ASRS Day 4 – Phentolamine Ophthalmic Solution for Mydriasis Reversal, Results of the MIRA Trials

Archana Nair, MD MS
Vitreoretinal Fellow
Vanderbilt Eye Institute

In the surgery symposium 7, moderated by Dr. Timothy Murray and Dr. Audina Berrocal, Dr. David Boyer presented his exciting phase 3 data for the two MIRA trials. This clinical trial featured phentolamine ophthalmic solution to reverse pharmacological mydriasis.

A dilated funduscopic exam is a common component of an ophthalmic exam. However, patients are often frustrated by the side effects of dilation that can last up to 6 to 24 hours after the exam. Phentolamine mesylate is a nonselective alpha 1 and alpha 2 antagonist that is approved for pheochromocytoma and reversal of oral anesthesia. Ocuphire pharma has reformulated the medication as a propriety topical eye drop. The medication works by blocking the alpha 1 receptors on the iris dilator muscle and causes moderate miosis without affecting the ciliary muscle.

In the MIRA-2 trial, a total of 185 patients older than 12 years of age at 12 different clinical sites were enrolled, and 368 patients at 16 sites were enrolled in the MIRA-3 trial. These patients were dilated using 2.5% phenylephrine, 1% tropicamide, and Paremyd. At 1.5 hours after dilation in the control arm, 6% of patients in MIRA-2 and 7% in MIRA-3 returned to ≤ 0.2 mm of pupillary diameter. This number increased to 58% of patients in MIRA-2 and 49% in MIRA-3 after treatment with phentolamine.

Dr. Boyer concluded his talk by presenting the secondary endpoints. Patients on average experienced 4 hours less of dilation in the phentolamine arm. Phentolamine worked on all 3 dilating agents and on both dark and light irises. This effect was seen if patients had one or two dilating drops administered. Patients also experienced faster improvement in their near visual acuity.

These phase 3 results for reversing pharmacological mydriasis are highly promising and hopefully soon, phentolamine drops are something we can offer our patients.