Quantitative analysis of choriocapillaris alterations in swept source OCT angiography in diabetic patients.

PURPOSE To evaluate quantitative alterations of the choriocapillaris in swept source (SS) OCT-Angiography (OCT-A) in diabetic patients. METHODS We included normal patients and diabetic patients with and without diabetic retinopathy (DR), excluding patients with macular edema. Angiograms in 3x3mm were acquired with Plexelite 9000 SS OCT-A. Choroidal flow voids were analyzed after removal of projection artefacts. The main evaluation was the correlation between choroidal flow voids area (FVA-CC) and DR stage. RESULTS A total of 120 eyes of 72 patients were analyzed. There were 17 eyes from healthy subjects, 30 eyes without DR, 22 eyes with minimal non-proliferative DR (NPDR), 30 eyes with moderate NPDR, 16 eyes with severe NPDR, and 5 eyes with proliferative DR (PDR). The percentage of FVA-CC for each group was respectively: 10.9 +/- 3.4 %; 14.6+/- 4.8 %; 17.6 +/- 3.5 %; 20.7 +/- 5.9 %; 19.9 +/- 2.9 %; and 26.6 +/- 4.4 %. FVA-CC and DR stage were significantly correlated (p<0.0001). FVA-CC was significantly increased in diabetic patients without DR compared to healthy subjects (p =0.008). CONCLUSION Diabetes is associated with quantifiable choriocapillaris alterations in SS OCT-A. These alterations precede clinical signs of DR and are correlated to DR stage.