Ischemic Stroke Risk in Medicare Beneficiaries with Central Retinal Artery Occlusion: A Retrospective Cohort Study

To determine the incidence of ischemic cerebral stroke in the 6-month periods preceding and following acute central retinal artery occlusion (CRAO) among Medicare beneficiaries.

A retrospective cohort study with comparison group conducted for calendar year 2013. Patients with CRAO were identified through National Medicare limited inpatient and institutional outpatient datasets for emergency services using ICD-9-CM code for CRAO (362.31). Patients with hip fractures (ICD-9-CM 820-820.9) during the same time period served as controls. Interval incident rates of ischemic stroke were determined from time-coded diagnoses of CRAO and hip fracture (index date zero) to date of principal discharge diagnosis of ischemic stroke (ICD-9-CM 434) recorded in the Medicare inpatient dataset. Risk of stroke was examined by comparing incidence among the two cohorts preceding and following the sentinel events.

There were 3338 patients with CRAOs during 2013. The incidence of ischemic stroke peaked the second week following CRAO relative to patients with hip fracture (relative incidence = 33.1 [95% confidence interval 9.8-84.6]).

Medicare beneficiaries who present to emergency rooms with CRAO or are hospitalized directly for this condition were at highest risk of ischemic stroke in the first 2 weeks following the ocular diagnosis. Patients with acute CRAO should be promptly evaluated for stroke and stroke prevention.