural Science Foundation of China (30973277) and the Key Projects for Hospital Clinical Disciplines Fund of the Chinese Ministry of Health in 2010–2012 (Project No.175 in Document 439 of the Planning and Finance Secretary of Ministry of Health, China)

Disclosures of interest: “The authors indicate no financial conflict of interest.”

Study period: July 2010 to January 2011

Trial registration: NCT01429532 (ClinicalTrials.gov)

We attempted to contact the authors but the email was returned undeliverable.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

"A number between 1 and 120, generated by a random number generator, was assigned to each subject. The number was divided by 3. If the remainder was 1, the patient was assigned to Group I; if the remainder was 2, the patient was assigned to Group II; and if the number was divisible by 3, the patient was assigned to Group III."

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Low risk

"Both the technician and the surgeon were masked during postoperative examinations to the participants' group assignment."

Incomplete outcome data (attrition bias)
All outcomes

Low risk

"All participants completed all follow‐up visits."

Selective reporting (reporting bias)

Low risk

This clinical trial has been registered at www.clinicaltrials.gov, registration number NCT01429532. All outcomes were reported.

Other bias

Low risk

Source of funding and conflicts of interest reported. "Publication of this clinical study was supported by the Natural Science Foundation of China (30973277)" (p838) "The authors indicate no financial conflict of interest." (p838)

Methods

Study design: parallel‐group RCT

Number randomized: 160 eyes of 160 participants total; 80 eyes of 80 participants in each group

Exclusions after randomization: none reported

Number analyzed: 160 eyes of 160 participants; 80 eyes of 80 participants in each group

Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant

Losses to follow‐up: none at 1 month

How were missing data handled? not reported

Reported power calculation: no

Unusual study design: no

Participants

Country: China

Mean age (SD): 69 (NR) overall; not reported by group

Age range: 48 to 82 years

Gender: 84 men (52%) and 76 women (48%) overall; number per group not reported

Inclusion criteria: age‐related cataract

Exclusion criteria: people with glaucoma, diabetes, or other eye diseases were excluded

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: B‐MICS (1.4‐millimeter incision) group with Acri.Smart46s (Acti.Tec) IOL inserted

Intervention 2: standard phacoemulsification (3.0‐millimeter incision) group with SENSER IOL (AMO) inserted.

We considered standard phacoemulsification with incisions ranging from 2.75 to 3.2 mm to be about 3.0 mm.

Length of follow‐up:

Planned: not reported

Actual: 1 month

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: uncorrected VA and SIA
Adverse events reported: yes, corneal edema

Intervals at which outcomes assessed: preoperatively and postoperatively at 1 day, 1 week, and 1 month

Notes

Full study name: Analysis of the visual quality after bimanual phacoemulsification via micro‐incision

Type of study: published

Funding sources: not reported

Disclosures of interest: not reported

Study period: August 2005 to February 2006

Trial registration: not reported

We attempted to contact the authors but the email was returned undeliverable.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

Protocol was not available. Trial registration not reported.

Other bias

Unclear risk

Source of funding and conflicts of interest not reported.

Methods

Study design: parallel‐group RCT

Number randomized: 30 eyes of 30 participants; 15 eyes of 15 participants per group

Exclusions after randomization: not reported

Number analyzed: not reported

Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant

Losses to follow‐up: none

How were missing data handled? not reported

Reported power calculation: no

Unusual study design? none

Participants

Country: Italy

Mean age (SD): 69.8 (NR) overall:

70.11 (NR) smaller C‐MICS group

69.44 (NR) C‐MICS (2.2‐millimeter incision) group

Gender: not reported

Inclusion criteria: age 65 to 75 years, axial length 23.0 to 24.0 mm, corneal astigmatism less than 3.00 diopters, nuclear cataract of grade 4 (nuclear opalescence ‐ NO4, Lens Opacities Classification System III), and corneal endothelial cell count greater than 1200/mm²

Exclusion criteria: anterior segment pathological alterations such as keratoconus, chronic uveitis, zonular dialysis, pseudo­exfoliation syndrome, glaucoma, and diabetes mellitus; other ocular pathologies impairing visual function; previous anterior or posterior segment surgery; and intraoperative or postoperative complications

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: smaller C‐MICS

Intervention 2: C‐MICS (2.2‐millimeter incision)

AcrySof SN60WF IOL (Alcon) was inserted for both groups.

