Objective: To review the published literature for evaluation of the safety and outcomes of phakic intraocular lens (pIOL) implantation for the correction of myopia and myopic astigmatism.
Methods: Literature searches of the PubMed and Cochrane Library databases were conducted on October 7, 2007, and July 14, 2008. The PubMed search was limited to the English language; the Cochrane Library was searched without language limitations. The searches retrieved 261 references. Of these, panel members chose 85 papers that they considered to be of high or medium clinical relevance to this assessment. The panel methodologist rated the articles according to the strength of evidence.
Results: Two pIOLs have been approved by the US Food and Drug Administration (FDA): one iris-fixated pIOL and one posterior-chamber IOL. In FDA trials of iris-fixated pIOLs, uncorrected visual acuity (UCVA) was >or=20/40 in 84% and >or=20/20 in 31% after 3 years. In FDA trials of posterior-chamber pIOLs, UCVA was >or=20/40 in 81% and >or=20/20 in 41%. Satisfaction with the quality of vision with both types of pIOLs was generally high. Toric anterior- and posterior-chamber pIOLs have shown improved clinical results in European trials compared with spherical pIOLs. Comparative studies showed pIOLs to provide better best spectacle-corrected visual acuity (BSCVA) and refractive predictability and stability compared with LASIK and photorefractive keratectomy and to have a lower risk of retinal detachment compared with refractive lens exchange. Reported complications and long-term safety concerns include endothelial cell loss, cataract formation, secondary glaucoma (pupillary block, pigment dispersion), iris atrophy (pupil ovalization), and traumatic dislocation.
Conclusions: Phakic IOL implantation is effective in the correction of myopia and myopic astigmatism. In cases of high myopia of -8 diopters or more, pIOLs may provide a better visual outcome than keratorefractive surgeries and better safety than refractive lens exchange. The short-term rates of complications and loss of BSCVA are acceptable. Comprehensive preoperative evaluation and long-term postoperative follow-up examinations are needed to monitor for and prevent serious complications, and to establish long-term safety.