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Removal of the crystalline lens was developed as a procedure to treat the media opacity, but advances in surgical techniques and in pseudophakic IOL technology have increased the functional use of lens-based refractive surgery, said William F. Wiley, MD.
Removal of the crystalline lens was developed as a procedure to treat the media opacity. However, advances in surgical techniques and in pseudophakic IOL technology have increased the functional use of lens-based refractive surgery, said William F. Wiley, MD.
Speaking at Refractive Surgery 2017, Dr. Wiley addressed the question of when to perform refractive lens exchange (RLE).
He s he considers the degree of lens pathology, the refractive error, and patient age. Presbyopic patients and patients with lens dysfunction should be considered over younger patients with functional lenses.
“As lens technology continues to improve, greater weight may be given to refractive error than to age,” said Dr. Wiley, Cleveland Eye Clinic, Brecksville, OH. “In a world of continued technological advancements, we will be seeing more patients having their eyes ‘fixed’ early.”
Dr. Wiley mentioned a refractive surgery grid developed by Kugler, Parkhurst, and Sandberg for providing guidance on choosing between different refractive procedures, taking into account patient age and refractive error. According to this grid, refractive lens exchange can be considered for people with a wide range of refractive errors and across a broad age range, from young presbyopes (i.e., patients in their late 30s) to much older individuals who have not yet developed a cataract.
A recently published study by Schallhorn et al. [Clin Ophthalmol. 2017;11:1569-1581] compared outcomes of RLE in younger and older presbyopes. It included nearly 1,300 patients categorized into four age groups (45-49, 50-54, 55-59, and 60-65 years) and found no significant differences between the groups in clinical or patient-reported outcomes, including for postoperative satisfaction, visual phenomena, dry eye symptoms, and distance or near vision activities.
One of the main reasons for not performing RLE in even younger adults is that younger age is a risk factor for retinal detachment after lens removal.
Having no posterior vitreous detachment is another risk factor, and patients should be screened for this feature using OCT, Dr. Wiley said.
There is also evidence that YAG laser capsulotomy increases the risk of retinal detachment, especially in high myopes.
Based on that information, Dr. Wiley suggested that when performing RLE, surgeons should select an IOL that is associated with a relatively low rate of posterior capsule opacification.
Discussing specific patient scenarios, Dr. Wiley suggested that although LASIK may be considered an option for treating myopia and hyperopia in patients aged 18 to 60 years, RLE may be considered a “slam dunk” for a 60-year-old with high hyperopia because of its favorable benefit:risk ratio.
“Corneal refractive surgery is not a great option for treating a high hyperopic error, and with RLE, it is possible to solve multiple problems,” he said.
“Often these patients have crowded angles and so are at risk for glaucoma,” Dr. Wiley said. “Removing the lens may cure these narrow-angle concerns, and these eyes also have a relatively low risk of retinal detachment.”
However, Dr. Wiley cautioned surgeons to watch for choroidal effusion because there is an increased risk for it to occur in very short eyes.
Discussing the refractive surgery decision for a 58-year-old high myope (-12.0 D), Dr. Wiley said that while phakic IOL implantation is a possibility, it may not be the best choice considering evidence that it can particularly induce cataract in people over age 45.
“RLE can be perfect in such a patient,” he said. “Here it also solves two problems with one procedure, correcting the refraction and eliminating the potential issue of cataract. Furthermore, with new IOLs, RLE can also treat presbyopia.”
The role for RLE may increase in the future subsequent to ongoing innovations in lens technology that include the development of adjustable, exchangeable, and upgradeable platforms.
These devices include the Light Adjustable Lens (Calhoun Vision), the Harmoni Modular IOL (ClarVista Medical), and the Gemini Refractive Capsule (Omega Ophthalmics).
Dr. Wiley noted that the latter device has space-occupying characteristics, may prevent the need for YAG capsulotomy, and has the potential to decrease or eliminate the risk of retinal tears and detachment.
“It could really open the space for clear lens surgery,” he concluded.
Dr. Wiley is a consultant to Omega Ophthalmics, receives grant support from Calhoun Vision, and is a consultant to and/or receives lecture fees from other companies that market products used in RLE surgery.