Influence of Fovea-Disc Angle on Intra- and Interocular RNFL and Macular Thickness Symmetry in Normal Eyes

Title Influence of Fovea-Disc Angle on Intra- and Interocular RNFL and Macular Thickness Symmetry in Normal Eyes
Author, Co-Author Melanie Akau, Michael Sullivan-Mee, Baharak Asefzadeh
Topic
Year
2015
Day
Friday
Program Number
155679
Room
203-205
Affiliation
Abstract Purpose: To investigate fovea-disc angle (FDA) as measured by the FoDi alignment feature on the Spectralis SD-OCT and its effects on within eye (intraocular) and between eye (interocular) retinal nerve fiber layer (RNFL) and posterior pole parameters in normal eyes.

Methods: Thirty-two normal patients (67 ± 11 years, 90% male, RE < ±5D) with normal optic nerves, normal visual fields, and free of significant macular pathology were included. RNFL circle scans and posterior pole asymmetry scans were obtained using the Heidelberg Spectralis SD-OCT. Posterior pole scans were rotated manually to align the fovea and the optic disc center. FDA was taken directly from the device with manual adjustment as needed. Analysis of both intraocular and interocular parameters was performed using paired t-tests and Spearman correlation.

Results: Mean FDA OS (-8.64 ± 5.16) was significantly more negative than mean FDA OD (-6.58 ± 3.42, p<0.05). Interocular FDA symmetry increased as macular thickness symmetry increased and RNFL symmetry decreased (p<0.05). While intraocular hemispheric macular thickness symmetry was not correlated with FDA, intraocular hemispheric RNFL became more asymmetric with more negative FDA (p<0.05.)

Conclusion: FDA as determined on the Spectralis SD-OCT was asymmetric between eyes and had greater influence on symmetry or asymmetry of RNFL thickness than posterior pole thickness. Future studies on FDA symmetry or asymmetry in patients with glaucoma and other factors that influence FDA are of interest.
Affiliation of Co-Authors Albuquerque VA Medical Center, Boston VA Healthcare System
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