Neonatal ocular misalignments reflect vergence development but rarely become esotropia
- Correspondence to: Anna Horwood, Orthoptic Department, Royal Berkshire Hospital, London Road, Reading, Berkshire, RG1 5AN, UK; a.m.horwood{at}reading.ac.uk
- Accepted 14 January 2003
Abstract
Background: 214 orthoptists’ infants have been followed for up to 15 years, relating neonatal misalignment (NMs) behaviour to onset of convergence and 20 Δ base out prism response, and also to later childhood ocular abnormalities.
Methods: In a prospective postal survey, orthoptist mothers observed their own infants during the first months of life and regularly reported ocular behaviour and alignment, visual development, and any subsequent ocular abnormalities.
Results: Results confirm previously reported characteristics of NMs. Infants who were misaligned more frequently were misaligned for longer periods (p <0.01) and were later to achieve constant alignment (p <0.001) but were earlier to attempt first convergence (p = 0.03). Maximum NM frequency was usually found at or before the onset of first convergence (p = 0.0002).
Conclusions: NMs occur in the first 2 months of life and usually reflect a normally developing vergence system. They appear to represent early attempts at convergence to near targets. Emerging infantile esotropia is indistinguishable from frequent NMs before 2 months.
Footnotes
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↵* Angle lambda is the angle between the pupillary axis and the line of sight formed at the centre of the pupil. A positive angle lambda causes the corneal reflection to be nasal to the pupil centre. The terms angle alpha or angle kappa are often used synonymously and are almost identical.
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↵† “Squinting” and “NMs” denote ocular misalignment that may be unilateral or bilateral and may or may not be pathological. At this age it is not possible to differentiate those infants who will progress to show pathological strabismus from those who will subsequently develop normal binocular vision.
