Abstract
PurposeThe authors assess the reproducibility of retinal nerve fiber layer (RNFL) thickness measurements using scanning laser polarimetry.MethodsThe right eyes of five healthy individuals were scanned by two trained operators (S.T.H., H.I.) using the Nerve Fiber Analyzer II (Laser Diagnostic Technologies, Inc., San Diego, CA, U.S.A.). Each participant was scanned six consecutive times per session for five sessions carried out over separate days within a two-week period. Intra- and interoperator measurement reproducibility was assessed.ResultsIntraoperator reproducibility was high. Mean coefficients of variation for total RNFL thickness measurements were 4.48 ± 1.76% and 4.92 ± 2.32% for operators 1 and 2, respectively. Interoperator reproducibility was high (p = 0.20–0.93) if a single ellipse was applied to the images of both examiners. However, measurement reproducibility worsened if each operator created his own measurement ellipse (p ≤ 0.05 for 3 out of 5 participants).ConclusionInteroperator error in image analysis can be minimized by using a single ellipse for the baseline and all subsequent scans even if subsequent scans are acquired by different operators.
