Prognostic factors in the development of manifest open angle glaucoma

Ninety-three patients, who during a mass screening for glaucoma in 1962-63 attended a thorough ophthalmological examination, were re-examined in 1980-82. At the mass screening 42 patients had IOP greater than or equal to 21 mmHg in at least 1 eye, but none of the 93 patients had glaucomatous optic disc excavations or visual field defects. At the re-examination, 28 patients (30.1%) had developed manifest open angle glaucoma in at least 1 eye. This development was significantly correlated to the height of the IOP, both at the mass screening, during the period of observation and at the follow-up study (P less than 0.05-P less than 0.002). A reduced outflow facility measured at the mass screening was also significantly associated with the later development of manifest glaucomatous damage (P less than 0.05-P less than 0.01). In addition, fibrillopathy (pseudoexfoliation), manifest glaucoma in the 'fellow eye' and a positive family history for glaucoma were found to be important risk factors.