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77 EW REFRACTIVE SURGERY November 2015 Future of cataract surgery In the next 5 years, according to Dr. Moshirfar, intraoperative aberrometry will be a part of cataract surgery. "Every surgeon doing cataract surgery won't proceed without intraoperative aberrome- try," Dr. Moshirfar said. A lot of clinicians have already implemented intraoperative aber- rometry in their practices, including Dr. Moshirfar. Secondly, clinicians will become much more meticulous about where the lens is going and about where the lens is regarding the visual axis and the center of vision (centration of the IOL with respect to the visual axis and decentration with respect to the pupil), he noted. Surgeons will become more interested in knowing the amount of decentra- tion in the IOL intraoperatively in order to evaluate the accuracy of the lens. "This will require some preop- erative capturing technology to give surgeons guidance in the operating room—to know where to put the lens in regards to the center of sight and the center of the pupil," Dr. Moshirfar said. Lastly, according to Dr. Moshirfar, clinicians will start to use the femtosecond laser to standardize the capsulorhexis with respect to the center of the capsular bag rather than the center of the pupil. "We will see these three things [intraoperative refraction and ab- errometry, centration technology used preoperatively in order to see postoperatively how accurate the surgeon was, and a customized capsulorhexis with respect to the visual axis in cataract surgery] become a lot more important in every surgeon's implementation for better accuracy of cataract surgery," he concluded. EW Editors' note: Dr. Moshirfar has no financial interest related to this article. Contact information Moshirfar: cornea2020@me.com Ablative procedures and piggyback IOLs There are major considerations in the use of ablative procedures (PRK and LASIK) for the correction of residual refractive error following cataract surgery. "I don't think LASIK is the best option for most of our patients," Dr. Moshirfar said. "For most patients [average age of 65 to 80], if I can rely on PRK, I would prefer PRK to LASIK," he said. According to Dr. Moshirfar, in dealing with a very normal ocular surface that has refractive error with great stability and predictability, LASIK has an extra advantage over PRK because of its faster recovery. "If the refractive error is small but the patient continues to have residual ocular surface dryness, I think PRK will be more forgiving than LASIK," he said. On the other hand, Dr. Moshirfar emphasized that when there is refractive error such that the corneal surface does not look ideal for ablative procedures, sometimes it is better to revert to a piggyback IOL, especially if the patient has a deep posterior chamber. "For example, in a high myope who has already undergone cataract extraction and has a multifocal lens and a small refractive error—and the cornea looks abnormal but has a deep posterior chamber space— piggyback IOL is the best thing to do," he said. Clinicians may already have a lot to handle in dealing with residu- al refractive error following cataract surgery, and throwing astigmatism into the mix makes it even more challenging. While mild astigmatism may not be a great problem in patients with monofocal treatment, it can be a lot more symptomatic in those patients who get multifocal IOLs. "Small amounts of astigmatism can be quite problematic in patients who have undergone [implantation of] premium multifocal IOLs," Dr. Moshirfar said. "In situations where patients end up with even 0.75 D of astigmatism after cataract surgery and premium multifocal IOLs, you cannot ignore that correction." residual refractive error as negligible as possible." Measure twice, cut once It is completely understandable, Dr. Moshirfar noted, that clinicians can never reach a residual refractive error of zero. As a matter of fact, a lot of people with excellent visual acuity (e.g., pilots) don't wear glass- es, but when measured have a very small refractive error. "We need to strive for most of our patients after cataract surgery to be within +/–0.5 D, and we need to think how we can bring them to that level of accuracy," he said. Today, according to Dr. Moshirfar, surgeons have become more stringent in terms of manag- ing patients for cataract surgery by looking at patients' eyes not just for cataract. This means that patients with significant cataract are not sent immediately to surgery. "We have to make them ready for the surgery and prime their ocular surface," he said. Cataract sur- gery will have a better resolution if surgeons start focusing on the ocular surface, Dr. Moshirfar said. "Watch out for corneal patholo- gy: blepharitis, dry eye, dystrophies, corneal abnormalities, and interior corneal steepening. Do preliminary ocular surface treatments (artificial tears, warm compresses, etc.) and repeat the scan again 4–6 weeks later to make sure that the integrity of the cornea is more stable," Dr. Moshirfar said. While it takes more time to do two rounds of examination, the up- shot is a higher degree of confidence about biometry and topography before surgery. Plus, patients under- stand the importance of measure- ments. "This creates a mindset in pa- tients that surgeons are doing their best to look at the numbers careful- ly, to be as accurate as possible, to measure twice and cut once," Dr. Moshirfar said. Even if the goal is not achieved, he noted, doing so still has a posi- tive impact on patients. How today's clinicians handle refractive surprise (or the lack of it) O nly 15 years ago, clinicians believed that a residual refractive error following cataract surgery of within 2.0 D of emmetropia was completely acceptable. "If our patients were between –1.0 and +2.0 D, we still thought that they did very well; we didn't think that it was a major issue," said Majid Moshirfar, MD, professor of ophthalmology, and director, Cor- nea and Refractive Surgery Division, Department of Ophthalmology, Moran Eye Center, University of Utah, Salt Lake City. But cataract surgery has changed tremendously since then. At pres- ent, even talking about a geriatric population or patients in their 50s and 60s, according to Dr. Moshirfar, these patients deservingly demand that the residual refractive error is less than +/–0.5 D with respect to emmetropia. "In the mid 1990s, for patients who had LASIK and PRK, if they were within +/–1.0 D of correction, it was acceptable," he said. "But now, patients need to be within +/–0.25 D of emmetropia." Over time, the availability of third to fourth generation IOLs and better biometry machines (laser-based biometry devices) have led to better ways of measuring ker- atometry and better ways of estimat- ing the lens position during cataract surgery. This is changing the cataract surgery game plan for clinicians and surgeons. Now it is very common for clinicians to see close to 90% of patients within 1.0 D of emmetropia and almost 70% of patients within 0.5 D of emmetropia. "That means we see about 10% of patients who are still outside 1.0 D of emmetropia, and 30% of patients are about 0.5 D off from the target," Dr. Moshirfar said. "While these are good statistics, the para- digm has shifted, and we are trying to [figure out] how to make the Approaches to residual refractive error by Matt Young and Gloria D. Gamat EyeWorld Contributing Writers

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