ROLE OF SERUM AND AQUEOUS HUMOR MAGNESIUM LEVELS AS A MARKER IN ASSESSMENT OF DIABETIC RETINOPATHY IN TYPE 2 DIABETIC AND NON DIABETIC PATIENTS

Abstract

Background: The burden of Type 2 Diabetes Mellitus related morbidity is increasing worldwide. Longer duration of the disease is associated with greater complications as well. Diabetic retinopathy is a microvascular complication of diabetes which is a significant cause of visual impairment. Various etiologies have been postulated for the same. Serum hypomagnesemia is one such cause of increased progression of diabetic retinopathy changes. This novel study aims to establish a relationship of aqueous humor magnesium concentration and its use as biomarker for the assessment of diabetic retinopathy changes. Methods: This case control study recruited a total of 54 patients fulfilling the inclusion criteria from December 2019 to May 2021. Group A consisted of diabetic cases with senile cataract and Group B included non-diabetic controls with senile cataract. All patients underwent standard cataract and fundus evaluation. HbA1c levels and serum magnesium levels were assessed in the blood samples. Intraoperatively, aqueous humor sample was aspirated and tested for magnesium levels. All the samples were analysed at Central Diagnostic Laboratory Services (CDLS), a unit of R.L. Jalappa Hospital & Research Centre attached to Sri Devaraj Urs Medical College, Kolar. Results: The mean serum magnesium concentration in cases and controls were 1.70 mg/dL and 1.90 mg/dL respectively. The mean aqueous humor magnesium levels among cases and controls were 1.70 mg/dL and 1.80 mg/dL respectively. The mean HbA1c concentration among the diabetics and non-diabetics controls was 7.5% and 5.70% respectively. Observed values were xiv statistically significant with a p value of <0.05. Majority of the diabetic cases with HbA1c >7% had serum and aqueous humor magnesium in the range of 1.5-1.7 mg/dL. Mild non proliferative diabetic retinopathy (NPDR) was the most common retinopathy change observed. The mean serum and aqueous humor magnesium among these mild NPDR cases was 1.7 mg/dL and 1.67 mg/dL. A strong positive, statistically significant correlation was observed between serum and aqueous humor magnesium. Conclusion: Hypomagnesemia is associated with diabetes and associated retinopathy changes. Aqueous humor magnesium level can be used as a novel biomarker to assess diabetic retinopathy changes