Discrimination between Normal and Early Stage of Glaucomatous Eyes Using the Stratus Optical Coherence Tomography

Abstract

Purpose: To evaluate the diagnostic ability of Stratus optical coherence tomography (OCT) parameters to distinguish normal eyes from those with early glaucomatous visual field defects. Methods: One eye each of 52 normal-tension glaucoma patients with early visual field defects (mean deviation, -3.98±1.30dB; range, -0.01 to -5.86dB) and 88 age-matched normal subjects were enrolled. The Peripapillary retinal nerve fiber layer (RNFL) and optic nerve head regions were scanned using the Stratus OCT. Areas under the receiver operating characteristic curve (AROC) and the sensitivity and specificity for various OCT parameters were used to assess the performance of OCT. Results: The AROC for the C/D area ratio was 0.865. Other high AROC values included the vertical C/D ratio (0.848), the average RNFL thickness (0.813), and the RNFL thickness in the inferior quadrant (0.791). A stepwise discriminant analysis found that a combination of the C/D area ratio and RNFL thickness in the inferior quadrant could correctly identify 86.4% of the normals and 80.8% of the glaucoma patients (AROC=0.893). Conclusions: In our sample of patients with early visual field defects, Stratus OCT parameters showed moderate discriminating abilities. Combining the C/D area ratio and RNFL thickness in the inferior quadrant by discriminant analysis improved the diagnostic ability to detect glaucoma.