Zeiss GDx vs Zeiss Cirrus- Comparison of Three Examinations OD
Although the (clrcumpapillary) GDx RNFL does demonstrate a dramatic change and loss inferiorly. the Cirrus (circumpapillary) RNFL is essentially normal following the inferior artery occlusion. Note that GDx Is measuring the polarization or birefringence of the RNF1. but the OCT is measuring optical reflectivity. Since the blood vessels do not exhibit birefringence, they do not interfere with the assessment of the RNF1. on GDx. Does blrefringence yield a more accurate assessment of the RNFL than does optical reflectivity?³