Phakic intraocular lenses (PILs) can provide optically superb correction of relatively high degrees of ametropia that lie well beyond the recommended range for keratorefractive procedures, such as laser in situ keratomileusis and photorefractive keratectomy. Although hundreds of thousands have been implanted, the predominant concern surrounding these devices remains that of long-term safety. Three lens types based on anatomical location have been developed—angle supported, iris fixated, and posterior chamber—each with its particular risk to benefit profile. Angle-supported implants can induce endothelial cell loss and corneal decompensation, as well as pupil ovalization, whereas iris-fixated implants pose risks of cataract, corneal decompensation, endothelial cell loss, and dislocation.1 Posterior chamber PILs are intended to vault over the crystalline lens, but anterior subcapsular cataract was soon recognized as a relatively common occurrence with this design, especially with longer follow-up.
McLeod SD. Long-term Clinical Outcomes and Cataract Formation Rates After Posterior Phakic Lens Implantation for Myopia. JAMA Ophthalmol. 2016;134(5):494-495. doi:10.1001/jamaophthalmol.2015.6150