Refractive Lens Exchange

Abstract

Currently there are two general approaches to correct a refractive error: refractive corneal surgery and intraocular refractive surgery. In either case, the main goal of refractive surgery is to achieve the smallest residual refractive error preserving quality of vision with the same visual capacity. Surgical manipulation of the crystalline lens is one of our frequent refractive surgeries. The correction of high myopia and high hyperopia is still a controversial topic. Refractive surgical procedures are usually performed at the cornea. Correction of myopia is relatively easier, but the correction of hyperopia by means of corneal surgery is used by few refractive surgeons due to its technical and conceptual complexity (it is clearly easier to flatten than to steepen the cornea), its lower predictability and more frequent unsatisfactory results [10, 11]. The correction of low to moderate myopia or hyperopia at the corneal plane provides acceptable quality of vision, but high corrections cause significant optical aberrations and poor quality of vision especially under dim light conditions [19, 25, 30, 42], such that intraocular refractive surgery becomes a valid alternative to correct cases of high ametropia. Refractive lens extraction (RLE) is an intraocular refractive surgery consisting of the extraction of the natural lens and its substitution by an posterior chamber intraocular lens (IOL) of proper dioptric (D) power (Fig 16.1 and 16.2). When it is not associated with a cataract, others call it “clear or semi-clear lens extraction” or “refractive lensectomy” or “refractive lens exchange”. This is a very ancient surgical technique; Fukala [13] first reported RLE in 1778. He is considered the pioneer of the refractive lensectomy concept. Later on, the increasing risk of retinal detachment (RD) with this procedure was reported, due to it this surgical technique was left of side and was finally abandoned. Nowadays, RLE is a surgical technique that has been revived and is under constant investigation [38]. Theoretically, RLE is a surgical procedure with the same risks and complications as cataract extraction surgery. According to Werblin [47], in experienced hands, the incidence of permanent visual loss from an intraoperative or postoperative complication of IOL surgery is between 0.5% and 1.0%. In this regard, the procedures and materials have evolved promptly during the last 30 years, changing the Refractive Lens Exchange