Failure of medical therapy despite normal intraocular pressure.

The disease glaucoma is now defined by characteristic optic disc and visual field change, without specific reference to the intraocular pressure (IOP). Success of treatment is no longer judged by the mere attainment of IOP less than 21 mmHg. Controversy remains, however, in deciding appropriate management where optic disc and/or visual field damage continues to progress despite a 'normal' IOP having been achieved with medical treatment. A panel of international glaucoma experts has provided management recommendations in four clinical scenarios--open-angle glaucoma, open-angle glaucoma in a myopic contact lens wearer, uveitic glaucoma and open-angle glaucoma in combination with visually significant cataract--where optic nerve and visual field progression has continued despite an IOP less than 21 mmHg on full medical treatment. Surgical intervention with mitomycin trabeculectomy is the most favoured further therapy.