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LYNX-1: A Phase 3 Study of 0.75% Phentolamine Ophthalmic Solution in Subjects With Dim Light Vision Disturbances
Jay S Pepose1, Stephen Montaquila2, David Wirta3
1From the Pepose Vision Institute (J.S.P.), Chesterfield, Missouri, USA; Department of Ophthalmology and Visual Sciences (J.S.P.), Washington University School of Medicine, St. Louis, Missouri, USA; Opus Genetics (J.S.P., M.B., K.C.), Durham, North Carolina, USA.
Objective Or Purpose:
To evaluate the efficacy and safety of 0.75% phentolamine ophthalmic solution (POS) for the treatment of dim light disturbances (DLD) in subjects with reduced mesopic low-contrast vision, including postkeratorefractive subjects.
Design:
Phase 3, multicenter, double-masked, randomized, placebo-controlled trial.
Subjects, Participants, And/Or Controls:
About 145 subjects with self-reported symptoms of DLD, mesopic pupil diameter of ≥5 mm, and 30 ETDRS letters (equivalent to 20/63 Snellen) or worse mesopic low-contrast best-corrected distance visual acuity (mLCVA) in the study eye, were randomized 1:1 to receive POS or placebo. The largest subset (25) of the enrolled subjects was status postkeratorefractive surgery.
Methods, Intervention, Or Testing:
One drop of POS or placebo was self-administered in each eye once nightly for 14 days.
Main Outcome Measures:
Assessments included visual acuity testing, pupil diameter measurement, wavefront aberrometry, intraocular pressure (IOP), slit-lamp biomicroscopy, and a questionnaire assessing visual symptoms.
Results:
POS-treated subjects demonstrated significant improvement in mLCVA at Day 8 (13% vs 3% placebo; P < .05) and Day 15 (21% vs 3% placebo; P < .01). Subjects receiving POS reported significant reduction in overall severity of DLD (on a scale of 1-7), and photic phenomena including glare, halos and starburst (on a scale of 0-3) at Day 8 and 15 (P < .01). There was no significant difference between arms in conjunctival hyperemia or vital signs. Results from posthoc analysis of postkeratorefractive surgery patients also showed significant improvement in mLCVA at Day 8 and 15 and significant improvement in patient reported outcome measures, such as overall severity of DLD.
Conclusions:
POS significantly improved mesopic low-contrast best-corrected distance visual acuity in subjects with reduced mesopic vision and dim light disturbances of varying etiologies, including postkeratorefractive patients. Treatment-emergent adverse events were predominantly mild and transient. These findings suggest POS may warrant further clinical investigation as a potential pharmacologic approach for patients experiencing dim light disturbances associated with reduced mesopic low-contrast visual acuity and photic symptoms.