This study is a randomized, double-masked (study participants and outcome assessors) trial. During the enrollment period, consecutive patients from LEI who are planning to have trabeculectomy surgery and who meet the study enrollment criteria will be randomized to receive standard trabeculectomy or microtrabeculectomy. The primary outcome is complications and change in intraocular pressure after a 3 month follow-up period. We will perform subgroup analyses by stratifying the population according to skin pigmentation to determine whether pigmentation is a predictor of treatment success.