NEW YORK, May 9 (UPI) — Everyone’s eyes change with age, making presbyopia, declining near vision or worsening nearsightedness, among the most common conditions in the world.
There is no cure or way to prevent the onset of presbyopia, meaning that virtually all adults age 40 years and older will experience its effects to varying degrees as they age and likely find themselves dependent on eyeglasses or contact lenses.
That may be changing, however. Last year, the Food and Drug Administration approved Vuity, a once-daily eyedrop designed to relieve some of the symptoms of presbyopia, including worsening nearsightedness.
And people seeking freedom from reading glasses, bifocals or bifocal contact lenses as they age may have even more options in the near future, experts told UPI.
Racing to finish line
“Numerous companies are racing to the finish line” with new eyedrops to manage “age-related near-vision loss,” Dr. Marguerite McDonald told UPI in an email.
However, these drugs are for “age-related vision loss only,” and not near- or farsightedness in younger adults and children, said McDonald, a clinical professor of ophthalmology at NYU Langone Medical Center in New York City.
Presbyopia is a normal part of aging, and it occurs when the lens, or the inner part of the eye that helps it focus, stops processing light efficiently on the retina, the light-sensitive layer of tissue at the back of the eye, according to the National Eye Institute.
The condition makes it difficult for middle-aged and older adults to see things up close, and it can affect those who already may be farsighted, or have difficulty seeing distant objects. For some, worsening near vision necessitates using glasses or contact lenses for reading and other close-up activities, the institute says.
For those already dealing with farsightedness, bifocal or progressive eyeglasses or contact lenses may be needed.
How Vuity works
Vuity, which received FDA approval in October, is a miotic eyedrop, meaning it is designed to cause the pupil of the eye to contract, said ophthalmologist Michael Korenfeld, who was involved in early clinical trials for the drug and others used to treat presbyopia.
The drug contains the pilocarpine, a medication classified as anticholinergic, which means it works by blocking the neurotransmitters in the brain that control certain eye functions, according to Allergan, the company that makes it.
By reducing the diameter of the pupil when applied once a day, Vuity enhances users’ depth of focus, helping them see things up close better without the need for corrective eyewear, said Korenfeld, who practices in Washington, Mo.
The effects of the drug are temporary, so they wear off by the end of the day and, if users decide to stop applying the drops, their vision will return to its prior state, McDonald said.
However, when users apply the eyedrops, their pupils not only will contract, but they also will “lose their dynamic ability … to get bigger and smaller when the ambient lighting changes,” Korenfeld said.
This means that while on Vuity, people may have trouble seeing at night or in other “low-light” settings, because their pupils will not be able to dilate in response to these conditions, he said.
“There’s no question that most people who use Vuity will see some improvement in their uncorrected near vision,” Korenfeld told UPI in a phone interview.
“However, they will also see changes in their night vision and, for some, it may not be worth the trade-off,” he said.
Another potential side effect of Vuity is a rare chance of retinal detachment, in which the retina of the eye separates from its supportive tissue — a condition that left untreated can cause vision loss and even blindness, according to the drug’s prescribing information.
In addition, some users experience a “cramp-like” pain in their eyes, which is caused by the drug’s effect on the muscles of the pupil, Korenfeld said.
Still, the FDA’s approval of Vuity is considered “a landmark moment in this history of eyecare,” ophthalmologist George O. Waring IV said in a video produced by the product’s manufacturer, Allergan.
“This is the first and only FDA-approved prescription drug for the treatment of age-related blurry near-vision in adults,” said Waring, who practices in Mount Pleasant, S.C., and was one of the principal investigators during clinical trials for Vuity.
As well as improving near-vision, Vuity also was found to improve intermediate vision — or what people might need to work at a computer screen, for example — in clinical trials, he said.
Vuity is an option for aging adults “who really hate reading glasses, because they find them inconvenient or think they make them look older,” said Korenfeld, who has offered patients samples of Vuity to try, but has yet to prescribe it because it does not cure or prevent presbyopia.
An eyedrop that does blunt the effects of the eye condition may be on the horizon, however.
At least two drug companies are developing antioxidant eyedrops designed to reverse the abnormal binding of proteins within the lens of the eye that are caused by aging, Korenfeld said.
Unlike Vuity, these drugs do not impact the function of the pupil — meaning they do not impact night or low-light vision — and may actually reverse or even prevent presbyopia, he said.
One of these products, which for now is called UNR844 by drugmaker Novartis, is in early-stage clinical trials to test its safety and effectiveness.
The twice-daily eyedrop will need to successfully navigate through three phases of clinical trials before the manufacturer can apply for FDA approval, meaning it might be at least two or three years before it can be marketed in the United States.
However, if it is successful, users who have had their distance vision corrected by laser surgery “might retain very good functional vision for most of their lives without any corrective lenses,” Korenfeld said.
Using the antioxidant drops could “breathe youth” back into their eyes, he said.