Methods

Single centre, single surgeon prospective randomised trial

Participants

Setting: Magrabi Eye and Ear Centre, Abu Dhabi, United Arab Emirates

Numbers randomised: 90 eyes of 61 consecutive patients

Age: range 21 to 47 years (mean, 33.7+/‐ 7.1 years)

Gender: 37 (60.7%) were female

Inclusion criteria: Age of at least 21 years, documented stable refraction for 1 year, spherical equivalent refraction between 9.0 and 19.5 D of myopia, refractive astigmatism less than 3.0 D, spectacle‐corrected visual acuity of 20/40 or better, corneal thickness permitting the surgeon to leave at least 250 µm deep to the ablation, pupil size less than 6 mm in dim illumination for eyes with myopia of 15.50 D or less, and 5 mm for eyes with myopia greater than 15.50 D, and realistic expectations concerning the outcome

Exclusion criteria: Previous refractive surgery, keratoconus or keratoconus suspected by videokeratography, active ocular disease, dry eyes, systemic disease likely to affect corneal wound healing (e.g. connective tissue disease) and inability to achieve the follow‐up schedule given to the patients before surgery

Interventions

Emetropia was the refractive aim in all eyes

Artisan phakic intraocular lens implantation: Lens power was calculated based on the refraction at the corneal plane according to a customised clinical nomogram based on the manufacturer's instructions and the authors previous experience with Artisan lens implantation

LASIK: Nidek EC‐5000 excimer laser with mean ablation zone diameter 5.6 +/‐ 0.3 mm (range, 5.0 to 6.0 mm); and transition zone 1 mm. A personal customised clinical nomogram was used for all LASIK procedures. A Carriazo‐Barraquer microkeratome with a manually advanced turbine motor head was used to create a 160 µm flap for all LASIK procedures

Outcomes

All patients were examined, at 1 day, 1 week, and 1, 3, 6 and 12 months postoperatively. Slit lamp microscopy, manifest refraction, uncorrected and spectacle corrected visual acuity were performed at all visits from one month onwards. Contrast sensitivity, videokeratography, and specular microscopy were done at the 1, 6 and 12 month examinations

One year after surgery, a patient satisfaction questionnaire was given to the 18 patients (29.5%) who had Artisan lens in one eye and LASIK in the other eye

Notes

LASIK enhancement procedures were performed in both groups 4 to 6 months after the primary procedure if there was a residual refractive error of more than 1.0 D at the 3 month examination. One Artisan eye (2.3%) and seven LASIK eyes (16.3%) had enhancement procedures

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

A random number table was used to generate the sequence

Allocation concealment (selection bias)

Unclear risk

Not specified

Blinding (performance bias and detection bias)
Participants

High risk

Not mentioned but presumably not done as both procedures are inherently different and participants would know which procedure they were undergoing

Blinding (performance bias and detection bias)
Providers

High risk

Not mentioned but presumably not done as both procedures are inherently different and assessors would know which procedure had been performed

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Losses to follow‐up were reported although no explanation was given as to why participants were lost to follow‐up

Selective reporting (reporting bias)

Low risk

There was no evidence of selective outcome reporting

Other bias

Low risk

No other sources of bias were detected

Methods

Two surgeon, two centre prospective, single masked randomised trial with paired eye control

Participants

Numbers randomised: 25 consecutive patients (50 eyes)

Age: range 31 to 52 years (mean 38.4 +/‐ 7.6 years)

Gender: 17 (68%) were female

Inclusion criteria: Stable myopia for 2 years and unsatisfactory correction by glasses or contact lenses. They had bilateral myopia between ‐8.0 and ‐12.0 with an astigmatism < 1.5 D. The anterior chamber depth was ≥ 3.0 mm, the endothelial cell count was ≥ 2000 cells/mm², the corneal thickness was ≥ 530 µm and the mean keratometry was 42.0 to 45.0 D

Exclusion criteria: Patients under the age of 30 years, corneal disease including keratoconus suspect with videokeratography, glaucoma, uveitis or a history of retinal detachment

Interventions

Emmetropia was the target refraction in all eyes

LASIK procedure: Keracor Technolas 217 C (Bausch & Lomb Surgical, Claremont, CA) was used. The software used was version 2.67, subgroup 036, with an ablation zone diameter of 5 mm and a peripheral treatment zone from 6 to 8.5 mm. The Hansotome (Bausch & Lomb Surgical, Claremont, CA) microkeratome was used to create a 160 µm flap

Artisan procedure: The Artisan phakic intraocular lens, a convex‐concave, iris claw‐fixated lens with a 6 mm optical zone diameter (Artisan lens; Ophtec B.V., Groningen, Netherlands) was used. Patient refractive error, anterior chamber depth and keratometric values (Van der Heijde formula) were used to calculate the dioptric power of the lens

