advertisement
Abstract #11242 Published in IGR 6-3
Comparison of retinal nerve fiber layer thickness measured by optical coherence tomography and scanning laser polarimetry (GDx)
Yamada K; Osako M; Tachibana K; Usui-MJournal of Tokyo Medical University 2004; 62: 545-551
PURPOSE: Optical coherence tomography (OCT) and scanning laser polarimetry (Nerve Fiber Analyzer, GDx) are optical devices that directly measure retinal nerve fiber layer (RNFL) thickness. In this study, we compared the RNFL thickness measured by these two instruments under the same conditions, and also investigated the relationship between the visual field and RNFL thickness. METHODS: Thirteen eyes of 13 glaucoma patients, 4 eyes of 4 patients with ocular hypertension, and 6 eyes of 6 normal subjects were studied (mean age ± standard deviation, 56.0 ± 13.6 year). Mean deviation (MD) of the Humphrey Field Analyzer (HFA) was -3.8 ± 4.9 dB in glaucoma patients. Three consecutive measurements of peripapillary RNFL thickness were performed by a single operator using OCT and GDx. The same circular scan area with a radius of 1.7 mm centered on the optic disc was used for the determination of RNFL thickness using both instruments. The mean RNFL thickness was calculated for the total area and for each quadrant (superior, nasal, inferior, temporal) of the scanned circle. Cases with a coefficient of variance (standard deviation divided by mean RNFL thickness) greater than 10% were excluded from analysis. RESULTS: The mean overall RNFL thickness for OCT and GDx were 105.8 ± 17.3 μm and 79.3 ± 14.6 μm, respectively, and a significant difference was observed (p < .0001). A significant correlation between RNFL thickness measured by OCT and GDx was obtained in the total area and superior and inferior quadrants, but not in nasal and temporal quadrants. A significant correlation between corrected pattern standard deviation (CPSD) determined by HFA and RNFL thickness was observed for OCT but not for GDx. CONCLUSIONS: The RNFL thickness obtained using OCT is generally greater than that using GDx. Furthermore, a better correlation between visual function and RNFL thickness was obtained for OCT compared with GDx.
Dr. K. Yamada, Department of Ophthalmology, Tokyo Medical University, 6-7-1, Nishishinjuku, Shinjuku-ku, Tokyo 160-0023, Japan
Classification:
6.9.1 Laser scanning (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis)
6.9.2 Optical coherence tomography (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis)
