EVALUATION OF THE RETINAL NERVE-FIBER LAYER

In normal eyes, the retinal nerve fiber layer (RNFL) is usually best v isible in the inferior temporal part of the fundus, followed by the su perior temporal region, the nasal superior region and the nasal inferi or region. This distribution correlates with the configuration of the neuroretinal rim, the diameter of the retinal arterioles, the location of the foveola, and the lamina cribrosa morphology. With increasing a ge, the RNFL visibility decreases diffusely without preferring special fundus regions and without the development of localized defects. With all optic nerve diseases, the visibility of the RNFL is decreased in addition to the age-related loss, in a diffuse and/or a localized mann er. The localized defects are wedge-shaped and not spindle-like defect s, running toward or touching the optic disk border. Typically occurri ng in about 20% of all glaucoma eyes, they can be found also in other ocular diseases, such as optic disk drusen, toxoplasmotic retinochoroi dal scars, longstanding papilledema or optic neuritis due to multiple sclerosis. Since they are not present in normal eyes, they almost alwa ys signify an abnormality. RNFL evaluation is especially helpful for e arly glaucoma diagnosis and in glaucoma eyes with small optic disks. I n advanced optic nerve atrophy, other examination techniques, such as perimetry, may be more helpful for following optic nerve damage. Consi dering its great importance in the assessment of optic nerve anomalies and diseases and taking into account the feasibility of its ophthalmo scopic evaluation using green light, the retinal nerve fiber layer sho uld be examined during any routine ophthalmoscopy.