Phakic Intraocular Lenses An Overview

Abstract

Delhi J Ophthalmol 2013; 24 (1): 7-15 Currently, there are four general approaches to correct refrac ve errors: refrac ve corneal surgery, crystalline lens surgery, and implanta on of an intraocular lens (IOL) Laser corneal refractive surgery has been used to correct a wide range of refractive errors and has proven to be eff ective and safe in most cases. Despite the use of highly optimized and customized laser treatments such as wave front-guided, aspheric, and topographyguided ablations, the physical limitations of corneal thickness, curvature, and tissue remodeling limit the indications for a safe corneal refractive procedure. Moreover, the optical quality of the outcomes may not be as good as desired, especially when treating high refractive errors.When keratorefractive surgery is not the appropriate approach, either phakic intraocular lens (pIOL) implantation or refractive lens exchange (RLE) with IOL implantation should be considered. One of the main concerns about RLE in highly myopic eyes is the increased risk for retinal detachment (RD), especially in younger patients and in eyes with long axial lengths (>26 mm). The incidence of RD after RLE ranges from 0% to 8%. 1,2 RLE causes loss of accommodation and should be avoided when the natural lens is still functional. In the absence of contraindications, pIOL implantation is the best approach in young patients with moderate to high refractive errors and in those who have a contraindication to a corneal refractive procedure (eg, thin corneas). Advantages are that pIOL implantation maintains accommodation and is reversible. TypesPhakic IOLs comprise 3 types: angle-supported anterior chamber, irisclaw anterior chamber, and posterior chamber. Each design has its own features, selection criteria, surgical technique, results, and complications. (Table 1) summarizes the main features of those that are U.S. Food and Drug Administration (FDA) approved or has CE marking. Angle Supported Anterior Chamber phakic IOLsIn 1953, Strampelli 3 implanted the fi rst minus power anterior chamber IOL in phakic eyes to correct myopia. In 1959, Barraquer 4 reported the results of 239 implantations. Although the fi rst results were encouraging, many pIOLs had to be explanted owing to complications such as chronic loss of corneal endothelial cells, iris retraction and atrophy, peripheral anterior synechiae, subsequent pupil ovalization, and uveitis-glaucomahyphema syndrome. 5,6 Current ModelsPolymethyl methacrylate Angle-Supported Anterior Chamber pIOLs: With the advent of foldable models, PMMA anglesupported pIOLs have been almost abandoned.

Visian® ICLV4c™ and Artiflex®: Comparative Analysis with the HD Analyser™ and Integration with Subjective Performance and Anatomical Parameters

“…Despite phakic intraocular lens (PIOL) implantation (irisclaw and posterior chamber) has been associated with good visual outcomes, there are still some issues regarding the visual quality and long-term safety of these lenses. [1][2][3] Regarding most patients implanted being young and active, and the fact that many of them present retinal alterations or cortex limitations in the form of amblyopia, the evaluation and comparison of both refractive lens performance and the overall real quality of life achieved is imperative.…”