Contrast Sensitivity Changes in Center Involving Diabetic Macular Edema Treated with Aflibercept

To characterize the changes in contrast sensitivity (CS) and retinal anatomy in patients with center involving diabetic macular edema (CDME) measured from baseline to post-loading doses of aflibercept.

This single center, prospective, open-label, non-controlled evaluation of five aflibercept intravitreal injections for treatment of CDME over a 16-week period. One eye in each of the forty patients will receive aflibercept every 4 weeks. Subject testing includes measurements of central retinal thickness (CRT), best corrected visual acuity (BCVA), Pelli-Robson (PR) CS, and CamBlobs (CB) CS at 20 weeks post baseline.

A total of 40 eyes from 40 patients with CDME were analyzed. The mean age was 62.9 ±10.6 years and 55% were male. At baseline, CRT was 365 ±94.6µm with logMAR BCVA 0.25±0.20. CS PR at baseline was 1.46±0.13 logCS compared to the normal population 1.79±0.10 logCS (P=<0.01), and the CS CB was 1.55±0.16 logCS compared to 1.92±0.08 logCS in the normal population (P=<0.01). At the completion of the study, CRT was decreased to 289 ±43.7µm (P=<0.001), and the logMAR BCVA improved to 0.18±0.02 (P=<0.05). At the same point the CS PR was 1.52±0.16 and CS CB was 1.62±0.16 logCS. At the end of the study 85% of eyes obtained BCVA of 0.3 logMAR or better. There was a reduction from baseline of 82.5% to 57.5% in the number of patients that had a CS that was two standard deviations below the mean. The greatest improvement in CS was associated with those patients that had the greatest reduction in CRT.

CS impairment in patients with CDME is significant. Although treatment can be associated with improvement, there still remains a group with decreased CS that could impact activities of daily living. Earlier intervention using reduction in CS as a metric may be associated with reduced residual deficit associated with treatment.