EyeWorld Asia-Pacific September 2013 Issue

42 EWAP CAtArACt/IOL September 2013 A patient in Dr. Chu’s office is tested for her dominant eye. Source: Y. Ralph Chu, MD Monovision revisited by Erin L. Boyle EyeWorld Senior Staff Writer Some patients can adapt to the reverse of the usual dominant eye for distance M onovision remains a viable option as a less expensive treatment for presbyopia, with dominance important for achieving best results. “Monovision offers a less costly option for patients who want to have a good functional spectacle- free life or reduced spectacle dependence, and I recommend that anyone consider doing it,” said John A. Hovanesian, MD , clinical instructor, Jules Stein Eye Institute, University of California, Los Angeles, Calif., USA. He said monovision can be an excellent way for surgeons to accustom themselves to the premium IOL surgery market. “For the surgeon who’s new to refractive cataract surgery, offering monovision is a comfortable, easy way to use familiar lens implants AT A GLANCE • Monovision is a viable option for presbyopia patients. • The dominant eye can be determined in multiple ways. • A contact lens test is a successful way of testing for monovision. • Emmetropia is necessary in the distance eye. and techniques that allow them to give patients great functional vision at less cost to the patient,” he said. When targeting monovision, the nondominant eye is usually targeted for near and the dominant eye for distance. However, some patients are able to have the reverse, he said. “There are some [patients] who can tolerate, very comfortably, using the opposite from the usual,” Dr. Hovanesian said. “The usual is to use the dominant eye for distance, but many patients can do the opposite and do just fine with it.” Y. Ralph Chu, MD , clinical professor of ophthalmology, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA; adjunct associate professor of ophthalmology, University of Minnesota, Minneapolis; and medical director, Chu Vision Institute, Bloomington, Minn., USA, said that monovision is an important option for patients who are 40 years and older who want refractive surgery or presbyopia correction. “I do tell patients that a majority of patients do not tolerate the imbalance between their eyes but that I want them to hear about this as an option. I think it’s important to determine the best situation for patients, whether it’s through a contact lens trial or a discussion of past experience with monovision. I think following those general guidelines will help you be successful with monovision in your patients,” said Dr. Chu. Vance Thompson, MD , Vance Thompson Vision, Sioux Falls, SD, USA, said that he offers the option of monovision to all patients 38 years and older. “I love monovision, so I offer it to all presbyopes, even if they have never tried it. They are comforted by the fact that we can fine-tune the near eye to distance if they do not like it. They are also comforted that we can fine-tune the near eye to [a] stronger near if they tolerate monovision well but hoped near would be better,” he said. targeting monovision There are a variety of ways to determine the dominant eye, physicians say, with each aiming to establish a patient’s natural choice for the eye that should receive distance vision. Dr. Thompson is a strong advocate of monovision simulation, which he calls an important step when evaluating monovision as an option for patients. He said the “both eyes open” simulation technique is key to helping choose the eye that is best, or most “comfortable,” for monovision. “I do this test at distance and near,” said Dr. Thompson. “My main concern is distance comfort, and thus I simply hold a +1.25 lens in front of each eye with both eyes open and ask them which one feels more comfortable, which basically means which one is least noticeable at a distance. Most of the time patients like their dominant eye as the distance eye and the nondominant eye as the near eye, but this test helps them understand how tolerable monovision is and also uncovers if they are going to like their dominant eye as their near eye.” Dr. Thompson added that the best test for monovision is contact lenses, minimizing for cylinder for best results. “For some folks, this means a toric lens. A lot of my patients do not want to invest in a toric lens. So I basically put them in a soft disposable and say, ‘If you like that (without treating the cylinder), you are probably going to like true laser vision monovision even better,’” he said. Dr. Chu said his practice employs several methods of determining dominance in patients, including targeting through a small aperture and asking the patient to point. “We use one of the standard ways—we do it a couple of