Question 12

An 8 year old male presents with a 2 month history of "chronic conjunctivitis OU". The patient was first seen by his pediatrician who suspected viral conjunctivitis, but it persisted, so he was treated for allergic conjunctivitis with olopatadine gtts. There was no improvement with olopatadine gtts so the patient was referred to you. On exam, vision is 20/20 OU, pupils are normal and IOP is 16 OU. There are bilateral upper and lower eyelid large dense conjunctival pseudomembranes on the palpebral conjunctiva. The bulbar conjunctiva is white and quiet. You strip the pseudomembranes and start the patient on erythromycin ointment and prednisolone gtts. You see them again the next day and the pseudomembranes have started to reform. This disease is associated with which systemic enzyme deficiency?