Comparison of Retinal Thickness betweenDiabetic Patients without Diabetic Retinopathy and Non-Diabetic Controls Using SD-OCT

Abstract

Purpose: To determine retinal thickness in diabetic patients without diabetic retinopathy and non-diabetic controls using Spectral Domain Optical Coherence Tomography (SD-OCT). Study Design: Cross-sectional observational study. Place and Duration of Study: Diabetic Eye Clinic and General Eye OPD of Al-Ibrahim Eye Hospital, Karachi from July 2018 to August 2018. Methods: Patients with type 2 diabetes and non-diabetic healthy control eyes of either genderand age between 20 and 60 years were recruited. Patients with any other systemic and ocular disease affecting retinal thickness were excluded. After initial examination and informed written consent, patients were referred to ocular investigation department for detailed retinal examination and SD-OCT for measuring central retinal thickness. Data were analyzed for continuous and categorical variable using SPSS. Results: Average Central Retinal thickness was 297±21 and 315±13µmand Central Foveal Thickness was 246±16 and 249±19µmin diabetic and non-Diabetic patients respectively. Quadrant-wise evaluation revealed retinal thickness as follows; nasal 310 and 324µm), temporal (291and 304µm), superior (297and 316µm) and inferior (292and 314µm) in diabetics and non-diabetics respectively. Retinal thickness was greater at nasal and lesser at temporal regions. Conclusion: Diabetic patients without DR had thinner central retinal thickness compared to non-diabetic controls, as measured by Spectral Domain Optical Coherence Tomography (SD-OCT). Specifically, the average central retinal thickness and central foveal thickness were slightly reduced in diabetic patients. Quadrant-wise analysis revealed that the retinal thickness was consistently greater in the nasal region and lesser in the temporal region in both diabetic and non-diabetic patients.