The Corneal Wound Healing Process Following Limbal Relaxation Incision in Rabbits

Background: Through animal experiments, the effects of Limbal relaxation incision (LRI) on corneal healing were preliminarily observed, aiming to explore the process of corneal limbal wound healing. Methods: A rabbit LRI surgical model was established and dynamically observed until 90 days after the operation. The haze scoring system and a modified Draize eye irritation test were used to quantify corneal opacity and irritation responses. Corneal epithelial integrity and dry eye disease were evaluated using fluorescein sodium staining. Hematoxylin and eosin (HE) staining was applied to observe the pathological changes in corneal tissue. Immunofluorescence staining was used to detect the expression of the proliferation marker Ki-67 in epithelial cells and the myofibroblast marker α-smooth muscle actin (α-SMA). Results: At 7 days postoperatively, the cornea showed opacity, dilation, epithelial defect and inflammatory responses. Ki-67 expression, a marker of epithelial cell proliferation, peaked at 7 days after the surgery and then gradually decreased. The activation of myofibroblasts α-SMA peaked at 30 days after the surgery, accompanied by corneal stroma thickening. From 30 to 60 days after the surgery, corneal opacity, inflammatory responses, dry eye syndrome and epithelial damage gradually improved. By 90 days after the surgery, corneal transparency was largely restored, vascular congestion was no longer evident, and the tissue architecture nearly returned to normal. The expression of α-SMA declined to a low level. Conclusion: LRI triggered a wound healing response, resulting in significant recovery of corneal transparency, epithelial integrity, and stromal structure. This indicates that although the limbal dissection incision induces corneal injury, the wound-healing process eventually occurs with relatively mild long-term fibrosis. The results of this study will provide a theoretical basis for a deeper understanding of corneal healing after LRI surgery and contribute to the treatment of residual astigmatism after clinical cataract surgery.