Nitric oxide may influence progression of diabetic retinopathy

The presence of nitric oxide in ocular tissues may play a role in the progression of diabetic retinopathy, a study suggests.

Abnormal nitric oxide (NO) synthesis has been associated with the pathogenesis of diabetes mellitus. Researchers Der-Chong Tsai and colleagues in Taiwan performed a study to determine the potential influence of NO levels in the aqueous humor and in plasma on diabetic retinopathy (DR).

The researchers measured the levels of NO in 45 patients with diabetes mellitus and 19 patients with cataract but no diabetes mellitus.

The patients with diabetes mellitus were divided into four groups: proliferative DR (nine cases) with active neovascularization, proliferative DR with regressed or inactive neovascularization (six cases), background DR (16 cases) and no DR (14 cases).

The researchers found that aqueous NO levels in the active proliferative DR group were significantly higher than those of the background DR group and in diabetics without DR, they reported. NO levels in the active proliferative DR group were also higher than in the group with regressed proliferative DR, although this difference was not significant. There was no significant difference among the diabetic subgroups in the plasma NO levels.

The study is published in Ophthalmologica.