Longitudinal analysis of microvascular perfusion and neurodegenerative changes in early type 2 diabetic retinal disease

摘要

To prospectively monitor subclinical changes in capillary perfusion and retinal layer thickness in patients with type 2 diabetes and early diabetic retinal disease over 2?years.In this longitudinal study we performed biannual retinal vascular imaging using optical coherence tomography angiography (RTVue) to analyse the foveal avascular zone (FAZ) area, perimeter, acircularity index (AI) and parafoveal superficial/deep vessel density (VD). Spectral-domain optical coherence tomography (Spectralis) was used to measure the thickness of nine macular layers and the peripapillary nerve fibre layer.Among 117 eyes (58 left) of 59 patients (21 female), 105 had no diabetic retinopathy (DR), 6 mild and 6 moderate non-proliferative DR at baseline. We found DR progression in 13 eyes at year 2. The FAZ area (+0.008±0.002?mm2/year, p<0.0001), perimeter (+0.036±0.010?mm/year, p=0.006) and AI (+0.005±0.002/year, p=0.0280) increased significantly. A pronounced decrease was found in the superficial (?1.425±0.290%/year, p<0.0001) but not the deep VD. Inner neuroretinal loss was confined to the ganglion cell (?0.539±0.150?μm/year, p=0.0004) and the inner plexiform layer (?0.361±0.127?μm/year, p=0.0045). In the outer retina, we observed a statistically significant decrease in thickness in the outer plexiform, photoreceptor layer and pigment epithelium of ?0.921±0.161?μm/year, ?0.325±0.139?μm/year and ?0.385±0.084?μm/year, respectively.Subclinical signs of microangiopathy and neurodegeneration appear in parallel and are highly progressive even in the earliest stages of diabetic retinal disease.