Eyeworld

56 | EYEWORLD | SEPTEMBER 2021 R EFRACTIVE by Ellen Stodola Editorial Co-Director About the physicians Shamik Bafna, MD Cleveland Eye Clinic Brecksville, Ohio George Waring IV, MD, FACS Waring Vision Institute Mt. Pleasant, South Carolina the treatment options for presbyopia by what is accessible in the U.S. and what's available outside the U.S. "In the U.S., there are modali- ties that you can employ within the cornea and modalities to employ within the lens," he said. Within the cornea, Dr. Bafna said the most common option is monovision. PRK, LASIK, or SMILE can be used where you take the non-dominant eye and under correct a little to give near vision and correct the dominant eye for distance vision, he explained. Most patients like monovision quite a bit, but the main drawback is it's not a long-term solution. "You're dealing with presbyopia, which continues to progress," Dr. Bafna said. "Some- one may be able to read initially, [but] they may lose near vision over time and have more intermediate vision when the presbyopia gets worse." Monovision works well for patients in their 40–50s. For those in their late 50s–60s, monovi- sion doesn't work as well, he said. In the past, many people would defocus the near eye, Dr. Bafna said, to a target of –2 to –2.5 D. Over time, they realized that creates too much anisometropia, and patients don't like losing that much distance vision in the near eye. They lose more depth of field and depth of focus because the eyes aren't working together. These days, he said patients prefer –1.25 to –1.5 D, so there's less difference between the two eyes. This is better tolerated by patients and there's not as much loss of distance vision. With monovision there is some compromise associated; you have to give up distance vision to get near vision and vice versa. "When we target monovision, we try to simulate it with a contact lens trial to make sure a patient likes it," Dr. Bafna said. While monovision is one of the most popular options within the U.S. for presbyopia correction, another strategy Dr. Bafna's prac- tice employs is an inlay, specifically the Kamra (AcuFocus). He explained how Kamra increases the depth of field using small aperture optics. "You don't sacrifice as much distance vision in the near eye as when you do traditional mono- vision." However, there is not a lot of market demand for the inlay, he said. Presbyopia treatment options now and on the horizon T he large number of patients world- wide with presbyopia creates a unique opportunity for eyecare providers to improve patients' quality of life, according to George Waring IV, MD, FACS. There are more than 2.1 billion presby- opes worldwide. Dr. Waring noted the many implications of this large number, not just from a quality of life standpoint but also in terms of economic burden related to falls. Many falls are related to bifocal glasses, Dr. Waring said, which most people with presbyopia require at some point in their life. "Our discussions and surgical decision mak- ing regarding presbyopia are framed in terms of dysfunctional lens syndrome," which Dr. Waring said is a characterization of the aging process of the internal crystalline lens. Stage 1 is presbyopia; stage 2 is presbyopia and early lens opacity; and stage 3 is a cataract affecting daily activities adversely. "We have proposed an algorithm for the treatment of presbyopia based on age, refractive status, and lens opacity," he said. 1,2 Dr. Waring said treatment options are largely dictated by patients' refractive status, meaning if they're hyperopic and the higher the degree of hyperopia, the earlier a lens-based intervention procedure may be recommended. "The more myopic they are, we may have a higher threshold to do a lens-based procedure, maybe even a lens replacement procedure, and a lower threshold for a cornea-based procedure or implantable contact lens," he said. For the plano presbyope, Dr. Waring said they are moving toward a lens-based proce- dure to maintain binocularity, which he thinks improves vision performance and may lead to higher patient satisfaction. "When considering age, once pharmacolog- ic therapies are approved for the treatment of presbyopia, we may initially recommend that as an alternative to glasses and contacts," Dr. War- ing said. "However, as patients move through various stages of lens dysfunction, in the context of their refractive errors and/or desires, then we would look at surgical interventions." Surgical options Shamik Bafna, MD, said he tends to break down

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