Objective:To examine the progression of lens opacity in Asian people after trabeculectomy and determine associated risk factors.Methods:This was an observational case series of 243 people aged 36 to 82 years.Trabeculectomy was performed on 1 eye of each subject.Lens opacity was measured yearly using the Lens Opacification Classification System III.The main outcome measure was worsening of lens opacity defined as an increase of 2 or more Lens Opacification Classification System III units in any of the 3 lens regions,nuclear,cortical,and posterior subcapsular.Risk of progression was evaluated using logistic regression models.Results:Data for 177 people were analyzed.One hundred seventeen(66%) of 177 subjects showed progression in opacity in any lens region at 3 years.Seventy-seven(66%) of 117 of those who progressed did so during the first year.Of these,63(82%) of 77 had lens opacity in the posterior subcapsular region.Factors associated with progression of posterior-subcapsular lens opacity at 1 year were diabetes(odds ratio,2.4;95% confidence interval,1.0-5.4) ,use of antiglaucoma medication,dosage of topical steroid postoperatively,and being operated on by a trainee surgeon(odds ratio,2.3;95% confidence interval,1.0-5.2) .Conclusions:Trabeculectomy is associated with progression of lens opacity predominantly in the posterior subcapsular region.Modification of risk factors such as postoperative steroid use may delay progression. Objective: To examine the progression of lens opacity in Asian people after trabeculectomy and determine associated risk factors. Methods: This was an observational case series of 243 people aged 36 to 82 years .Trabeculectomy was performed on 1 eye of each subject. measured yearly using the Lens Opacification Classification System III. The main outcome measure was worsening of lens opacity defined as an increase of 2 or more Lens Opacification Classification System III units in any of the 3 lens regions, nuclear, cortical, and posterior subcapsular. of progression was evaluated as logistic regression models. Results: Data for 177 people were analyzed. One hundred seventeen (66%) of 177 subjects showed progression in opacity in any lens region at 3 years. those who progressed did so during the first year. Of these, 63 (82%) of 77 had lens opacity in the posterior subcapsular region. Factors associated with progression of posterior-subcapsular lens opa city ​​at 1 year were diabetes (odds ratio, 2.4; 95% confidence interval, 1.0-5.4), use of antiglaucoma medication, dosage of topical steroid postoperatively, and being operated on by a trainee surgeon (odds ratio, 2.3; 95% confidence interval, 1.0-5.2) .Conclusions: Trabeculectomy is associated with progression of lens opacity predominantly in the posterior subcapsular region. Modification of risk factors such as postoperative steroid use may delay progression.