Encore Vision’s innovative research may restore near focus in the blink of an eye.
One of the characteristics humans experience as they age beyond 40 is presbyopia. It’s like death and taxes; no one (almost no one) gets to miss it. People who become presbyopic and have the means to obtain optical correction buy eyeglasses or contact lenses to relieve the problem. Those without the resources deal with the poor near and intermediate vision presbyopia inflicts. Encore Vision is working to change that by developing an eye drop to restore close-up vision.
The implications for this product, currently in development, are enormous. According to Essilor’s Vision Impact Institute, over one billion people have presbyopia worldwide, and 50% of them are uncorrected.
A team of scientists, headed by Bill Burns, President and CEO of Encore Vision, are working on the eye drop strategy. Burns was introduced to this idea when an ophthalmologist and optometrist told him about a patent they had developed and issued for a method to treat presbyopia this way. With his decades of executive experience at big pharma in the eyecare industry, Burns immediately recognized the potential of this concept, signed on to the project, and set out to transform the concept into a functional product.
Early research focused on using an off-the-shelf chemical solution to soften animal lenses. The experiments were a surprisingly quick success. The premise of this research is that with aging, the crystalline lens stiffens due to oxidation, reducing accommodation, which inhibits clear near vision. If the lens can be softened, it will become more flexible again, thereby restoring near vision.
From a chemical perspective, the crystalline lens becomes more rigid with aging because disulfide bonds form between the large crystalline proteins inside the lens fiber cells, which makes it difficult for the lens to change shape. To restore flexibility to the lens, a reducing agent was tried in order to eliminate the disulfide bonds.
With positive outcomes from the initial research, Burns and his team took their results to a toxicology lab. The next round of experiments were performed on human eye bank lenses, which resulted in the same outcome and proved the concept was viable. Further research focused on developing a compound unique to Encore Vision that would soften the lens without causing harm to the eye or surrounding structures. What they discovered was a natural reducing agent that is made in all cells in the body and lens fiber cells called lipoic acid. The challenge then became getting this agent across the cornea and into the lens, which the team has now accomplished.
“It is too early to tell how often drops will work, might need to be administered, how many treatments might be needed, and if treatments are a lifelong prospect or only for some period of time. That’s what the current research is investigating,” Burns mentioned. He further noted that lens hardening occurs over time, so softening it will be gradual as well. This means that dosing and the period of time needed for treatment will vary based on individual patient circumstances. The first human trials began on October 5, 2015. Subjects will receive drops twice a day in both eyes for three months.
Is this product a game changer? Burns suggests that the answer depends on the outcome of the human trials. “If it’s wildly successful, it can be. It might reduce dependence on ‘readers’ and provide another tool for treating presbyopia. It’s difficult to predict just yet. Accommodation is a complicated system, and presbyopia results from more than just the flexibility of the crystalline lens.”
Using eye drops for correcting presbyopia is surely an innovative way of approaching a visual problem the ophthalmic world has aided with eyeglasses and contact lenses for centuries. It’ll surely create a lot of excitement to be able to treat something medically that’s more common than the common cold.
Ed De Gennaro, MEd, ABOM, is Director, Professional Content of First Vision Media Group.