A 55 year old female comes to the eye casualty with history of severe eye pain, redness and diminished vision. On examination, the visual acuity is 6/60, there is circumcorneal congestion, corneal oedema and a shallow anterior chamber. Which of the following is the best drug of choice –: (A) Atropine ointment, (B) IV mannitol, (C) Ciprofloxacin eye drops, (D) Betamethasone eye drops
Answer is B. Approach in acute congestive glaucoma 

Start i.v. mannitol or i.v. acetazolamide
When IOT starts falling, start topical pilocarpine or β-blocker (timolol).
Apraclonidine/latanoprost may be added.
Once i.o.t. is reduced, surgery is done.