Early But Not Late Treatment With Bevacizumab (Avastin) Can Inhibit Rabbit Corneal Neovascularization Caused By Closed Eye Contact Lens Wear

Yan-Ming Chen^1,2, Fung-Rong Hu^2,3, Wei-Li Chen^2,3

¹Department of Ophthalmology, E-Da Hospital/I-Shou University, Kaohsiung, Taiwan
²Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
³Center of Corneal Tissue Engineering and Stem Cell Biology, National Taiwan University Hospital, Taipei, Taiwan

Purpose: To evaluate the therapeutic effects of early and late subconjunctival injection of bevacizumab on a rabbit model of corneal neovascularization (NV) caused by closed eye contact lens wear.

Methods: Corneal NV was induced by closed eye contact lens (CLs) wear in adult New Zealand white rabbits. Subconjunctival injections of 5.0mg bevacizumab was performed weekly for 1 month immediately after CLs wear (early treatment group) or 1 month after CLs wear (late treatment group). The percentage of involved corneal surface (PICS)/centricity/extent of corneal NV was evaluated. Immunohistochemistry (IHC) with anti-human IgG antibody was used to determine the intracorneal diffusion of bevacizumab after injection. IHC with anti-vimentin antibody was used to determine the formation of pericytes after NV formarion.

Results: Immunohistochemistry showed that single injection of bevacizumab can induce intracorneal diffusion for at least 7 days in both early and late treatment groups. Pericyte formation was found at 1 month after induction of corneal NV. Early bevacizumab treatment can significantly inhibit corneal NV at 4 weeks after treatment (p<0.01) while late treatment group can not ( p> 0.05).

Conclusions: Bevacizumab can diffuse to corneal stroma for at least 7 days after subconjunctival injections in both early and late treatment groups. Early but not late bevacizumab injection can significantly inhibit corneal NV induced by closed eye CLs wear in rabbits.