Elsheikha 2015.

Study characteristics
Methods	Study design: RCT (10 bilateral and 21 unilateral participants) Number randomized (total and per group): 41 eyes of 31 children; 21 eyes for viscotrabeculotomy and 20 for conventional trabeculotomy Number analyzed (total and per group): 14 eyes in viscotrabeculotomy and 12 eyes in conventional trabeculotomy Losses to follow‐up: 7 eyes in viscotrabeculotomy and 8 eyes in conventional trabeculotomy Length of follow‐up: Planned: 6 months Actual: 6 months Sample size calculation (Y/N): N
Participants	Country: Egypt Age: viscotrabeculotomy: 6.8 ± 6.5 months; conventional trabeculotomy: 6.9 ± 5.65 months Gender: viscotrabeculotomy: 14/21 boys (66.6%) and 7/21 (33.4%) girls; conventional trabeculotomy: 8/20 (40%) boys and 12/20 (60%) girls Inclusion criteria: primary congenital glaucoma in the first two years of life or primary congenital glaucoma with a previous single failure of goniotomy surgery Exclusion criteria: secondary glaucoma, patients previously operated for trabeculotomy or combined trabeculotomy–trabeculectomy, and those with anterior segment dysgenesis syndrome Equivalence of baseline characteristics: comparable
Interventions	Intervention 1: viscotrabeculotomy Intervention 2: conventional trabeculotomy
Outcomes	Outcomes: Mean IOP Complete success defined as IOP of 18 mmHg or less, under chloral hydrate sedation or general anesthesia, without the need for medication or reoperation, with no progression of disc cupping or corneal diameter, and no devastating visual complications Corneal diameter C/D ratio Intervals at which outcome assessed: week 1, 2, 3, month 1, 2, 3, 4, 5, and 6 Issues with outcome assessment: for some participants, both eyes of the same child were included, but study did not consider intraperson correlation Adverse effects: intraoperative complication reported
Notes	Type of study: published Funding: "This research received no specific grant from any funding agency in the public, commercial or not‐for‐profit sectors." Declaration of interest: "The authors report no competing interest." Study period: not specified Clinical trial registry: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of random sequence generation was not reported: "Patients were randomly allocated to either one of two groups: group A undergoing viscotrabeculotomy and group B (control group) undergoing conventional trabeculotomy."
Allocation concealment (selection bias)	Unclear risk	Allocation concealment was not reported.
Masking of participants and personnel (performance bias)	Unclear risk	Masking of participants and investigators to treatment was not described.
Masking of outcome assessment (detection bias)	Unclear risk	Masking of outcome assessor was not described.
Incomplete outcome data (attrition bias) All outcomes	High risk	Seven (33.3%) eyes in viscotrabeculotomy group and eight (40%) eyes in conventional trabeculotomy group were not included in the analysis.
Selective reporting (reporting bias)	Unclear risk	Neither protocol nor clinical trial registry was found.
Other bias	Low risk	None identified.