Purpose: To investigate the effect of poly (lactic-co-glycolic acid) (PLGA) implants loaded with mitomycin C (MMC) and with different adjuvant treatments after glaucoma filtration surgery (GFS), in comparison to standard treatments.
Methods: Forty-two New Zealand White rabbits underwent bilateral GFS and received different treatments: topical MMC (group 1); topical 5-fluorouracil (5-FU; group 2); PLGA implant (group 3); MMC-loaded and -coated PLGA implant (group 4); MMC-loaded and 5-FU-coated PLGA implant (group 5); subconjunctival bevacizumab (group 6); MMC-loaded PLGA implant and subconjunctival bevacizumab (group 7); and no treatment (right eye of all animals; control group). Intraocular pressure (IOP) and filtering bleb were evaluated on different days after GFS. Histology was performed to examine the conjunctiva, sclerotomy, filtering bleb, and persistence of the implant.
Results: The best hypotensive results were achieved in the MMC-loaded and -coated PLGA implant group, which presented the lowest IOP values on days 1, 5, 7, 14, and 28 after GFS. Excluding the implant groups, in which the bleb could not be properly measured, bleb survival was superior to controls in groups 1, 2 and lower in group 6. Group 7 presented greater extension, height, and vascularization of the bleb. Epithelial thinning and lymphoplasmacytic infiltrate were observed in groups 1, 2, 4, 5, and 7. The rates of closure of the sclerotomy and bleb were 100% and 76%, respectively, and implant persistence was 95%.
Conclusions: MMC-loaded and -coated implants have optimal surgical results, followed by topical MMC application. In this experimental model, bevacizumab could interact with MMC.
Keywords: PLGA; antimitotics; glaucoma; implant; ocular drug delivery systems; trabeculectomy.