A Modified Intravitreal Methotrexate Protocol for the Prevention of Proliferative Vitreoretinopathy after Silicone Oil Removal

Objective: To utilize a modified intravitreal (IVT) methotrexate (MTX) protocol for the prevention of proliferative vitreoretinopathy (PVR) after silicone oil (SO) removal (SOR). Design: Single-center nonrandomized retrospective comparative case series. Subjects: Eyes with grade C PVR who underwent retinal detachment (RD) repair and SO placement between 2019 and 2022 with >6 months of follow-up after SOR. A control group of age-and sex-matched eyes was included. Methods: Eyes were treated with 1 of 2 MTX protocols. Eyes in Group 1 received 6 IVT MTX injections after SO placement and another 6 IVT MTX injections after SOR. Eyes in Group 2 received 6 IVT MTX after SO placement only. Each series of 6 IVT MTX injections (400 mg/0.1 mL) consisted of 3 injections every 2 weeks followed by 3 injections every 4 weeks. Main Outcome Measures: The primary outcome was the retinal attachment rate at 6 months post-SOR without redetachment or reoperation. Secondary outcomes included change in visual acuity and rates of complications after SOR. Results: Fifty-two eyes of 52 patients (13 Group 1, 13 Group 2, 26 control) (mean age 59.8 years, 80.8% male) were included with a mean follow-up of 31.0 months. In aggregate, Group 1 and Group 2 eyes received a median (interquartile range [IQR]) of 6 (5.25, 7) IVT MTX injections pre-SOR; eyes in Group 1 received a median (IQR) of 5 (3, 6) IVT MTX injections post-SOR. Twelve (92.3%) Group 1 eyes, 11(84.6%) Group 2 eyes, and 21 (80.8%) control eyes had primary retinal attachment at 6 months post-SOR (P > 0.05). Visual acuity outcomes did not significantly differ between groups (P > 0.05). Rates of epiretinal membrane (ERM) and cystoid macular edema (CME) were significantly lower in Group 1 eyes (7.7% and 15.4%) compared with Group 2 (53.8% and 92.3%) and control (44.3% and 65.4%) eyes, respectively (P < 0.05). Conclusions: The use of IVT MTX injections in eyes with PVR undergoing RD repair was associated with a high rate of primary retinal attachment after SOR. Eyes that received IVT MTX injections after SOR had significantly lower rates of ERM and CME than eyes that did not. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. (c) 2024 by the American Academy of Ophthalmology