[Hydrophobic AcrySof lenses or heparin-modified PMMA lenses in combined vitrectomy surgery -- results of a four-year...

Combining pars plana vitrectomy with phacoemulsification and implantation of an intracapsular IOL provides many advantages and is performed as a routine operation.

Over a period of 3 years we compared foldable acrylic lenses AcrySof (Alcon) to heparin-modified PMMA lenses (Pharmacia) in a prospective study. The last implanted lenses had a follow-up period of at least 1 year. Out of 396 eyes from 329 patients we implanted 182 AcrySof lenses and 214 heparin-modified lenses.

Both a smaller scleral tunnel incision and a lower rate of secondary cataract are advantages of foldable AcrySof lenses. Higher vulnerability of an AcrySof lens and a less stable lens-iris-diaphragm are of disadvantage. Heparin-modified PMMA lenses do not show these disadvantages, however, in consequence of using them you have to accept the wider scleral tunnel incision and a higher adhesion to cells. Furthermore, we found slightly more posterior synechiae with these lenses.

In all, both types of intraocular lenses are suitable for combined surgery. We recommend using heparin-modified PMMA lenses in case of pre-existent instability of the lens-iris diaphragm or of patients' inability to maintain the prone position.