Abstract
Purpose: :
To characterize a novel model of bFGF–induced mouse corneal neovascularization (NV) with hemilimbal and hemiepithelial debridement.
Methods: :
Mice were divided into 4 groups: wild type (n=5), MMP2 knock–out (KO; n=5), MMP7 KO (n=5), collagen 18 KO (n= 5). After half of the corneal and limbal epithelium was removed, 100ng bFGF pellet was inserted in the midline of the cornea at the 12 o’clock position. Mouse corneas were examined and photographed prior to and following the onset of corneal NV. The areas of corneal neovascularization in the wounded and unwounded halves of the corneas were calculated using ImageJ software.
Results: :
Corneal neovascularization was significantly higher in the undebrided temporal side of the cornea when compared to the debrided nasal side at postoperative days 2 and 7. Mean surface area of vascularization for the temporal undebrided and nasal debrided sides at postoperative day 2 were 1.57mm2 and 0.15mm2 for MMP2 KO mice, 2.28mm2 and 0.14 mm2 for MMP7 KO mice, 2.26mm2 and 0.93 mm2 for collagen 18 KO mice, and 2.36mm2 and 0.39 mm2 for wild type mice (P<0.01). Mean surface areas of vascularization in the temporal undebrided and nasal debrided sides at the postoperative day 7 were 3.59mm2 and 1.75mm2 for MMP2 KO mice, 4.01mm2 and 0.81mm2 for MMP7 KO mice, 2.73mm2 and 1.72mm2 for collagen 18 KO mice, and 2.75mm2 and 1.81mm2 for wild type mice (P<0.01). Confocal immunohistochemical staining of wild type mouse corneas showed positive localization of VEGF–A and VEGF–C in the debrided area but not in the undebrided area.
Conclusions: :
Removal of half of the limbus (hemilimbal deficiency) led to corneal NV from the opposite side of the cornea where the limbus was intact, questioning the function of limbus as a barrier to corneal NV. VEGF–A and VEGF–C may play a role in the regulation of corneal neovascularization in the limbal deficiency model.
Keywords: cornea: basic science • neovascularization