Structural Measurements for Monitoring Change in XXXX : Comparing Retinal Nerve Fiber Layer Thickness With Minimum Rim Width and Area.

@entity1 @entity101 @entity16 @entity726
PURPOSE: Minimum rim width (MRW) and area (MRA) have been introduced as anatomically defensible measures of neuroretinal rim tissue observable using spectral-domain optical coherence tomography (SDOCT). They have been reported to change earlier than retinal nerve fiber layer thickness (RNFLT) in @entity726 . This study sought to determine which is better to distinguish subsequent change from variability, using the previously described longitudinal signal-to-noise ratio (LSNR). METHODS: Data from 157 eyes of 157 @entity1 with high-risk ocular @entity101 or non-end-stage @entity726 (mean deviation [MD] from -22 to +3 dB) were used. @entity1 were tested approximately every 6 months for at least six visits. For each eye, MRW, MRA, and RNFLT were regressed linearly against time. Longitudinal signal-to-noise ratio for each eye was defined as the rate of change over time (signal) divided by the standard deviation of residuals from this trend (noise). These were compared between parameters using a Wilcoxon signed rank test. RESULTS: The median LSNRs were -0.58y      for RNFLT (bootstrapped 95% confidence interval -0.69 to -0.48y     ); -0.44y      (-0.59 to -0.32y     ) for MRW; and -0.23y      (-0.32 to -0.08y     ) for MRA. Longitudinal signal-to-noise ratios were significantly more negative for RNFLT than for MRW (P = 0.025) or for MRA (P < 0.001). CONCLUSIONS: Retinal nerve fiber layer thickness measured by SDOCT had a better LSNR than MRW or MRA. Although MRW and MRA may be more sensitive for early detection of @entity16 , these data suggest that RNFLT may be preferable for monitoring change.
