Decreased optical coherence tomography-measured pericentral retinal thickness in patients with diabetes mellitus type 1 with minimal diabetic retinopathy

Aim: A comparison of retinal thickness (RT) measurements with optical coherence tomography (OCT) in patients with type 1 diabetes mellitus (DM) and no or minimal diabetic retinopathy (DR) versus healthy controls. Methods: Fifty-three patients with type 1 DM with no or minimal DR underwent full ophthalmic examination, fundus photography and OCT. Mean RT measured by OCT was calculated for the central fovea, the fovea, the pericentral and the peripheral area of the macula, and compared to healthy controls. Results: Mean RT in the pericentral area was lower in patients with minimal DR ( 267 mu m +/- 20 mm; n = 23) compared to healthy controls (281 mu m +/- 13 mm; p = 0.005; n = 28). Mean pericentral RT in patients without DR ( 276 mu m +/- 14 mu m; n = 30) was less than pericentral RT in healthy controls, but higher than in patients with minimal DR, without being statistically significant. None of the other regions showed a significant change. Conclusion: In this study a significantly decreased pericentral RT was measured in patients with minimal DR compared to healthy controls. This could be explained by a loss of intraretinal neural tissue in the earliest stage of DR.