Development of After-cataract in Pseudophakic Eyes with Silicone or PMMA Intraocular Lens

ABSTRACT

Foldable intraocular lenses(IOLs) arebeing used and wide spread with some advantages such asn little surgically induced astigmatism and rapid visual rehabilitation, but the effect of foldable IOLs on long-term safety and the formation of after-cataract was not understood clearly yet. 48 patients(54 eyes) which underwent Nd-YAG capsulotomy from 1995 to 1997 at the Kangnam St. Mary`s Hostpital were studied. All the cases had been operated by one operator(Joo) with the same technique except for incision method. The average interval from cataract surgery to Nd-YAG capsulotomy was 31 months in PMMA group and 15 months in silicone group. This difference between the two groups was statistically significant(P=0.0002). The ratio of Elschnig pearl type to fibrosis type in after-c attract was 166 in PMMA group and 1318 in silicone group. The average of the total energy used in Nd-YAG laser capsulotomy was 256mJ in PMMA group and 309mJ in silicone group. However, damages caused by YAG laser were severer and more common on the silicone IOLs than on the PMMA IOLs. Silicone IOL induces after-cataract faster than PMMA IOL and the major type of after-cataract in pseudophakia with silicone IOL is fibrosis.