Earlier Diagnosis of Glaucoma using the Nerve Fiber Layer Exam

Earlier Diagnosis of Glaucoma using the Nerve Fiber Layer Exam

The nerve fiber layer examination

There are at least 15 million suspects for glaucoma in the United States. None of the examination methods available to ophthalmologists determine with precision which of these suspects are already at an early stage of damage. The present methods include evaluation of the optic disc and automated visual field testing. The Wilmer Glaucoma Service developed examination of the retinal nerve fiber layer (NFL) as an additional means to determine if glaucoma injury has begun. In a long-term follow-up study of over 1,000 patients that lasted for over 10 years, NFL evaluation predicted the future development of initial visual field loss more than 5 years before functional damage was detectable.

The NFL examination is used either as a clinical examination at the slit lamp, or through use of photographs taken with standard fundus cameras and black and white film. Dr. Quigley has recently written an inexpensive manual of how to read NFL photographs that is published by Igaku-shuin Publishers.

There are several instruments that promise to estimate the NFL thickness. These would provide automated methods to determine if early glaucoma is present. Two of these instruments are presently being used at the Wilmer Glaucoma service.