Abstract
Abstract: :
Purpose: To develop a novel model of corneal neovascularization by epithelial debridement of the superior half of the cornea and limbus assisted by excimer laser ablation of the limbus in wild-type and MMP-2, -3, -7, and -12 knockout mice. Methods: Hemi-limbal deficiency was induced in the corneas of wild-type (C57BL/6), MMP-2, -3, -7, and -12 knockout mice by surgical excision of the superior half of the corneal epithelium and limbus followed by phototherapeutic keratectomy (193 nm ArF) of the superior limbus (n=26). After surgery, the pattern of epithelial healing and the extent of corneal neovascularization were determined using serial slit lamp photomicrography, daily for 3 days, then once per week for 6 weeks and confirmed by histological analysis at the termination of the experiment. Results: Hemi-limbal deficiency of the mouse cornea caused 3 patterns of epithelial healings and corneal neovascularization: (i) Rapid avascular epithelial closure: epithelial closure occurred within 3 days without any corneal neovascularization; (ii) Delayed epithelial closure: Epithelial defect persisted for 7-10 days and was associated with subsequent confluent corneal neovascularization and conjunctivalization originating from the inferior limbal region; and (iii) Rapid neovascular epithelial closure: Epithelial closure occurred within 3-5 days associated with corneal neovascularization tracking along the junction of treated and untreated epithelium. This was associated with limbal neovascularization in the inferior (untreated) cornea. Rapid neovascular epithelial closure was observed with varying frequencies depending on the matrix metalloproteinase deficiency. However, the differences in frequency per sub-group could not be statistically confirmed. Conclusion: Corneal neovascularization occurs using hemi-limbal deficiency followed by excimer laser ablation of the superior half limbus in wild-type and MMP-2, -3, -7, and -12 knockout mice.
Keywords: 370 cornea: basic science • 483 neovascularization • 606 transgenics/knock-outs