Central Corneal Epithelial Wounding Accelerates Aniridia-Associated Keratopathy in PAX6-Deficient Mice.

Purpose: To investigate corneal healing in a Pax6+/- mouse model of aniridia-associated keratopathy (AAK) when challenged with a mild epithelial wound. Methods: Pax6+/- small-eye (Sey) mice (n = 15) and Pax6+/+ wild-type mice (n = 4) on the 129S1/SvImJ background underwent 1 mm central corneal mechanical epithelial debridement. Corneal status before and four weeks after wounding was evaluated by slit-lamp imaging. Longitudinal corneal thickness was measured using optical coherence tomography (OCT), and AAK was graded in Sey mice. Wounded corneas were additionally compared to unwounded contralateral corneas for AAK status. Immunofluorescence staining was used to assess inflammation, wound healing, and the presence of corneal blood and lymphatic vessels. Results: In wild-type mice, the central epithelial wound healed normally. In contrast, wounded corneas in Sey mice exhibited significantly accelerated AAK progression at 4 weeks compared to unwounded contralateral corneas (P = 0.011), with a corresponding increase in mean AAK grade relative to pre-wounding levels (P = 0.001). AAK grade correlated positively with increased central corneal thickness in wounded (P = 0.031) and unwounded (P = 0.0006) Sey mice. Wounded corneas in Sey mice exhibited strong hemangiogenesis and lymphangiogenesis and altered epithelial phenotype with decreased CK12 and elevated MUC5AC expression, along with an increase in F4/80, IL-6, and IL-1β inflammation markers. Aberrant epithelial differentiation and stem/progenitor maintenance (CK15, SOX9), and persistent tissue repair (Ki-67) were present and were consistent with disease progression. Conclusions: Central epithelial wounding accelerates AAK progression in Sey mice, highlighting the epithelial fragility in Pax6-aniridia and providing an efficient and robust accelerated model of AAK progression for preclinical studies.