Posterior chamber silicone intraocular lens for the correction of myopia: an experimental study in rabbits

Purpose. To establish whether ocular lesions arise after implantation of po sterior chamber silicone intraocular lenses (IOL) for the correction of hig h myopia. Methods. Twenty-three posterior chamber silicone IOL were implanted in 23 e yes of the same number of pigmented rabbits. After different follow-up time (from one week to one year) the eyes were enucleated and processed for his topathological study after determining the protein concentration in the acq ueous humor. The IOL were removed for staining and examination, and adhered cells were counted. Ten eyes analogous to those operated upon were used as controls. Results. intense inflammation was observed in the early postoperative perio d in all cases. Protein concentration in the acqueous humor was initially h igh and decreased over time, though without reaching normal values at one y ear. Mono- and multinucleated cells were seen adhering to the IOL, though t hey decreased in number over time and were practically absent after one yea r. Friction between the posterior surface of the iris and the IOL had no cl inical repercussions. The only pigment accumulations were in the iris and i n the peritrabecular zone. There were no siginificant differences in the ac cumulation of granules in relation to IOL diameter or power. Excluding thre e cataracts morphologically similar to traumatic cataracts, five lens opaci fications were observed: two were anterior subcapsular cataracts, and the o f her three were only precapsular deposits. The IOL had no synechiae to the ocular tissues. Conclusions. Opacification of the lens is the main concern with implantated posterior chamber silicone IOL. Larger series of eyes must be analysed to establish the true incidence and reversibility of these opacities.