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V pattern

A V pattern is a horizontal strabismus that changes with vertical gaze, so the eyes are relatively more divergent in upgaze and more convergent in downgaze. In V esotropia the deviation increases in downgaze and decreases in upgaze, and in V exotropia the deviation increases in upgaze and decreases in downgaze.1

The superior rectus and inferior oblique share elevation, and the inferior rectus and superior oblique share depression. A V pattern appears when these contributions are abnormal and the balance of their horizontal vectors in upgaze and downgaze is deranged. Displaced rectus muscle pulleys can produce the same effect.2 Causes include inferior oblique overaction with a fourth nerve palsy, superior oblique underaction with later inferior oblique overaction, superior rectus underaction, Brown syndrome, and craniofacial anomalies with shallow orbits and downslanting palpebral fissures.2

The examiner compares the alternate cover test in upgaze and downgaze, and names the pattern eso or exo from the deviation in primary position.3 A V pattern is significant when the difference between upgaze and downgaze is 15 prism diopters or more.1,2 The threshold is higher than the 10 prism diopters used for an A pattern because a V pattern of about 5 prism diopters is a normal variant.3,1

More detail

The deviation is best measured at 33 cm with the refractive error fully corrected, with the eyes in 25° of elevation and 35° of depression while fixating an accommodative target.1 The 15 prism diopter threshold establishes vertical incomitance, and functional significance depends on how much the pattern disturbs binocular vision in primary position and downgaze, the reading position. An asymptomatic V exotropia of 15 prism diopters in upgaze, with orthotropia and normal binocular vision in downgaze, is clinically insignificant.1

In infantile esotropia with superior oblique underaction, the eyes are often straight in upgaze with a marked esodeviation in downgaze.2 Related variants include the X pattern, with little deviation in primary position and exotropia in upgaze or downgaze, and the Y pattern, with exotropia only in upgaze. Both are modifications of the classic A and V patterns and are not separate entities.1

Sources (10)
  1. von Noorden and Campos, Binocular Vision and Ocular Motility, ch. 19
  2. Kanski, Clinical Ophthalmology (2024), ch. 18
  3. Eperjesi and Rundström, Practical Binocular Vision Assessment, ch. 8
  4. American Academy of Ophthalmology. 2020. Pediatric Ophthalmology/Strabismus: Basic and Clinical Science Course. San Francisco: American Academy of Ophthalmology.
  5. Ansons, A.M. and Davis, H. eds. 2014. Diagnosis and management of ocular motility disorders. 4th ed. Oxford: Wiley-Blackwell.
  6. Kushner, B.J. 2010. Surgical treatment of vertical strabismus. Journal of AAPOS, 14(1), pp.27-33.
  7. Noorden, G.K. and Campos, E.C. 2002. Binocular vision and ocular motility: theory and management of strabismus. 6th ed. St. Louis: Mosby.
  8. Rutstein, R. and Daum, K. 1997. Anomalies of Binocular Vision: Diagnosis & Management. St. Louis: Mosby.
  9. Rowe, F.J. 2012. Clinical orthoptics. 3rd ed. Oxford: Wiley-Blackwell.
  10. Von Noorden, G.K. and Campos, E.C. 2002. Binocular vision and ocular motility: theory and management of strabismus. 6th ed. St. Louis: Mosby.

Reviewed October 2026

Related terms

Nearby in the glossary

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