SummaryEighty-nine and a half per cent of the population of a general practice over the age of 49 years were screened for glaucoma and high risk ocular hypertension requiring treatment. Screening took place using semi-automated intraocular pressure and visual field equipment operated by non-ophthalmologicaUy trained staff. An experi enced ophthalmologist examined aU patients in a single blind manner to reduce false negatives to a minimum. Patients suspected of requiring treatment on the grounds of raised intraocular pressure, abnormal visual fields or suspicious optic discs were subsequently examined in a hospital clinic. Treatment criteria, as commonly prac ticed, were carefully defined and the sensitivities and specificities of the methods of screening used were calculated. One and three tenths per cent of the practice popula tion were known to be receiving treatment prior to the study and a further 1.4%were found to require treatment after screening.The sensitivity and specificity of the non-contact tonometer were 91.7% and 95.6% respectively with a predictive power of 22.5% for a positive result. The mean time taken to perform the test in both eyes was two minutes. Seventy per cent of the patients with pressures over 22 mmHg in both eyes on screening were found to require treatment. The routine use of the field screener did not increase either the sensitivity or specificity of the screening process but its use in cases with raised intraocular pressure is advised to indicate the degree of urgency of the referral.An algorithm based on the results of the study is suggested when planning the use of semi-automated equipment to screen for ocular disease related to raised intra ocular pressure.Chronic Simple Glaucoma (CSG) is a com mon disease of middle age and the elderly, prevalence rising from 0.5-1 % of the popula tion over the age of 401,2 to 6.6% over 75.3 It is responsible for up to 16.8% of registrable blindness in the population of the United Kingdom aged over 65 years.4CSG is characterised by a triad of physical signs: raised intraocular pressure (lOP),

Nottingham SummaryThe cost of detecting a case of glaucoma in a community based screening programme was calculated using data from a pilot study on a population aged 50 and over.The cost per screen was estimated at £3.35 with a total cost of £311 per case detected. These estimates include the cost of both the algorithmically based screen ing programme and the hospital assessment of true and false positives.These costs are considered to compare favourably with the potential costs incurred by paying optometrists to screen high risk groups whilst providing the opportunity to detect over twice the number of cases of occult glaucoma.