VEGF-C and 5-Fluorouracil Improve Bleb Survival in a Rabbit Glaucoma Surgery Trabeculectomy Model

Abstract

Purpose To evaluate VEGF-C–induced lymphoproliferation in conjunction with 5-fluorouracil (5-FU) antimetabolite treatment in a rabbit glaucoma filtration surgery (GFS) model. Methods Thirty-two rabbits underwent GFS and were assigned to four groups ( n = 8 each) defined by subconjunctival drug treatment: (a) VEGF-C combined with 5-FU, (b) 5-FU, (c) VEGF-C, (d) and control. Bleb survival, bleb measurements, and IOP were evaluated over 30 days. At the end, histology and anterior segment OCT were performed on some eyes. mRNA was isolated from the remaining eyes for RT-PCR evaluation of vessel-specific markers (lymphatics, podoplanin and LYVE-1; and blood vessels, CD31). Results Qualitatively and quantitatively, VEGF-C combined with 5-FU resulted in blebs which were posteriorly longer and wider than the other conditions: vs. 5-FU ( P = 0.043 for longer, P = 0.046 for wider), vs. VEGF-C ( P < 0.001, P < 0.001) and vs. control ( P < 0.001, P < 0.001). After 30 days, the VEGF-C combined with 5-FU condition resulted in longer bleb survival compared with 5-FU ( P = 0.025), VEGF-C ( P < 0.001), and control ( P < 0.001). Only the VEGF-C combined with 5-FU condition showed a negative correlation between IOP and time that was statistically significant (r = −0.533; P = 0.034). Anterior segment OCT and histology demonstrated larger blebs for the VEGF-C combined with 5-FU condition. Only conditions including VEGF-C led to increased expression of lymphatic markers (LYVE-1, P < 0.001–0.008 and podoplanin, P = 0.002–0.011). Expression of CD31 was not different between the groups ( P = 0.978). Conclusions Adding VEGF-C lymphoproliferation to standard antimetabolite treatment improved rabbit GFS success and may suggest a future strategy to improve human GFSs.