Date of Award

January 2011

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Milton B. Shields

Subject Area(s)



The purpose of this study was to identify variables measured by spectral-domain Cirrus high-definition optical coherence tomography (HD-OCT) (Carl Zeiss Meditec Inc, Dublin, CA) that were correlated with a discrepancy between retinal nerve fiber layer (RNFL) thickness and clock-hour maps, as indicators of glaucomatous damage. We hypothesized that the RNFL thickness and clock-hour maps may not always indicate the same level of glaucomatous damage and that certain variables likely influence the discrepancy.

This was a retrospective case study of glaucoma patients with Cirrus HD-OCT imaging. Discrepancies between RNFL thickness and clock-hour maps were calculated by determining the difference between assigned stages of glaucomatous damage. The means of selected variables (symmetry, signal strength, peak amplitude difference, peak horizontal deviation, and quadrant thickness) were compared between groups with discrepancies and groups without discrepancies.

Data was collected from 118 patients, including 231 eyes and 446 quadrants. Approximately 18% of quadrants demonstrated a discrepancy of greater than or equal to 2 stages. Only the average quadrant thickness was significantly different between discrepant and non- discrepant groups.

Technological advances have provided us with increasingly higher resolution images of the optic nerve head, but no instructions regarding their utility. More research is required to determine the most clinically relevant optical coherence tomography data. Quadrant thickness measurements are correlated with discrepancies between other maps.