Intravitreal Dexamethasone Implant in Retinitis Pigmentosa-related Cystoid Macular Edema

Purpose: To report the clinical outcome after intravitreal dexamethasone implant in patients with retinitis pigmentosa and cystoid macular edema. Methods: Multicenter retrospective case series of eyes with retinitis pigmentosa and cystoid macular edema that underwent intravitreal dexamethasone implant. Primary outcome measures were best-corrected visual acuity in LogMAR and central macular thickness. Statistical analyses used two-tailed comparison with Wilcoxon signed-rank test. Results: There were a total of 45 eyes from 34 patients with a mean age of 32.7 years (range 16-57) and mean follow-up of 15.5 ± 13.0 months. At Month 3 after the first injection, mean initial best-corrected visual acuity improved from 0.61 ± 0.38 (20/81) to 0.37 ± 0.16 (20/47) (P = 0.012), whereas mean central macular thickness (m) decreased from 506 ± 288 m to 311.7 ± 71.6 m (P < 0.001) and mean intraocular pressure increased from 15.7 ± 2.3 mmHg to 19.8 ± 11.0 mmHg (P = 0.01). Fourteen eyes had multiple injections (1-7 reinjections) at a mean interval of 6 months. Treatment effect was durable with multiple injections, but with seven eyes developing visually significant cataracts. Conclusion: Best-corrected visual acuity improved up to 4 months in around half of the eyes. Eyes that benefited the most were pseudophakic, steroid nonresponsive, with large initial central macular thickness, and profuse fluorescein dye leakage.