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A UNIFYING HYPOTHESIS FOR THE MULTIPLE WAVEFORMS OF INFANTILE NYSTAGMUS AND THEIR IDIOSYNCRATIC VARIATION WITH GAZE ANGLE AND THERAPY

Wang, Zhong
http://rave.ohiolink.edu/etdc/view?acc_num=case1210605209

Abstract Details

2008, Doctor of Philosophy, Case Western Reserve University, Biomedical Engineering.
Infantile Nystagmus Syndrome (INS) is an ocular motor instability characterized by involuntary oscillations of the eyes. The purpose of this thesis is to better understand the underlying mechanisms of INS in terms of static characteristics, dynamic properties, and changes after extraocular muscle (EOM) surgeries, and to incorporate these findings into a behavioral Ocular Motor System (OMS) model. Accurate recordings of eye-movement responses to visual stimuli under certain experimental paradigms were analyzed and used as templates for model simulations. The effectiveness of the four-muscle tenotomy surgical procedure was evaluated and the post-surgical effects were categorized in order to set up the clinical criteria governing the use of this procedure. Also, combination of tenotomy with other commonly practiced strabismus/nystagmus surgeries was explored. The eXpanded Nystagmus Acuity Function (NAFX), which is a mathematical function that linearly relates foveation quality of nystagmus waveforms to the maximum possible visual acuity, was used as the direct measurement of post-surgical waveform changes. The differential effect of tenotomy on the fast and slow eye movements of INS was carefully examined to elucidate a working mechanism for tenotomy. The effects of target timing in INS on target acquisition (of both step and pursuit stimuli) were also investigated as an initial exploration of the INS dynamic characteristics. Incorporating the above INS properties to our OMS model, as well as simulating the mechanisms that determine the idiosyncratic gaze angle where the NAFX peak/nystagmus "null" (the field of gaze angles in which the NAFX is maximal) appears, had greatly expand the behavioral OMS by allowing simulations of more diverse variations of pathological conditions, and therefore greatly assist in our understanding of the OMS.
Louis F. Dell'Osso, Ph.D. (Advisor)
Robert F. Kirsch, Ph.D. (Committee Chair)
Patrick Crago, Ph.D. (Committee Member)
R. John Leigh, M.D. (Committee Member)
Kenneth A. Loparo, Ph.D. (Committee Member)
Robert L. Tomsak, M.D., Ph.D. (Committee Member)
359 p.
Biomedical Research
eye movement; nystagmus; extraocular muscle surgery; visual function; model

Recommended Citations

Citations

  • Wang, Z. (2008). A UNIFYING HYPOTHESIS FOR THE MULTIPLE WAVEFORMS OF INFANTILE NYSTAGMUS AND THEIR IDIOSYNCRATIC VARIATION WITH GAZE ANGLE AND THERAPY [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1210605209

    APA Style (7th edition)

  • Wang, Zhong. A UNIFYING HYPOTHESIS FOR THE MULTIPLE WAVEFORMS OF INFANTILE NYSTAGMUS AND THEIR IDIOSYNCRATIC VARIATION WITH GAZE ANGLE AND THERAPY. 2008. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1210605209.

    MLA Style (8th edition)

  • Wang, Zhong. "A UNIFYING HYPOTHESIS FOR THE MULTIPLE WAVEFORMS OF INFANTILE NYSTAGMUS AND THEIR IDIOSYNCRATIC VARIATION WITH GAZE ANGLE AND THERAPY." Doctoral dissertation, Case Western Reserve University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1210605209

    Chicago Manual of Style (17th edition)

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© 2008, all rights reserved.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.