EyeWorld Asia-Pacific March 2021 Issue

REFRACTIVE EWAP MAR C H 2021 31 disc. That gives us so much information.” One of Dr. Ristvedt’s recent patients came in wanting a PanOptix trifocal IOL (Alcon), but some things on her measurements were not adding up and Placido showed blurred rings. “We treated her dryness and had her come back for repeat measurements. Not only did the power of astigmatism change but also its orientation,” she said. “If I would have gone ahead with a premium lens, we would have been in trouble postop.” Dr. Lee discussed how pterygium, anterior basement membrane dystrophy, and Salzmann’s nodular degeneration could also impact astigmatic measurements. “[I]deal astigmatism correction will address those underlying conditions before phaco. If the irregularity is mild or peripheral, I tell [patients] they can proceed without superficial keratectomy or PTK if they are willing to make that compromise,” he said. Dr. Wiley takes the patient’s outcome goals into consideration at this point. “If their goals are to see without glasses and have their astigmatism corrected, I urge them to get PTK first to regularize the cornea so we know what we’re treating at the time of cataract surgery. If their goal is more of a basic cataract surgery, maybe I’ll hold off on the PTK,” he said, explaining that the procedure could be done later to regularize the basement membrane disorder, if needed. “Consider what’s important to the patient. Sometimes the patient is not motivated to treat their astigmatism. If that’s the case, we make note of it and go with the basic cataract surgery. But if they’re motivated, we want to make sure we’re measuring properly and make sure we’re not measuring something that’s a dynamic process. … We want to make sure their dry eye disease is stable before we do a treatment plan.” Treating regular astigmatism Toric IOLs are an obvious choice for regular astigmatism, but Dr. Swan pointed out that, at least in the U.S., low-add toric powers are not available. “Below a diopter becomes hard,” he said. For astigmatism that is less than a diopter, he said he’ll occasionally use an LRI, but over LRIs and torics, Dr. Swan is turning more to the Light Adjustable Lens (RxSight). “In a patient with regular astigmatism, the results when you look at the FDA trial for the Light Adjustable Lens vs. the FDA trials for many of the other standard toric lenses that we use, the percentage of patients who got to 20/20 with the Light Adjustable Lens is almost twice as high as the PMMA studies looking at the other lenses. I think the accuracy of the Light Adjustable Lens is fantastic. For post-refractive it is a wonderful technology … but even for a primary astigmatic patient with a naive cornea, it is still a nice option.” A patient who presented for cataract evaluation wanting a trifocal IOL. Blurred Placido images indicated dryness, which was then treated before she returned for repeat measurements. The power and orientation of the patient’s astigmatism changed after treating the dry eye. Source: Deborah Ristvedt, DO