OCT-RNFL-Discordance – page 25 of 29

• Review of the images of the circumpapillary RNFL using all three OCT systems tested did not reveal any segmentation errors and hence the false negative findings are not easily explainable.
• One explanation is that circumpapillary OCT RNFL thickness measurements include blood vessels (which artificially increase the RNFL measurement) whereas GDx does not since blood vessels do not exhibit birefringence.^3,5
• GDx, GCC, and SD OCT vertical scans through the macula all outperformed the OCT circumpapillary RNFL findings and hence should be obtained in questionable cases.
• Structure/function relationships with GCC and maia microperimetry may prove to be very helpful clinically and deserve further study.