Purpose To investigate the combinational therapeutic effects of topical administration of doxycycline temperature-sensitive hydrogel (DTSH) and bevacizumab on corneal neovascularization (CNV) and corneal wound healing (CWH); to explore the underlying mechanisms of doxycycline on CNV and CWH.

Methods Rats were treated with a saline solution (control group), topical DTSH (0.1%), subconjunctival injection of bevacizumab (2.5 mg/0.1 ml), or a DTSH and bevacizumab combination. For the basic fibroblast growth factor-induced CNV model (n=15/group), the length and area of CNV were measured and analyzed on day 7. In the alkali burn model (n=33/group), the length and area of CNV were determined on days 3, 7, 14, and 21 after alkali burn. The activity of matrix metalloproteinase (MMP)-2 and MMP-9 was determined by a fluorogenic peptide substrate. Western blot, real-time PCR and ELISA were used to analyze the expression of induced nitric oxide synthase (iNOS), VEGF, MMP-2, MMP-9 and the production of IL-1β.

Results The combinational therapy more effectively inhibited CNV than the topical administration of bevacizumab or DTSH alone. The DTSH combined with bevacizumab significantly accelerated delayed CWH caused by the topical application of bevacizumab in the alkali burn model (p=0.018). With the DTSH treatment, doxycycline inhibited the activity of MMP-2 and MMP-9 and reduced the expression of iNOS and the production of IL-1β in alkali-burned cornea.

Conclusion Doxycycline enhanced the inhibitory effects of bevacizumab on CNV and prevented its side effects on CWH. The combination of topical doxycycline and bevacizumab could be a good alternative treatment for the clinical CNV.