The present invention provides a method of treating glaucoma or ocular hypertension which comprises applying to the eye of a person in need thereof an amount sufficient to treat glaucoma or ocular hypertension of a compound of formula Iwherein Y, Q, Z, R, R1 and R2 are as defined in the specification. The present invention further comprises pharmaceutical compositions, e.g. ophthalmic compositions, including said compound of formula I.
