Killing two birds with one stone: the potential effect of cataract surgery on the incidence of primary angle-closure glaucoma in a high-risk population

Background: To estimate the proportion of cataract surgery performed at various visual acuity and lens opacity thresholds that would coincidentally treat early angle‐closure disease, and to estimate the effect of this surgery on the incidence of primary angle‐closure glaucoma. Design: Cross‐sectional, population‐based survey in Meiktila, Myanmar. Participants: Total of 2076 inhabitants, 40 years of age and over were included. Methods: Eyes with cataract‐induced visual impairment, and primary angle‐closure disease were identified. Analyses were stratified by various pinhole‐corrected visual acuity and Lens Opacity Classification System III scores thresholds. Main Outcome Measures: The dual role of cataract surgery in primary cataract treatment and primary angle‐closure glaucoma prevention was estimated. Results: Of 4153 eyes available for analysis, 261 eyes were either primary angle‐closure suspect or primary angle closure; 975 eyes had a visual acuity of <6/18 and Lens Opacity Classification System III score ≥3 on the nuclear or cortical scales. Of these, 86 eyes had either primary angle‐closure suspect or primary angle closure. If cataract surgery were performed on all 975 eyes, this would potentially prevent up to 86 cases of primary angle‐closure glaucoma in this population; 8.82% (95% confidence interval 7.12–10.78%) of the cataract surgery would address the cataract and prevent primary angle‐closure glaucoma. This would achieve a 38.46% (95% confidence interval 20.23–59.43%) relative reduction in the incidence of primary angle‐closure glaucoma in the adult population. Conclusion: In populations with a high prevalence of both visually significant cataract and angle‐closure disease, quality cataract extraction can serve a dual role of visual restoration and reducing the incidence of angle‐closure disease in the population: killing two birds with one stone.