Outcomes

The primary outcome measure was the postoperative spherical equivalent refraction at 1 year. The secondary outcome measure was safety measured by the percentage of eyes losing 2 or more Snellen lines of spectacle corrected visual acuity and the safety index

Patients were examined postoperatively at 1 day, 1, 3 , 6 and 12 months after surgery. After day 1 postoperative all examinations included uncorrected and spectacle‐corrected visual acuity, refraction, slit‐lamp microscopy, applanation tonometry and corneal topography. At 3 months and 1 year postoperative an endothelial evaluation using a specular microscope was performed as well as contrast sensitivity. At 1 year postoperative a subjective evaluation and quality of vision score was calculated

Notes

The evaluators did not participate in the surgical process. Both evaluators worked independently from any objective testing, such as slit‐lamp examination and corneal topography, which could have unmasked the surgical procedure. For this purpose independent evaluators performed objective tests

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Low risk

A random number table was used to generate the sequence

Allocation concealment (selection bias)

Unclear risk

Not specified

Blinding (performance bias and detection bias)
Participants

High risk

Not mentioned but presumably not done as both procedures are inherently different and participants would know which procedure they were undergoing on each eye

Blinding (performance bias and detection bias)
Providers

Low risk

The evaluators did not participate in the surgical process. Both evaluators worked independently from any objective testing, such as slit‐lamp examination and corneal topography, which could have unmasked the surgical procedure

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Losses to follow‐up were reported although no explanation was given as to why participants were lost to follow‐up

Selective reporting (reporting bias)

Low risk

There was no evidence of selective outcome reporting

Other bias

Low risk

No other sources of bias were detected

Methods

Single centre, uncertain number of surgeons, prospective randomised trial

Participants

Number randomised: 88 eyes of 46 patients

Age: PRK group 32.6 +/‐ 7 years, Toric Implantable Collamer Lens (TICL) group 30.8 +/‐ 6 years

Gender: PRK group 37% female, TICL group 44% female

Inclusion criteria: Phakic patients with moderate to high myopia (‐6.0 to ‐20.0 D sphere) measured at the spectacle plane and astigmatism in the range of 1.0 to 4.0 D cylinder with a best spectacle‐corrected visual acuity of 20/40 or better in the eye to be treated. Patients had to be between the ages of 21 and 45 years and have a stable refraction for the last 12 months as documented by previous clinical records

Exclusion criteria: Patients with a history of previous intraocular surgery, diabetes, glaucoma, ocular hypertension, amblyopia and any other serious ophthalmic or non‐ophthalmic conditions that may have precluded study completion

Interventions

PRK: This was performed using a conventional PRK technique partnered with the use of mitomycin C (MMC). The VISX Star S3 (VISX Inc, Santa Clara, Calif) excimer laser was used with specifications of a 6.5 mm optical zone (major axis) with an 8.0 mm treatment zone

TICL: The Visian TICL (STAAR Surgical) was implanted in all 43 eyes in the series. The TICL is designed to be placed behind the iris and to vault anteriorly to the crystalline lens. All TICL patients received iridotomies using an Nd:YAG laser 2 weeks prior to surgery. The TICL was inserted through a horizontal temporal 3 mm corneal incision then injected into the eye and dialled into position

Outcomes

Visual measurements were collected to include uncorrected and best spectacle corrected vision and contrast sensitivity. Study follow up was 1 day, 1 week, and 1, 3, 6 and 12 months postoperatively. Additionally a psychometric subjective quality of vision and satisfaction after surgery questionnaire was given at the preoperative, 3 to 6 month and 12 month time points

Notes

Risk of bias

Bias

Authors' judgement

Support for judgement

Random sequence generation (selection bias)

Unclear risk

Not specified

Allocation concealment (selection bias)

Unclear risk

Not specified

Blinding (performance bias and detection bias)
Participants

High risk

Not mentioned but presumably not done as both procedures are inherently different and participants would know which procedure they were undergoing

Blinding (performance bias and detection bias)
Providers

High risk

Not mentioned but presumably not done as both procedures are inherently different and assessors would know which procedure had been performed

Incomplete outcome data (attrition bias)
All outcomes

Low risk

Losses to follow‐up were reported although no explanation was given as to why participants were lost to follow‐up

Selective reporting (reporting bias)

Unclear risk

There was no clear evidence of selective outcome reporting, however it should be noted that the one patient in the phakic IOL group who developed a cataract attended his one month postoperative visit and was then lost to follow up until 2 years after the surgery

Other bias

Low risk

No other sources of bias were detected