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Acuity development in infantile nystagmus
1Division of Ophthalmology, Roger H. Johnson Clinical Vision Lab, Children's Hospital, Seattle, Washington 98105, USA. avery.weiss@seattlechildrens.org
Insights
Visual acuity development in infantile nystagmus is similar regardless of associated visual defects. However, sensory deficits significantly reduce acuity more than isolated infantile nystagmus.
Area of Science:
- Ophthalmology
- Pediatric Ophthalmology
- Visual Development
Background:
- Infantile nystagmus (IN) is an involuntary eye movement condition.
- IN can occur in isolation or be associated with visual sensory defects.
- Understanding acuity development in IN is crucial for early intervention.
Purpose of the Study:
- To compare visual acuity development in children with isolated IN versus IN associated with visual sensory defects.
- To determine if gaze-holding instability or sensory deficits impact acuity progression.
- To quantify differences in acuity reduction between IN subtypes.
Main Methods:
- Assessed visual acuity using Teller acuity cards in 57 children (1 month-4 years) with IN.
- Classified IN groups: isolated IN, albinism, aniridia, and bilateral optic nerve hypoplasia (BONH).
- Quantified acuity development rate using linear regression and compared to normative data.
Main Results:
- The rate of acuity development was similar across all IN groups, paralleling normative data.
- No significant differences in the rate of acuity development were found between groups.
- Mean acuity was reduced by 1.2 octaves in isolated IN and 1.7-2.5 octaves in IN with sensory defects compared to norms.
Conclusions:
- The rate of visual acuity development in infantile nystagmus is largely unaffected by gaze-holding instability or associated visual sensory defects.
- Reduced mean acuity in albinism, aniridia, and BONH is primarily due to the underlying visual sensory defect.
- Sensory defects cause greater acuity reduction than isolated infantile nystagmus.
Purpose:
To compare development of acuity in patients with isolated infantile nystagmus and infantile nystagmus associated with a visual sensory defect.
Methods:
Visual acuities in 57 children (1 month to 4 years of age) with infantile nystagmus were assessed by using Teller acuity cards oriented vertically during binocular viewing. Twenty-two had isolated infantile nystagmus, 21 had albinism, 7 had aniridia, and 7 had mild or moderate bilateral optic nerve hypoplasia (BONH). Longitudinal acuity was measured in 40 of these patients (mean 1.8, 2.3, 3.1, and 3.3, measurements per patient group, respectively). The rate of acuity development across the study groups was quantified by linear regression of log acuity versus log age and compared to published normative data.
Results:
The rate of acuity development was similar across all groups and paralleled the normative data. The slope of log grating acuity versus log age (+/-SEM) was normal, 0.73; isolated infantile nystagmus, 0.80 +/- 0.11; albinism, 0.80 +/- 0.11; aniridia, 0.87 +/- 0.16; and BONH, 0.79 +/- 0.18. The slopes were not significantly different (ANCOVA, F(4,142) = 0.21, P = 0.93). Compared with published binocular normative data, mean acuity adjusted for age was reduced by 1.2 octaves in isolated infantile nystagmus and by 1.7 to 2.5 octaves in nystagmus with associated sensory defect.
Conclusions:
The rate of acuity development in infantile nystagmus is largely independent of the gaze-holding instability or an associated visual sensory defect. Reduction of mean acuity in albinism, aniridia, and BONH is due to the visual sensory defect and exceeds the acuity reduction observed in isolated infantile nystagmus.