Length of follow‐up:

Planned: not reported
Actual: 90 days

Outcomes

Primary outcome, as defined in study reports: uncorrected VA and BCVA, keratometric astigmatism, endothelial cell count, and corneal thickness at incision site. The amount and axis of astigmatic change induced by the cataract surgery were assessed by calculating the SIA. Power vector analysis of keratometric astigmatic change between preoperative and postoperative values was performed.
Secondary outcomes, as defined in study reports: intraoperative parameters including mean torsional time, CDE, and BSS used
Adverse events reported: not reported

Intervals at which outcomes assessed: postoperatively at 1 day, 7 days, 30 days, and 90 days

Notes

Full study name: Microcoaxial torsional cataract surgery 1.8 mm versus 2.2 mm: functional and morphological assessment

Type of study: published

Funding sources: not reported

Disclosures of interest: the authors have no financial or proprietary interest in the materials

Study period: not reported

Trial registration: not reported

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

"Participants were randomly assigned to group 1 or group 2 the day before surgery by block randomization (randomly assigned by computer‐generated numbers)"

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Low risk

"Participants and examiners performing preoperative and postoperative controls were masked to the surgical technique used in each case"

Masking of outcome assessment (detection bias)

Low risk

"Participants and examiners performing preoperative and postoperative controls were masked to the surgical technique used in each case"

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

Protocol was not available. Trial registration not reported.

Other bias

Low risk

Source of funding not reported. "The authors have no financial or proprietary interest in the materials presented herein." (p114)

Methods

Study design: parallel‐group RCT

Number randomized: 100 eyes of 89 participants overall:

32 eyes of NR participants in the smaller C‐MICS group

38 eyes of NR participants in C‐MICS (2.2‐millimeter incision) group

30 eyes of NR participants in standard phacoemulsification with 2.8‐millimeter incision group

Exclusions after randomization: none reported

Number analyzed: 100 eyes of 89 participants overall:

32 eyes of NR participants in the smaller C‐MICS group

38 eyes of NR participants in C‐MICS (2.2‐millimeter incision) group

30 eyes of NR participants in standard phacoemulsification with 2.8‐millimeter incision group

Unit of analysis: unclear as trial investigators did not report how 11 participants with both eyes included were analyzed

Unit of randomization: unclear whether both eyes of the 11 participants were assigned to the same or different groups

Losses to follow‐up: none reported

How were missing data handled? no missing data reported

Reported power calculation: no

Participants

Country: South Korea

Mean age (SD): 65.2 (NR) overall:

64.5 (10.5) years old in the smaller C‐MICS group

61.8 (15.3) years old in C‐MICS (2.2‐millimeter incision) group

69.4 (10.0) years old in standard phacoemulsification with 2.8‐millimeter incision group

Age range: not reported

Gender: 30 men and 59 women total; number per group not reported

Inclusion criteria: "the subjects with corneal astigmatism less than 2.25 diopters were examined" (p408)

Exclusion criteria: "the patients who underwent corneal surgery including refractive surgery, eyes that can not measure the corneal curvature due to corneal opacity, surgery that affects corneal astigmatism during surgery, or other types of intraocular lenses were excluded from the study." (p408)

Interventions

Intervention 1: smaller C‐MICS with MI60 IOL (Bausch & Lomb, Rochester, NY, USA)

Intervention 2: C‐MICS (2.2‐millimeter incision) with AcrySof IQ IOL (Alcon, Fort Worth, TX, USA)

Intervention 3: standard phacoemulsification (2.8‐millimeter incision) with Akreos AO IOL (Bausch & Lomb)

We considered standard phacoemulsification with incisions ranging from 2.75 to 3.2 mm to be about 3.0 mm.

Length of follow‐up:

Planned: no protocol available

Actual: baseline, 1 and 3 months

Outcomes

Primary outcome, as defined in study reports: SIA and high‐order aberrations (coma, trefoil, and spherical aberration)
Secondary outcomes, as defined in study reports: coma–root mean square (RMS) and trefoil‐RMS were evaluated at 1 month after the cataract operation.
Adverse events reported: no

Intervals at which outcomes assessed: baseline, 1 and 3 months

Notes

Type of study: published full text

Funding sources: not reported

Disclosures of interest: not reported

Study period: March 2009 to August 2009

Trial registry number: not reported

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

Protocol was not available. Trial registration not reported.

Other bias

Unclear risk

Funding sources, disclosures of interests were not reported.

Methods

Study design: parallel‐group RCT

Number randomized: 94 eyes of 64 participants total; 43 eyes in standard phacoemulsification group, 51 eyes in B‐MICS group

Exclusions after randomization: none

Number analyzed: 94 eyes of 64 participants; 43 eyes in standard phacoemulsification group, 51 in B‐MICS group

Unit of analysis: unclear as trial investigators did not report how 30 participants with both eyes included were analyzed

Unit of randomization: unclear whether both eyes of the 30 participants were assigned to the same or different groups

Losses to follow‐up: standard phacoemulsification group had none reported at 1 month, 3 participants at 3 months and 5 participants at 6 months; B‐MICS had none reported at 1 month, 3 participants at 3 months, and 3 participants at 6 months.

