Purpose. To test a new software algorithm for measuring retinal nerve fiber layer (RNFL) thickness by optical coherence tomography. Methods. Circular peripapillary OCT scans were performed in 10 normal and 10 glaucomatous eyes in human subjects. The scan pattern was 3.37 mm in diameter and centered on the optic nerve head. RNFL thickness was computed using a new pixel-counting algorithm. Results. In normal eyes, the average s.d. of repeat measurements in the same eye was 2.8 μm for overall average, 4.1 μm for vertical & horizontal averages, 6.6 μm for quadrant averages and 10.1 μm for clockhour averages. The respective numbers for glaucomatous eyes were, 4.4, 5.3, 7.9, and 11.2 μm. In normal eyes, overall average RNFL thickness (OA) was 136.6±6.7 μm and the ratio of RNFL thickness in vertical v. horizontal quadrants (VH) was 1.335±0.026. 8 of 10 glaucomatous eyes has either OA or VH below 2 s.d. of the normal eyes. The 2 glaucomatous eyes with normal OA and FH had early glaucoma with normal visual fields. Conclusion. The new OCT RNFL algorithm provides highly reproducible RNFL parameters that should prove useful for tracking progressive RNFL loss and for distinguishing glaucomatous eyes from normal eyes.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - Feb 15 1996|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience