Relation between increased anaerobic glycolysis and visual acuity in long-standing type 2 diabetes mellitus without retinopathy

In long-standing diabetes mellitus, blood flow to essential organs including the retina is reduced owing to macrovascular and/or microvascular changes. Poor glycolytic pathway of glucose metabolism owing to tissue hypoxia caused by ischemia at capillary bed of essential organs produces excessive lactic acid and less of adenosine triphosphate, which lead to poor cellular function. The purpose of the study was to evaluate the relationship between increased anaerobic glycolysis and visual acuity in type 2 diabetes mellitus without retinopathy. Fifty patients of type 2 diabetes mellitus of 10-12 years duration, without retinopathy, constituted the study group. The controls were 50 age-matched healthy persons without diabetes mellitus. Blood lactate level and best-corrected visual acuity (BCVA) were measured in both the groups. The mean blood lactate level was 1.05 mM/l in the control group and 2.32 mM/l in the study group. BCVA of 20/20 (log MAR 0) was seen in 48 (96%) patients of the control group and in 27 (54%) patients of the study group. BCVA of 20/30 (log MAR 0.2) was seen in 23 (46%) patients in the study group and 2 (4%) in the control group. Association of higher blood lactate level with decreased BCVA in the study group was statistically significant (P< 0.001).