How were missing data handled? not reported

Reported power calculation: no

Unusual study design? no

Participants

Country: Spain

Mean age (SD): 70.53 (NR) overall:

69.02 (NR) years for standard phacoemulsification

72.04 (NR) years for B‐MICS

Gender: 24 men (37%) and 40 women (63%) overall; number not reported by group

Inclusion criteria: people scheduled for elective cataract surgery

Exclusion criteria: topographic astigmatism 42.0 diopters, intraoperative use of corneal sutures, or corneal disease

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: B‐MICS (1.5‐ to 2‐millimeter incision) with Acri.Smart 48S IOL (Acri.Tec, Hennigsdorf, Germany) inserted

Intervention 2: standard phacoemulsification (2.8‐millimeter incision) with Y601075 (AJL, A ́lava, Spain)

Length of follow‐up:

Planned: not reported

Actual: 6 months

Outcomes

Primary outcome, as defined in study reports: SIA and BCVA

Secondary outcomes, as defined in study reports: not reported

Adverse events reported: not reported

Intervals at which outcomes assessed: preoperatively and postoperatively at 1, 3, and 6 months

Notes

Full study name: Surgically induced astigmatism after biaxial phacoemulsification compared to coaxial phacoemulsification

Type of study: published

Funding sources: not reported

Disclosures of interest: no

Study period: not reported

Trial registration: not reported

We attempted to contact the authors but the email was returned undeliverable.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

The study mentioned that participants were randomized, but did not specify methods for random sequence generation.

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Low risk

"Neither the patient nor the examiner knew which technique had been applied."; double‐blind clinical trial

Masking of outcome assessment (detection bias)

Low risk

"Neither the patient nor the examiner knew which technique had been applied."

Incomplete outcome data (attrition bias)
All outcomes

Low risk

8 out of 94 participants (9.6%) were lost to follow‐up at 6 months.

Selective reporting (reporting bias)

Unclear risk

Protocol was not available. Trial registration not reported.

Other bias

Unclear risk

Source of funding and conflicts of interest not reported.

Methods

Study design: paired‐eye RCT

Number randomized: 60 eyes of 30 participants in total; 30 eyes of 30 participants per group

Exclusions after randomization: not reported

Number analyzed: not reported, assumed to be 60 eyes of 30 participants in total; 30 eyes of 30 participants per group

Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant

Losses to follow‐up: not reported

How were missing data handled? not reported

Reported power calculation: no

Unusual study design: none

Participants

Country: Bosnia and Herzegovina

Mean age (SD): 63.6 (NR) overall:

65.13 (NR) in standard phacoemulsification (3.0‐millimeter incision) group

62.06 (NR) in the larger C‐MICS group

Gender: not reported

Inclusion criteria: people from everyday operational program cataract surgery at the Eye Clinic of University Clinical Center Tuzla in the period of October 2009 to December 2009. People planned for cataract surgery and who met the inclusion criteria of the study were included.

Exclusion criteria: not reported

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: standard phacoemulsification (3.0‐millimeter incision)

Intervention 2: larger C‐MICS

The type of IOL inserted was not reported.

Length of follow‐up:

Planned: not reported

Actual: postoperatively at 1, 7, and 30 days; extended to 90 days for SIA

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: uncorrected distance VA, corneal keratometry, and corneal astigmatism and SIA were assessed 1, 7, and 30 days after cataract surgery.
Adverse events reported: not reported

Intervals at which outcomes assessed: postoperatively at 1, 7, and 30 days; extended to 90 days for SIA

Notes

Full study name: Corneal astigmatism after micro‐incision cataract operation

Type of study: published

Funding sources: not reported

Disclosures of interest: none

Study period: October 2009 to December 2009

Trial registration: not reported

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

High risk

The methods describe 4 outcomes; 2 of them, corneal keratometry and corneal astigmatism, were not found in the results section.

Other bias

Low risk

Source of funding not reported. "Conflict of interest: none declared." (p128)

Methods

Study design: parallel‐group RCT

Number randomized: 362 eyes of 362 participants in total:

211 eyes of 211 participants in C‐MICS 2.2‐millimeter group

151 eyes of 151 participants in standard phacoemulsification 2.8‐millimeter group

Exclusions after randomization: none reported

Number analyzed: 362 eyes of 362 participants in total:

211 eyes of 211 participants in C‐MICS 2.2‐millimeter group

151 eyes of 151 participants in standard phacoemulsification 2.8‐millimeter group

Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant

Losses to follow‐up: none reported

How were missing data handled? no missing data reported

Reported power calculation: none

Participants

Country: China
Mean age: not reported
Gender: not reported
Inclusion criteria: “择 2014‐07/2015‐03 在宝鸡市人民医院眼 科接受透明角膜切口白内障超声乳化+后房型折叠式人 工晶状体植入术的年龄相关性白内障患者 362 例 362 眼 术前矫正视力 0. 3 ˜ 光感。 眼压、光定 位和色觉检查均正常。” (p98)

age‐related cataract, undertaking clear corneal incision phacoemulsification + implantation of posterior chamber foldable intraocular lens
Exclusion criteria: “排除标准:高度近视、角膜病变、中央角膜内皮细胞臆1800个/mm2、眼底严重病变、青光眼、糖尿病眼底病变、葡萄膜炎、既往眼外伤 或眼手术史患者。” (p98)

high myopia, keratopathy, central corneal endothelial cell < 1800/mm², fundus diseases, glaucoma, diabetic retinopathy, uveitis, trauma, previous operation

Interventions

Intervention 1: C‐MICS 2.2‐millimeter group

Intervention 2: standard phacoemulsification 2.8‐millimeter group

The type of IOL inserted was not reported.

