Effect of Axial Length on Diabetic Retinopathy

We read with interest the recent article by Man et al, and would like to comment on it. In this cross-sectional study, Man et al investigated a population of patients with diabetes aged ≥18 years and found that patients with a mean axial length (AL) of 23.55 mm had no diabetic retinopathy (DR), whereas those with a mean AL of 23.30 mm were more likely to have mild, moderate, or severe DR. When interpreting these findings, the authors speculated that the protective effect of increased axial dimensions on DR could be partially owing to reduced blood flow with axial elongation, which in turn lowers the pressure exerted on vessel walls and results in reduced likelihood of capillary wall dilatation, leakage (edema and hard exudates), and rupture (hemorrhage).