Abstract
Purpose :
To evaluate corneal changes in patients with aniridia-related keratopathy (ARK) before and after corneal transplantation
Aniridia-related keratopathy (ARK) usually involves limbal stem cell-deficiency associated with epithelial impaired cell adhesion, corneal conjunctivalization and opacification.
Methods :
Two corneal buttons from patients with advanced aniridia submitted to penetrating keratoplasty and three corneal buttons from patients with advanced keratopathy that underwent centered or decentered retransplantation, as well as corneas from healthy controls were processed for immunohistochemistry. Antibodies against collagen I and IV, tenascin-C, a11 integrin chain, laminin a3 chain, fibronectin along with markers of wound-healing and fibrosis, cell differentiation and proliferation, including Notch1 and its inhibitors Dlk1 and Numb were used.
Results :
ARK corneas and retransplanted ARK corneas presented similar changes. The corneal epithelium was extremely irregular with marked variation in cell form and size. A fragmented epithelial basement membrane was present. The stroma was mainly affected in its anterior portion where lack of collagen I was noted. This disturbance of stromal architecture was accompanied by the presence of inflammation and proliferation markers in the same areas in ARK and retransplanted ARK corneas. The notch-inhibitor Dlk1 was detected in both ARK and retransplanted ARK corneas. Evaluation of retransplanted ARK corneas that were originally decentered transplants showed that regions initially including limbal stem cells presented similar changes to the recepient’s corneas of aniridia patients being transplanted for the first time.
Conclusions :
Severe disorganization of the stromal layer was present in both the ARK corneas and retransplanted ARK corneas with pannus and fibrotic markers, indicating that the underlying defect in aniridia has an impact on the transplanted donor cornea’s stroma. The niche environment seems to be important for limbal stem cell survival and the altered Notch1 cell signaling pathway apparently plays a role in aniridia.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.