Length of follow‐up:

Planned: not reported

Actual: 1 month

Outcomes

Primary outcome, as defined in study reports: uncorrected VA, BCVA, corneal astigmatism, corneal endothelial cell counting, ultrasonic energy, phacoemulsification time
Adverse events reported (Y/N): yes, corneal edema

Intervals at which outcomes assessed: 1 week and 1 month

Notes

Full study name: 同轴 2.2 mm 与 2.8 mm 切口白内障超声乳化手术疗效 评价

[Evaluation on curative effect of coaxial 2.2‐ and 2.8‐millimeter incision phacoemulsification for cataract]

Type of study: published full text

Funding sources: not reported

Disclosures of interest: not reported

Study period: July 2014 to March 2015

Trial registry number: not reported

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

No missing data reported.

Selective reporting (reporting bias)

Unclear risk

Protocol was not available. Trial registration not reported.

Other bias

Unclear risk

Funding sources, disclosures of interests were not reported.

Methods

Study design: parallel‐group RCT

Number randomized: 132 eyes of 98 participants overall:

60 eyes of NR participants in C‐MICS (2.2‐millimeter incision) group

72 eyes of NR participants in standard phacoemulsification (3.0‐millimeter incision) group

Exclusions after randomization: none

Number analyzed: not reported

Unit of analysis: unclear as trial investigators did not report how 34 participants with both eyes included were analyzed

Unit of randomization: unclear whether both eyes of the 34 participants were assigned to the same or different groups

Losses to follow‐up: not reported

How were missing data handled? not reported

Reported power calculation: no

Unusual study design: none

Participants

Country: China

Mean age (SD): 72 (NR) overall:

71 (NR) in C‐MICS (2.2‐millimeter incision)

73 (NR) in standard phacoemulsification (3.0‐millimeter incision)

Gender: not reported

Inclusion criteria: people with cataract with endothelial cell > 2000/mm²

Exclusion criteria: people with corneal degeneration, uveitis, or glaucoma

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: C‐MICS (2.2‐millimeter incision) with AcrySof IQ IOL inserted

Intervention 2: standard phacoemulsification (3.0‐millimeter incision) with AcrySof Natural IOL inserted

Length of follow‐up:

Planned: 3 months

Actual: 3 months

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: average ultrasound power, BCVA, SIA, ECL, incidence of capsule rupture and corneal edema

Adverse events reported: yes; posterior capsular rupture and corneal edema

Intervals at which outcomes assessed: postoperatively at 1 day, 1 month, and 3 months

Notes

Full study name: Clinical evaluation on the coaxial microincision cataract surgery in hard nuclear cataracts

Type of study: published

Funding sources: not reported

Disclosures of interest: not reported

Study period: October 2011 to October 2012

Trial registration: NCT01385878 (ClinicalTrials.gov)

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

Protocol was not available. Trial registration not reported.

Other bias

Unclear risk

Source of funding and conflicts of interest not reported. The study included both eyes of some participants in the same group, but did not account for intraperson correlation.

Methods

Study design: parallel‐group RCT

Number randomized: 100 eyes of 100 participants in total; 50 eyes of 50 participants per group

Exclusions after randomization: not reported

Number analyzed: 100 eyes of 100 participants in total; 50 eyes of 50 participants per group

Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant

Losses to follow‐up: none

How were missing data handled? not reported

Reported power calculation: yes: “A sample size of 100 participants was computed ... A difference of 0.175 log units or more was considered ... A sample size of 50 participants in each group would have an 80% power to capture the above‐mentioned difference between the 2 groups” (p566‐7)

Unusual study design: no

Participants

Country: India

Mean age (NR): 63.54 (NR) years overall:

64.42 (NR) years in the smaller C‐MICS group

62.67 (NR) years in C‐MICS (2.2‐millimeter incision) group

Gender: 50 men (50%) and 50 women (50%) overall:

24 men (48%) and 26 women (52%) in the smaller C‐MICS group

26 men (52%) and 24 women (48%) in C‐MICS (2.2‐millimeter incision) group

Inclusion criteria: people with uncomplicated ARC. People having nuclear or corticonuclear cataracts of grade 2 to 4 according to the Lens Opacities Classification System III were included. Ages eligible for study: 50 to 80 years

