Pilocarpine Hydrochloride 1.25% Improves Near Vision Without Distance Compromise

Pilocarpine hydrochloride 1.25% can significantly improve distance corrected near visual acuity when administered bilaterally and twice daily, according to research published in the American Journal of Ophthalmology. This presbyopia management method also demonstrates a tolerable safety profile with few treatment-related adverse events, according to the report.

Researchers conducted a randomized, controlled, multicenter, phase 3 study to evaluate the safety, efficacy, and pharmacokinetics of pilocarpine hydrochloride 1.25% compared with vehicle when administered twice daily during a 2-week study duration. The team included 230 participants (age range, 40-55 years; 57.4% women) with objective and subjective evidence of presbyopia impacting daily activities and randomly assigned them to treatment with pilocarpine hydrochloride 1.25% (n=114) or vehicle treatment (n=116).

The primary efficacy endpoint was the proportion of participants gaining 3 or more lines in high-contrast, binocular distance corrected near visual acuity with no more than a 5-
letter loss in corrected distance visual acuity (CDVA) in mesopic conditions (10-11 lux at target) at the study conclusion. The secondary efficacy endpoint involved meeting the same criteria in photopic conditions (≥251 lux at target). The research team performed a pilocarpine plasma level assessment among a subgroup of 10% of study participants and evaluated treatment-related adverse events among the entire cohort.

Overall, a significantly greater proportion of participants achieved the primary and secondary outcome measures with pilocarpine hydrochloride 1.25% compared with vehicle — between-treatment differences were 27.3% (95% CI, 17.3%-37.4%) and 26.4% (95% CI, 16.8%-36.0%), respectively.

Headache, which was reported in 8.8% (n=10) of individuals treated with pilocarpine hydrochloride 1.25% and 3.4% (n=4) of vehicle group participants, was the most common treatment-related adverse event. Pilocarpine accumulation index was 1.11 or less at the study conclusion among the subgroup participants who underwent pilocarpine plasma level assessment.

“[N]o clinically meaningful changes in [intraocular pressure], vital signs, CDVA, biomicroscopy, and ophthalmoscopy were reported, and the majority of participants in both groups described the eye drop as soothing, very comfortable, or comfortable,” according to the researchers. “It is also worth noting that the reductions in pupil size observed over time in the pilocarpine [hydrochloride] 1.25% [twice daily] group mirrored visual acuity improvements from Hour 0 to Hour 9, suggesting a mechanism of action primarily based on pupil constriction.”

Study limitations include failure to evaluate treatment efficacy after administration of the second daily pilocarpine hydrochloride 1.25% dose beyond 3 hours and failure to compare vision improvements vs a control group using spectacles or contact lenses.

Disclosure: This research was supported by Allergan. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.