Scott 2011.

Study characteristics
Methods	Study design: parallel‐group, randomized controlled trial Number randomly assigned: 116 eyes of 116 participants: 57 eyes of 57 participants to laser group and 59 eyes of 59 participants to control group Exclusions after randomization: 6 participants, 3 in each group, excluded after recruitment into the trial for not meeting inclusion criteria Losses to follow‐up: 5 participants ‐ 2 in the laser group and 3 in the control group ‐ withdrew immediately after randomization Number analyzed: 116 eyes of 116 participants: 57 eyes of 57 participants to laser group and 59 eyes of 59 participants to control group Unit of analysis: participant (1 eye per participant) Handling of missing data: Primary analysis was an available case analysis; intent‐to‐treat analysis using last‐observation‐carried‐forward was done as secondary analysis Sample size and power calculation: 43 eyes needed per group to detect difference with 80% power at the P value < 0.05 level
Participants	Country: United Kingdom Mean age: 48 years (range 30 to 74 years) in the laser group; 49 years (range 24 to 86 years) in the control group Gender: 39 (68%) men and 18 (32%) women in the laser group; 42 (71%) men and 17 (29%) women in the control group Inclusion criteria: ocular hypertension and pigment dispersion syndrome; "pigmented angles with at least 1 other feature of the following: Krukenberg’s spindle, midperipheral iris, transillumination defects; backward‐bowing iris configuration; reliable, full visual field tested using the Humphrey Field Analyzer 24‐2 full‐threshold strategy (≤ 15% false positives/negatives); ≤ 30% fixation losses; normal glaucoma hemifield test results; AGIS score 0; IOP >21 mmHg (off treatment); visual acuity of 20/40 or better" Exclusion criteria: other diseases leading to visual field loss; systemic medications that may alter IOP (ie, glucocorticoids, cardiac glycosides, beta‐adrenergic blockers); recent ocular trauma, infection, inflammation, or surgery Equivalence of baseline characteristics: "the groups were similar at baseline with regard to age, gender, spherical equivalent refraction, and baseline IOP"
Interventions	Laser: iridotomy using a neodymium:yttrium–aluminum–garnet (Nd:YAG) laser; apraclonidine 1% instilled immediately before and after laser treatment; pilocarpine 2% and local anesthetic drops instilled before treatment; Abraham lens inserted Control: no treatment Length of follow‐up: Planned: 3 years Actual: 3 years
Outcomes	Primary outcome, as defined by the trial: deterioration in visual field, first defined as an increase in AGIS score from 0 to 1, then revised by trial investigators to Ocular Hypertension Treatment Study criteria because the AGIS scoring system was developed for eyes with established glaucoma and may not be sensitive to detect changes in eyes with ocular hypertension (visual field abnormalities defined as a point being flagged at the P value < 0.05 level in the corrected pattern standard deviation, or having glaucoma hemifield test results outside normal limits on 3 consecutive tests, with abnormalities of the same type, index, and location in each successive field and determined independently by 2 readers) Secondary outcomes, as defined by the trial: addition of topical anti‐glaucoma medications over the study period; time to start of medications if needed; and time of visual field conversion if it occurred Safety outcomes, as defined by the trial: immediate complications (transient hemorrhage, elevated IOP, or iritis), repeat laser iridotomy, retinal detachment, cataract surgery Other measurements reported in the study: Snellen visual acuity recorded at each visit Intervals at which outcome assessed: every 4 months for 3 years Information on cost of interventions or quality of life: none reported
Notes	Study period: not reported Trial registration: none reported Source of funding: The Frost Charitable Trust, Surrey, UK; and the Special Trustees of Moorfields Eye Hospital London, United Kingdom Disclosures of interest: "The author(s) have no proprietary or commercial interest in any materials discussed in this article" Subgroup analyses: none reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomization was accomplished using a centralized computerized randomization system in the Research and Development office at Moorfields Eye Hospital using the weighted coin method"
Allocation concealment (selection bias)	Low risk	"Patients were randomized after consent and were assigned study identification numbers to which only the Research and Development office had unmasked access"
Masking of outcome assessors (detection bias) Visual field	Low risk	"However, post hoc visual field analysis was performed by 2 readers masked to treatment"
Masking of outcome assessors (detection bias) Intraocular pressure	Unclear risk	"The IOP was measured by unmasked clinicians at each visit"
Incomplete outcome data (attrition bias) All outcomes	Low risk	11/116 (9%) participants with missing data included in the final analyses
Selective reporting (reporting bias)	Unclear risk	No protocol or clinical trial registration record was available for assessment of selective outcome reporting. All outcomes mentioned in the Methods section of the published paper were reported in the Results section
Other bias	Low risk	None identified