Macular Optical Coherence Tomography Angiography in Nephropathic Patients with Diabetic Retinopathy in Iran: A Prospective Case–Control Study

BACKGROUND: Diabetic macular ischemia (DMI) is an important category of diabetic retinopathy (DR) which leads to severe visual loss. Clinically, it is defined by an enlargement of the foveal avascular zone (FAZ) that can be detected by optical coherence tomography angiography (OCTA). Studies have described a relationship between renal disease and these changes in FAZ area. The aim of this study was to compare disturbances in FAZ area in diabetic patients with or without overt nephropathy. METHODS: Following approval of the ethics committee, we examined diabetic patients with retinopathy. Patients were divided into two groups of DR, namely, with overt nephropathy and without overt nephropathy. The FAZ area was measured using OCTA. A P value of < 0.05 was considered to be statistically significant. RESULT: A total of 46 patients (78 eyes) were enrolled in this study. All eyes with DR showed significant changes in FAZ area, but the sizes of the FAZ area were larger in both the superficial and deep layers in patients with clinical albuminuria than in those with no microalbuminuria (P = 0.007 and P = 0.002, respectively). CONCLUSION: These results demonstrate that OCTA provides highly detailed information on retinal microvasculature and that it is a reliable modality to assess DR progression in patients with nephropathy. They also show that renal impairment as a systemic risk factor was associated with enlarged FAZ area in DM.