Background: 5-Fluorouracil (5-FU) is useful as an adjunct treatment for glaucoma filtering surgery. However, efficacy depends upon maintaining sustained drug levels, currently achieved by repeated daily injections of the drug for several days. To overcome this limitation, we designed a biodegradable implant for the sustained release of 5-FU.
Material and methods: The implant (0.79 mm diameter, 6 mm long, 2.2 mg weight) contains 0.66 mg of 5-FU and is loaded in a needle coupled to a custom-made instrument to permit subconjonctival insertion of the implant through a 2 mm wide snip incision. The in vitro and in vivo pharmacokinetics as well as the biocompatibility studies of the implants were assessed in the rabbit.
Results: No infection, inflammatory reaction or extrusion occurred. The implant released the drug at a constant rate of 1.20 micrograms/hr for over 18 days and totally biodegraded in less than 86 days.
Conclusion: Implantation of the device, after laser sclerostomy or conventional trabeculectomy shows great potential for the treatment of glaucoma. To determine the implant's efficacy, additional studies in the cat are underway.