Persistent diabetic macular edema is associated with elevated hemoglobin A1c

Purpose

To assess the correlation between persistent diabetic macular edema and hemoglobin A1c (HbA1C).

Design

Retrospective study.

Methods

Records of type 2 diabetic patients who received eye care for persistent clinically significant macular edema (CSME) from January 2002 to January 2004 were reviewed. Subjects who met one of two criteria were identified: 1) persistent CSME, detected by contact lens biomicroscopy and fluorescein angiography, despite at least two focal laser photocoagulations (FLP) performed at least 3 months before the current diagnosis, or 2) a history of CSME with resolution of macular edema at the time of examination. Patients also needed to have had their HbA1C measured at the Johns Hopkins Hospitals within 3 months of meeting these criteria.

Results

The study identified 92 patients (152) eyes with persistent CSME and 32 patients (56 eyes) with resolved CSME. HbA1C values ranged from 5.3% to 15.6% (mean, 8.9%; median, 8.7%) and 5.3% to 9.7% (mean, 6.7%; median, 6.6%) among patients with persistent and resolved edema (P = .0005). Among the 32 patients with persistent unilateral CSME, mean HbA1C was 8.6% (median 8.5%), and among the 60 patients with bilateral CSME, mean HbA1C was 9.1% (median, 8.9%). Of patients with persistent CSME, 74% had HbA1C greater than 7.5% compared with 12.5% of the patients with resolved CSME (P = .0005).

Conclusions

Persons with type 2 diabetes and persistent CSME have higher HbA1C at time of their disease than patients with resolved CSME. Patients with bilateral disease have more elevated HbA1C than those with unilateral disease.