ASSOCIATION BETWEEN DURATION OF DIABETES AND SEVERITY OF DIABETIC RETINOPATHY IN A CENTRAL INDIAN POPULATION

Abstract

Background: Diabetic retinopathy (DR) is one of the leading causes of preventable blindness and visual impairment in adults around the world due to the rising prevalence of type 2 diabetes mellitus (T2DM). The duration of diabetes is a known, non-modifiable risk factor for the development of microvascular complications. However, there is a dire need for regional epidemiological data mapping that associates the exact duration of diabetes with the graded severity of DR. This will help in designing localised public health and screening policies. The aim of this study was to evaluate the relationship between duration of diabetes and severity of diabetic retinopathy in a unique population of Central India.
Methods: A hospital-based, cross-sectional, observational study was conducted for a period of six months c at a tertiary care center in Central India. The study enrolled 75 adult patients with previously diagnosed type 2 diabetes mellitus (T2DM). Dilated ophthalmic examinations included slit-lamp biomicroscopy and binocular indirect ophthalmoscopy. Diabetic retinopathy was graded according to Early Treatment Diabetic Retinopathy Study (ETDRS) classification criteria. The obtained data such as age, sex, duration of diabetes, glycaemic control and systemic comorbidities were subjected to statistical analysis using descriptive statistics, Chi-square test and correlational analyses.
Results: Overall prevalence of DR was 58.7% (n=44) of 75 subjects evaluated. A statistically significant positive correlation was found between the duration of diabetes and the severity of DR. The prevalence of DR was low (22.2%) in patients with <5 years of diabetes duration and was characterised mainly by mild non-proliferative changes. Conversely, 91.7% of patients with diabetes for more than 15 years had retinal complications and severe NPDR and PDR were found in 41.7% of this group within this time. Synergistic effects on severity were observed for other variables, e.g., coexisting hypertension and increased HbA1c levels.
Conclusion: Chronicity of diabetes mellitus is the major determinant of the onset and progressive severity of diabetic retinopathy in Central Indian population. The exponential rise in vision threatening DR after a decade of disease duration emphasises the critical need for rigorous annual retinal screening in a protocol driven manner for all diabetic patients to detect early and intervene timely to prevent irreversible ocular morbidity.