Refractive lens exchange (RLE) is the removal of the crystalline lens with IOL implantation for the primary purpose of correcting refractive error. RLE may be considered for the correction of myopia, hyperopia, astigmatism, and presbyopia when alternative refractive procedures are not adequate to address the patient’s refractive error. RLE is typically used for refractive correction of presbyopic patients and in patients with lens opacity expected to progress quickly. RLE is generally not considered medically necessary and is usually not covered by the patient’s insurance. All FDA-approved IOLs are approved specifically for implantation at the time of cataract surgery, and implantation for RLE is considered an off-label use in the United States.
Refractive lens exchange carries risks and complications identical to those for routine cataract extraction with IOL implantation. Potential candidates must be capable of understanding the short-term and long-term risks of the procedure. Patients should be informed that unless they are targeted for residual myopia with monofocal, toric, or accommodating IOLs, or have an MFIOL implanted, they will not have functional near vision without correction. A consent form should be given to the patient prior to surgery to allow ample time for review and signature. A sample consent form for RLE for the correction of hyperopia and myopia is available from the Ophthalmic Mutual Insurance Company (OMIC) at www.omic.com.
Refractive lens exchange can be considered in patients with myopia of any level, although it is most commonly used in presbyopic patients with higher myopia, for whom corneal refractive procedures or PIOL implantation are not indicated. Myopia, however, is a significant risk factor for retinal detachment in the absence of lens surgery, and this risk rises with increased axial length. High myopia, defined as an axial length of 26 mm, or greater, is an independent risk factor for subsequent retinal detachment after lens extraction. Thus, a thorough retinal examination, including peripheral retinal evaluation, is indicated in these eyes prior to consideration of RLE.
American Academy of Ophthalmology Retina/Vitreous Panel. Preferred Practice Pattern Guidelines. Posterior Vitreous Detachment, Retinal Breaks, and Lattice Degeneration. San Francisco: American Academy of Ophthalmology; 2014. Available at www.aao.org/ppp.
Daien V, Le Pape A, Heve D, Carriere I, Villain M. Incidence, Risk Factors, and Impact of Age on Retinal Detachment after Cataract Surgery in France: A National Population Study. Ophthalmology. 2015;122(11):2179–2185.
Haug SJ, Bhisitkul RB. Risk factors for retinal detachment following cataract surgery. Curr Opin Ophthalmol. 2012;23(1):7–11.
If the amount of hyperopia is beyond the range of alternative refractive procedures, RLE might be the only available surgical option. As with correction for myopia, the patient must be informed about the risks of intraocular surgery. A patient with a shallow anterior chamber from a thickened crystalline lens or small anterior segment would not be a candidate for a PIOL and could benefit from the reduced risk of angle-closure glaucoma after RLE. In a highly hyperopic eye with an axial length less than 18 mm, nanophthalmos should be considered. Eyes with these characteristics have a higher risk of uveal effusion syndrome and postoperative choroidal detachment. (See BCSC Section 11, Lens and Cataract, for discussion of cataract surgery for a patient with high hyperopia and nanophthalmos.) Patients with hyperopia have a lower risk of retinal detachment than do patients with myopia.
With the advent of toric IOLs that cover an expanded range, patients with significant astigmatism are also candidates for RLE. In the United States, there are currently no FDA-approved toric MFIOLs, although a toric accommodating IOL has been approved. Thus, US patients planning to undergo implantation of a nonaccommodating toric IOL must understand the lack of uncorrected near acuity if targeted for distance; patients considering MFIOL implantation should understand that these IOLs will not sufficiently reduce astigmatism. Also, patients need to understand that an additional surgical procedure, usually LASIK, limbal relaxing incisions, or photorefractive keratectomy, may be necessary to maximize spectacle independence. Laser vision correction candidacy should be determined prior to lens-based surgery if it is being considered.
Discussion of correction of presbyopia, in addition to correction of myopia, hyperopia, and/or astigmatism, should be a component of the preoperative discussion in applicable patients. RLE is occasionally used primarily for the purpose of correcting presbyopia, with the implantation of multifocal or accommodating IOLs or the creation of monovision with lens implants. A patient selecting distance-focused toric or spherical IOLs in both eyes should be informed that reading glasses will be required for functional near vision.
Excerpted from BCSC 2020-2021 series: Section 13 - Refractive Surgery. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.