Exclusion criteria: glaucoma, shallow anterior chamber (anterior chamber depth < 2.1 mm), pupil dilation less than 6.0 mm, extremely dense cataract, posterior polar cataract, subluxated cataract, white mature cataract, diabetic retinopathy, high myopia (defined as axial length > 25 mm), uveitis, or previous ocular trauma or surgery

Equivalence of baseline characteristics (Y/N): yes

Interventions

Intervention 1: corneal incision system with the Stellaris PC system (Bausch & Lomb) using longitudinal ultrasound (C‐MICS 1.8‐millimeter incision) with MI60 IOL (Bausch & Lomb) inserted

Intervention 2: corneal incision system with the Infiniti Vision system (Alcon) using torsional ultrasound (C‐MICS 2.2‐millimeter) with AcrySof SN60WF IOL (Alcon) inserted

Length of follow‐up:

Planned: 3 months

Actual: 3 months

Outcomes

Primary outcome, as defined in study reports

Ingress of trypan blue from the ocular surface into the anterior chamber, SIA at 3 months

Intraoperative outcome measures: total surgical time, CDE, volume of BSS, incision enlargement, trypan blue ingress into the anterior chamber

Postoperative outcome measures: anterior segment optical coherence tomography ‐ incision morphology, localized Descemet membrane detachment (postoperatively at 1 day, 1 week, or 1 month), endothelial gaping or misalignment (postoperative at 1 day and 1 week), epithelial gaps (postoperatively at 1 day and 1 week), anterior segment inflammation (postoperatively at 1 day, 1 week, or 1 month), corneal endothelial morphology (postoperatively at 3 months), CCT (postoperatively at 1 day, 1 week, or 1 month), corneal clarity (postoperatively at 1 day, 1 week, and 1 month)

Secondary outcomes, as defined in study reports: not reported

Adverse events reported: not reported

Intervals at which outcomes assessed: postoperatively at 1 day, 7 days, 1 month, and 3 months

Notes

Full study name: Incision integrity and postoperative outcomes after microcoaxial phacoemulsification performed using 2 incision‐dependent systems

Type of study: published

Funding sources: not reported

Disclosures of interest: Iladevi Cataract & IOL Research Centre receives occasional travel support from Alcon Laboratories, Inc. No author has a financial or proprietary interest in any material or method mentioned.

Study period: September 2011 to February 2012

Trial registration: NCT01385878 (ClinicalTrials.gov)

We emailed the authors and included data provided through email correspondence.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

The study mentioned that participants were randomized, but did not specify methods for random sequence generation. We contacted the study investigator, and received the following reply: "Randomization was done using computer generated random numbers."

Allocation concealment (selection bias)

Low risk

From an email correspondence on 24 January 2017: "we prepared sequenced and sealed envelopes containing one of the two options which were stored in a dedicated box in the operating room. An unscrubbed nurse (1 of 2) opened the envelope and informed the operating surgeon of the incision size and phacoemulsification system to be used just prior to beginning of the surgery."

Masking of participants and personnel (performance bias)

Low risk

Both participants and outcome assessors were masked. We contacted the study investigator, and received the following reply: "The patients and outcome assessors were blinded to the technique used, however the surgeon was not. The outcome assessor was another ophthalmologist, and not the operating surgeon."

Masking of outcome assessment (detection bias)

Low risk

"This prospective randomized patient‐ and analyzer‐masked clinical trial comprised participants with uncomplicated age‐related cataract"; we contacted the study investigator, and received the following reply: "The patients and outcome assessors were blinded to the technique used, however the surgeon was not. The outcome assessor was another ophthalmologist, and not the operating surgeon."

Incomplete outcome data (attrition bias)
All outcomes

Low risk

"No participants were lost to follow‐up."

Selective reporting (reporting bias)

Low risk

The study is registered with ClinicalTrials.gov (NCT01385878). The outcomes described in the protocol are consistent with those in the paper.

Other bias

Unclear risk

"Iladevi Cataract & IOL Research Centre receives occasional travel support from Alcon Laboratories, Inc. No author has a financial or proprietary interest in any material or method mentioned." (p563)

Methods

Study design: parallel‐group RCT

Number randomized: 83 participants (129 eyes) in total:

NR participants (43 eyes) in C‐MICS (2.2‐millimeter incision) group

NR participants (42 eyes) in standard phacoemulsification (2.6‐millimeter incision) group

NR participants (44 eyes) in standard phacoemulsification (3.0‐millimeter incision) group

Exclusions after randomization: none reported

Number analyzed: 83 participants (129 eyes) in total:

NR participants (43 eyes) in C‐MICS (2.2‐millimeter incision) group

NR participants (42 eyes) in standard phacoemulsification (2.6‐millimeter incision) group

NR participants (44 eyes) in standard phacoemulsification (3.0‐millimeter incision) group

Unit of analysis: unclear as trial investigators did not report how 46 participants with both eyes included were analyzed

