Measurement of retinal nerve fiber layer thickness and macular volume for glaucoma detection using optical coherence tomography

Abstract

Purpose: To evaluate retinal nerve fiber layer (RNFL) thickness and macular volume in normal eyes and in the eyes of patients with glaucoma, and to compare the usefulness of these measurements in diagnosing glaucomatous eyes.

Methods: Eighty-one eyes were divided into three groups: normal control (n = 31), early glaucoma [n = 31, mean deviation (MD) >or= -6 dB], and advanced glaucoma (n = 19, MD < -6 dB). The RNFL thickness and macular volume were measured using Stratus OCT (optical coherence tomography). Then, the diagnostic power of these parameters was evaluated.

Results: In eyes with early glaucoma, RNFL thickness was decreased significantly in eight of the 12 peripapillary sectors, and macular volume was decreased significantly in six of the nine macular sectors, compared with normal eyes. In the advanced glaucoma eyes, RNFL and macular volume were decreased throughout, except in RNFL thickness in the papillomacular region, and in retinal thickness in the foveal region. The area under the receiver-operating characteristic curve (AUROC) of the average RNFL (0.963) was larger than the macular volume (0.919).

Conclusions: Both peripapillary RNFL thickness and macular volume were decreased even in the early stage of glaucoma. Average RNFL thickness had greater diagnostic power than macular volume.