Intravitreal injection of methotrexate in persistent diabetic macular edema: a 6-month follow-up study

Abstract

Purpose: To evaluate the efficacy of intravitreal injection of methotrexate (MTX) in patients with persistent diabetic macular edema (DME) nonresponsive to intravitreal bevacizumab.

Methods: In this prospective, interventional study, intravitreal injection of 400 μg MTX was performed in eyes with persistent center-involving DME unresponsive to at least three consecutive bevacizumab injections or two consecutive bevacizumab injections plus macular photocoagulation. Best-corrected visual acuity (BCVA), central subfield thickness (CST), and maximum retinal thickness (MRT) were recorded before and 1, 3, and 6 months after injections.

Results: Eighteen eyes of 16 patients with a mean age of 61.1 ± 6.7 years were included. Mean number of intravitreal bevacizumab injections was 3.9 ± 1.8 (range 2-8). The mean change in BCVA was -0.09 ± 0.19, -0.1 ± 0.19, and -0.1 ± 0.19 LogMAR at 1, 3, and 6 months after intravitreal MTX injections, respectively (all P = 0.04). Three eyes (16.6 %) had improvement of at least two lines of BCVA and no eye lost visual acuity. Mean change in CST was -23.7 ± 66.7, -28.7 ± 82.2 and 26.5 ± 83.4 μm at 1, 3, and 6 months after MTX injections, respectively (all P = 0.1). A decrease in CST was found in 13 eyes (72.2 %) at 1 and 3 months, and seven eyes (38.8 %) at 6 months of follow-up. Other eyes showed an increase in CST measurements. Mean change in MRT was -35.1 ± 76.4, -40.6 ± 86.3, and 29.8 ± 68.6 μm at 1, 3, and 6 months after MTX injections, respectively (P = 0.06, P = 0.06, and P = 0.08, respectively). No complication attributable to intravitreal MTX occurred.

Conclusion: In this study, intravitreal injection of MTX resulted in anatomical improvement in a significant proportion of eyes with persistent DME. Significant visual improvement was found in 16.6 % of eyes.

Keywords: Diabetic macular edema; Methotrexate; Optical coherence tomography.