Why Every Drug Has Failed Against Blinding Scar Tissue After Retinal Detachment

Proliferative vitreoretinopathy (PVR) is the dominant cause of surgical failure following rhegmatogenous retinal detachment repair and remains the primary driver of repeat vitreoretinal operations worldwide. Despite more than four decades of mechanistic research, no pharmacological adjunct has demonstrated clear clinical efficacy — a persistent and costly gap in ophthalmology. This narrative expert review asks why, and proposes a reconceptualized framework for tackling the disease.

The authors reframe PVR not as a discrete pathology but as a temporally evolving fibro-inflammatory continuum. This cascade begins with acute inflammation and chemotaxis, progresses through retinal pigment epithelial (RPE) cell activation and epithelial-mesenchymal transition, and advances into proliferation, extracellular matrix deposition, membrane contraction, and ultimately neurodegeneration. Each stage presents distinct molecular targets, but those windows shift and overlap unpredictably.

The review critically evaluates agents that have been tested or proposed: corticosteroids, antimetabolites (e.g., 5-fluorouracil, daunorubicin), anti-VEGF biologics, anti-fibrotics, and emerging RNA-based approaches. Newer biological frontiers — mechanobiology, cellular senescence, exosome signaling, epigenetic reprogramming, and ferroptosis — are assessed as potential next-generation targets. Each offers mechanistic rationale, though clinical translation remains early.

A key insight is that repeated trial failure reflects not one wrong target but a constellation of recurring design flaws: unselected patient populations, interventions poorly timed to disease stage, pharmacokinetic barriers in vitrectomized and silicone oil-filled eyes, and biological redundancy allowing compensatory pathways to dominate.

The authors advocate for biomarker-enriched prevention strategies targeting high-risk eyes before surgery, stage-matched combination pharmacology, novel delivery platforms engineered for the surgically altered vitreous cavity, and large multicenter trials that couple technical surgical excellence with appropriately timed drug administration. This represents a meaningful reorientation of the field.