A 53-year-old female presents with a gradual onset of pain i…

A 53-year-old female presents with a gradual onset of pain in her right eye. Her vision is blurred, and the patient reports having some photophobia. On exam, the conjunctiva is injected and the eye is tearing. The right pupil is small, irregular and poorly reactive. Visual acuity is 20/30 OS and 20/80 OD. The most likely diagnosis is: