High-Resolution Imaging of Parafoveal Cones in Different Stages of Diabetic Retinopathy Using Adaptive Optics Fundus Camera

• Published in: PloS one Vol. 11; no. 4; p. e0152788
• Main Authors: Soliman, Mohamed Kamel, Sadiq, Mohammad Ali, Agarwal, Aniruddha, Sarwar, Salman, Hassan, Muhammad, Hanout, Mostafa, Graf, Frank, High, Robin, Do, Diana V., Nguyen, Quan Dong, Sepah, Yasir J.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 08.04.2016; Public Library of Science (PLoS)
• Subjects: Adaptive optics; Biology and Life Sciences; Cameras; Care and treatment; Case-Control Studies; Complications; Complications and side effects; Cones; Correlation; Covariance; Density; Diabetes; Diabetes mellitus; Diabetes Mellitus, Type 2 - complications; Diabetic retinopathy; Diabetic Retinopathy - diagnosis; Diabetic Retinopathy - etiology; Diagnosis; Disease; Disease control; Edema; Engineering and Technology; Eye; Eye (anatomy); Female; Fovea Centralis - pathology; Glucose; Health care; Hemoglobin; Horizontal cells; Humans; Image acquisition; Image Processing, Computer-Assisted; Image resolution; Male; Medical imaging; Medicine and Health Sciences; Middle Aged; Mutation; Optics; Optics and Photonics; Packaging; Patients; Photography - instrumentation; Photoreceptors; Reading; Retina; Retinal Cone Photoreceptor Cells - pathology; Retinopathy; Science; Social Sciences; Tomography, Optical Coherence; Topography; Type 2 diabetes; Variance analysis; United States
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0152788

To assess cone density as a marker of early signs of retinopathy in patients with type II diabetes mellitus. An adaptive optics (AO) retinal camera (rtx1™; Imagine Eyes, Orsay, France) was used to acquire images of parafoveal cones from patients with type II diabetes mellitus with or without retinopathy and from healthy controls with no known systemic or ocular disease. Cone mosaic was captured at 0° and 2°eccentricities along the horizontal and vertical meridians. The density of the parafoveal cones was calculated within 100×100-μm squares located at 500-μm from the foveal center along the orthogonal meridians. Manual corrections of the automated counting were then performed by 2 masked graders. Cone density measurements were evaluated with ANOVA that consisted of one between-subjects factor, stage of retinopathy and the within-subject factors. The ANOVA model included a complex covariance structure to account for correlations between the levels of the within-subject factors. Ten healthy participants (20 eyes) and 25 patients (29 eyes) with type II diabetes mellitus were recruited in the study. The mean (± standard deviation [SD]) age of the healthy participants (Control group), patients with diabetes without retinopathy (No DR group), and patients with diabetic retinopathy (DR group) was 55 ± 8, 53 ± 8, and 52 ± 9 years, respectively. The cone density was significantly lower in the moderate nonproliferative diabetic retinopathy (NPDR) and severe NPDR/proliferative DR groups compared to the Control, No DR, and mild NPDR groups (P < 0.05). No correlation was found between cone density and the level of hemoglobin A1c (HbA1c) or the duration of diabetes. The extent of photoreceptor loss on AO imaging may correlate positively with severity of DR in patients with type II diabetes mellitus. Photoreceptor loss may be more pronounced among patients with advanced stages of DR due to higher risk of macular edema and its sequelae.