The effect of glycosylated hemoglobin levels on the response to intravitreal dexamethasone implant for treating diabetic macular edema

Abstract

This study investigates the impact of glycosylated hemoglobin (HbA1c) on the efficacy of intravitreal dexamethasone (DEX) implants in patients with diabetic macular edema (DME) over a 12-month period. We retrospectively reviewed 90 DME patients treated with DEX implants, categorizing them based on baseline HbA1c levels (≤ 7% and > 7%) and 12-month changes in HbA1c ("improved", "stable", "worsened"). At the 2-month mark, the mean central subfield thickness (CST) reduction in the HbA1c ≤ 7% group was − 147.22 ± 113.79 µm compared to -130.41 ± 124.50 µm in the > 7% group ( p = 0.506). Notably, 12-month outcomes between these groups showed no significant difference. The "improved" HbA1c subgroup experienced a more pronounced CST reduction at 2 months ( p = 0.042), with outcomes leveling off with other groups by 12 months. Conclusively, DEX implant outcomes in DME were not influenced by either baseline HbA1c levels or their changes over time. This suggests that local alterations in the inflammation milieu may have a potentially stronger impact on DME treatment outcomes, highlighting the importance of considering local factors in DME treatment.