Purpose: The purpose of the study was to investigate the diagnostic ability of the neurologic hemifield test (NHT) and retinal nerve fiber layer (RNFL) thickness measurements to detect chiasmal compression.
Methods: Thirty-seven patients with chiasmal compression, 35 patients with glaucoma, and 30 patients with glaucoma suspect were enrolled. The NHT score was established from a 30-2 visual field pattern deviation probability plot. Each test point value was calculated for a number that was inversely proportional to its pattern deviation probability. The NHT score was the absolute value of the difference in the sum of the point scores for two symmetrical regions of 16 points on either side of the vertical meridian. RNFL thickness was scored from 0 to 10 according to the pattern of RNFL loss and probability of abnormality. Solely present nasal or temporal RNFL defects were scored high, and exclusively appearing superior or nasal RNFL defects were scored low. The differences in the NHT and RNFL scores among the three groups were compared. Diagnostic ability was assessed by receiver operating characteristic (ROC) analysis.
Results: The NHT and RNFL scores were significantly higher in patients with chiasmal compression than in patients with glaucoma and glaucoma suspect. The area under the ROC curve (AROC) was 0.734 of the NHT score and 0.613 of the RNFL score. When AROC was calculated using the NHT and RNFL scores concurrently, AROC was increased to 0.807.
Conclusions: The NHT score and RNFL score have diagnostic ability to detect chiasmal compression, and simultaneous assessment of NHT and RNFL scores improves the diagnostic power.