Presbyopia eye drops
Anti-crosslinking drug may restore natural accommodation
Richard Lindstrom MD
In a proof-of-concept clinical trial, a topical compound designed to increase the flexibility of the natural crystalline lens in presbyopic patients significantly improved near vision in as little as eight days, Richard L Lindstrom MD told the 2017 ASCRS•ASOA Symposium & Congress in Los Angeles, USA.
The compound, lipoic acid choline ester 1.5% (EV06, Encore Vision) is the first topical presbyopia treatment shown to restore some of the visual accommodation lost as the natural lens stiffens with age, he said.
EV06 targets disulfide bonds that form among proteins in the crystalline lens in response to oxidative challenge and UV light that both stiffen and cloud the lens
Eventually, EV06 or a similar preparation might also help slow or even reverse nuclear cataract formation, which is thought to result from the same chemical process that causes presbyopia, added Dr Lindstrom, who is founder of Minnesota Eye Consultants, Bloomington, Minnesota, USA, and a board member and equity owner of Encore Vision.
EV06 targets disulfide bonds that form among proteins in the crystalline lens in response to oxidative challenge and UV light that both stiffen and cloud the lens. The choline preparation helps the compound penetrate the cornea. Inside the eye, it reduces to lipoic acid and dihydrolipoic acid, which in turn dissolve the disulfide bonds. “We’re basically un-crosslinking the natural lens,” Dr Lindstrom said.
In the clinical trial, involving 75 patients, EV06 worked faster than expected, and the effect increased progressively throughout the trial, Dr Lindstrom said. Mean logMAR distance corrected near visual acuity in the treatment group improved from 0.397 at baseline to 0.206 at day 91, compared with 0.408 at baseline to 0.313 at day 91 in the control group. At day 91, 84% reached 20/40 or better from a baseline of 30% in the treatment group, compared with 48% from 28% among controls.
Overall, 84% of treated patient gained at least one line of near vision, 53% two or more lines and 22% three lines, and 12% four lines at 90 days, with no loss of corrected distance vision. While a few patients reported minor irritation taking EV06 twice daily, comfort scores were similar in the treatment and placebo groups. No significant adverse events were observed and no patients dropped out of the trial.
A post-treatment study found the treated group continued to show better near vision than controls out to 301 days, though the effect declined slightly over time, Dr Lindstrom added.
Richard L Lindstrom: rllindstrom@ mneye.com