SAN DIEGO — An experimental combination of drugs can temporarily correct the vision of people with presbyopia, a new study shows.
"With one drop in the morning, you don't need glasses all day," said Herbert Kaufman, MD, from Louisiana State University in New Orleans.
Dr Kaufman presented the results here at the American Society of Cataract and Refractive Surgery 2015 Symposium on behalf of Almamoun Abdelkader, MD, from Al-Azhar University in Cairo, who was not able to obtain a visa to attend the meeting.
Dr Kaufman has patented the combination of a parasympathomimetic drug and an alpha agonist that creates optically beneficial miosis, reducing the effect of presbyopia.
To evaluate safety and efficacy, Dr Abdelkader compared the combination of carbachol and brimonidine with placebo in two groups of patients with emmetropic presbyopia.
All the patients were 41 to 60 years of age and had uncorrected Jaeger scores of at least 5. None had myopia, hyperopia, or astigmatism higher than 0.25 diopters.
In the first group, the nondominant eye of 30 patients was treated with a combination of 2.25% carbachol plus 0.2% brimonidine, and of 18 patients was treated with placebo.
In the second group, 10 patients received 3% carbachol, 0.2% brimonidine, a combination of the two, or placebo. All patients were switched among these treatments, with a week of washout between tests.
Dr Kaufman showed a graph in which the mean Jaeger scores for patients taking the combination dropped from more than 8 to about 2 in the first hour, and then gradually rose to just above 2 at 8 hours.
Patients who received carbachol monotherapy experienced a drop to a little above 5 in the first hour, which rose to just above 7 at 8 hours. Patients who received brimonidine monotherapy experienced a drop to about 8 and a rebound to about 8.5.
Dr Kaufman did not report on any changes in the placebo group.
From these results, Dr Abdelkader determined that the optimal formula is a combination of carbachol and brimonidine.
A "mild burning sensation" was reported by some subjects in each of the groups, including the placebo group, but most frequently in the carbachol monotherapy group.
Other adverse events included a dull headache in 10% of patients. And one person reported difficulty seeing in dim light for the first couple of weeks.
There was no evidence of tolerance; the effect of the drops persisted during the 3-month follow-up period. The patients also showed no sign of tachyphylaxis.
Because of the increased depth of field from the smaller pupil, patients do not lose distance or intermediate vision in the way that patients sometimes do with monovision, said Dr Kaufman.
The perception of normal brightness in the untreated eye eliminates symptoms of dimming from the smaller pupil of the treated eye, he explained.
He speculated that the drug combination could also help people with low nonpresbyopic hyperopia, and said he is planning to study it in patients with pseudophakic presbyopia.
The people who received the carbachol and brimonidine combination said they liked it and would use it as a therapy if it were available. Those who received the placebo said they would not use it.
After the presentation by Dr Kaufman, session moderator Mike Holzer, MD, from the University of Heidelberg in Germany, asked if the drugs have any influence on surface disease, and wondered whether they are preservative-free.
Tear flow and surface disease were not assessed, Dr Kaufman reported. However, "these drugs have been used for year and years to treat glaucoma, both of them, and we know they're safe and effective," he said.
The agents "are not preservative-free," he added, "but they're only given once a day."
The treatment holds promise for special populations, especially people with emmetropic presbyopia, said panelist Shachar Tauber, MD, from the Mercy Clinic in Springfield, Missouri.
It might bring new patients to ophthalmology practices, Dr Tauber told Medscape Medical News. "Those who are entering presbyopia at age 37 to 48 rarely get an eye exam," he said. "This is their introduction to eye care."
Any physician can prescribe these drugs off-label, "but I would hate for physicians to start using them without working with the scientific presenters," he added.
This study was funded by Dr Abdelkader. Dr Kaufman holds a patent for this combination of drugs. Dr Tauber reports financial relationships with Abbott Medical Optics, Alergan, and Calhoun, and has a patent for a drug-delivery contact lens.
American Society of Cataract and Refractive Surgery (ASCRS) 2015 Symposium. Presented April 19, 2015.
Medscape Medical News © 2015 WebMD, LLC
Send comments and news tips to firstname.lastname@example.org.
Cite this: Carbachol-Brimonidine Combo Promising for Presbyopia - Medscape - Apr 20, 2015.