Alterations of macular retinal thickness in diabetic retinopathy

Objective:To identify the alterations of macular retinal thickness in diabetic retinopathy(DR),and to investigate the correlation among central macular thickness,fluorescein angiography and the serum level of HbA 1C. Methods:Retinal thickness of 30 normal volunteers(30 eyes)and 84 cases(107 eyes)with diabetic mellitus(DM)that were classified into six groups(normal,DM-no-DR,DRⅠ,DRⅡ,DRⅢ,DRⅣ)were measured by OCT in 9 macular areas as in the Early Treatment Diabetic Retinopathy Study.The correlations among central macular thickness,fluorescein angiography and the serum level of HbA 1C were analyzed. Results:The mean central macular thickness of normal group was 168±17 μm.There was a significant difference in the retinal thickness between the normal and DM group(P0.05),and also the significant difference among the five DM groups(P0.05)but between DRⅠand DRⅡ(P0.2).Only the eyes with diffuse leakage had statistically significant macular thickening(P0.001).There was no relationship between central macular thickness and HbA 1C. Conclusions:Central retinal thickness has already thickened in sub-clinical retinopathy or initial stage of retinopathy,and increased significantly with the development of DR,but not correlated with HbA 1C.