Optic nerve and macular thickness studied by CirrusTM OCT in Type 1 Diabetes Mellitus patients without retinopathy

Abstract

Abstract Purpose To compare optic nerve and macular thickness in patientes with Diabetes Mellitus (DM) type 1 without retinopathy, with healthy subjects. Methods Comparative cross‐sectional study. One eye per patient was randomly selected from fifty healthy subjects and 50 patients with type I DM without retinopathy with intensive glycemic control. Patients were scanned using Cirrus HD‐OCT (Carl Zeiss Meditec, Inc., Dublin, CA). The scan protocols were optic disc cube 200x200 and 512x128 volumen cube to assess the retinal nerve fiber layer and the macular thickness respectively. Results Mean age of control group was 30.26 years and 30.08 in DM patients. In optic nerve study, statistically significant differences were found in temporal and nasal quadrants. In macular thickness study we did found differences in all the studied parameters including macular volumen, average thickness, superior, nasal ant temporal of the 3 mm ETDRS ring, and all of the 6 mm ETDRS ring; excluding the central 1 mm ETDRS ring and inferior value of the 3 mm ETDRS ring (all the values were higher in DM patients). Conclusion Cirrus OCT is no able to detect retinal nerve fiber layer lost in type I diabetes mellitus patients without retinopathy. Cirrus showed an increase of retinal thickness in patients with DM, even when there is no sign of retinopathy or macular edema, and even when these patients are preserving the foveal shape. These data support the importance of increasing our knowledge of optic nerve study in diabetic patients and the follow up of macular thickness.