Abstract
Purpose :
Patients with dim light vision disturbances (DLD) experience photic phenomena and decreased mesopic vision due to the effects of higher order aberrations and ocular scatter. LYNX-1 evaluated the efficacy and safety of 0.75% phentolamine ophthalmic solution (POS) for treatment of patients with DLD.
Methods :
In this study 145 adult subjects with dim light vision disturbances were randomized 1:1 to POS or placebo (vehicle), self-administered in both eyes for 14 consecutive nights at bedtime. Subjects underwent visual function testing and ophthalmologic examination on study Day 8 and Day 15. The primary efficacy endpoint is the percent of POS-treated subjects with ≥ 3 lines of improvement in mesopic low-contrast distance visual acuity (mLCVA) relative to placebo. A number of secondary efficacy endpoints and safety measures were assessed on Day 8 and 15.
Results :
The primary efficacy endpoint was met at Day 8 with 13% of POS subjects gaining ≥ 3 lines of mLCVA versus 3% on placebo (p<0.05). The effect of POS increased at Day 15, with 21% of subjects gaining ≥3 lines of mLCVA compared to 3% on placebo (p<0.01). POS also significantly increased the percent of subjects gaining ≥ 2 lines at Day 8, with 41% versus 22% on placebo (p<0.05), and at Day 15, with 44% versus 23% on placebo (p<0.05). POS showed a favorable safety and tolerability profile. There were no serious adverse events or withdrawals due to AEs. The most common AEs were primarily mild and included low incidence of instillation site irritation (9% vs 0% placebo), instillation site pain (13% vs 0% placebo), conjunctival hyperemia (9% vs 3% placebo), and dysgeusia (11% vs 0% placebo).
Conclusions :
This is the first pivotal Phase 3 clinical trial demonstrating that a modest reduction in pupil diameter from POS treatment could improves visual function in patients with DLD. In addition, there was no evidence of tachyphylaxis or retinal tears or detachment, consistent with POS not engaging the ciliary muscle. Based on the favorable safety and positive efficacy results of LYNX-1, POS has the potential to be a first treatment option to improve night vision disturbances, diminish unwanted photic phenomenon, and improve quality of life and quality of vision in patients with DLD.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.