comitant strabismus
Comitant strabismus is a manifest deviation whose angle stays constant, for a given fixation distance, wherever in the field the eyes are directed.1 In a comitant esotropia, the angle varies by no more than across the horizontal gaze positions.2
An incomitant deviation changes with the direction of gaze as a result of abnormal innervation or restriction.2 The angle of an incomitant deviation also differs according to the fixating eye.3 A new or changing incomitant deviation carries a high risk of a pathological cause and needs referral. Every strabismus examination should therefore look for incomitance.4
Most comitant strabismus has no pathological cause and can be managed in community optometric practice.4 A recently acquired comitant strabismus still needs close monitoring for signs of pathology.4
More detail
Most adults with long-standing strabismus have adapted to it and need spectacles for their refractive error only.4 Many children, however, respond to optometric treatment, and patients with a recent onset and distressing symptoms need medical investigation.4
Sources (8)
- Pickwell's Binocular Vision Anomalies, Appendices (glossary)
- Kanski, Clinical Ophthalmology (2024), ch. 18
- Pickwell's Binocular Vision Anomalies, ch. 17
- Pickwell's Binocular Vision Anomalies, ch. 15
- Albert, D.M. et al. (eds) (2022) Albert and Jakobiec's Principles and Practice of Ophthalmology. Cham: Springer International Publishing.
- Kanski, J.J. and Bowling, B. (2011) Clinical Ophthalmology: A Systematic Approach. 7th edn. Edinburgh: Elsevier/Saunders.
- Noorden, G.K. von and Campos, E.C. (2002) Binocular Vision and Ocular Motility: Theory and Management of Strabismus. 6th edn. St. Louis: Mosby.
- Rowe, F.J. (2012) Clinical Orthoptics. 3rd edn. Chichester, West Sussex: Wiley-Blackwell.
Reviewed October 2026