ASSOCIATION OF MCP-1 LEVELS WITH VISUAL ACUITY OUTCOMES IN DIFFERENT STAGES OF DIABETIC RETINOPATHY

Objective: To evaluate the association between serum MCP-1 levels and visual acuity in different stages of diabetic retinopathy. Methodology: This cross-sectional study was conducted at Physiology Department, BMSI, JPMC Karachi from April 2019 to October 2020. One hundred participants aged 40-65 years were divided into four groups: Group-A (n=25) diabetic patients 5-7 years duration without retinopathy; Group-B (n=25) diabetic patients 8-10 years duration with mild retinopathy; Group-C (n=25) diabetic patients 10-15 years duration with moderate retinopathy; Group-D (n=25) healthy controls. Visual acuity was assessed using Snellen chart. Serum MCP-1 levels were measured by ELISA. Pearson's correlation coefficient evaluated the relationship between MCP-1 and visual acuity. Results: Mean age was 53.17±6.36 years. MCP-1 levels progressively increased from controls (18.6±4.7 ng/dl) to moderate DR (503.0±43.7 ng/dl). All Group-A patients maintained 6/6 vision despite elevated MCP-1 (125.6±14.2 ng/dl). Group-B showed variable visual impairment (6/9-6/60) with MCP-1 343.4±19.6 ng/dl. Group-C demonstrated severe visual compromise (6/18-FC) with highest MCP-1 levels. Strong negative correlation existed between MCP-1 and visual acuity (r=-0.812, p<0.001). MCP-1 cutoff >150 ng/dl predicted any visual impairment (sensitivity 92.3%, specificity 88.5%); >450 ng/dl predicted severe impairment (specificity 94.8%).   Conclusion: Elevated MCP-1 levels strongly correlate with visual acuity deterioration in diabetic retinopathy. MCP-1 elevation precedes clinical visual impairment, suggesting its utility as predictive marker for functional visual outcomes.