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

Abstract

ObjectiveTo utilize a modified intravitreal (IVT) methotrexate (MTX) protocol for the prevention of proliferative vitreoretinopathy (PVR) after silicone oil (SO) removal (SOR). DesignSingle-center nonrandomized retrospective comparative case series. SubjectsEyes with grade C PVR who underwent retinal detachment repair and SO placement between 2019-2022 with at least 6 months of follow-up after SOR. A control group of age- and sex-matched eyes was included. MethodsEyes were treated with one of two MTX protocols. Eyes in Group 1 received 6 IVT MTX injections following SO placement, and another 6 IVT MTX injections following SOR. Eyes in Group 2 received 6 IVT MTX following SO placement only. Each series of 6 IVT MTX injections (400 μg/0.1 mL) consisted of 3 injections every 2 weeks followed by 3 injections every 4 weeks. Main Outcome MeasuresThe primary outcome was the retinal attachment rate at 6 months post-SOR without re-detachment or re-operation. Secondary outcomes included change in visual acuity (VA) and rates of complications after SOR. ResultsFifty-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 (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). VA 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 to Group 2 (53.8% and 92.3%) and control (44.3% and 65.4%) eyes, respectively (P < 0.05). ConclusionsThe 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.