Determination of macular retinal thickness by frequency-domain optical coherence tomography in patients with diabetes mellitus

Objective To measure the normal frequency domain optical coherence tomography(OCT) and the district diabetic retinopathy in patients with macular retinal thickness and mean macular retinal thickness and total macular volume in patients with type 2 diabetes mellitus,and the correlation between macular retinal thickness and volume characteristics with normal retinal thickness and macular volume in patients with type 2 diabetes mellitus.Methods About 185 cases(317 eyes) were enrolled that diagnosed with type 2 diabetes mellitus in our hospital from January 2010 to September 2011.According to convential mydriasis for examination of fundus,fundus photography and FFA examination and based on International Clinical Classification of Diabetic Retinopathy in 2002,all cases were divided into 3 groups,normal diabetic retinopathy(NDR;50 cases,89 eyes) group,non-proliferative diabetic retinopathy(NPDR;73 cases,126 eyes) group,proliferative diabetic retinopathy(PDR;62 cases,102 eyes) group.The fourth group was normal group of 52 cases(98 eyes).Frequency domain OCT in the four groups was taken macular scanning,and automated analysis of nine partitions was taken.Data and thickness of various macular retinal thickness and mean macular volume were recorded.Results The retinal thickness at 1 mm diameter of central fovea of macular area were(246.37±17.50)μm,(252.13±16.24)μm,(316.28±56.99)μm and(407.90±214.89)μm for normal group,NDR group,NPDR group and PDR group.The average macular retinal thicknesses were(285.07±10.42)μm,(289.45±11.19)μm,(332.31±39.71)μm and(390.20±64.17)μm in 4 groups;The total volumes were(10.22±0.39)mm3,(10.12±1.03)mm3,(11.99±3.29)mm3 and(13.87±5.13)mm3.Compared with the normal group,macular retinal thickness,average macular retinal thickness,total macular volume in NPDR group and PDR group at A1 to A9 areas were statistically significant(all P0.05),but no difference was found between normal group and NDR group(all P0.05);There were statistical differences in each index between each pair of diabetic patients' groups(all P0.05).Conclusions Macular retinal thickness and volume have relation with degree of DR.Frequency-domain OCT can quantitatively and qualitatively observe the subtle diabetic macular changes in diabetic patients with macular disease,and provides a reliable detection for the early diagnosis and treatment.