Comparison of retinal nerve fiber layer measurements using Stratus OCT fast and regular scan protocols in eyes with band atrophy of the optic nerve and normal controls

Purpose: To compare retinal nerve fiber layer (RNFL) measurements made with two different protocols of optical coherence tomography in eyes with band atrophy (BA) of the optic nerve and controls. Methods: Twenty-nine eyes with BA from chiasmal compression and 30 normal eyes underwent RNFL scans using both the fast (256 A-scans) and the regular (512 A-scans) protocols. The two sets of measurements were compared. Results: In eyes with BA, fast RNFL measurements were significantly greater compared with regular RNFL measurements in the superior and inferior quadrants and significantly smaller at the 30-degree segments located at the 3 and 6 o'clock meridians. In normal eyes, fast RNFL measurements of the total average, superior and inferior quadrants and the segments corresponding to the 1, 3, 4 and 12 o'clock meridians were significantly greater than regular protocol measurements. Measurements with both protocols were significantly different in eyes with BA compared to normal eyes. Conclusions: Although both fast and regular RNFL measurements were equally efficient at differentiating eyes with BA from controls the fast protocol yielded greater values in areas with thick RNFL and smaller values in areas with thin RNFL when compared with the regular scanning protocol. One should be aware of such differences when comparing measurements with both scanning protocols.