Diabetic retinopathy severity inversely tied to cognition

(HealthDay)—For patients with type 2 diabetes, the severity of diabetic retinopathy (DR) is inversely linked to cognitive impairment, according to a study published online April 30 in Diabetes Care.

Roxanne R. Crosby-Nwaobi, Ph.D., from King's College London, and colleagues recruited 380 patients with type 2 diabetes from a population-based eye screening program. Participants were grouped by severity of DR: no/mild DR (252 patients) or proliferative diabetic retinopathy (PDR; 128 patients). Participants underwent psychosocial evaluation; depression screening; ophthalmic and physical examination, including blood assays; and cognitive assessments.

The researchers found that there was a significant inverse correlation between the severity of DR and cognitive impairment. The observed variance was partially explained by ethnicity (16 percent), education (7.3 percent), and retinopathy status (6.8 percent). Cognitive impairment scores on the Addenbrooke's Cognitive Examination-Revised were significantly lower in the no/mild DR group versus the PDR group. Twelve percent of the no/mild DR group and 5 percent of the PDR group had positive screening results for dementia or significant cognitive impairment, based on the Mini-Mental State Examination cut-off scores.

"Patients with minimal DR demonstrated more cognitive impairment than those with advanced DR," the authors write. "The increased prevalence of cognitive impairment in diabetes may be associated with factors other than evident retinal microvascular disease."