If you haven’t yet experienced it yourself, you’ve certainly seen older family members start to hold smartphones and restaurant menus up to their noses, squinting at the small text. That’s because as we age, we all develop presbyopia, or age-related farsightedness—trouble focusing on close objects or text. That’s where surgery or reading glasses usually come in, but new research suggests there could be another option.
Researchers have demonstrated that after taking special eye drops two or three times a day, most participants in a retrospective study could read an extra two or more lines on the Jaeger chart, an eye chart used to test near visual sharpness. Giovanna Benozzi, director of the Center for Advanced Research for Presbyopia in Buenos Aires, presented the research on Sunday, September 14, at the 43rd Congress of the European Society of Cataract and Refractive Surgeons (ESCRS).
Surgery is not for everyone
“We conducted this research due to the significant unmet medical need in presbyopia management,” Benozzi said in an ESCRS statement. “There is a group of presbyopia patients who have limited options besides spectacles, and who are not candidates for surgery; these are our primary focus of interest. We sought to provide robust clinical evidence supporting an innovative pharmacological solution to offer patients a non-invasive, convenient and effective alternative.”
Presbyopia seems to be the family business. It was Benozzi’s father, the late Jorge Benozzi, a researcher at his daughter’s same center, who developed the eye drops. The formula contains two active ingredients—pilocarpine, which constricts pupils and contracts the ciliary muscle (a muscle involved in the eye’s ability to see objects at different distances), and diclofenac, a non-steroidal anti-inflammatory drug (NSAID) that counters the inflammation and discomfort often caused by pilocarpine.
The 766 patients (373 women, 393 men, average age of 55) in the study took the eye drops twice a day, with the possibility of a third administration when needed. While everyone received eye drops with the same dose of diclofenac, the pilocarpine concentration was either 1%, 2%, or 3%. The researchers tested patients with the Jaeger chart an hour after the first administration and then continued monitoring them for two years.
“Our most significant result showed rapid and sustained improvements in near vision for all three concentrations. One hour after having the first drops, patients had an average improvement of 3.45 Jaeger lines. The treatment also improved focus at all distances,” Benozzi told the congress, as noted in the statement. “Impressively, 99% of 148 patients in the 1% pilocarpine group reached optimal near vision and were able to read two or more extra lines. Approximately 83% of all patients maintained good functional near vision at 12 months.”
69% of the 248 patients who took the 2% formulation and 84% of the 370 patients taking the 3% formulation could read three or more extra lines on the Jaeger chart. The improvements seen in the trial lasted for up to two years, and Benozzi has patients outside of the study who have taken the eye drops for over a decade.
More research needed
Pilocarpine can commonly cause, among other side effects, blurred vision, dim or dark vision, seeing flashes of light or “floaters,” and, in some rare cases, detached retinas. Some of the adverse side effects experienced by the patients in the recent study include temporary dim vision, irritation during the administration of the eyedrops, and headache, but no one discontinued the treatment.
“Nearly all patients experienced positive improvements in near visual acuity, although the magnitude of the improvement depended on the status of their vision before treatment at baseline,” Benozzi explained. “Patients with less severe presbyopia responded best to 1% concentrations, while those with more advanced presbyopia required higher 2% or 3% concentrations to achieve significant visual improvement.”
Benozzi argued that the eye drops are a convenient alternative for dealing with presbyopia that can reduce patients’ need for reading glasses, though they are not meant to replace surgery. “Eye care professionals now have an evidence-based pharmacological option that expands the spectrum of presbyopia care beyond glasses and surgery.”
While the study is impressive for its large number of patients followed over a significant period, it’s limited by being a retrospective single-center study—meaning all the patients were treated at the same center and their data was collected after the fact.
“The single-centre retrospective study by Dr Benozzi suggests that eye drops containing pilocarpine and diclofenac may improve near vision for up to two years, but the limited design means the results may not apply to everyone,” said Burkhard Dick, chair of the ophthalmology department at the University Eye Hospital Bochum, in Germany, who was not involved in the study. “Long-term pilocarpine use can sometimes cause side effects … Broader, long-term, multi-centre studies are needed to confirm safety and effectiveness before this treatment can be widely recommended.”
Even with these limitations, the results hint at a future where a simple eye drop could help delay the need for reading glasses.