Intracapsular controlled drug release implant (CDRi) designed to prevent secondary cataract

Purpose. In vitro and in vivo safety and efficacy evaluation of a CDRi made of poly(D,L-lactide-co-glycolide) 50/50 and a 5-FU antimitotic. Methods. The flexible "C" shaped CDRi device (0.7mm cross-section, 21mm long) contains 2mg of 5-FU and was calculated to release 4.5p,g 5-FU/hr to maintain a = 10[j.g 5-FU/ml concentration in the capsular bag-anterior chamber space, well above therapeutic threshold (= 0.2[4.g/ml) and below toxic level (60|0.rn/ml). In vitro characteristics were assessed in an artificial eye at 36°C with an aqueous flow of 20M-l/min. (10 times normal). The device is inserted in the empty capsular bag using a 19ga instrument. 3 control groups: 6 rabbits without capsule polishing, 6 with capsule polishing, 6 with capsule polishing and a CDRi without 5-FU. A fourth group of 6 receives a 5-FU CDRi. Follow-up stops 1 week after the onset of secondary cataract and histology is performed. Result?. The CDRi released 5-FU for = 50 days m vitro. In vivo, the onset of secondary cataract in controls was =3 weeks. Implant biodégradation takes =100days. The pharmacological, clinical, and histological results of this ongoing study will be presented. Conclusion. The intraocular 5-FU concentrations and long term effect on comeal endothelium have to be further assessed. The 5-FU CDRi needs refinement for insertion though a 3mm corneal incision and is promising.