Hi Mary:
There are several considerations with glaucoma and diving. Glaucoma itself isn't necessarily a contraindication to diving. The pressure changes involved in diving are unlikely to be a concern.
People with glaucoma sometimes have visual impairments as a result of their condition that can interfere with their ability to dive. Treatment for glaucoma can also interfere with the ability to dive. Beta-blocking eye drops (Timolol, etc.) can be systemically absorbed and reduce the ability of the heart to speed up when necessary, but it is uncommon to absorb enough of the medicine. A filtering bleb is sometimes surgically placed in the eye so the excess fluid can leak out in a controlled fashion, and not enough is known about (or at least I don't know enough about) that procedure and diving to know if it's OK. Laser trabeculoplasty doesn't seem to interfere with diving once the patient is released by their physician.
The list of medications that cannot be used with glaucoma sometimes seems endless. Many medications often used by divers such as dimenhydrinate (e.g. Dramamine, etc.), meclizine (e.g. Dramamine Less Drowsy, Bonine, etc.), and scopolamine (e.g. Transderm Scop, etc.) cannot be used with glaucoma.
HTH,
Bill
