VEGA-1 Trial: Focusing on presbyopia

Investigators test the efficacy of phentolamine alone and with low-dose pilocarpine.

The combination therapy provided a durable near-vision gain through 18 hours, with an enhanced gain in near vision for at least 6 hours.

Reviewed by Mitchell A. Jackson, MD

A combination product of 0.75% phentolamine drops and 0.4% low-dose pilocarpine rapidly improved distance-corrected near visual acuity (DCNVA), with durable effects for up to 18 hours after the dose of phentolamine and for an additional 6 hours following instillation of low-dose pilocarpine as an adjunctive therapy, according to Mitchell Jackson, MD.

Jackson, who is in private practice in Lake Villa, Illinois, and colleagues conducted a prospective, place-controlled, phase 2 trial testing the efficacy of phentolamine ophthalmic solution by itself and in combination with low-dose pilocarpine for improving near vision. The primary end point of the study was the percentage of patients who achieved improvement in the DCNVA of 3 lines or greater compared with placebo.

Phentolamine works by blocking the α1 receptors on the iris dilator muscle, which causes a moderate decrease in pupil size for up to 24 hours with no effect on the ciliary or iris sphincter muscles. Pilocarpine activates the iris sphincter to add to the pupillary reduction induced by phentolamine, Jackson explained.

VEGA-1 trial

VEGA-1 (NCT04789330) was a multicenter, randomly assigned, placebo-controlled trial that included participants aged 40 to 64 years with a photopic DCNVA of 20/50 or worse. A total of 150 participants with presbyopia were randomly assigned to treatment with 1 of the drugs alone, placebo, or the phentolamine-pilocarpine combination. The photopic near and distance vision was measured at various time points.

Investigators noted that when phentolamine alone was tested in 43 patients, 29% had an increase of 15 or more letters and 53% achieved a 10-letter or greater increase in DCNVA without loss of 1 line of DCVA 12 hours after instillation (P = .005 vs placebo).

According to investigators, when phentolamine was combined with low-dose pilocarpine as an adjunctive therapy in 43 patients, 61% of them gained 3 lines or more and 79% gained 2 lines or more in DCNVA at 1 hour after instillation compared with placebo (P = .005).

When low-dose pilocarpine was administered alone, 26% of patients achieved a gain of 15 letters or more in DCNVA 30 minutes after instillation (P = .08 vs placebo). When phentolamine was administered alone, 33% of patients gained 15 letters or more in DCNVA (P = .03 vs placebo).

The takeaway messages are that the combination therapy provided a durable near-vision gain through 18 hours, with an enhanced gain in near vision for at least 6 hours. The combination treatment was statistically superior to both drugs administered separately at 30 minutes, Jackson reported. In addition, it exhibited a favorable safety and tolerability profile, with no headaches, blurry vision, or axial myopia exclusions.

Jackson concluded that phentolamine alone and the combination of phentolamine and low-dose pilocarpine significantly improved presbyopia compared with placebo and exerted significant effects for up to 18 hours. The therapy had a rapid onset of 30 minutes and durable effects to 6 hours.

Mitchell A. Jackson, MD

E: mjlaserdoc@msn.com

Jackson is a consultant to numerous drug manufacturers.[GC1]Is there a brand name that should go in parenthesis after on first mention?

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