Jebmh.com Original Article J. Evid. Based Med. Healthc., pISSN- 2349-2562, eISSN- 2349-2570/ Vol. 3/Issue 84/Oct. 20, 2016 Page 4565 A COMPARATIVE STUDY OF CENTRAL MACULAR THICKNESS IN DIABETICS WITH DIFFERENT STAGES OF DIABETIC RETINOPATHY Manasvini Sharma 1 , Ashish Chander 2 , Rupali Chopra 3 , Nitin Batra 4 1 Postgraduate Resident, Department of Ophthalmology, Christian Medical College and Hospital, Ludhiana. 2 Associate Professor, Department of Ophthalmology, Christian Medical College and Hospital, Ludhiana. 3 Professor, Department of Ophthalmology, Christian Medical College and Hospital, Ludhiana. 4 Professor and HOD, Department of Ophthalmology, Christian Medical College and Hospital, Ludhiana. ABSTRACT BACKGROUND Macular oedema is one of the important causes of vision impairment in patients with diabetic retinopathy. In diabetic retinopathy, single measurements of central foveal thickness using OCT correlate with visual acuity. The purpose of the study is to assess Central Macular Thickness (CMT) in diabetics with and without diabetic retinopathy and to compare CMT within different stages of retinopathy. MATERIALS AND METHODS A total of 500 eyes of 250 diabetic subjects and 150 eyes of 75 age and gender matched controls were included. Complete ophthalmological examination was done and they were divided into 5 subgroups according to the diabetic retinopathy grading. OCT scanning was performed using Nidek RS-3000 Lite OCT, which generated a topographical map of the macula. Central macular thickness was defined as the average thickness in the central 1 mm diameter. Other parameters like body mass index, duration of diabetes and glycated haemoglobin levels of last 3 months were also assessed. RESULTS A statistically significant difference was observed in the mean central macular thickness between the study and control group (p<0.001). Among the subgroups, subjects in the CSME group showed maximum CMT (394.0±105.3 µm) while minimum CMT was seen in no diabetic retinopathy group (248.3±21.8 µm). Central macular thickness was seen to increase progressively with increasing stages of diabetic retinopathy. CMT in no DR and mild NPDR differed significantly with each of the other subgroups (p<0.001). The difference in central macular thickness between moderate NPDR subgroup and severe NPDR (p=0.431) and PDR subgroup (p=0.106) was not statistically significant. On regression analysis, increased duration of diabetes and glycated haemoglobin correlated with higher CMT. CONCLUSION Subclinical macular thickening was observed in diabetics, which increased with increasing stages of diabetic retinopathy without evidence of any clinically significant macular oedema. KEYWORDS Diabetic Retinopathy, Central Macular Thickness, Optical Coherence Tomography. HOW TO CITE THIS ARTICLE: Manasvini S, Chander A, Rupali C, et al. A comparative study of central macular thickness in diabetics with different stages of diabetic retinopathy. J. Evid. Based Med. Healthc. 2016; 3(84), 4565-4569. DOI: 10.18410/jebmh/2016/966 BACKGROUND Diabetic retinopathy is responsible for a majority of cases of blindness in adults, especially those in the working age group. 1 Macular oedema is one of the important causes of vision impairment in patients with diabetic retinopathy. Therefore, early diagnosis and metabolic control are of critical significance for prevention or at least postponement of potential visual compromise. Macular oedema has been reported in 10% of diabetics and occurs more frequently in type 2 diabetes mellitus. 2 Their visual acuity is often dependent on the central foveal involvement, perifoveal capillary blood flow velocity, severity of perifoveal capillary occlusion and retinal thickness at the central fovea. 3 Optical Coherence Tomography (OCT) a noninvasive imaging modality has been applied in the diagnosis of a variety of macular diseases and in evaluation of treatment effects. In patients with diabetes and diabetic retinopathy, single measurements of central foveal thickness using OCT correlate with visual acuity. 4 Despite its widespread clinical use, there are only few studies on the distribution and correlations of OCT measured retinal thickness mostly in white ethnic groups. Normative data in general populations is essential to allow pathological changes to be compared, identified and characterised. It is Financial or Other, Competing Interest: None. Submission 20-09-2016, Peer Review 28-09-2016, Acceptance 11-10-2016, Published 18-10-2016. Corresponding Author: Dr. Manasvini Sharma, H. No. 123, KVM Colony, Rishi Nagar, Ludhiana, Punjab. E-mail: drmanasvini.sharma@gmail.com DOI: 10.18410/jebmh/2016/966