Intraocular lenses for uncomplicated senile cataracts

Harstall C, Schneider W L
Record ID 31999009739
English
Authors' objectives: This report has been prepared because of interest in the increasing use of newer types of intraocular lenses (IOLs) and in their comparative advantage. The focus of the report is on the safety, efficacy and effectiveness of the three types of intraocular lenses (PMMA, silicone and foldable acrylic).
Authors' recommendations: Cataract surgery with implantation of an intraocular lens (IOL) is a successful technology for treatment of uncomplicated senile cataract. The results from a meta-analysis indicated that cataract surgery gives excellent results for visual acuity in approximately 95% of eyes without pre-existing ocular co-morbidity. The surgical techniques for removal of senile uncomplicated cataracts continue to evolve. The advent of small incision cataract surgery and the development of phacoemulsification stimulated the search for new IOL materials that allow for the folding of the lens prior to insertion. Surveys indicate a trend to increasing use of foldable IOLs. Some degree of foreign body reaction occurs in all eyes after cataract surgery with IOL implantation, regardless of the IOL material. Cellular proliferation on the surface of an IOL is an indication of the biocompatibility of the lens' material. Posterior capsular opacification (PCO) is the most common cause of visual morbidity following cataract surgery with the insertion of a posterior chamber IOL. A meta-analysis found that rates of visually significant PCO incidence in patients undergoing standard cataract surgery were 11.8% at one year, 20.7% at three years and 28.4% at five years after surgery. The most convenient method for treating PCO is Nd:YAG laser capsulotomy. The incidence of damage to IOLs by Nd:YAG laser has been reported to vary from 4% to 40%. Significant modifications of PMMA IOL design have occurred as a result of the developments in surgical methods. PMMA remains a popular material for IOL optics and is still the standard against which other materials are compared. Only a few studies have compared all three optical lens types. Most of these have methodological limitations and small numbers of subjects. At present, there is limited information on which to base decisions regarding the choice of IOL. A large number of IOL products are available, and their safety and effectiveness are functions of a complex interaction between the lens and the surgical procedure. Moreover, there are several different designs, configurations and materials from which to choose. On the basis of the relatively weak scientific evidence that is currently available, foldable acrylic IOLs appear to offer greater short-medium term benefits than other optical lens types in terms of biocompatibility and risk of PCO.
Authors' methods: Systematic review
Details
Project Status: Completed
Year Published: 1999
English language abstract: An English language summary is available
Publication Type: Not Assigned
Country: Canada
MeSH Terms
  • Humans
  • Cataract
  • Lens, Crystalline
  • Lenses, Intraocular
Contact
Organisation Name: Institute of Health Economics
Contact Address: 1200, 10405 Jasper Avenue, Edmonton, Alberta, Canada, T5J 3N4. Tel: +1 780 448 4881; Fax: +1 780 448 0018;
Contact Name: djuzwishin@ihe.ca
Contact Email: djuzwishin@ihe.ca
Copyright: <p>Alberta Heritage Foundation for Medical Research</p>
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