Intraocular pressure and visual field defects.

During a five-year study period, therapeutic levels of intraocular pressure (IOP) and visual field defects were assessed in 108 patients with open-angle glaucoma. In a group of 53 glaucoma patients with non-progressive visual field changes (mean age 65.2 +/- 6.3 years), the IOP level was 15.8 +/- 2.6 mm Hg, whereas in a group of 58 patients with progressive visual field changes (mean age 68.7 +/- 8.3 years) the IOP level was 19.9 +/- 2.9 mm Hg. Study results suggested that preservation of the visual field in glaucoma patients requires therapeutic IOP levels of < 16 mm Hg.