Reproducibility of retinal nerve fiber thickness measurements using the stratus OCT in normal and glaucomatous eyes.
OBJECTIVE
To determine the reproducibility of Stratus Optical Coherence Tomography (OCT) retinal nerve fiber layer (RNFL) measurements around the optic nerve in normal and glaucomatous eyes.


METHODS
One eye was chosen at random from 88 normal subjects and 59 glaucomatous subjects distributed among mild, moderate, and severe glaucoma, determined by visual field testing. Subjects underwent six RNFL thickness measurements performed by a single operator over a 30-minute period with a brief rest between sessions. Three scans were taken with the high-density Standard RNFL protocol, and three were taken with the Fast RNFL protocol, alternating between scan protocols.


RESULTS
Reliability, as measured by intraclass correlation coefficient (ICC), was calculated for the overall mean RNFL thickness and for each quadrant. The ICC for the mean Standard RNFL thickness (and lower 95% confidence interval [CI]) in normal and glaucomatous eyes was 0.97 (0.96 CI) and 0.98 (0.97 CI), respectively. The ICC for the mean Fast RNFL thickness in normal and glaucomatous eyes was 0.95 (0.93 CI) and 0.97 (0.95 CI), respectively. Quadrant ICCs ranged between 0.79 and 0.97, with the nasal quadrant being the least reproducible of all four quadrants, using either the Standard or Fast RNFL program. The test-retest variability ranged from 3.5 microm for the average RNFL thickness measurements in normal eyes to 13.8 microm for the nasal quadrant measurements in glaucomatous eyes, which appeared to be the most variable.


CONCLUSIONS
Reproducibility of RNFL measurements using the Stratus OCT is excellent in normal and glaucomatous eyes. The nasal quadrant appears to be the most variable measurement. Standard RNFL and Fast RNFL scans are equally reproducible and yield comparable measurements. These findings have implications for the diagnosis of glaucoma and glaucomatous progression.
Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, Miami, Florida 33136, USA. dbudenz@med.miami.edu
Donald L
DL
Budenz
Robert T
RT
Chang
Xiangrun
X
Huang
Robert W
RW
Knighton
James M
JM
Tielsch
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003941:Diagnostic Techniques, Ophthalmological; D005189:False Positive Reactions; D005260:Female; D005901:Glaucoma / Q000473:pathology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000473:pathology*; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*