Retrocorneal Membrane After Penetrating Keratoplasty: Clinicopathologic Correlation And Long-Term Surgical Outcomes

To describe the diagnostic approach, histopathologic origin, and surgical management of a late retrocorneal membrane (RCM) following penetrating keratoplasty (PKP), and to evaluate long-term anatomical and visual outcomes after complete excision combined with repeat PKP. The report highlights the role of anterior segment OCT for early recognition, the value of immunohistochemistry in differentiating endothelial–mesenchymal transformation from epithelial downgrowth, and the importance of tailored surgical planning in eyes with graft decompensation caused by dense adherent membranes.

Institutional case report performed at a tertiary referral cornea center (Oftalmocenter and Clínica de Ojos Larco Visión, Quito, Ecuador). Multimodal imaging, microsurgical management, and histopathologic and immunohistochemical analysis were carried out with long-term postoperative follow-up.

An 80-year-old pseudophakic woman presented with progressive visual loss in her left eye two years after PKP performed for pseudophakic bullous keratopathy. Best-corrected visual acuity was 20/400. Slit-lamp examination showed a dense retrocorneal opacity associated with stromal edema and a clear anterior chamber. Intraocular pressure was 18 mm Hg. Anterior segment OCT revealed a continuous hyperreflective membrane posterior to the graft with central pachymetry of 604 µm. Specular microscopy showed an endothelial cell density of 490 cells/mm². Due to poor visual prognosis and graft failure, repeat PKP was performed. After host trephination, viscodissection allowed identification of a thick, elastic, and firmly adherent membrane, which was completely removed using manual peeling. A new donor cornea, slightly oversized, was secured with interrupted 10-0 nylon sutures. Histopathology demonstrated fibrocellular proliferation with spindle-shaped cells embedded in a collagenous matrix. Immunohistochemistry was positive for α-smooth muscle actin and vimentin and negative for CK7, confirming endothelial–mesenchymal transformation as the underlying mechanism. Postoperatively, the graft remained clear without recurrence or rejection. At 48 months, BCVA improved to 20/40 with stable intraocular pressure.

Retrocorneal membrane is a rare but vision-threatening late complication after PKP that may lead to graft failure. Slit-lamp biomicroscopy supported by anterior segment OCT enables accurate diagnosis and surgical planning. Immunohistochemistry is essential to determine the cellular origin and exclude epithelial downgrowth. In cases of dense and adherent membranes, meticulous excision combined with repeat PKP provides excellent long-term graft clarity and significant visual recovery. Early recognition and complete removal are key to preventing recurrence and optimizing outcomes.