What are the most common causes of strabismus (crossed eyes)?

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From the Guidelines

The most common causes of strabismus in adults include recurrent, decompensated, or unresolved childhood strabismus, sensory strabismus, convergence insufficiency, and divergence insufficiency, as well as conditions such as Graves’ disease, orbital trauma, and cranial nerve palsies. According to the most recent study on adult strabismus, published in 2024 in the journal Ophthalmology 1, these causes can lead to misalignment of the eyes and may result in binocular diplopia. The study highlights that accurate diagnosis of the etiology of strabismus in an adult requires expertise to recognize associated signs and symptoms and familiarity with studies that may confirm the diagnosis.

Some of the notable causes of strabismus in adults, as outlined in the study, include:

  • Recurrent, decompensated, or unresolved childhood strabismus
  • Sensory strabismus
  • Convergence insufficiency
  • Divergence insufficiency
  • Sagging eye syndrome
  • Strabismus associated with high axial myopia
  • Graves’ disease
  • Orbital trauma
  • Strabismus associated with other ophthalmic surgery
  • Cranial nerve palsies, such as 4th nerve palsy, 6th nerve palsy, and 3rd nerve palsy
  • Myasthenia gravis
  • Fixation switch diplopia
  • Foveal misregistration (binocular central diplopia)

The study also notes that the goals of treatment should be broader and include sensory recovery when possible, as well as gains in psychosocial and functional domains of vision-related quality of life 1. Success rates for treatment vary widely depending on the type of strabismus, but overall, they are approximately 80% after one procedure and may exceed 95% if a second procedure is performed on eyes failing the first intervention 1.

From the Research

Causes of Strabismus

The most common causes of strabismus include:

  • Congenital esotropia, which is the most common type of strabismus, typically characterized as a large angle, constant esotropia with onset during the first six months of life 2
  • Comitant esotropia, which is most commonly a childhood condition treated with glasses and surgery 3
  • Comitant exotropia, which is often a childhood condition that may require surgical correction 3
  • Microvascular disease, which is the most common cause of ocular cranial nerve palsies in adult patients 3

Strabismus in Specific Populations

In children with cerebral palsy, strabismus of congenital esotropia type is common, as is exotropia of early onset 4 In patients with cerebral palsy, esotropia is the most common ocular misalignment, and strabismus surgery should be considered for psychosocial reasons as well as for potential successful ocular realignment and restoration of binocular vision 5

Genetic Contribution to Strabismus

Family, population, and twin studies all support a role of genetics in the development of strabismus, although its precise genetic mechanisms have not yet been defined 6 Genome-wide association studies have identified two risk loci and three copy number variants in white populations, and causative genes have been identified in congenital cranial dysinnervation disorders 6

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Congenital esotropia.

Survey of ophthalmology, 1987

Research

Strabismus.

Primary care, 2015

Research

Strabismus in children with cerebral palsy.

Acta ophthalmologica Scandinavica, 1996

Research

Strabismus in cerebral palsy: when and why to operate.

The American orthoptic journal, 2014

Research

Genetics of strabismus.

Frontiers in ophthalmology, 2023

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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