Unit of randomization: unclear whether both eyes of the 46 participants were assigned to the same or different groups

Losses to follow‐up: none reported

How were missing data handled?: no missing data reported

Reported power calculation: no

Participants

Country: China

Overall mean age: 72 years

Mean age (SD): 69 (9) in C‐MICS (2.2‐millimeter incision) group

69 (7) in standard phacoemulsification (2.6‐millimeter incision) group

71 (8) in standard phacoemulsification (3.0‐millimeter incision) group

Overall age range: 49 to 83 years

Gender: 33 men (40%) and 50 women (60%)

Inclusion criteria: people diagnosed with age‐related cataract

Exclusion criteria: "patients with corneal disease, glaucoma, uveitis, age‐related maculopathy, high

myopia, or history of ocular trauma or surgery were excluded." (p665)

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: C‐MICS (2.2‐millimeter incision)

Intervention 2: standard phacoemulsification (2.6‐millimeter incision) (excluded from review)

Intervention 3: standard phacoemulsification (3.0‐millimeter incision)

AcrySof Natural SN60AT IOL (Alcon) was inserted for both groups.

Length of follow‐up:

Planned: protocol not available
Actual: 3 months

Outcomes

Outcomes, as defined in study reports: SIA, BCVA, CDE, CCT, anterior chamber depth, ultrasound time
Adverse events reported: authors reported no intraoperative complications.

Intervals at which outcomes assessed: 1 and 3 months

Notes

Full study name: The effect of micro‐incision and small‐incision coaxial phaco‐emulsification on corneal astigmatism

Type of study: published full text

Funding sources: not reported

Disclosures of interest: not reported

Trial registry number: not reported

Study period: September 2006 to February 2007

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

“Patients were randomized into three groups: 43 eyes into the 2.2‐mm group, 42 eyes into the 2.6‐mm group and 44 eyes into the 3.0‐mm group.” (p665)

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Low risk

"Patients and examiners were masked to the group assignment.” (p665)

Masking of outcome assessment (detection bias)

Low risk

"Patients and examiners were masked to the group assignment.” (p665)

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

No missing data reported.

Selective reporting (reporting bias)

Unclear risk

Protocol is not available. Trial registration not reported.

Other bias

Unclear risk

Source of funding and conflicts of interest not reported.

Methods

Study design: parallel‐group RCT

Number randomized: 280 eyes total:

146 eyes in B‐MICS group

134 eyes in standard phacoemulsification group

Exclusions after randomization: none

Number analyzed: 280 eyes total:

146 eyes in B‐MICS group

134 eyes in standard phacoemulsification group

Unit of analysis: unclear as number of participants in each group was not reported

Unit of randomization: unclear as number of participants in each group was not reported

Losses to follow‐up: not reported

How were missing data handled? not reported

Reported power calculation: no

Unusual study design: no

Participants

Country: China

Mean age : 69 years overall:

69 years in B‐MICS group

69 years in standard phacoemulsification group
Age range: 51 to 86 years

Gender: 126 men (45%) and 154 women (55%) overall:

64 men (44%) and 82 women (56%) in B‐MICS group

62 men (46%) and 72 women (54%) in standard phacoemulsification group

Inclusion criteria: not reported

Exclusion criteria: people with corneal diseases, glaucoma, and uveitis or surgery history of eye were excluded.

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: B‐MICS (1.5‐millimeter incision) group with Acri.Smart46s (Acti.Tec) IOL inserted

Intervention 2: standard phacoemulsification (3.0‐millimeter incision) group with Staar KS‐1 (Canon) IOL inserted

We considered standard phacoemulsification with incisions ranging from 2.75 to 3.2 mm to be about 3.0 mm.

Length of follow‐up:

Planned: 3 months

Actual: 3 months

Outcomes

Primary outcome, as defined in study reports: phacoemulsification time, VA, CCT, ECL, SIA
Secondary outcomes, as defined in study reports: not reported

Adverse events reported: no

Intervals at which outcomes assessed: postoperatively at 1 day and 3 months

Notes

Full study name: Clinical evaluation on the bimanual microincision cataract surgery

Type of study: published

Funding sources: not reported

Disclosures of interest: not reported

Study period: January 2006 to May 2007

Trial registration: not reported

Data were clarified by an author of this review.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

"The study used 'random numbers table' for sequence generation"

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Low risk

"Participants were masked to their treatment groups"

Masking of outcome assessment (detection bias)

Low risk

"Outcome assessors were masked to their treatment groups"

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

Protocol is not available. Trial registration not reported.

Other bias

Unclear risk

Source of funding and conflicts of interest not reported.

