Date of Award

January 2022

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Christopher Teng


Purpose: Acute primary angle closure (APAC) is an ophthalmologic emergency. Nationwide data on the epidemiology and clinical characteristics of APAC are lacking despite the associated visual morbidity.

Methods: Retrospective cross-sectional study using the Nationwide Emergency Department Sample (NEDS). The NEDS was queried by ICD-9/10 code for cases of APAC presenting to the United States emergency departments over a ten-year period from 2008 to 2017. All identified cases were included to produce nationally representative estimates. Linear regression and seasonality tests were used to identify trends. Reported outcomes include the incidence, demographics, seasonality, and economic impact of APAC regionally and nationwide.

Results: A total of 23,203 APAC related ED visits were identified. The mean (SD) and median ages were 58.8 (16.2) and 60 years, respectively. Females (59.4%, p<0.01), those in the lowest income quartile (6,983, 30.1%, p<0.01), and those in the seventh decade of life (5,599, 24.1%) presented more frequently with APAC. Incidence of ED presentations within each age group rose with age, and annual incidence nationally increased significantly over the study period (p<0.01). The Northeast region had the highest average incidence (0.93 per 100,000 population). Significant seasonal variation was seen regionally and nationally (p<0.01). Median inflation adjusted charge per ED visit was $2496.10 and total inflation adjusted charges equaled $101.5 million.

Conclusions: The incidence of APAC related ED visits in the United States is rising. High-risk groups include women, individuals of low socioeconomic status, and those between ages 50 and 70. Significant seasonal and regional trends were observed in ED presentations of APAC.


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