Acute Angle Closure Incidence in a Large Countywide Safety Net Teleretinal Screening Program

Area of Science:

• Ophthalmology
• Public Health
• Medical Informatics

Background:

• Pharmacologic pupillary dilation is crucial for diagnosing eye diseases.
• Concerns about triggering acute angle closure (AAC), an ophthalmic emergency, often lead to avoidance of dilation.
• Validating methods for identifying AAC cases is essential for patient safety and research.

Purpose of the Study:

• To determine the incidence of AAC following pharmacologic pupillary dilation.
• To assess the accuracy of International Classification of Diseases (ICD) codes in identifying AAC cases post-dilation.
• To evaluate the safety of dilation in a large-scale diabetic retinopathy screening program.

Main Methods:

• Retrospective cohort study of patients in a teleretinal diabetic retinopathy screening (TDRS) program.
• Identification of potential AAC cases using ICD codes and procedural codes within specific timeframes post-dilation.
• Manual medical record review for AAC case verification and data extraction.

Main Results:

• A total of 168,796 dilations were performed on 84,008 patients.
• Four confirmed cases of AAC occurred post-dilation, resulting in an incidence of 0.002% per dilation.
• The risk of AAC was found to be low, particularly within a high-volume screening program serving a diverse population.

Conclusions:

• Pharmacologic pupillary dilation demonstrates a low risk of inducing acute angle closure, even in a diverse, high-volume screening setting.
• The findings support the overall safety of pupillary dilation for eye disease screening.
• Further discussion regarding the contraindication of AAC risk for dilation is warranted.