A Study of Prevalence and Risk Factors of Diabetic Retinopathy in Patients with Non-Arteritic Anterior Ischemic Optic Neuropathy (NA-AION)

Purpose: To estimate prevalence and risk factors for diabetic retinopathy (DR) in diabetic patients with Non-Arteritic Anterior Ischemic Retinopathy (NA-AION). Methods: This was a retrospective chart review of patients with diabetes diagnosed with NA-AION. Patients with clinical anomalies affecting the optic nerve, diabetic papillopathy, and features suggestive of arteritic AION (raised erythrocyte sedimentation rate/positive temporal artery biopsy) were excluded. Clinical diagrams, notes, and fundus photographs, if available, were evaluated for optic disc edema, optic disc atrophy, presence or absence of small discs, retinal vessel abnormalities, presence of DR, and the presence of sight-threatening DR (STDR). Results: A total of 153 eyes of 109 subjects were included in the study. 82 subjects (75.2%) were men. Mean age of the subjects was 55 +/- 9 years. 58 subjects (53.7%) had hypertension and 21 (19.3%) were insulin-dependent. 80 subjects (52.3%) had a duration of diabetes of five years or greater. DR with NA-AION was seen in 46 eyes (30.1%, 95% CI: 22.7 to 37.4) and STDR with NA-AION was seen in 20 eyes (13.1%, 95% CI: 7.7 to 18.5). Logistic regression analysis revealed the duration of diabetes to be significantly associated with both the presence of DR (OR: 1.07, 95% CI: 1.01 to 1.14, p = 0.02) and STDR (OR 1.08, 95% CI: 1.02-1.15, p = 0.01). Conclusions: Prevalence of DR and STDR in eyes with NA-AION was 30.1% and 13.1%, respectively. Duration of diabetes was an important risk factor for both presence and severity of DR in subjects with NA-AION.