Jessica Y Chen1, Alan Le2,3,4, Lindsay M De Andrade2,4, Toshiaki Goseki2,4, Joseph L Demer2,3,4,5,6. 1. Computational and Systems Biology Interdepartmental Program, University of California, Los Angeles, Los Angeles, California, United States. 2. Department of Ophthalmology, University of California, Los Angeles, Los Angeles, California, United States. 3. Bioengineering Interdepartmental Program, University of California, Los Angeles, Los Angeles, California, United States. 4. Stein Eye Institute, University of California, Los Angeles, Los Angeles, California, United States. 5. Department of Neurology, University of California, Los Angeles, Los Angeles, California, United States. 6. David Geffen Medical School, University of California, Los Angeles, Los Angeles, California, United States.
Abstract
Purpose: The optic nerve becomes tethered in adduction in most people, which deforms the disc. We investigated the effect of horizontal ocular duction and subject age on choroidal volume at the macular side of the optic disc. Methods: In 25 younger (18-33 years) and 15 older (50-73 years) normal subjects, the disc and the peripapillary choroid were imaged with optical coherence tomography (OCT) in central gaze and 35° adduction and abduction. The choroid temporal to the optic disc underlying the region between the Bruch's membrane opening and fovea was segmented into regions that were multiples of the disc radius for determination of local choroidal thickness. Regional volume changes from central gaze were determined in adduction and abduction. Results: In adduction, regional choroidal volume decreased by 42.4 ± 3.4 nanoliters (nL) (standard error of the mean) in younger (P < 0.0001) and 6.2 ± 2.6 nL in older (P < 0.02) subjects. Relative volume reduction in adduction was 7.5% ± 0.6% in younger (P < 0.001) and 1.3% ± 0.6% in older (P < 0.02) subjects. Volume reduction was greatest near the disc and significant up to three disc radii from it in younger and 1 radius in older subjects but was insignificant in abduction. Conclusions: Horizontal duction compresses the temporal peripapillary choroid, more in adduction than in abduction and more in younger than older subjects. This reflects duction-related peripapillary tissue deformation probably related, at least in part, to optic nerve tethering in adduction.
Purpose: The optic nerve becomes tethered in adduction in most people, which deforms the disc. We investigated the effect of horizontal ocular duction and subject age on choroidal volume at the macular side of the optic disc. Methods: In 25 younger (18-33 years) and 15 older (50-73 years) normal subjects, the disc and the peripapillary choroid were imaged with optical coherence tomography (OCT) in central gaze and 35° adduction and abduction. The choroid temporal to the optic disc underlying the region between the Bruch's membrane opening and fovea was segmented into regions that were multiples of the disc radius for determination of local choroidal thickness. Regional volume changes from central gaze were determined in adduction and abduction. Results: In adduction, regional choroidal volume decreased by 42.4 ± 3.4 nanoliters (nL) (standard error of the mean) in younger (P < 0.0001) and 6.2 ± 2.6 nL in older (P < 0.02) subjects. Relative volume reduction in adduction was 7.5% ± 0.6% in younger (P < 0.001) and 1.3% ± 0.6% in older (P < 0.02) subjects. Volume reduction was greatest near the disc and significant up to three disc radii from it in younger and 1 radius in older subjects but was insignificant in abduction. Conclusions: Horizontal duction compresses the temporal peripapillary choroid, more in adduction than in abduction and more in younger than older subjects. This reflects duction-related peripapillary tissue deformation probably related, at least in part, to optic nerve tethering in adduction.
Authors: Ya Xing Wang; Hongli Yang; Haomin Luo; Seung Woo Hong; Stuart K Gardiner; Jin Wook Jeoung; Christy Hardin; Glen P Sharpe; Kouros Nouri-Mahdavi; Joseph Caprioli; Shaban Demirel; Christopher A Girkin; Jeffrey M Liebmann; Christian Y Mardin; Harry A Quigley; Alexander F Scheuerle; Brad Fortune; Balwantray C Chauhan; Claude F Burgoyne Journal: Am J Ophthalmol Date: 2020-04-13 Impact factor: 5.488