Relationship between contrast sensitivity and metabolic control in diabetics without retinopathy

Authors: Dr. Sangeetha T, Devi Sindhuja, Hanumanthappa B.O

DOI: 10.18231/j.ijceo.10587.1761815606

Keywords: Contrast sensitivity, Glycaemic control, Duration, Diabetes mellitus, Retinopathy

Abstract: INTRODUCTION Diabetic retinopathy (DR) being a microvascular disease, also involves early retinal neurodegeneration causing visual impairments such as reduced contrast sensitivity, colour perception changes, and altered temporal perception, often before changes in visual acuity or retinal structure. Current DR screenings mainly assess retinal morphology and circulation, missing early functional visual changes. This study seeks to investigate the relationship between metabolic control and contrast sensitivity in individuals with Type 2 diabetes who do not have diabetic retinopathy. METHODS: This cross-sectional study was carried out between August 2022 to December 2023 involving 106 eyes from 53 patients with Diabetes Mellitus (DM). The assessment included factors such as age, gender, duration and treatment of diabetes, visual acuity, contrast sensitivity, and glycated haemoglobin (HbA1c) levels. Pearson’s correlation and Chi square test were applied to determine the mean differences between paired data. A p-value of <0.05 was considered statistically significant. RESULTS: Among the 53 patients, 30(56.6%) were male and 23(43.3%) were female, with an average age of 60.16±7.80 years (ranging from 40 to 70years) and an average diabetes duration of 7.21±4.37 years. The mean fasting blood glucose level was 127.28±40.75 mg/dl, postprandial blood glucose was 174.37±59.52 mg/dl, and the HbA1c level averaged 7.72±1.85% (ranging from 5.5 to 12.1%). A significant positive correlation was found between the duration of diabetes and decreased contrast sensitivity in both eyes (p-value = 0.001). Similarly, contrast sensitivity showed negative correlation with HbA1c levels which was statistically significant (P<0.0001). CONCLUSION: This study highlights the critical interplay between diabetes duration, glycemic control, and visual impairment. As the duration of diabetes prolonged, there was a significant decline in contrast sensitivity. Also, poor glycemic control significantly affected the CS as well. These findings shall encourage healthcare providers to focus on comprehensive diabetes management strategies to prevent or delay the onset of visual disabilities in such patients.