The objective of the report is to examine the comparative effectiveness and cost-effectiveness of various intraocular lenses (IOLs) for the treatment of age-related cataracts.

A cataract is a hardening and clouding of the normally transparent crystalline lens that may result in a progressive loss of vision depending on its size, location and density. The condition is typically bilateral, seriously compromises visual acuity and contrast sensitivity and increases glare. Cataracts can also affect people at any age, however, they usually occur as a part of the natural aging process. The occurrence of cataracts increases with age from about 12% at age 50 years, to 60% at age 70. In general, approximately 50% of people 65 year of age or older have cataracts. Mild cataracts can be treated with a change in prescription glasses, while more serious symptoms are treated by surgical removal of the cataract and implantation of an IOL.

In Ontario, the estimated prevalence of cataracts increased from 697,000 in 1992 to 947,000 in 2004 (35.9% increase, 2.4% annual increase). The number of cataract surgeries per 1,000 individuals at risk of cataract increased from 64.6 in 1992 to 140.4 in 1997 (61.9% increase, 10.1% annual increase) and continued to steadily increase to 115.7 in 2004 (10.7% increase, 5.2% increase per year).

IOLs are classified either as monofocal, multifocal, or accommodative. Traditionally, monofocal (i.e.. fixed focusing power) IOLs are available as replacement lenses but their implantation can cause a loss of the eye’s accommodative capability (which allows variable focusing). Patients thus usually require eyeglasses after surgery for reading and near vision tasks. Multifocal IOLs aim to improve near and distant vision and obviate the need for glasses. Potential disadvantages include reduced contrast sensitivity, halos around lights and glare. Accommodating IOLs are designed to move with ciliary body contraction during accommodation and, therefore, offer a continuous range of vision (i.e. near, intermediate and distant vision) without the need for glasses. Purported advantages over multifocal IOLs include the avoidance of haloes and no reduction in contrast sensitivity.

Polymethyl methacrylate (PMMA) was the first material used in the fabrication of IOLs and has inherent ultraviolet blocking abilities. PMMA IOLs are inflexible, however, and require a larger incision for implantation compared with newer foldable silicone (hydrophobic) and acrylic (hydrophobic or hydrophilic) lenses. IOLs can be further sub-classified as being either aspheric or spheric, blue/violet filtered or non-filtered or 1- or 3-piece.

A literature search was conducted from January 2003 to January 2009 that included OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), The Cochrane Library, and the International Agency for Health Technology Assessment/Centre for Review and Dissemination.

The conclusions of the systematic review of IOLs for age-related cataracts are summarized in Executive Summary Table 1.