When should methotrexate injections be initiated for proliferative vitreoretinopathy?

This is an excellent question with a nuanced answer. Currently, we lack substantial level 1 evidence to guide precise treatment strategies for off-label use of methotrexate (MTX) in the treatment or proliferative vitreoretinopathy (PVR). Based on animal and human clinical retrospective studies, the presence of primary or secondary grade C PVR generally is an indication to use off-label methotrexate (with or without intraoperative MTX in the infusion bottle). Protocols for treatment vary widely, however, the phase I GUARD study examining high-risk eyes with RD and PVR required 13 injections over a 4 month period. The results from the GUARD trial were in favor of using MTX to prevent re-detachment due to PVR, but given the difficult patient p...

Anterior segment toxicity from intravitreal MTX can be somewhat mitigated by using the smallest diameter (32-34 gauge) needle available, minimizing the injection schedule, and immediately irrigating the eye with copious artificial tears.