Potentially Missed Opportunities in Prevention of Acute Angle-Closure Crisis.

Importance: If an anatomic narrow angle is not appropriately diagnosed and treated, it can result in acute angle-closure crisis (AACC) and lead to substantial vision loss.
Objective: To identify patients who presented with AACC and assess for factors that may have been associated with risk of developing it.
Design, Setting, and Participants: This population-based retrospective cohort study conducted from January 1, 2001, to December 31, 2015, included a 20% nationwide sample of 1179 Medicare beneficiaries. Patients aged 40 years or older with AACC were identified with billing codes. A 2-year lookback period from the date of initial presentation of AACC was used to identify patients who had at least 1 eye care visit, received a diagnosis of open-angle glaucoma (OAG) or suspected OAG, or received at least 1 medication associated with risk of AACC. Of the patients who had at least 1 eye care visit, those who underwent gonioscopy, received a diagnosis of an anatomic narrow angle before developing AACC, or both were identified.
Main Outcomes and Measures: Proportions of patients who had at least 1 eye care visit, had OAG or suspected OAG, received at least 1 medication associated with risk of AACC, underwent gonioscopy, or received a diagnosis of an anatomic narrow angle before development of AACC.
Results: A total of 1179 patients had a confirmed diagnosis of AACC. The mean (SD) age of patients with AACC was 66.7 (11.8) years (range, 40-96 years), 766 were women (65.0%), 57 were Asian (4.8%), 109 were Black (9.2%), 126 were Latino (10.7%), 791 were White (67.1%), and 96 were other race and ethnicity (8.1%). Of these patients, only 796 (67.5%) consulted an optometrist or ophthalmologist at least once during the 2-year lookback period. A total of 464 individuals (39.4%) had OAG or suspected OAG, and 414 (35.1%) had received at least 1 medication associated with increased risk of AACC before developing it. Of the 796 patients who consulted an optometrist or ophthalmologist in the lookback period, less than one-third underwent gonioscopy in the 2 years before developing AACC (n = 264 [33.2%]), and less than one-half of all patients undergoing gonioscopy received a diagnosis of an anatomic narrow angle (n = 113 [42.8%]). Most patients underwent gonioscopy in the 1 to 4 weeks preceding the AACC.
Conclusions and Relevance: In this group of Medicare patients, there appear to have been multiple opportunities for interventions that may have averted AACC. Interventions aimed at addressing risk factors associated with AACC and improving performance of gonioscopy might be associated with reduced risk for ocular morbidity.