Diabetes is the cause of 2.6% of global blindness which occur due to diabetic retinopathy caused by long term accumulated damage of small blood vessels in the retina. Hypothyroidism is common endocrine disorders that coexist with diabetes mellitus. Concurrent hypothyroidism, treated with thyroxin, appears to have a sparing effect on the risk of developing retinopathy among patients with type 2 diabetes.
Material and method: This is a prospective observational study conducted in the department of ophthalmology. During our study period we have enrolled 240 patients with diabetes mellitus based on selection criteria and evaluated for diabetic retinopathy and hypothyroidism. A standard diagnostic criterion was followed for diagnosis of diabetes mellitus and all patients were assessed by two senior ophthalmologists for detection of retinopathy. Classification of diabetic retinopathy was based on the early treatment of diabetic retinopathy study (ETDRS).
Result: Diabetic retinopathy was present in 12(30%) patients in type 2 diabetes mellitus group and 18(45%) patients in type 2 DM plus hypothyroidism group. In DM plus hypothyroidism patients, Mild nonproliferative retinopathy present in 4 (22.22%) patients, Moderate nonproliferative retinopathy 8(44.44%) patients, severe nonproliferative retinopathy 1(5.5%) patients, Early proliferative retinopathy 4(22.22%) patients and High-risk proliferative retinopathy 1(5.5%) patients.
Discussion and conclusion: From present study we can conclude that that prevalence of hypothyroidism was higher among type 2DM mellitus patients in comparison to general population without type 2 DM. Diabetic retinopathy was more common on type 2 DM plus hypothyroidism group then type 2 diabetes mellitus group. We have observed that Moderate nonproliferative retinopathy is more common in both group but early proliferative retinopathy is more common in type 2 DM plus hypothyroidism group then yrs type 2 diabetes mellitus group.