Glare Testing in Patients with Cataract after Dilation

Reversal of Pharmacologically Induced Mydriasis with Phentolamine Ophthalmic Solution

PURPOSE

To evaluate the safety and efficacy of 0.75% phentolamine ophthalmic solution (POS), an α-adrenergic antagonist, in reversal of pharmacologically induced mydriasis.

DESIGN

Two phase 3, multicenter, placebo-controlled, randomized, double-masked clinical trials in healthy participants.

PARTICIPANTS

Five hundred fifty-three healthy 12- to 80-year-old participants were randomized 1:1 (MIRA 2) and 2:1 (MIRA 3) to receive either POS or placebo eye drops in both eyes.

METHODS

Participants received POS or placebo administered 1 hour after mydriasis, induced by instillation of either 2.5% phenylephrine, 1% tropicamide, or 1% hydroxyamphetamine / 0.25% tropicamide.

MAIN OUTCOME MEASURES

Percent of participants returning to within 0.2 mm of baseline pupil diameter in study eye 90 minutes after POS administration. Safety measures included treatment-emergent adverse events and tolerability measures, including conjunctival hyperemia.

RESULTS

A total of 553 participants were randomized to treatment with placebo (n = 215) or POS (n = 338). A statistically significant greater percentage of participants treated with POS showed reversal of mydriasis at 90 minutes compared to placebo (MIRA 2: 48.9% vs. 6.6% [P < 0.0001]; MIRA 3: 58% vs. 6% [P < 0.0001]) and as early as 60 minutes (MIRA 2: 27.7% vs. 2.2% [P < 0.0001]; MIRA 3: 42% vs. 2% [P < 0.0001]). Between 28% and 34% of participants receiving placebo did not returned to baseline PD at 24 hours after pharmacologic dilation compared with 8% to 11% of patients treated with POS (P < 0.0001).

CONCLUSIONS

Treatment with POS reduced PD within 60 to 90 minutes, with a statistically significant time savings of 5 to 6 hours to return to baseline PD compared with placebo. One or 2 drops of POS rapidly reversed mydriasis in all participants regardless of mydriatic agent or iris color. More participants receiving POS reported a benefit in the resolution of visual symptoms caused by pharmacologically induced mydriasis compared with placebo, with statistically significant differences noted as early as 1 hour. The safety profile was favorable, with the most common adverse effects being mild transient conjunctival hyperemia (11.2%), instillation site discomfort (10.9%), and dysgeusia (3.6%).

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Genetics and Disease Expression in the CNGA3 Form of Achromatopsia: Steps on the Path to Gene Therapy

PURPOSE

Achromatopsia (ACHM) is a congenital, autosomal recessive retinal disease that manifests cone dysfunction, reduced visual acuity and color vision, nystagmus, and photoaversion. Five genes are known causes of ACHM. The present study took steps toward performing a trial of gene therapy in ACHM by characterizing the genetics of ACHM in Israel and the Palestinian Territories and analyzing retinal function and structure in CNGA3 ACHM patients from the Israeli-Palestinian population and US patients with other origins.

DESIGN

Case series study.

PARTICIPANTS

Patients with clinically suspected ACHM, cone dysfunction phenotypes, and unaffected family members were included. The protocol was approved by the local institutional review board and informed consent was obtained from all participants.

METHODS

Genetic analyses included homozygosity mapping and exome sequencing. Phenotype was assessed with electroretinography (ERG), optical coherence tomography, psychophysics, and photoaversion testing.

MAIN OUTCOME MEASURES

Single nucleotide polymorphism microarray, exome analysis, DNA sequence analysis, visual function testing including ERG, and photoaversion.

RESULTS

We identified 148 ACHM patients from 57 Israeli and Palestinian families; there were 16 CNGA3 mutations (5 novel) in 41 families and 5 CNGB3 mutations (1 novel) in 8 families. Two CNGA3 founder mutations underlie >50% of cases. These mutations lead to a high ACHM prevalence of ∼1:5000 among Arab-Muslims residing in Jerusalem. Rod ERG abnormalities (in addition to cone dysfunction) were detected in 59% of patients. Retinal structure in CNGA3 ACHM patients revealed persistent but abnormal foveal cones. Under dark- and light-adapted conditions, patients use rod-mediated pathways. Photoaversion was readily demonstrated with transition from the dark to a dim light background.

CONCLUSIONS

Among Israeli and Palestinian patients, CNGA3 mutations are the leading cause of ACHM. Retinal structural results support the candidacy of CNGA3 ACHM for clinical trials for therapy of cone photoreceptors. Efficacy outcome measures would include chromatic light-adapted psychophysics, with attention to the photoreceptor basis of the response, and quantitation of photoaversion.