Nerve fiber layer photography. A comparative study.

Abstract

Observation of the retinal nerve fiber layer with red-free light is an important means of evaluating optic nerve integrity. Many investigators have attempted to increase the usefulness of the technique by improving photographic procedures. Most reports comparing various parameters neither indicate the method of comparison nor give quantitative measure of the improvement gained with different films, filters, cameras, or processing procedures. We have compared in a masked fashion the parameters most recently recommended in the literature. Twelve trained observers compared 12 masked pairs of nerve fiber layer photos taken from the same eye in the same manner on two cameras and preferred those taken with a Canon CF-60Z camera 69% of the time and those taken with a Zeiss FF-111 17% of the time (this difference was statistically significant, P less than 0.01). Fourteen observers compared 14 pairs of photographs and judged Panatomic-X film to be superior to Plus-X film 51% of the time and both films to be of the same quality 25% of the time (this difference was also significant P less than 0.05). Fifteen observers compared 12 pairs and preferred the Standard SE-40 blue filter 2:1 over the green Spectrotech 540 filter. This difference was not statistically significant, and the preference was found to be dependent on fundus pigmentation and clarity of the media. The blue filter gave better contrast for the nerve fiber layer in patients with lightly pigmented fundi, and use of the green filter resulted in less light scatter in patients with ocular media opacities.