The Scarborough glaucoma survey.

A glaucoma screening survey was carried out in Scarborough, Ontario, to detect previously unsuspected cases of the disease.General practitioners were employed to perform Schiotz tonometry. Suspected cases were further tested with applanation tonometry and tonography with water drinking.Of the 17,968 persons examined, 999 had a family history of glaucoma. Forty-one of these had obvious clinical glaucoma. The use of Schiotz tonometry plus applanation tonometry in individuals with a positive family history uncovered 463 suspected of having glaucoma. Tonography with water drinking revealed 348 persons with abnormal findings. Of this number, 228 had clinical glaucoma and 120 preclinical glaucoma.Mass screening by tonometry was found to be valuable in detecting glaucoma in the early stages. In most instances, blindness from this disease can be prevented by early diagnosis.