Abstract
Purpose :
To evaluate the ability of the pupil to respond dynamically to changes in lighting conditions while improving distance-corrected near visual acuity (DCNVA) in presbyopes treated with 0.75% phentolamine ophthalmic solution (POS)
Methods :
In VEGA-1, a Phase 2, multi-center, randomized, placebo-controlled, double-masked clinical trial, presbyopic subjects with DCNVA of 20/50 or worse were randomized to receive either POS (n=73) vs placebo (n=74) for 3-4 evening doses. The morning following the last evening dose, pupil diameter (PD) under mesopic and photopic lighting conditions and visual acuity were assessed at multiple time points. PD was measured in mm using the NeurOptics Pupillometer VIP-300. Pupillary response to light was determined by subtracting the pupil diameter in photopic conditions from that measured in mesopic conditions. DCNVA was assessed binocularly using ETDRS chart in photopic lighting conditions
Results :
The average baseline pupil diameter was 4.5 mm (photopic) and 5.0 mm (mesopic) in the POS group and 4.3 mm (photopic) and 5.1 mm (mesopic) in the placebo. Consistent with data across 12 clinical trials, POS reduced pupil diameter by ~1-1.5mm compared to placebo at all time points (12 to 18 hours) in both lighting conditions. Larger PD reductions were found in subjects with larger baseline PD. Pupillary response with POS treatment was similar to that observed with placebo treatment as seen by a ~1 mm reduction in mean PD as lighting conditions changed from mesopic to photopic. Furthermore, POS demonstrated a statistically significant difference in the percent of subjects gaining ≥3 line DCNVA vs placebo (30% vs 14%; p=0.0303) with no loss of best-corrected distance vision in presbyopic subjects at 12 hours while maintaining a dynamic pupillary response
Conclusions :
In presbyopes, POS treatment resulted in a durable improvement in near vision with a favorable safety profile. POS’s mechanism uniquely reduces pupil size by inhibiting the iris dilator muscle, which preserves dynamic pupillary responses in light and dark conditions, in contrast to miotic eyedrops that contract the sphincter muscle with a more limited pupillary response. POS will be advancing into Phase 3 pivotal trials as a potential once-a-day eye drop treatment for presbyopia
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.