The relationship between blood sugar levels (glycosylated haemoglobin) and the risk of development of diabetic retinopathy
Abstract
Introduction: Diabetic retinopathy is a major cause of visual impairment and blindness in India and with its early detection and timely treatment, the risk of visual loss can be reduced significantly. Onset and progression of retinopathy is determined by fasting and postprandial blood sugar levels and other risk factors such as duration of diabetes, hypertension, nephropathy, hypercholesterolemia and obesity. This study was done to evaluate the role of glycosylated hemoglobin and its association with the severity of retinopathy.
Materials and Methods: A total of 100 patients were included. This was a prospective study conducted over 1 year in Sri Ramachandra University, Chennai, India. Fundus examination was done using slit lamp biomicroscopy and indirect ophthalmoscopy on all patients. Ancillary investigations such as fundus fluorescein angiography and optical coherence tomography were performed. HbA1c was measured along with fasting, postprandial, lipid profile and urine sugars.
Results: High and uncontrolled levels of HbA1c were associated with maculopathy. A statistically significant difference (p < 0.01) was found in them. The retinopathy however was not related to HbA1C alone. The most frequent type of maculopathy noted was cystoid macular oedema and the level above which it occurred was 7% of HbA1C. Besides HbA1C, the other important factor that was associated with maculopathy was duration of diabetes mellitus.
Conclusion: HbA1c value >7.0% was significantly related with maculopathy. The severity of retinopathy is dependent on the level of blood sugar and duration of diabetes. Control of sugar levels is crucial to prevent diabetic retinopathy and its complications which can lead to irreversible complications in the eye.
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References
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