Changes in inner retina thickness and macular sensitivity in diabetic 2 patients with moderate diabetic retinopathy

To analyze total retinal(RT) and inner retinal layers(IRL) thicknesses in type 2 diabetes mellitus (DM2) patients and retinal sensitivity, using swept source OCT(SS-OCT), and microperimetry. A total of 54 DM2 subjects with moderate diabetic retinopathy(DR) with no signs of diabetic macular edema(DME) and 73 age-matched healthy individuals were assessed by SS-OCT to quantify retinal thickness in the nine macular areas of the ETDRS grid. Retinal sensitivity was measured by microperimetry with MAIA. Mean ages were 64.06 ± 11.98 for the DM2 group and 60.79 ± 8.62 years for the control group. DM2 patients presented lower visual acuity (p < 0.001) and thicker RT (260.70 ± 19.22µm in the control group vs. 271.90 ± 37.61 µm in the DM2 group, p = 0.01). Retinal nerve fiber layer (RNFL) was significantly lower in the outer nasal area (50.38 ± 8.20µm vs 45.17 ± 11.25µm, p = 0.005) as ganglion cells and inner plexiform layers(GCL+) in DM2. A positive correlation between LDL-C and RNFL and a negative correlation between HDL-C levels and inner temporal and central RNFL thickness were detected. The central and inner nasal areas presented a negative correlation between RNFL (p = 0.015) and MAIA (p = 0.008), while the outer inferior area showed a positive correlation(p = 0.025). Retinal sensitivity and macular RNFL thickness decrease in DM2 with moderate DR with no DME.