Adaptive Optics (rtx1) High-Resolution Imaging of Photoreceptors and Retinal Arteries in Patients with Diabetic Retinopathy

Background. Diabetic retinopathy (DR) is the leading cause of impaired vision in patients with diabetes mellitus. An adaptive optics retinal camera (rtx1 (TM); Imagine Eyes, France) was used to capture images of cones and retinal arteries from patients with DR. Objective. Cone parameters (density, interphotoreceptor distance, and regularity) and retinal artery parameters (wall thickness, lumen diameter, WLR, and WCSA) were analyzed in 36 patients with nonproliferative DR (NPDR; 22 with mild NPDR and 14 with moderate NPDR) and in 20 healthy volunteers (the control group). Results. Cone density at 2 degrees eccentricities was significantly lower in the DR compared to the control group (19822 +/- 4342 cells/mm(2) vs. 24722 +/- 3507 cells/mm(2), respectively). Cone density and regularity decreased with increasing severity of DR. The artery walls were significantly thicker in the DR group. The WLR and WCSA differed significantly between the DR and the control groups (WLR 0.339 +/- 0.06 vs. 0.254 +/- 0.04; WCSA 5567 +/- 1140 vs. 4178 +/- 944, respectively). Conclusions. Decreased cone regularity and density are seen in patients with mild and moderate NPDR. Abnormalities of retinal arterioles show signs of arteriolar dysfunction in DR. Retinal image analysis with the rtx1 offers a novel noninvasive measurement of early changes in the neural cells and retina vasculature in diabetic eyes.