April 2019

REFRACTIVE

Research Highlight
Monovision methods


by Maxine Lipner EyeWorld Senior Contributing Writer


A patient is tested for her dominant eye.
Source: Y. Ralph Chu, MD

 

When selecting a monovision approach for presbyopia, it is very important to keep the patient’s individual needs in mind, according to Edward Lai, MD. In a review1 published in Current Opinions in Ophthalmology, various studies indicated that old and new methods of monovision and mini-monovision such as implantation of corneal inlays, LASIK, SMILE, and use of IOLs tend to be comparable, although each modality has specific benefits and compromises.
One reason investigators wanted to revisit monovision is that they think that near work is different in this era of technology. “The biggest change we see is that people use smartphones and other devices that allow them to increase fonts and lighting so near visual tasks are not as difficult; mini-monovision works well for that,” Dr. Lai said. He added that when patients receive full monovision to get good vision for near, large degrees of anisometropia decrease stereopsis and distance vision is poor. Unless a patient had good blur suppression, the technique doesn’t work well. But now, people are looking for more of an intermediate computer vision in one eye and distance vision in the other, so they need a more moderate correction of around –1.25, which also provides better stereopsis.

Examining modalities

In the review, the most recent studies on monovision modalities such as use of the KAMRA inlay (AcuFocus), traditional corneal refractive surgery, SMILE, phakic IOLs or refractive lens exchange were compared. Investigators found that all of these methods provided acceptable visual results and comparable patient satisfaction with high rates of spectacle independence.
Still, success with such monovision approaches depends on what the patient wants. “If the patient doesn’t read a lot, sometimes the inlays will work well,” he said. One of the advantages of the inlays is that this approach is reversible as opposed to a lens exchange, which carries a higher complication risk, Dr. Lai said.
When it comes to use of phakic IOLs for monovision, Dr. Lai has found practitioners tend to shy away from them because of the possibility of pupillary block as well as cataract formation. Practitioners tend to be more comfortable replacing the lens as they would in cataract surgery. “The only caveat to that is it depends on how old the patient is,” he said. “If someone still has some accommodation, monovision with LASIK works well, especially mini-monovision.”

Successful start

Before trying any form of monovision, Dr. Lai recommends giving patients a trial monovision run using contact lenses. If a mildly myopic patient who can read unaided requires surgery, Dr Lai recommends fully correcting the dominant eye for distance and leaving the non-dominant eye as is for reading. That way the patient can see if they like and/or can tolerate monovision.
The monovision approach is not for everyone. “If someone doesn’t have good blur suppression, they won’t like it because they can notice a difference between the eyes,” Dr. Lai said, adding that it is important to keep in mind the patient’s personality and reading habits.
Dr. Lai thinks that until a better multifocal lens comes out, practitioners should consider mini-monovision as a good alternative for greater spectacle independence. Surgeons are likely to get more patient satisfaction in this era of expandable fonts and well-lit screens, he concluded.

About the doctor
Edward Lai, MD
Associate professor of ophthalmology
Weill Cornell Medical College
New York

Reference
1. Mahrous A, et al. Revisiting monovision for presbyopia.
Curr Opin Ophthalmol. 2018;29:313–317.

Financial interests
Lai: None

Contact information
Lai
: ecl2001@med.cornell.edu

Monovision methods Monovision methods
Ophthalmology News - EyeWorld Magazine
283 110
220 200
,
2019-04-05T09:24:32Z
True, 4