EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/1516463
SPRING 2024 | EYEWORLD | 63 C The group found the majority of people (more than 50%) are strongly dominant (90– 100% preference for one eye), about a quarter have weaker dominance (70–80% preference for one eye), and a quarter have equidominance (50–60% preference for one eye). "This is new breakthrough data that we have no idea what to do with yet," Dr. Durrie said, noting that the group that gathered the data would soon be discussing its possible impli- cations, which could lead to future studies. Dr. Durrie said that because the SimVis Gek- ko is easy to use and integrates well into clinic flow—and because of its usefulness to simulate different types of IOLs and vision options—a practice could start gathering real-world data on patients' sensory dominance and their distance and near preferences. "Record the data on a group of patients, then keep doing what you're doing with your IOL selection. Retrospectively come back and if you have patients who were having trouble adapting to their lenses, you can say, 'Let's look back and see what preference group they were in,'" he said. IOL selection and target setting for mono/blended vision Dr. Durrie said that while there is now an expanded understanding of ocular dominance/ sensory preference, it's too soon to make any practice changes. "Keep doing what you're doing and let the research develop," Dr. Durrie said. "This is new information, and I don't want it to complicate IOL discussion with patients until more data is gathered." Dr. Cummings said eye dominance remains critically important for lens and target selection. He said it is "the difference between success and failure." Like the findings Dr. Durrie spoke about, Dr. Cummings, and Andrew Kopstein, MD, both said they consider not motor dom- inance but sensory dominance when helping patients choose a lens and setting their target. "Most think that this is motor dominance, where the finger point or thumb forefinger aper- ture is determinant. It is not. It relies on 'sensory dominance,' which is tested by showing one eye corrected to distance and the other to a myopic target, then compared to the reverse scenario where the fellow eye is corrected to distance and the other to the same myopic target. The combination that feels better is 'sensory domi- nance.' My experience is that motor and sensory dominance correspond 85% of the time," Dr. Cummings said. Dr. Cummings incorporates several tests to determine whether a patient will tolerate mono- vision, mini-monovision, or blended vision and to determine which eye tolerates which tasks. He shows the patient their eyes fully corrected, followed by 0/–1.50 (fully correcting the right eye and correcting the left eye to a myopic tar- get). He asks the patient to rate this out of 100 compared to their prior fully corrected vision. "If this is rated at 80% or higher, the odds of blended vision working are well above 95%," he said. Then he'll move to –1.50 in the right eye and fully correct the left. "Score this against the 100% score. If this is scored at 85% or 90%, you have the answer. Correcting the left eye to emmetropia and the right eye for reading is destined to work." If the score is less than 80%, he puts the pa- tient in a trial frame with the right eye targeted to –1.5 and left eye targeted for emmetropia, giving the patient up to 30 minutes to test this range of vision. "Some will come back saying they love it. … Others will say they dislike it, and that rules out blended vision. Others will say that they need more time or that they want to test this in their own home and work environment, and they continue with [a contact lens trial]," Dr. Cummings said. continued on page 64 Brain training Dr. Cummings recommended this video for patients to improve neuroadaptation to blended vision or monovision.