In vivo functionality of a corneal endothelium reconstituted by injection of endothelial cells in the anterior chamber of a feline model

Abstract

Purpose: To assess the in vivo functionality of a corneal endothelium reconstituted by injection of corneal endothelial cells (CEC) in the anterior chamber (AC) of a feline endothelial deficiency model.

Methods: The central corneal endothelium of one eye was scraped off and human (2 x 10⁶/0.2 mL; n = 1 animal) or feline (1 x 10⁷/0.2 mL; n = 2) cultured CEC supplemented with 100 μM ROCK inhibitor were injected in the AC. Animals were placed eye-down for 3 hours to promote adherence of CEC to the Descemet’s membrane by gravity. Follow-up included slit lamp biomicroscopy, pachymetry and tonometry to assess corneal transparency (0 (opaque) to 4 (crystal clear) scale), biocompatibility, presence of CEC deposits on iris or lens, central corneal thickness (CCT) and intraocular pressure (IOP). The xeno-transplanted animal was followed for 7 days, one of the allo-transplanted animals for 16 days and the third animal is still in follow-up. Post-mortem assessment consisted in the characterization of injected CEC by immunofluorescent staining of K8/18, Na+/K+-ATPase and ZO-1.

Results: Postoperative intraocular inflammation was minimal and completely resolved by day 4 in the three eyes. On day 7, all cell-injected eyes had a transparency score of 2.5; on day 14, both allo-grafted eyes had a score of 3. CCT was 1084 μm in the xeno-grafted eye on day 7, and 671 and 538 μm in the allo-grafted eyes on day 16. No IOP elevation or CEC deposits on the iris were observed in any of the eyes, while discrete CEC deposits could be seen on the lens. Post-mortem analysis revealed that the newly formed endothelium expressed K8/18, Na+/K+-ATPase and ZO-1.

Conclusions: This study shows that the feline animal model can be used to assess the feasibility of transplanting a corneal endothelium by cell injection therapy. Cultured CEC were able to repopulate the decellularized Descemet’s membrane and form a functional endothelium in vivo. This therapeutic concept has promising impact for the treatment of endotheliopathies.

Keywords: 481 cornea: endothelium • 741 transplantation • 666 pump/barrier function