Methods

Study design: parallel‐group RCT

Number randomized: 89 eyes of 89 participants in total:

45 eyes of 44 participants in the smaller C‐MICS group

44 eyes of 44 participants in standard phacoemulsification (3.0‐millimeter incision) group

Exclusions after randomization: 1 eye of 1 participant in microincision cataract surgery (1.8‐millimeter incision) group

Number analyzed: 80 eyes of 80 participants total; 40 eyes in each group

Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant

Losses to follow‐up: 9 participants

How were missing data handled? not reported

Reported power calculation: no

Unusual study design: no

Participants

Country: China

Mean age: 72 years overall; number not reported by group

Gender: 29/80 men (36%) and 51/80 women (64%) overall; number not reported by group

Inclusion criteria: ARC with astigmatism < 2.00 diopters

Exclusion criteria: people with corneal diseases, uveitis, glaucoma, age‐related macular degeneration, high myopia, eye trauma, or surgery history of eyes were excluded.

Equivalence of baseline characteristics: yes

Interventions

Intervention 1: smaller C‐MICS with Akreos MI 60 IOL inserted

Intervention 2: standard phacoemulsification (3.0‐millimeter incision) with Akreos Adapt IOL inserted

Length of follow‐up:

Planned: 3 months
Actual: 3 months

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: average ultrasound power, effective phacoemulsification time, uncorrected VA, BCVA, ECL, SIA
Adverse events reported: no

Intervals at which outcomes assessed: postoperatively at 1 day, 1 week, 1 month, and 3 months

Notes

Full study name: Clinical evaluation on the coaxial 1.8 mm microincision cataract surgery

Type of study: published

Funding sources: National Eleventh Five‐Year Technology Support Program (2006BAI02B04), Zhejiang Key Creative Group of Technology (2009R50039)

Disclosures of interest: not reported

Study period: July 2009 to May 2010

Trial registration: not reported

Data were clarified by an author of this review.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

"The study used random numbers table for sequence generation"

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Low risk

"Participants were masked to their treatment groups"

Masking of outcome assessment (detection bias)

Low risk

"Outcome assessors were masked to their treatment groups"

Incomplete outcome data (attrition bias)
All outcomes

Low risk

9 out of 89 participants (10%) lost to follow‐up, but reasons not reported. 4 cases dropped out at 1 month, 5 extra cases dropped out at 3 months.

Selective reporting (reporting bias)

Unclear risk

Protocol is not available. Trial registration not reported.

Other bias

Unclear risk

Source of funding and conflicts of interest not reported.

Methods

Study design: parallel‐group RCT

Number randomized: 150 eyes of 150 participants in total; 50 eyes of 50 participants in each group

Exclusions after randomization: none reported

Number analyzed: not reported, assumed to be 150 eyes of 150 participants in total; 50 eyes of 50 participants in each group

Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant

Losses to follow‐up: none reported

How were missing data handled? no missing data reported

Reported power calculation: no

Participants

Country: China
Mean age (SD) : 70.44 (NR) overall:

70.30 (6.67) in the smaller C‐MICS group

70.68 (6.98) in microincision (2.0‐millimeter) group

70.34 (7.23) in standard phacoemulsification group
Gender: not reported
Inclusion criteria: “ages between 50 and 80y, with no medication history or other eye disease.” (p400)
Exclusion criteria: “diabetes or other diseases which may influence the biomechanical properties of the cornea were also excluded” (p400)
Equivalence of baseline characteristics: yes

Interventions

Intervention 1: smaller C‐MICS group with Akreos MI 60 IOL (Bausch & Lomb) inserted
Intervention 2: microincision (2.0 mm) (excluded from review)

Intervention 3: standard phacoemulsification (3.0‐millimeter incision) group with PY‐60 IOL implantation (Hoya, Japan) inserted
Length of follow‐up:
Planned: not reported
Actual: 3 months

Outcomes

Outcomes, as defined in study reports: intraoperative data and postoperative outcomes including SIA, corneal incision thickness, wavefront aberrations and modulation transfer function of cornea were obtained.
Adverse events reported: not reported

Notes

Full study name: A comparable study of clinical and optical outcomes after 1.8, 2.0 mm microcoaxial and 3.0 mm coaxial cataract surgery

Type of study: published full text

Funding sources: supported by the Key Program of the National Natural Science Foundation of China (No. 81130018); National Twelfth Five‐Year Plan Foundation of China (No. 2012BAI08B01); Zhejiang Key Innovation Team Project of China (No. 2009R50039); Zhejiang Key Laboratory Fund of China (No. 2011E10006)

Disclosures of interest: "none" (p404)

Trial registry number: ChiCTR‐TRC‐12002565

Study period: not reported

Data were clarified by an author of this review.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

"The postoperative follow‐up was performed by the same independent examiner, who did not perform any of the surgeries."

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Loss to follow‐up was not reported.

Selective reporting (reporting bias)

Low risk

All prespecified outcomes in the trial registry were reported.

