Retinal nerve fibre layer photography in glaucomatous and normal eyes

The technique of retinal nerve fibre photography has been developed and tested in specialized centres and glaucoma clinics. The usefulness of a modified technique in clinical practice is the subject of this prospective study. Retinal nerve fibre photos from 41 patients with open-angle glaucoma and 40 normal patients were examined in a blind study, a total of 161 eyes. Photos from 5 eyes were of insufficient quality to allow evaluation. Nerve fibre loss was found in 36% of the normal eyes, 42% of glaucomatous eyes without visual field defects, and 87% of eyes with glaucomatous visual field defects. Sensitivity was 86% and specificity was 62% totally. In the younger patients aged less than 65 years both values were 82%. Photographic nerve fibre loss was found in 69% of normal eyes from patients aged more than 65 years, leading to a low specificity of 31% in this age group. Age related nerve fibre loss and clinically insignificant cataracts were the most obvious causes of non-glaucomatous nerve fibre loss.