P 241 Comparative study of one implantation of hema and PMMA iols in the rabbit

m Implantation of posterior ch.unber lenses (intmcalar lens = IOL) is an established method to replace opaque lenses. Prefered positioning of implanted lenses is in the capsular bag. either with or without touching the posterior capsule. Purpose of the present study is to determine the real position of the implanted lens in relation to the posterior capsule and to measure a possible distance between IOL and posterior capsule by Scheimpflug-photography. Method: 62 eyes of 50 patients with uncomplicated senile cataract underwent pbacoemulsification and implantation of a posterior chamber lens during a period of 6 months. Postoperatively the position of the IOL was measured by Scheimpflug-photography. &&& Out of 62 pseudophacic eyes of 50 patients 48 photos were reproducible. 33 photos showed a measurable distance between posterior IOL and posterior capsule. In 15 photos the posterior IOL touched the posterior capsule. Conclusion: Against general assompt~on that the IOL normally touches the posterior capsule our results show that only about 30% of implanted posterior chamber lenses touch the posterior capsule. P240 A new coating method to improve intraocular lenses tolerance Puroose. Several attempts to trnprove the intraocular lenses tolerance by surface modification had been tried A new method of crosslinked heparin grafting is presented. Methods. A modified heparin 1s crosslinked on a pretreated PMMA surface. Heparin grafted clnto the surface is equivalent to a free short length chain An analysis of the surface has been carrred out by ESCA (electron spectroscopy for chemical analysrs). ReSultS The thrckness of the treat'nent was about 3 to 5 nm. The treated lenses were found biocompatible The coating was found mechamcally stable but also resistant to pH variation and to washing As antr-thrombogenic sites were used to graft the heparrn, the coating should not exhibit any ant+-thrombogenic effect In vitro experiments demonstrated that short length heparin chatns rnhrbrt fibroblasts growth factor activitya. Undergoing exoenments and clinical trials wc?re desraned to confirm these hypotheses. Results of these tests. will be presented. Conclusions: A new method has been developped to crosslinked heparin on lenses. Other properties than anti-inflammatory ones are expected from this new technique of heparin grafting. Experiments are underway to dernontrate them. Purpose: To investigate ocular biocompatibility of a new HEMA (hydroxyethylmetacrylate) foldable IOL. Material and methods: 16 albino rabbits underwent extracapsular lens extraction in the right eye, under general anesthesia, and were followed for one year: 6 rabbits were implanted with a 6mm HEMA IOL …