Abstract

In chronic simple (open-angle) glaucoma loss of visual field may be prevented by improving the outflow of aqueous humour from the eye and thus lowering the raised intra-ocular pressure. This is achieved mainly by miotic drugs which constrict the pupil and make the ciliary muscle contract. These either mimic acetylcholine, acting directly on the ciliary muscle, or inhibit cholinesterase and so allow acetylcholine to accumulate.