To investigate the comparison of retinal nerve fiber layer (RNFL) thickness parameters measured by optical coherence tomography (Stratus OCT 3000TM) and visual field indices in early normal-tension glaucoma (NTG) and early primary open-angle glaucoma (POAG).

Sixty-one early normal-tension glaucomatous eyes, 21 early primary open-angle glaucomatous eyes and 34 healthy control eyes were enrolled in this cross-sectional study. Each subject received a visual field test (Humphrey C30-2) and the fast RNFL thickness algorithm test by OCT. The correlations between RNFL thickness and visual field indices were analyzed. The sensitivity and specificity for the detection of early glaucoma were determined with the area under the receiver operating characteristics curve (AUROC).

All RNFL thickness values except for the temporal quadrant RNFL thickness were significantly decreased in the early NTG and POAG groups ( p <0.05). In early POAG, the average and superior quadrant RNFL thicknesses were significantly thinner than in the early NTG group. Significant correlations were observed between the PSD and the average and superior quadrant RNFL thicknesses in the early NTG and POAG groups ( p <0.05). The average RNFL thickness for early glaucoma had the widest AUROC among all of the parameters.

In the early NTG group with visual field defects similar to those of early POAG, RNFL defects measured by OCT were less severe, particularly in the average and superior quadrant RNFLs.