Abstract

Importance: Pharmacologic dilation is vital for eye disease screening but is often avoided due to concerns about triggering acute angle closure (AAC), a sight-threatening ophthalmic emergency. Objective: To assess AAC incidence after dilation and validate the use of International Classification of Diseases (ICD) codes for identifying AAC cases. Design: Retrospective cohort study Setting: Primary care-based teleretinal diabetic retinopathy screening (TDRS) program Participants: Eligible participants were Los Angeles County (LAC) Department of Health Services (DHS) patients who underwent teleretinal screening by dilated fundus photography between August 23, 2013, and March 1, 2024. Potential AAC cases were identified using ICD codes for angle closure, including acute angle closure glaucoma (AACG), primary angle closure glaucoma (PACG), and anatomical narrow angle (ANA), within three months of dilation. All urgent care, emergency department, and eye clinic encounters within the next calendar day after TDRS and encounters with Current Procedural Terminology (CPT) codes for iridectomy/iridotomy or lens extraction within 14 calendar days of TDRS were also identified. Manual chart review was conducted to verify AAC cases and extract clinical information. Exposures: Dilation with 1.0% or 0.5% tropicamide. Main Outcomes and Measures: Cumulative incidence of AAC after dilation. Results: 84,008 patients received 168,796 dilations with a mean of 2.01 +/- 1.50 (mean +/- standard deviation) dilations per patient. 55.1% were female. Mean age was 55.4 +/- 10.7 (mean +/- standard deviation) years. The cohort was 67.7 …

Date

August 7, 2025

Authors

Tracy Lang, Benjamin Y Xu, Zhiwei Li, Sreenidhi Iyengar, Carl Kesselman, Jose-Luis Ambite, Kyle Bolo, Jiun Do, Brandon Wong, Lauren Daskivich

Journal

medRxiv

Pages

2025.06. 26.25330091

Publisher

Cold Spring Harbor Laboratory Press