PERIPAPILLARY NERVE-FIBER LAYER THICKNESS MEASUREMENT REPRODUCIBILITYUSING SCANNING LASER POLARIMETRY

Purpose: The authors assess the reproducibility of retinal nerve fiber layer (RNFL) thickness measurements using scanning laser polarimetry. Methods: The right eyes of five healthy individuals were scanned by t wo trained operators (S.T.H., H.I.) using the Nerve Fiber Analyzer II (Laser Diagnostic Technologies, Inc., San Diego, CA, U.S.A.). Each par ticipant was scanned six consecutive times per session for five sessio ns carried out over separate days within a two-week period. Intra- and interoperator measurement reproducibility was assessed. Results: Intr aoperator 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 image s of both examiners. However, measurement reproducibility worsened if each operator created his own measurement ellipse (p less than or equa l to 0.05 for 3 out of 5 participants). Conclusion: Interoperator erro r in image analysis can be minimized by using a single ellipse for the baseline and all subsequent scans even if subsequent scans are acquir ed by different operators.