How Does Cataract Surgery Rate Affect Angle-closure Prevalence

Abstract

Prcis: A data simulation study suggests that prevalence of occludable angle will decrease when the cataract surgical rate increases in particularly when the surgery focuses on 70+ years old.

Purpose: The purpose of this study was to estimate the effects of cataract surgical rates (CSR) on the prevalence of primary angle-closure glaucoma in the Chinese population.

Methods: Participants aged 50 years and older from the Liwan Eye Study were included as the study sample. Occludable angle (OA) as a surrogate of primary angle-closure glaucoma was evaluated using static gonioscopy and anterior chamber depth was measured before dilation using A-mode ultrasound. Random sampling was used to generate 50 cohorts with a sample size of 200 for each predefined CSR at 2000, 4000, 6000, 8000, 10,000, 12,000, according to the multinomial distribution. The mean anterior chamber depth and OA rates of each cohort were calculated. Logistic function models of nonlinear least-squares estimation were used to predict the prevalence of OA.

Results: Data of the right eye from 1280 participants were included. The prevalence of cataract surgery and OA was 2.27% and 11.3%, respectively. The projected prevalence of OA in the cohorts with CSR of 2000, 4000, 6000, 8000, 10,000 and 12,000 was 11.4% [95% confidence interval (CI), 10.8%-12.0%], 11.2% (95% CI, 10.6%-11.9%), 10.9% (95% CI, 10.3%-11.6%), 11.4% (95% CI, 10.8%-12.1%), 10.8% (95% CI, 10.2-11.4%), and 10.1% (95% CI, 9.46-10.7%), respectively. The OA rates decreased remarkably as CSR increased for those aged 70 years and older.

Conclusions: Our study indicated that with CSR increased, the OA prevalence could decrease remarkably especially in the older population. It is advisable to perform cataract surgery at an appropriate time for patients in their late 60s to 70s with significant cataracts.