Measurement of peripapillary retinal nerve fiber layer volume in glaucoma

PURPOSE: To measure peripapillary retinal nerve fiber layer volume in norma l subjects and patients with ocular hypertension, primary open-angle glauco ma, and low-tension glaucoma. METHODS: Sixty five subjects were classified into four groups of normal sub jects and subjects with ocular hypertension, primary open-angle glaucoma, a nd low tension glaucoma on the basis of intraocular pressure measurements, visual field loss, and optic disk appearance, Groups were matched for sex, age, and optic disk area. Peripapillary retinal nerve fiber layer volume me a surements were made with a modification of software version 1.11 of the H eidelberg Retina Tomograph confocal scanning laser ophthalmoscope. Retinal nerve fiber layer volume measurements were taken at 0.1-mm increments from the disk margin for a global 360-degree assessment and at four predefined s egments using two different reference planes, Statistical analysis was carr ied out using analysis of variance with Bonferroni correction, RESULTS: Retinal nerve fiber layer volume measurements showed a gradation f rom normal to ocular hypertension and from ocular hypertension to glaucoma groups. Mean group measurements showed statistically significant difference s (P < .05) in peripapillary retinal nerve fiber layer volume for most segm ental measures between the groups. Measurements with the default reference plane in the 0.0-mm to 0.1-mm and 0.1-mm to 0,2-mm increments for the super otemporal segment showed the greatest differences between groups (P < .0000 5). CONCLUSION: Peripapillary retinal nerve fiber layer volume measurements dif fer between groups of normal subjects and patients with ocular hypertension , primary open-angle glaucoma, and low tension glaucoma, This measure offer s a further method of assessment of retinal nerve fiber layer in patients w ith glaucoma and glaucoma suspects, (C) 2000 by Elsevier Science Inc, All r ights reserved.