Those at greatest risk of glaucoma are not the most likely to attend for sight tests

There is no formal screening programme for glaucoma in Britain, and current practice can best be described as opportunistic surveillance, with no attempt to define clearly, or cover, the entire population at risk. To facilitate this surveillance, certain sections of the population are exempt from sight test charges, including first degree relatives of people with glaucoma, diabetic patients, and people receiving income support. However, probably about half of cases of glaucoma remain undiagnosed,1 and patients continue to present late in the course of the disease.

Detecting presymptomatic chronic glaucoma requires two independent events. Firstly, an individual must attend for a sight test, and, secondly, the practitioner must use appropriate tests: intraocular pressure measurement, optic disc assessment, and visual field testing–preferably all three.2 We know roughly how often optometrists perform tests for glaucoma from work done by the International Glaucoma Association,2 but until recently we lacked information on who consults optometrists and how often–particularly since charging for sight tests began in 1989. …