Efficacy and safety of pilocarpine hydrochloride ophthalmic solution USP 1.25% w/v versus placebo ophthalmic solution for the treatment of presbyopia - A multicentric clinical trial.

Purpose: To evaluate the efficacy and safety of 1.25% pilocarpine compared to placebo for the treatment of presbyopia.

Methods: This multicenter, randomized, double-masked clinical trial compared pilocarpine 1.25% to placebo in presbyopic individuals aged 45-55 years, meeting standard near vision impairment criteria. Participants were randomized 1:1 using a computer-generated sequence, with identical, unmarked bottles ensuring masking. Distance-corrected near visual acuity (DCNVA) and distance-corrected intermediate visual acuity (DCIVA) were assessed under mesopic and photopic conditions across multiple visits (days 1, 3, 7, 14, and 30). The primary outcome was a ≥ 3-line gain in mesopic, high-contrast, binocular DCNVA at day 30, hour 3. Secondary outcomes included photopic and intermediate vision improvements.

Results: A total of 234 participants (mean age 49 ± 3 years, 57% male) were randomized equally. By day 3, pilocarpine demonstrated a significant half-line improvement in high-contrast, binocular mesopic DCNVA (0.47 ± 0.1 vs. 0.51 ± 0.1 logMAR, P = 0.03), progressing to 1.3 lines by day 30 (0.37 ± 0.1 vs. 0.50 ± 0.1, P < 0.001). Nearly 50% achieved a two-line gain (n = 54 [46%] vs. 10 [8%], P = 0.001), and one-third gained three lines (n = 36 [31%)] vs. 5 [4%], P < 0.001). Pilocarpine's effect was cumulative, with each visit's baseline DCNVA surpassing prior measurements (P < 0.001). Photopic DCNVA followed a similar trend (0.31 ± 0.1 vs. 0.43 ± 0.1 logMAR, P = 0.02 at day 30, hour 3). Intermediate DCIVA showed a modest half-line improvement by day 30. No adverse drug reactions or ophthalmic side effects were observed during the study.

Conclusion: Pilocarpine 1.25% effectively improves near vision in presbyopia, with sustained benefits up to day 30 and potential long-term adaptability.