title: [Hydrophobic AcrySof lenses or heparin-modified PMMA lenses in combined vitrectomy surgery -- results of a four-year study].
abstract: BACKGROUND
  Combining pars plana vitrectomy with phacoemulsification and implantation of an intracapsular IOL provides many advantages and is performed as a routine operation.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Klinik und Poliklinik für Augenheilkunde, Martin-Luther-Universität Halle-Wittenberg. dirkehrich@hotmail.com
authors.forename: Dirk
authors.initials: D
authors.lastname: Ehrich
authors.forename: Astrid
authors.initials: A
authors.lastname: Stein
authors.forename: Frank
authors.initials: F
authors.lastname: Wilhelm
authors.forename: Gernot I W
authors.initials: GI
authors.lastname: Duncker
mesh_terms: D000179:Acrylates; D020099:Coated Materials, Biocompatible; D003131:Combined Modality Therapy; D019544:Equipment Failure Analysis; D005500:Follow-Up Studies; D006493:Heparin; D006801:Humans; D007910:Lenses, Intraocular; D019904:Polymethyl Methacrylate; D011183:Postoperative Complications / Q000209:etiology*; D011474:Prosthesis Design; D014821:Vitrectomy
chemical_list: D000179:Acrylates; D020099:Coated Materials, Biocompatible; D006493:Heparin; D019904:Polymethyl Methacrylate; C036658:acrylic acid