Patients With Diabetes and CRAO at Increased Risk of Ocular Neovascularization

An ophthalmologist checks the fundus of the patient.
An ophthalmologist checks the fundus of the patient.
Researchers recommend close, monthly monitoring up to 9 months after CRAO.

Monthly follow-up examinations should be performed in patients with ocular neovascularization after a central retinal artery occlusion (CRAO) diagnosis, according to research results published in Clinical Ophthalmology. 

The currently reported incidence of ocular neovascularization following CRAO is variable — and most studies use institution-based data from large tertiary care centers and may be biased to more severe disease. To avoid this potential bias, the current research made use of a population-based cohort to determine the incidence of ocular neovascularization and associated systemic diseases. 

Using data from the Rochester Epidemiology Project, medical records of patients diagnosed with central retinal artery occlusion between 1976 and 2016 in Olmstead County, Minnesota, were identified. Researchers performed a retrospective chart review to confirm diagnosis based on clinical history, ophthalmic exam, and ancillary testing. 

A total of 965 unique patient charts were reviewed, with 89 patients confirmed with new CRAO during the study period. Median patient age was 76 (range, 46-100) and 56% of patients were men. 

Age- and sex-adjusted incidence of central retinal artery occlusion was 2.58 per 100,000 (95% CI, 2.04-3.11). Of the patients with CRAO, 16% subsequently developed ocular neovascularization. Patient characteristics were generally similar between those with and without neovascularization, excepting diabetes which was present in 64% of those with neovascularization vs 23% of those without. 

Within a subgroup of 26 patients with both CRAO and diabetes, 34.6% developed neovascularization compared with 8% of those without diabetes. Disease etiology was similar between groups, although 3 of the patients with neovascularization experienced central retinal vein occlusion as the arterial occlusion cause. 

Excluding those with central retinal vein occlusion, 13% of 89 patients developed neovascularization “directly as a result” of CRAO. 

Within the group of 14 patients who developed ocular neovascularization, neovascularization of the iris was noted in 64% of patients; neovascularization of the angle developed in 71%, neovascularization of the disc developed in 14%, and 7% developed neovascularization elsewhere. 

Mean time from CRAO diagnosis to neovascular glaucoma was 221 days (range, 22-1380), while mean time from neovascularization to neovascular glaucoma was 154 days (range, 0-1385). Excluding patients with either proliferative diabetic retinopathy or central retinal artery occlusion caused by central retinal vein occlusion, mean time to a diagnosis of neovascularization was 80 days. 

Among 14 patients with neovascularization, 64% developed neovascular glaucoma. Mean change in intraocular pressure (IOP) from baseline to diagnosis was 30.3 mmHg. Of the 5 patients who did not develop neovascular glaucoma, 1 patient was observed, 2 were treated with intravitreal anti-VEGF injections and PRP, 1 was treated with PRP alone, and 1 was treated with anti-VEGF injections alone. 

Study limitations include those inherent to retrospective research, a lack of standardized follow-up exams, and a lack of generalizability to other patient demographics. 

“Due to the ocular morbidity of [neovascular glaucoma], we stress the importance of monthly follow-up examinations for these patients with undilated gonioscopy beginning after their CRAO diagnosis,” according to researchers. “Our data suggest that close monitoring up to 9 months after CRAO may be warranted.” 

“Patients with diabetes…should be educated that they are at higher risk for ocular [neovascular] complications,” the report says.. “Future studies may help determine factors that may reduce the [neovascularization] risks.”


Tanke LB, Chodnicki KD, Olsen TW, Bhatti MT, Chen JJ. Population-based incidence of ocular neovascularization following central retinal artery occlusion in Olmstead County, Minnesota. Clin Ophthalmol. Published online August 21, 2021. doi:10.2147/OPTH.S327704