Table 3. Averaged RNFL birefringence values using different RNFL thickness thresholds for the same set of healthy volunteers, diabetic and glaucoma patients as used in Table 2. Areas of RNFL thickness > 75 µm, RNFL thickness > 100 µm (values of Table 2) and RNFL thickness > 125 µm are considered, respectively, in the three different columns. The statistically significantly reduced birefringence in the RNFL of diabetic patients as compared to the heathy subjects is seen for all of the three threshold values tested.