Study of clinical significance of optical coherence tomography in diagnosis & management of diabetic macular edema

Background: 26 million people were estimated to be affected by diabetes in 2010 across the globe. Diabetic macular edema (DME) is the most important cause of visual impairment due to diabetic retinopathy. Optical Coherence Tomography (OCT) is a non-invasive modality which produces cross-sectional or three-dimensional, high-resolution images of the retinal layers and quantitative assessment of retinal thickness Aim of study was to study the incidence of different patterns of diabetic macular edema on Optical coherence tomography (OCT), to decide treatment & follow-up protocol. Material & Methods: 200 eyes of 167 patients attending the M & J Institute of Ophthalmology and having diabetic macular edema were enrolled in this study. Base line examination like best corrected visual acuity, anterior segment examination, indirect ophthalmoscopy, slit lamp biomicroscopy, OCT and fundus fluorescein angiography were done in all patients. The patients will be classified according to type of macular edema on OCT. Follow up visits will be scheduled one week, one month post procedure and every two monthly thereafter. Results: In this non-randomized, prospective study, 200 eyes of 167 patients with diabetic macular edema were enrolled. Out of 167 patients 33 (19.7%) patients were having DME in both eyes. Single type of edema was present in 122 (61%) eyes, combination of two types of edema in 56 (28%) eyes & combination of three types of edema in 22 (11%) eyes. Grid laser treatment was given in 72 (36%) eyes. Intravitreal triamcinolone injection was given in 110 (55%) eyes. Parsplana vitrectomy was done in 18 (9%) eyes. Discussion: Diabetic macular edema is the most important cause of visual impairment in patients with diabetes. OCT is a noninvasive and reproducible tool for obtaining high resolution, cross-sectional images of the retina. In our study spongy edema was most common type found (36%), followed by cystoid edema (14%), serous detachment (7%) & vitreomacular traction in 2%. OCT provides a better anatomical description of CSME for deciding treatment protocols. Conclusion: Identifying the structural changes in eyes with DME using OCT may allow more effective management of these patients.