![]() This prospective interventional study enrolled 8 patients (11 eyes), from January 2012 to December 2013, who had preoperative PMD and cataract diagnosis. The aim of this study is to evaluate the efficacy of a toric IOL (AcrySof IQ Toric IOL, Fort Worth, TX, USA) implanted after a conventional phacoemulsification in order to reduce the high myopic astigmatism in patients with PMD. Previous studies have analyzed the results of several toric IOL implantations after cataract surgery and have shown good rotational stability and good functional results. The toric IOL was devised by Shimizu et al 8 in 1994 and has been used clinically since then. 6 Others reported a case in which toric intraocular posterior chamber phakic Collamer lenses (ICL) effectively corrected the refractive errors of PMD. Some authors proposed the implantation of toric phakic iris-fixated IOL (Verisyse/Artisan). Full-thickness interventions include the removal of only the abnormally thinned cornea, or of the total cornea with the replacement of all cornea layers.Ĭorneal independent interventions involve the use of lenses and comprise spectacles and contact lenses (nonsurgical) and toric, phakic, and pseudophakic intraocular lenses (IOLs). 5 Partial-thickness techniques comprise interventions involving the removal of only the anterior layer of the abnormally thinned cornea, with partial cornea replacement or the removal of the total cornea preserving the host endothelium. Structural interventions include techniques designed to strengthen the structure of the corneal stroma, such as corneal collagen cross-linking (CXL), 4 or techniques designed to modify the curvature and the mechanical properties of the corneal stroma, such as intrastromal corneal ring segments (ICRS). Management of affected patients depends on the level of visual disability and can be organized in structural, partial-thickness, full-thickness, and corneal-independent interventions. The area of ectasia is cylindrical, rather than conic as in keratoconus, and occurs just above, rather than inside, the area of greatest thinning creating an against the rule astigmatism. The zone of thinning is generally 1–2 mm wide, and separated 1 or 2 mm from the limbus by an area of normal cornea. The onset of the disease is usually between the ages of 20 and 40 years. Pellucid marginal degeneration (PMD) is an idiopathic, noninflammatory thinning disorder normally involving the inferior peripheral part of the cornea, concentric with the limbus, between the 4 and 8 o'clock meridians.
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