Résumé
Objective To observe the retinal thickness of macular in type 2 diabetic mellitus (T2DM) patients without clinical features of diabetic retinopathy (DR).Methods Totally 40 patients (40 eyes) with T2DM without DR and 70 healthy volunteers (70 eyes) from August 2017 to October 2017 were enrolled in this study.Usage of spectral domain optical coherence tomography (SD-OCT) and the software of automatic segmentation to measure the average thickness of total retinal (R),inner retinal layer (IRL) and outer retinal layer namely photoreceptor layer (PL) in macular.The foveal center was divided according to three concentric circle with the diameter of 1 mm,3 mm and 6 mm (including the partition of R total,R-1,R-3,R-6,IRL-1,IRL-3,IRL-6,PL-1,PL-3 and PL-6),and the average retinal thicknesses of these partitions between these two group were compared and analyzed.Results The thickness of PL-1 and PL-3 in no DR group was significantly thinner than that in the normal control group [(71 ± 4)μm vs.(73 ± 3) μm and (66 ± 2) μm vs.(67 ± 2) μm,respectively] (both P ＜ 0.05).In the normal control group,except the IRL-6 and PL-1,the difference of the thickness was significant in the other macular regions between various genders (all P ＜ 0.05).In the male subjects,the thickness of PL-3 and PL-6 in no DR group was significantly thinner than that in the normal control group [(67 ± 2) μm vs.(68 ± 2) μm and (65 ± 2) μm vs.(66 ± 2) μm,respectively] (both P ＜ 0.05).In the female subjects,the mean thicknesses of PL-3 and PL-6 in no DR group was significant thinner than those in normal control group [(65 ± 2) μm vs.(67 ± 2) μm and (63 ± 2) μm vs.(64 ± 2) μm,respectively] (both P ＜ 0.05).There was no obviously difference in the other parts between these two groups,Conclusion The mean retinal thicknesses of the parafovea and perifovea are significantly thinner in no DR group than that of the normal control group.The measurement of the PL thickness of macular by SD-OCT may promote the study of early stage of DR,and become an important biological marker for early monitoring of DR.