Ocular Motor Abnormalities in Children Characterized Using the Nidek MP1 Microperimeter

Abstract

Purpose: : Ocular motor abnormalities are prevalent in children treated for dense cataracts, strabismus, and anisometropia. Although ocular motor dysfunction may interfere with an optimal response to amblyopia therapy and longterm visual acuity outcomes, the expertise and expense required to implement routine electrophysiological or behavioral investigation of the ocular motor system has limited its use by pediatric eye care professionals. We evaluated whether a widely available medical device that uses digital fundus imaging for quantitative fixation tracking, the Nidek MP1 microperimeter, can be used in a clinical setting to evaluate ocular motor abnormalities in children.

Methods: : Children (age range: 5-12 years) at risk for abnormal ocular motor outcomes due to cataracts (N=8), hyperopic anisometropia (N=8), or strabismus (N=9) were evaluated monocularly using the Nidek MP1 fixation autotracking feature (30 sec per eye) and, as a gold standard exam, the EyeLink1000 video remote binocular eye tracker (20 sec per eye). Eye movement data from both devices were qualitatively evaluated by a masked examiner experienced in pediatric ocular motor evaluation.

Results: : Using the EyeLink1000, 11 children (44%) had jerk infantile nystagmus syndrome (INS) or jerk fusion maldevelopment nystagmus syndrome (FMNS); all 11 were correctly identified with the Nidek MP1. An additional 6 children (24%) were characterized by the Eyelink1000 as having pathologic saccadic oscillation (SO); all had pathologic SO in their Nidek records but 1 of the 6 also had occasional bursts of jerk FMNS. The remaining 8 children (32%) were assessed as normal using the EyeLink1000; 6 had normal Nidek records but 2 had occasional bursts of jerk FMNS.

Conclusions: : Overall, ocular motor evaluation with the Nidek MP1 was successful in children as young as 5 years of age and showed good agreement with the gold standard ocular motor evaluations. All ocular motor abnormalities noted in the EyeLink1000 records were also present in the Nidek records. The only discrepancy observed was that some children exhibited bursts of jerk FMNS in Nidek records that were not seen in EyeLink1000 records. The Nidek MP1 provides a simple approach for qualitative monocular ocular motor evaluation in pediatric clinical settings.

Keywords: strabismus • eye movements • imaging/image analysis: clinical