Intravitreal Bevacizumab Injection in Diabetic Macular Edema:
Comparison Between Different Types Based on OCT Finding

Eungsuk Kim

Purpose: The purpose of the study was to evaluate the clinical results of intravitreal bevacizumab injection in patients with diabetic macular edema (DME) and to compare the results in different types of DME according to the classification based on OCT findings.

Methods: The medical records for 54 eyes of 49 patients were reviewed, and each subject was classified into one of three DME types according to the OCT features: Type 1, diffuse retinal thickening; Type 2, cystoid macular edema; and Type 3, serous retinal detachment. Each subject was given 3 consecutive intravitreal injections of bevacizumab (1.25 mg/0.05 ml, 6 weeks interval), and the best corrected visual acuity (BCVA) and central foveal thickness (CFT) were examined using the ETDRS chart and OCT, respectively, prior to the treatment and at 1, 6, 12, 24 and 52 weeks following the procedure. On follow-up, repeated injections were done when DME was aggravated.

Results: Of the 54 eyes with DME examined, 23 eyes were of the diffuse type, 18 of the cystoid type, and 13 of the serous type. In the eyes with type 1, BCVA was improved and CFT decreased in a statistically significant manner 1, 6, 12 and 24 weeks after the procedure (p<0.05). In the eyes with type 2, BCVA improved 1 week following the treatment (p<0.05), but no further change from the preoperative value was observed 6, 12, 24 and 52 weeks following the procedure; no statistically significant change was observed in the CFT after the treatment. The BCVA in the eyes with type 3 did not differ significantly following the treatment, but the CFT was decreased significantly 16, 12, 24 and 52 weeks after the intravitreal injection (p<0.05).

Conclusions: This study found that there were differences in the therapeutic effect of intravitreal bevacizumab injection among patients with different DME patterns. According to the OCT findings, intravitreal injection of bevacizumab was more effective in the diffuse retinal thickening than in the cystoid macular edema or serous retinal detachment.