Glaucoma is not uncommon in PBGVs. Typically when diagnosed they start the meds to try and reduce the pressure. If that does not work, then removing the affected eye is recommended. Pretty standard recommendations for the disease. A Vet Opthal should be consulted.
Julia

Had a similar problem with my 10yr.old girl. She had glaucoma symptons, took her to an opthamologist and it was a melanoma. She had the eye removed and is doing great.

They need to go to a vet ophthalmologist pronto. He may have a tumor in that eye.

Cornell uses laser surgery for melanoma. Saves the eye and works well. Not sure if laser can be used for glaucoma.