Singab 2017.

Study characteristics
Methods	Study design: quasi‐RCT (13 bilateral and eight unilateral participants) Number randomized (total and per group): 34 eyes of 21 children; 17 in each group Number analyzed (total and per group): 30 eyes of 18 children; 15 eyes of nine children in each group Losses to follow‐up: 3 eyes lost to follow‐up; 1 eye excluded due to intraoperative inadvertent scleral perforation Length of follow‐up: Planned: 12 months Actual: 12 months Sample size calculation (Y/N): N
Participants	Country: Egypt Age: combined trabeculotomy and trabeculectomy with collagen matrix implant: 9 ± 4 months; combined trabeculotomy and trabeculectomy with MMC application: 8 ± 5 months Gender: combined trabeculotomy and trabeculectomy with collagen matrix implant: 7/9 (77%) boys and 2/9 (23%) girls; combined trabeculotomy and trabeculectomy with MMC application: 6/9 (66%) boys and 3/9 (34%) girls Inclusion criteria: patients aged less than three years with primary congenital glaucoma as evidenced by history of lacrimation, photophobia, blepharospasm, and/or eye enlargement in addition to signs of elevated IOP, increased corneal diameters, corneal haze, and/or increased cup‐to‐disc ratio Exclusion criteria: patients with secondary glaucoma; patients with other ocular pathologies, e.g. congenital cataract; patients with previous ocular surgery including glaucoma surgery; patients who could not adhere to the follow‐up schedule (lost from follow‐up for more than two visits) Equivalence of baseline characteristics: comparable (age, gender, IOP, corneal diameter)
Interventions	Intervention 1: combined trabeculotomy and trabeculectomy with collagen matrix implant Combined trabeculotomy and trabeculectomy with Ologen implantation. A cylindrical collagen matrix implant (one mm in height and 12 mm in diameter) was used. The implant was divided unequally into two parts: a smaller part and a larger part. The smaller part was implanted under the scleral flap over the scleral bed, and the scleral flap was closed with one 10‐0 nylon suture, leaving the two ends of the smaller part bulging from both sides of the scleral flap. The remaining larger part was inserted in the sub‐Tenon’s space over the scleral flap. Intervention 2: combined trabeculotomy and trabeculectomy with MMC application Combined trabeculotomy and trabeculectomy with MMC application, with a concentration of 0.4 mg/mL, were placed deeply in the subconjunctival space as follows: one sponge at 12 o’clock, two sponges on both sides of superior rectus position, and the fourth sponge was applied between the scleral bed and the scleral flap and left for two minutes followed by irrigation of the eye with balanced salt solution.
Outcomes	Outcomes: Success Corneal clarity Corneal diameter Bleb status Fundus examination Adverse events Intervals at which outcome assessed: week 1 and 2, month 1, 2, 4, 6, 9, and 12 Issues with outcome assessment: study included both eyes of the same participant for some participants, but did not consider intraperson correlation Adverse effects: yes
Notes	Type of study: published Funding: not reported Declaration of interest: "The authors declare that there is no conflict of interest regarding the publication of this paper" Study period: April 2014 to October 2015 Clinical trialregistry: PACTR201703002113756
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	"The patients were divided into two equal groups, each included 17 eyes (odd numbers for the first group and even numbers for the second group)."
Allocation concealment (selection bias)	High risk	Participants could foresee the upcoming assignment: "The patients were divided into two equal groups, each included 17 eyes (odd numbers for the first group and even numbers for the second group)."
Masking of participants and personnel (performance bias)	Unclear risk	Masking of participants and personnel was not reported.
Masking of outcome assessment (detection bias)	Unclear risk	Masking of outcome assessors was not reported.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Four eyes (11.7%) that were lost to follow‐up or excluded were not included in the final analysis.
Selective reporting (reporting bias)	Unclear risk	Neither protocol nor clinical trial registry was found.
Other bias	Unclear risk	Source of funding was not reported.