Management and Histological Analysis of a Retroprosthetic Membrane as a Novel Complication After EndoArt Implantation.

PURPOSE: EndoArt is a novel endothelial keratoprosthesis recently introduced to treat corneal endothelial decompensation. Retroprosthetic membrane (RPM) formation after EndoArt implantation has not been described. This article reports its incidence, risk factors, and management, along with histological analysis.

METHODS

A retrospective analysis of patients who underwent EndoArt implantation at Cologne University Hospital (Germany) between June 2023 and March 2025 was conducted. Eyes with RPMs were identified using routine anterior segment optical coherence tomography. Clinical data, treatment approaches, and surgical outcomes were analyzed. Surgical membranectomy was performed in one eye and analyzed by light microscopy with hematoxylin-eosin staining and immunohistochemistry.

RESULTS

Sixty-nine eyes underwent EndoArt implantation, and 3 (4.35%) developed RPMs. The main indication was endothelial failure with chronic corneal edema in eyes at high risk of graft failure. Risk factors included multiple previous failed Descemet membrane endothelial keratoplasty (n = 3), aphakia (n = 2), glaucoma (n = 2; one with congenital glaucoma, one with angle-closure glaucoma), glaucoma surgery (n = 1), aniridia (n = 1), iridocorneal endothelial syndrome (n = 1), cyclodialysis (n = 1), artificial iris (n = 1), and pseudophakia (n = 2). The mean time to RPM formation was 7.3 months. One eye had a recurrence 2 months after membranectomy. Histology revealed abundant type III collagen (vimentin+) and macrophages (CD68+), but no significant leukocytes (CD45-) or myofibroblasts (α-SMA-), suggesting chronic remodeling without acute inflammation.

CONCLUSIONS

RPM formation after EndoArt implantation is rare and has not been previously described. Surgical removal improves clinical outcomes and preserves implant stability; however, recurrence may occur, highlighting the need for follow-up and additional research. RPM formation may result from chronic blood-aqueous barrier breakdown in eyes with altered anatomy and a history of multiple surgeries.