Abstract
Purpose :
The Spectralis SD-OCT measured Bruch’s membrane opening minimum rim width (BMO-MRW) has been shown to be feasible for the detection of glaucoma. While peripapillary retinal nerve fiber layer thickness (RNFLT) measurements are standardized in its size, the BMO-MRW bears different optic nerve circumferences (ONC) as a biasing factor. We evaluated the confounding role of the ONC and proposed a correction factor.
Methods :
We included in this retrospective study 80 eyes of 80 healthy patients (mean age 26.29, standard deviation 3.24). BMO-MRW and circular peripapillary scans were obtained using Spectralis SD-OCT (Heidelberg Engineering) complying with OSCAR-IB criteria. Mean RNFLT of the 3.5mm scan, global BMO-MRW, and manual measured ONC (in µm) were recorded. Using Pearson correlation RNFLT and BMO-MRW, as well BMO-MRW and manual ONC were compared. BMO-MRW was corrected using the measured ONC and standardized based on the mean ONC. The results were correlated with the RNFLT to reveal the hypothesized advantage.
Results :
RNFLT and BMO-MRW had a significant correlation with a Pearson correlation coefficient of r=0.41 (p=0.002). BMO-MRW had a significant correlation of r=-0,61 (p<0.0001). The ONC-based standardized BMO-MRW was on average -6.45±43.74 µm different from the original BMO-MRW. Correlation between RNFLT and ONC-based standardized BMO-MRW had a significant correlation of r=0,53 (p<0.0001), demonstrating a higher correlation as the original BMO-MRW.
Conclusions :
We found that the BMO-MRW has a high correlation with the ONC and seems to be confounded by it. In our results, ONC-based standardized BMO-MRW had a superior correlation with the RNFLT. Therefore, we propose that BMO-MRW measurements should take the ONC into account for a higher accuracy.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.