Other bias

Low risk

Reported no conflict of interest and government‐funded trial

Methods

Study design: parallel‐group RCT
Number randomized: 160 participants with 168 eyes in total:

84 eyes of 80 participants in the smaller C‐MICS group

84 eyes of 83 participants in the standard phacoemulsification group
Exclusions after randomization: none reported
Number analyzed: not reported, assumed to be 160 participants with 168 eyes in total:

84 eyes of 80 participants in the smaller C‐MICS group

84 eyes of 83 participants in the standard phacoemulsification group

Unit of analysis: unclear as trial investigators did not report how 8 participants with both eyes included were analyzed

Unit of randomization: unclear whether both eyes of the 8 participants were assigned to the same or different groups
Losses to follow‐up: none reported
How were missing data handled? no missing data reported
Reported power calculation: no
Unusual study design: none

Participants

Country: China
Mean age : 68.5 overall:

67.5 in the smaller C‐MICS group

69.8 in the standard phacoemulsification group

Age range: 50 to 83 years overall:

50 to 83 years in the smaller C‐MICS group

52 to 81 years in the standard phacoemulsification group
Gender: 83 women and 77 men overall:

45 women and 35 men in the smaller C‐MICS group

38 women and 42 men in the standard phacoemulsification group
Inclusion criteria: “age‐related cataract, lens nucleus hardness LOCS level 2‐5” (p671)
Exclusion criteria: “history of eye trauma, corneal scar, glaucoma, diabetic retinopathy, macular degeneration” (p671)
Equivalence of baseline characteristics: yes

Interventions

Intervention 1: smaller C‐MICS group with ZEISS ASPHINA 509M IOL inserted

Intervention 2: standard phacoemulsification with 3.2‐millimeter incision group with ZEISS SPHERIS 209M IOL inserted

Length of follow‐up:

Planned: protocol not available

Actual: 1 day, 1 week, and 1 month

Outcomes

Outcomes, as defined in study reports: postoperative astigmatism, uncorrected VA
Secondary outcomes, as defined in study reports: none
Adverse events reported: not reported

Intervals at which outcomes assessed: 1 day, 1 week, 1 month

Notes

Full study name: Effect of 1.8 coaxial micro‐incision cataract phacoemulsification on corneal astigmatism

Type of study: published full text

Funding sources: not reported

Disclosures of interest: not reported

Trial registry number: not reported

Study period: January 2012 to June 2012

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Not reported

Selective reporting (reporting bias)

Unclear risk

Protocol is not available. Trial registration not reported.

Other bias

Unclear risk

Source of funding and conflicts of interest not reported.

Methods

Study design: paired‐eye RCT
Number randomized: 90 eyes of 45 participants in total; 45 eyes of 45 participants in each group
Exclusions after randomization: none reported
Number analyzed: 90 eyes of 45 participants in total; 45 eyes of 45 participants in each group

Unit of analysis: 1 eye per participant

Unit of randomization: 1 eye per participant
Losses to follow‐up: none reported
How were missing data handled? no missing data reported
Reported power calculation: no
Unusual study design: the study randomized participants and included both eyes of the same participant in the same intervention, but they did not account for intraperson correlation.

Participants

Country: China

Mean age : 67.7 overall:

66.8 years in the larger C‐MICS group

68.4 years in the standard phacoemulsification 3.0‐millimeter group

Age range: 39 to 83 years overall:

39 to 80 years in the larger C‐MICS group

48 to 83 years in the standard phacoemulsification 3.0‐millimeter group

Gender: 24 men (53%) and 21 women (47%) in total and by group
Inclusion criteria: "patients with age‐related cataract undertaking phacoemulsification and intraocular lens implantation" (p1434)
Exclusion criteria: none reported
Equivalence of baseline characteristics: yes

Interventions

Intervention 1: larger C‐MICS

Intervention 2: standard phacoemulsification with 3.0‐millimeter incision

The type of IOL inserted was not reported.

Length of follow‐up:

Planned: not reported
Actual: 3 months

Outcomes

Primary and secondary outcomes not differentiated.

Outcomes, as defined in study reports: VA, corneal endothelial cell counting, CCT, SIA

Intervals at which outcomes assessed: 1 day, 1 week, 1 month, 3 months

Notes

Full study name: 不同切口同轴白内障超声乳化术的疗效比较

[Comparison of 2.2‐millimeter microincision and 3.0‐millimeter incision coaxial phacoemulsification]

Type of study: published full text

Funding sources: not reported

Disclosures of interest: not reported

Trial registry number: not reported

Study period: January 2012 to June 2013

We attempted to contact the authors but did not receive any response.

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not reported

Allocation concealment (selection bias)

Unclear risk

Not reported

Masking of participants and personnel (performance bias)

Unclear risk

Not reported

Masking of outcome assessment (detection bias)

Unclear risk

Not reported

Incomplete outcome data (attrition bias)
All outcomes

Unclear risk

Losses to follow‐up or missing data were not reported.

Selective reporting (reporting bias)

Unclear risk

Protocol not reported. Trial registration not reported.

Other bias

Unclear risk

Funding sources and disclosure of interest not reported.