EyeWorld India March 2015 Issue

45 EWAP CATARACT/IOL March 2015 these eyes is always a challenge for the surgeon, and the expectations of these patients are difficult to fulfill without any postoperative means of refractive shaping.” Pros and cons Although the lens has great potential, there are some limitations, Dr. Jones said. “Currently one of the biggest limitations is pupil dilation. You must be able to treat the lens optic and not leave any untreated material in the lens,” he said. Other potential areas of concern “can be very acceptable if properly presented to the patient,” he said, including why the patient must wear a filtering pair of spectacles until the lock-in appointment. Dr. Wiley was “a little worried” about patient response to the glasses, but has been pleasantly surprised that no one seems bothered by them. “They just don’t seem like an issue for patients,” he said, acknowledging that may change once the lens is available commercially and not as part of a clinical study. Being able to “try out different refractive situations in daily life while wearing the UV light protecting spectacles” makes patients happy, Dr. Hengerer said. “They benefit from the precise adjustments within 0.25 D range from target refraction. We can simulate monovision, and in case the patient is not happy, we can change the values with another adjustment.” Dr. Lehmann said the lens is “perfect” for the post-laser vision correction patient. The ability to adjust the lens after the initial surgery takes a considerable amount of pressure off the surgeon, he said. All refractive adjustments occur “under active fixation” so lens decentration and lens tilt are not issues, as all the adjustments “are applied according to the line of sight. Even cylindrical adjustments can be done safely and precisely a few days after implantation,” Dr. Hengerer said. Dr. Lehmann said a “study- related” disadvantage of the lens is the number of postop visits. “In the clinical study, we have to do 2 adjustments and 2 lock-ins, so there are 4 visits, 3 days apart,” he said. “Future versions of the lens will be able to get that down to 2 to 3 visits.” Dr. Wiley concurs, adding a logical argument for some patients is to just implant a monofocal lens, wait 3 months, and perform LASIK for any residual refractive error at that point. The lens is a 3-piece design with a silicone optic, “so there are differences from a single piece acrylic design/material. The incision size is 3.0–3.5 mm, which may seem large if surgeons are routinely doing 2.0–2.5 mm incisions,” Dr. Jones said. But another potential upside to the lens is that it obviates the need (and expense) of intraoperative aberrometry. “Currently, we have so many ways of measuring the eye before and during surgery, yet with all of these expensive devices we still lack the precision in refractive outcomes that we desire (and that some patients demand). The LAL may make current intraoperative and preoperative measurements irrelevant if we can adjust the lens noninvasively, after surgery,” Dr. Lehmann said. Learning curves Dr. Hengerer said learning curves are on the low side; the LAL is a silicone type IOL with an optic diameter of 6 mm and an overall length of 13 mm. It is available from 10 D to 30 D. It can be implanted through an incision size of 2.9 mm using a disposable injector system, he said. Attention does have to be paid, however, “while the lens is entering the anterior chamber as silicone lenses expand faster than acrylic ones. Using a medium viscous OVD in the anterior chamber can help to slow down the extraction in a safe way,” he said. Dr. Jones recommends surgeons use smaller incisions for the cataract removal and then enlarge the incision for the implantation. “Once the lens is in the capsular sac, I prefer to use bimanual I/A for viscoelastic removal as this avoids manipulation of the [now] larger incision,” he said. “I don’t have to switch to a larger infusion sleeve on the coaxial I/A tip to fill the larger incision as the bimanual handpieces work through paracenteses.” Because the LAL has unpolymerized macromers in a silicone matrix, it’s “a lot softer than a typical IOL,” Dr. Lehmann said. “Traditional silicone lenses can be fairly rigid.” Each light treatment, or “adjustment,” of the lens creates a diffusion gradient through selective polymerization, causing a shift in the remaining unpolymerized macromers that changes the shape of the IOL, creating a more “plus” or “minus” lens. Any pattern can be programmed in a light treatment, including correction of astigmatism. Think of the adjustments as “activating” the polymers, Dr. Wiley said. Drawing them to the center results in a myopic shift and subtly changes the shape of the lens, he said. Simply put, “this lens and associated adjustments permit the best possible refractive outcome of any technology,” Dr. Jones said. EWAP Editors’ note: Drs. Jones, Lehmann, and Wiley are investigators for the U.S. studies, but do not have any financial interests related to their comments. Dr. Hengerer currently has financial interests with Calhoun Vision; he did not have financial interests during the period in which he conducted clinical studies on the lens. Contact information Hengerer: Fritz.Hengerer@kgu.de Jones: jasonjonesmd@mac.com Lehmann: lehmann@focalpointvision.com Wiley: drwiley@clevelandeyeclinic.com