Iris-Fixated Phakic Intraocular Lenses: New Results

Phakic intraocular lens (pIOL) implantation to correct refractive error is considered most often as an alternative to laser corneal refractive surgery in the setting of relatively high refractive error when there is an opportunity to retain the patient's ability to accommodate. There are 3 main designs: angle-supported anterior chamber, iris-claw anterior chamber, and posterior chamber, with several models commercially available. Because each pIOL offers different features, clinicians must match the pIOL specification carefully against their patients' needs and desired visual outcomes. For iris-fixated pIOLs, the main complication is endothelial cell loss (ECL).1Kohnen T. Kook D. Morral M. Guell J.L. Phakic intraocular lenses—part 2: results and complications.J Cataract Refract Surg. 2010; 36: 2168-2194Abstract Full Text Full Text PDF PubMed Scopus (137) Google Scholar An early study on the Artisan pIOL (Ophtec BV, Groningen, the Netherlands) by Tahzib et al2Tahzib N.G. Nuijts R.M. Wu W.Y. Budo C.J. Long-term study of Artisan phakic intraocular lens implantation for the correction of moderate to high myopia: ten-year follow-up results.Ophthalmology. 2007; 114: 1133-1142Abstract Full Text Full Text PDF PubMed Scopus (130) Google Scholar found that refractive stability was maintained without late-onset complications or long-term ECL over the study's 10-year period (endothelial cell density [ECD] reported at 3.62±16.97% at the 10-year follow-up). However, the authors found that to achieve this outcome, strict inclusion criteria and meticulous surgical technique were essential. They highlighted comparable visual acuity outcomes from a study of the long-term results of myopic photorefractive keratectomy on myopic patients. Other long-term follow-up studies of anterior chamber pIOLs have yielded similar visual outcomes. However, it should be noted that implantation of the Artisan myopia claw iris-fixated pIOL (Ophtec BV) has been reported to result in substantial loss of ECD between years 3 and 7.3Dick H.B. Budo C. Malecaze F. et al.Foldable Artiflex phakic intraocular lens for the correction of myopia: two-year follow-up results of a prospective European multicenter study.Ophthalmology. 2009; 116: 671-677Abstract Full Text Full Text PDF PubMed Scopus (82) Google Scholar In this issue of Ophthalmology, Jonker et al4Jonker S.M.R. Berendschot T.T.J.M. Ronden A.E. et al.Long-term endothelial cell loss in patients with artisan myopia and artisan toric phakic intraocular lenses: 5- and 10-year results.Ophthalmology. 2018; 125: 486-494Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar (see page 486) report on long-term changes in ECD after the implantation of the Artisan myopia and toric iris-fixated pIOLs. Their data showed a total chronic ECL of 16.6% and 21.4% from 6 months to 10 years in the myopic and toric groups, respectively, as well as 6.0% and 4.8% explantation rates resulting from ECL. They highlight the importance of preoperative ACD as a risk factor for increased ECL as others have also shown.5Shajari M. Scheffel M. Koss M.J. Kohnen T. Dependency of endothelial cell loss on anterior chamber depth within first 4 years after implantation of iris-supported phakic intraocular lenses to treat high myopia.J Cataract Refract Surg. 2016; 42: 1562-1569Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar Jonker et al4Jonker S.M.R. Berendschot T.T.J.M. Ronden A.E. et al.Long-term endothelial cell loss in patients with artisan myopia and artisan toric phakic intraocular lenses: 5- and 10-year results.Ophthalmology. 2018; 125: 486-494Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar suggest the need for a higher threshold of preoperative age-related ECD to ensure that the cornea is able to endure future cataract surgery and pIOL explantation. Current research indicates improved visual outcomes with low complication rates for myopic patients with more than 6 diopters in the long-term and potentially less than 6 diopters in the right circumstances. However, more long-term data are needed to give surgeons the opportunity to offer stronger evidence-based recommendations to patients. This requires patient participation in long-term studies and careful reporting of outcomes such as in the report from Jonker et al.4Jonker S.M.R. Berendschot T.T.J.M. Ronden A.E. et al.Long-term endothelial cell loss in patients with artisan myopia and artisan toric phakic intraocular lenses: 5- and 10-year results.Ophthalmology. 2018; 125: 486-494Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar Long-Term Endothelial Cell Loss in Patients with Artisan Myopia and Artisan Toric Phakic Intraocular Lenses: 5- and 10-Year ResultsOphthalmologyVol. 125Issue 4PreviewTo evaluate the long-term change in endothelial cell density (ECD) after the implantation of 2 types of rigid iris-fixated phakic intraocular lenses (pIOLs) for the treatment of myopia and astigmatism. Full-Text PDF