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Foveation dynamics in congenital nystagmus IV: vergence.
Doc Ophthalmol. 2020 06; 140(3):221-232.DO

Abstract

PURPOSE

To evaluate foveation dynamics and characteristics of vergence eye movements during fixation of static targets at different distances and while tracking a target moving in depth in a subject with congenital nystagmus (CN).

METHOD

Eye movements of a well-studied subject with CN were recorded using the magnetic search coil technique and analyzed using the OMtools software, including the eXpanded Nystagmus Acuity Function (NAFX).

RESULTS

Both the phase planes and NAFX values during fixation of targets at various near distances were equivalent to those during fixation of a far target. When applied to vergence data, the NAFX values ("binocular" NAFX) were higher than for the individual eye data. Vergence tracking of targets moving in depth was demonstrated and was accurate for targets moving at speeds up to ~ 35°/sec.

CONCLUSIONS

Target foveation qualities during fixation of targets at various near distances were equivalent to that during fixation of a far target. Stereo discrimination was limited by the foveation quality of the eye with the higher NAFX waveform. Foveation period slopes during vergence tracking demonstrated vergence movements despite the ongoing CN oscillation. Similar to what we found with fixation, pursuit, and the vestibulo-ocular systems, these findings establish that vergence in both static and dynamic viewing conditions functions normally in the presence of the CN oscillation.

Authors+Show Affiliations

Daroff-Dell'Osso Ocular Motility Laboratory, Louis Stokes Cleveland, Department of Veterans Affairs Medical Center, CASE Medical School, Case Western Reserve University and University Hospitals Case Medical Center, 10701 East Boulevard, Cleveland, OH, 44106, USA. lfd@case.edu. Departments of Neurology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, OH, USA. lfd@case.edu. Departments of Biomedical Engineering, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, OH, USA. lfd@case.edu.Department of Neuroscience, ErasmusMC, Rotterdam, The Netherlands.Department of Psychology, University of Maryland, College Park, MD, USA.Department of Neuroscience, ErasmusMC, Rotterdam, The Netherlands.

Pub Type(s)

Case Reports
Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

31776760

Citation

Dell'Osso, Louis F., et al. "Foveation Dynamics in Congenital Nystagmus IV: Vergence." Documenta Ophthalmologica. Advances in Ophthalmology, vol. 140, no. 3, 2020, pp. 221-232.
Dell'Osso LF, Van Der Steen J, Steinman RM, et al. Foveation dynamics in congenital nystagmus IV: vergence. Doc Ophthalmol. 2020;140(3):221-232.
Dell'Osso, L. F., Van Der Steen, J., Steinman, R. M., & Collewijn, H. (2020). Foveation dynamics in congenital nystagmus IV: vergence. Documenta Ophthalmologica. Advances in Ophthalmology, 140(3), 221-232. https://doi.org/10.1007/s10633-019-09738-y
Dell'Osso LF, et al. Foveation Dynamics in Congenital Nystagmus IV: Vergence. Doc Ophthalmol. 2020;140(3):221-232. PubMed PMID: 31776760.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Foveation dynamics in congenital nystagmus IV: vergence. AU - Dell'Osso,Louis F, AU - Van Der Steen,Johannes, AU - Steinman,Robert M, AU - Collewijn,Han, Y1 - 2019/11/27/ PY - 2019/08/15/received PY - 2019/11/12/accepted PY - 2019/11/30/pubmed PY - 2020/10/3/medline PY - 2019/11/29/entrez KW - Congenital nystagmus KW - Infantile nystagmus syndrome KW - Tracking KW - Vergence SP - 221 EP - 232 JF - Documenta ophthalmologica. Advances in ophthalmology JO - Doc Ophthalmol VL - 140 IS - 3 N2 - PURPOSE: To evaluate foveation dynamics and characteristics of vergence eye movements during fixation of static targets at different distances and while tracking a target moving in depth in a subject with congenital nystagmus (CN). METHOD: Eye movements of a well-studied subject with CN were recorded using the magnetic search coil technique and analyzed using the OMtools software, including the eXpanded Nystagmus Acuity Function (NAFX). RESULTS: Both the phase planes and NAFX values during fixation of targets at various near distances were equivalent to those during fixation of a far target. When applied to vergence data, the NAFX values ("binocular" NAFX) were higher than for the individual eye data. Vergence tracking of targets moving in depth was demonstrated and was accurate for targets moving at speeds up to ~ 35°/sec. CONCLUSIONS: Target foveation qualities during fixation of targets at various near distances were equivalent to that during fixation of a far target. Stereo discrimination was limited by the foveation quality of the eye with the higher NAFX waveform. Foveation period slopes during vergence tracking demonstrated vergence movements despite the ongoing CN oscillation. Similar to what we found with fixation, pursuit, and the vestibulo-ocular systems, these findings establish that vergence in both static and dynamic viewing conditions functions normally in the presence of the CN oscillation. SN - 1573-2622 UR - https://www.unboundmedicine.com/medline/citation/31776760/Foveation_dynamics_in_congenital_nystagmus_IV:_vergence_ L2 - https://doi.org/10.1007/s10633-019-09738-y DB - PRIME DP - Unbound Medicine ER -