Susaritha Govindan1
ABSTRACT BACKGROUND In India, according to International Diabetes Federation, the prevalence of diabetes in 2017 is 8.8%. Diabetes mellitus is a chronic disease caused by impaired metabolism of carbohydrate causing hyperglycaemia which results in multiple end organ damage like nephropathy, retinopathy and neuropathy. Increasing prevalence of this disease increases the burden of diabetic retinopathy. Diabetic retinopathy is an important and leading cause of visual disability. Most important and frequent cause of visual loss due to diabetic retinopathy is diabetic macular oedema. Patients with diabetic retinopathy will develop diabetic macular oedema at any stage of the disease. Patients with diabetic macular oedema mostly present with loss of vision, but vision loss can be prevented if it is diagnosed earlier. Early diagnosis, treatment, regular follow-up of diabetic eye disease can prevent vision loss. The aim of the study is to correlate the visual acuity with the current tools of investigations- Fundus Fluorescein Angiography and Optical Coherence Tomography and incorporate routine investigation in screening protocol. MATERIALS AND METHODS Diabetic patients who attended the outpatient department at Karpaga, Vinayaga Institute of Medical Sciences, Chinnakolambakkam, Kanchipuram District, Tamil Nadu, during the period October 2015- 30th May 2018. RESULTS Visual acuity is best correlated with central foveal thickness. The mean best corrected visual acuity was 0.18 ± 0.25SD at 257.36±82 µm mean central foveal thickness. Correlation is significant at p<0.01 (2-tailed). ROC curve was drawn based on macular thickness measured with OCT, it showed increased accuracy in diagnosing macular oedema at foveal thickness of >235µm and also thickening of nasal quadrant at the inner ring of ETDRS grid, with area under the curve 0.75 and 0.80 respectively. Significant correlation between different patterns of FFA and visual acuity. p<0.006. CONCLUSION Functional impact of diabetic macular oedema is quantified by visual acuity, but it cannot be used as an indicator of development of diabetic macular oedema, since most of them had normal vision until involvement of foveal centre, in Ocular coherence tomography. Focal leaks at macula in Fundus Fluorescein Angiography away from fovea did not affect vision and OCT did not show associated thickening at macula. Therefore, it is concluded that inclusion of OCT, FFA in screening protocol along with routine evaluation can prevent vision loss in diabetic retinopathy.
