A 68-year-old female patient is seen on the ward. She
complains of severe pain in her right eye. There is blurring of vision and she
feels nauseated and has vomited several times. Earlier in the day she has
undergone colonoscopy for evaluation of her long-standing Crohn's disease. The
endoscopist has made a comment that the examination was difficult. What is the
likely cause of her painful red eye?
