Prevalence of Diabetic Macular Edema Using Optical Coherence Tomography in Type 2 Diabetics With Nephropathy in Comparison With Type 2 Diabetics Without Nephropathy.

introductionThe primary vision-threatening complication in patients with diabetic retinopathy (DR) is diabetic macular edema (DME). Diabetic nephropathy (DN) often has DR that threatens their vision and has a risk of developing DME. Hence, the presence of DN could be the only risk factor for developing DME without the presence of other factors. Hence, this study proposes to predict the prevalence of DME using optical coherence tomography (OCT) in type 2 diabetics with nephropathy in comparison with diabetics without nephropathy.

methodsThis is a cross-sectional study done on patients visiting the Ophthalmology Department at Saveetha Medical College and Hospital, Chennai, for one year. A total of 120 patients were included in the study, with 60 diabetic patients without nephropathy in Group 1 and 60 diabetic patients with nephropathy in Group 2. A detailed history was recorded. Their recent blood reports of fasting blood sugar, postprandial blood sugar, hemoglobin A1c (HbA1c), renal function test, and urine protein/creatinine ratio were all noted. Chronic kidney disease (CKD) staging in nephropathy patients as done by the nephrologist was also documented. The best corrected visual acuity (BCVA) was assessed for distant and near vision. A slit lamp examination and dilated fundus examination were done. Fundus findings were independently graded according to the Early Treatment Diabetic Retinopathy Study (ETDRS) classification. OCT was done in all patients to confirm DME.

resultsIn our study. males and females were 60 each in number. The majority of patients (32.5%) were >70 years old. A small percentage of patients (1.7%) in Group 1 had DM of >10 years, and 41.7% of the patients in Group 2 had DM of >10 years. Meanwhile, 73.3% of the patients in Group 1 had an HbA1c level between 6% and 7.5%, and 83.3% of the patients in Group 2 had an HbA1c level >7.5%. The percentage of patients with DME in Group 1 was 1.7%, and that in Group 2 was 21.7%. The majority of patients who had BCVA of 6/6 were in Group 1. The majority of patients with DME (46.4%) had stage V nephropathy.

conclusionThe coexistence of nephropathy in diabetic patients increases the incidence of DME. With long-standing diabetes and uncontrolled blood sugar levels being risk factors for developing DN and subsequently DME, such patients are to be screened regularly and advised on adequate glycemic control for achieving good visual prognosis and limit retinopathy progression. Moreover, the severity of DN should be kept in mind by nephrologists, and patients are to be promptly referred to the ophthalmology department for complete evaluation.