A Comparison Of Subconjunctival Wound Healing Between Different Methods Of Dissecting Subconjunctival Tissues

Objective: To compare different methods for dissecting subconjunctival tissues by developing subconjunctival wound healing models. Methods: New Zealand white rabbits were separated into 3 groups based on the method by which the rabbit subconjunctival wound healing model was generated: subconjunctival tissues were dissected episclerally (EPI) or subepithelially (SUB), with a corresponding blank control (CON). All the cases in the experimental groups were surgically prepared with conjunctival flaps, and they were sacrificed on the third postoperative day. At the surgical sites, the protein levels of hypoxia-inducible factor-1 (HIF-1)-alpha, vascular endothelial growth factor (VEGF)-A, and matrix metalloproteinase (MMP)-2 were detected by Western blot, morphological vascularity was measured by Adobe Photoshop, and subconjunctival fibrosis was assessed by histology. Results: Compared with the CON group, both the EPI and SUB groups showed significantly upregulated protein levels of HIF-1 alpha, VEGF-A, and MMP-2. In addition, the protein levels of HIF-1 alpha, VEGF-A, and MMP-2 were higher in the EPI group than in the SUB group. Morphological vascularity was significantly elevated in the EPI group compared with the SUB and CON groups. Collagen content was markedly increased in the EPI group compared with the SUB and CON groups. Conclusions: Dissecting subconjunctival tissues subepithelially inhibits subconjunctival fibrosis, which may be instructive in tenonectomy in filtration surgery.