Although capillary dropout is a hallmark of diabetic retinopathy (DR), its role in visual loss remains unclear, until now. A team of researchers recently sought to find the association between macular vessel density and visual acuity in patients with DR and poorly controlled type 1 diabetes—and uncovered some interesting findings.

Using optical coherence tomography angiography, the investigators found decreased visual acuity may be associated with the degree of capillary loss in the deep capillary complex in patients with type 1 diabetes without macular edema but with severe non-proliferative or proliferative DR. Their findings were reported in a recent online edition of JAMA Ophthalmology.

In a cohort study of 22 eyes of 22 patients with type 1 diabetes and DR without macular edema, 41% were found to have decreased vision. Vessel density was lower in eyes with DR and decreased vision than in eyes with DR and normal vision. The researchers also found the loss of vessel density was greater in the deep capillary complex, particularly the deep capillary plexus, than in the superficial vascular plexus.

“These findings suggest that decreased vision in patients with diabetic retinopathy may be associated with the degree of capillary loss in the deep capillary complex,” the researchers said.