This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Glaucoma, Subject name: Ophthalmology
[{'content': 'Prophylactic treatment in fellow eye of angle closure glaucoma: \nSelect and explain. \nA. PG analogues, B. Trabeculectomy, C. Iridotomy, D. Trabeculoplasty', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Iridotomy is the prophylactic treatment in fellow eye of angle closure glaucoma. Yag Iridotomy Done in cases of occludable angles. Can increase risk of cataract. Nd Yag/ Argonlaser is used. LASER is fired over crypts. Pre-operative pilocarpine is given Not effective if there is Peripheral anterior synechiae > 270 deg. Prophylactic treatment of fellow eye of angle closure glaucoma. Iridotomy', 'role': 'assistant'}]