Eyeworld

EW REFRACTIVE 62 January 2018 Refractive editor's corner of the world by Michelle Stephenson EyeWorld Contributing Writer should be considered for patients who are eligible for laser vision cor- rection," he said. "One of the nice things about phakic IOLs, including great quality of vision, is that they leave all options open for the future, and this is one of the reasons we chose phakic IOLs for my wife's re- fractive surgery even though she was a good candidate for LASIK." Jorge L. Alió del Barrio, MD, PhD, Alicante, Spain, agreed. "Pha- kic IOLs are capable of correcting high ametropias that conventional laser refractive surgery can't reach," he said. "For those high ametropias that may still be corrected with laser refractive surgery, phakic IOLs do not induce corneal aberrations, leaving better quality of vision and the cornea intact. Importantly, the patient will not be limited for future laser corneal surgery treatments if the ametropia progresses. This is particularly important for young high myopes." When these patients become presbyopic later in life and go on to develop cataracts, they will still have virgin corneas and their natural crys- talline lens, so all of the available treatment options will be available to them, including corneal inlays and presbyopia-correcting IOLs. Dr. Parkhurst noted that not all patients are candidates for phakic IOLs. For example, patients must have adequate anterior chamber depth and enough room in front of the eye to fit the phakic IOL safely. "Different surgeons have different cut-offs. The Visian ICL [STAAR Surgical, Monrovia, California] label recommends a minimum anterior chamber depth of 3.0 mm. A lot of surgeons that I know are com- fortable going down to 2.9 or 2.8, but ultimately there is a minimum depth at which there's just not ade- quate space," he said. Additionally, surgeons must wait until children achieve ocular maturity or ocular adulthood before correcting their myopia. "Most people reach ocular maturity some- where between the ages of 18 and 21. It's quite rare to do any refractive surgery before that age, although it's not unheard of," Dr. Parkhurst said. "There have been reports of using phakic IOLs in children as amblyopia therapy. But routinely, for the correction of myopia, we're waiting until they're adults on the refractive surgery but desire spec- tacle independence. "This would include people with abnormal cor- neal topography, such as those with thin corneas," Dr. Parkhurst said. "A Preferred Practice Patterns paper put out by the American Academy of Ophthalmology advises not going below 250 µm in the bed. 1 Patients who aren't eligible for LASIK based on residual bed calculation, signif- icant dry eye disease, or who just don't like the idea of having laser surgery are the first patients in whom to consider phakic IOLs." However, Dr. Parkhurst noted that he doesn't reserve phakic IOLs just for those patients who are not laser vision correction candidates. "Studies have shown that phakic IOLs have many advantages and Some surgeons have embraced them for refractive purposes, while others have chosen not to incorporate them into their practices Phakic IOLs in refractive surgery T here are three main methods to sur- gically correct refractive error: corne- al refractive surgery, phakic IOLs, and lens replacement. For the comprehensive refractive surgeon, they are all quality options in the right situation. In general, if the correction is not too high and the cornea is thick enough, corneal refractive surgery is the preferred approach. For patients who see well with optical devices (meaning no lenticular changes) but are not good candi- dates for corneal refractive surgery, phakic IOLs can be a great option, as long as the anterior chamber depth and endothelial cell count are healthy and there are no other problems such as pigment dispersion. The benefits of phakic IOLs in high correction can be summarized in "image quality." Phakic IOL patients are some of a refractive surgeon's happiest patients because of the accuracy and the fact that corneal shape was not altered, which results in impressive image quality. But I also tell phakic IOL candidates that it is a temporary correction. What I mean by this is that the same anteri- or chamber depth that makes them a good candidate now eventually shallows because of increasing lens thickness, and at that time the phakic IOL will need to be removed and if there is a cataract, that surgery can be performed at that time. They may have a 20–40 year run with their phakic IOL or it may be shorter, but it is critically import- ant to monitor these patients yearly by measuring their anterior chamber depth and endothelial cell count. It is also important that these patients understand the hazards of eye rubbing. Thank you to Jorge Alió del Barrio, MD, Gregory Parkhurst, MD, and Uday Devgan, MD, for sharing their insights on phakic IOLs. Done properly with diligent fol- low-up, phakic IOLs can be one of the most impactful, life changing procedures we can give our patients with high corrections who are having difficulties with optical devices. Vance Thompson, MD, Refractive editor Artiflex IOL for a high myopic patient Source: Jorge L. Alió del Barrio, MD, PhD A phakic IOL causing a cataract years after insertion Source: Uday Devgan, MD T he refractive surgery market continues to grow, and there are more options for correcting refractive error than ever before. "We are now encouraging ophthalmolo- gists to think of themselves not so much as LASIK surgeons, but as comprehensive refractive surgeons," said Gregory Parkhurst, MD, San Antonio. "This requires them to offer all of the procedures that may be applicable to different patients, depending on their age, their refrac- tive error, and their anatomy." Incorporating phakic IOLs into practice Many surgeons get started with phakic IOLs in those patients who are not good candidates for corneal

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