Optical coherence tomography and localized defects of the retinal nerve fiber layer
To test the capability of the optical coherence tomography (OCT) to demonstrate and quantitate retinal nerve fiber layer (RNFL) defects.
The authors examined 6 eyes of 6 chronic open angle glaucoma patients with the OCT. The patients had abnormal Humphrey 30–2 visual fields which corresponded to RNFL defects visible in monochromatic fundus images taken with a digital imaging system. The RNFL images were used for directing the OCT scans to areas where most information was believed to be obtainable. Several linear scans of different lengths across healthy and abnormal RNFL regions were made.
When the OCT images were compared to RNFL photographs, the defective areas showed reduced backscattering with the OCT, being distinctly different from the adjacent normal RNFL. Except for one case the RNFL thickness values were smaller in the areas of abnormal appearance compared to areas of normal appearance.
This preliminary study suggests that the OCT examination results of the RNFL are in good agreement with the RNFL appearance in monochromatic fundus images.