Poster Presentation at the North American Neuro-Ophthalmology Society North America 2016 Annual Meeting

Capturing the Efferent Side of Vision in Multiple Sclerosis: New Data from a Digitized Rapid Number Naming Task

Authors: Clotilde Hainline1, John-Ross Rizzo2, Todd E. Hudson1,2, WeiWei Dai1,2, Joel Birkemeier1, Rachel C. Nolan1, Lisena Hasanaj1, Laura J. Balcer1,3,4, Steven L. Galetta1,3, Ilya Kister1, Janet C. Rucker1,3; (1 NYU Langone Medical Center/ Department of Neurology, NY, NY, USA; 2 NYU Langone Medical Center/ Department of Rehabilitation Medicine, NY, NY, USA; 3 NYU Langone Medical Center/ Department of Ophthalmology, NY, NY, USA; 4 NYU Langone Medical Center/Department of Population Health NY, NY, USA)
Publication: Poster Presentation at the North American Neuro-Ophthalmology Society North America 2016 Annual Meeting
Date: April 4, 2016
Tags: Multiple Sclerosis,Vision,

Introduction:

Visual function in multiple sclerosis (MS) has been well characterized from an afferent standpoint using low-contrast acuity, optical coherence tomography (OCT) and quality of life (QOL). Compared to controls, patients with MS also demonstrate slowed reading times on the King-Devick (K-D) test, a rapid number naming task that captures widely distributed aspects of efferent function, particularly saccades. Slowed times in MS are associated with neurologic dysfunction and reduced vision-specific (QOL). However, the ocular motor underpinnings of such slowing have not been determined. We sought to determine ocular motor performance and characterize deficits leading to slowed KD reading times using recorded eye movements during a digitized King-Devick (K-D) test.

Methods:

We tested 13 patients with MS (mean age 37) and compared their results to those of our normative database of control participants without MS (n=38, mean age 31). Participants completed the digitized K-D task with simultaneous video-oculographic eye movement recording (EyeLink 1000+). Data were analyzed off-line in Matlab and Stata 14.0.

Results:

Digitized K-D completion times in the MS cohort were longer (worse) relative to controls (52.6 ± 14.1 sec vs. 43.7 ± 8.5 sec, p=0.02, ttest). Intersaccadic intervals (ISI), which represent a combination of saccadic latency and fixation duration between saccades, were prolonged in MS patients (397 ±137 msec vs. 312 ± 53 msec, p=0.02, t-test). Within the MS cohort, test times were longer for the digitized vs. spiral-bound hand-held K-D test (52.0 ± 9.2 sec vs. 43.7 ± 9.7 sec, p=0.01, linear regression).

Conclusions:

In this ongoing study of ocular motor performance in MS, we have demonstrated that K-D reading times are slower secondary to prolonged ISI. The K-D test captures efferent visual dysfunction in MS and is likely to be a sensitive performance-based outcome measure for future research, practice and clinical trials.

Summary Points:

  • Laboratory-based eye movement study completed to determine oculomotor performance and characterize KD deficits in multiple sclerosis (MS).
  • Digitized KR reading times were prolonged for MS patients compared to controls.
  • Average inter-saccadic intervals (ISI) represents a combined measure of saccade latency and fixation duration.
  • ISI was prolonged in MS patients.
  • The K-D test captures efferent visual dysfunction in MS as such is a sensitive performance-based outcome measure for future research, practice, and clinical trials.
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