Material and Method: Forty-eight eyes of glaucoma, 48 glaucoma suspect eyes, and 35 healthy eyes were included. The circumpapillary and macular retinal nerve fiber layer (RNFL) thickness were measured using the CirrusTM OCT (Carl Zeiss Meditec, Inc., Dublin, CA, USA). One-way analysis of variance was used to compare the different parameters among groups. Calculating areas under receiver operating characteristic (AROC) curves evaluated the discriminating power of each parameter.

Results: The average circumpapillary RNFL thickness in normal, glaucoma suspects, and glaucomatous eyes were 100.31±7.69 μm, 90.27±9.22 μm, and 71.40±13.08 μm, respectively (p<0.001). The largest AROC curve among the circumpapillary parameters was the inferior quadrant thickness (0.974, p<0.001). The macular volume had the largest AROC curves (0.898, p<0.001) of all macular parameters. For glaucoma suspect eyes versus early glaucomatous eyes, the best value of circumpapillary parameters was inferior quadrant thickness (0.835, p<0.001). Among the macular parameters, the best value was the macular cube volume (0.766, p<0.001).

Conclusion: Circumpapillary parameters have better diagnostic performance than macular parameters especially the inferior quadrant thickness that has the best discriminating power.

Keywords: Spectral-domain, Optical coherence tomography, Discrimination, Glaucoma suspect, Glaucoma