RESUMO
AIM: To compare the changes of optic disc parameters, peripapillary retinal nerve fibers layer(pRNFL)thickness and macular ganglion cell layer(mGCL)thickness among patients with early diabetes retinopathy and healthy controls by Cirrus HD-optical coherence tomography(OCT).METHODS: In this cross-sectional comparative study, 45 non-diabetic retinopathy(NDR), 52 mild nonproliferative diabetic retinopathy(NPDR), 55 moderate NPDR with type 2 diabetes mellitus(T2DM)and 64 age-matched healthy controls were included. The fasting blood glucose(FBG), duration of diabetes, glycosylated hemoglobin(HbA1c)and past history of the patients were collected in detail. Optic disc parameters(i.e., binocular RNFL thickness symmetry percentage, rim area, optic disc area, cup-to-disc ratio, cup volume), pRNFL thickness and mGCL thickness were measured by Cirrus HD-OCT. The comparison of different groups was performed by one-way analysis of variance.RESULTS: Compared with the control group, the binocular RNFL thickness symmetry percentage and rim area were significantly decreased, while the average C/D and vertical C/D were significantly increased in the NDR group, mild NPDR group and moderate NPDR group(all P<0.05). Compared with the control group, the peripapillary RNFL thicknesses(superior, temporal, inferior, nasal)and macular GCL thickness(average, minimum, superior, supero-temporal, infero-temporal, inferior, supero-nasal, and infero-nasal)became thinner in the NDR group, mild NPDR group, and moderate NPDR group(all P<0.05).CONCLUSION: Patients with early DR have significantly decreased binocular RNFL thickness asymmetry, rim area, pRNFL and mGCL thickness, while they have significantly increased cup-to-disc ratio when compared to healthy controls. The results support the statement that DM causes inner retinal neurodegenerative changes even in T2DM patients without overt microangiopathy.
