Prevalence of Strabismus in the US and Globally
Strabismus affects approximately 4% of adults in the United States, with varying prevalence rates globally ranging from 1.9% to 2.65% depending on population and region. 1
US Prevalence Data
Children
- In the Baltimore Pediatric Eye Disease Study:
- 3.3% of white children and 2.1% of African American children aged 6-71 months had manifest strabismus 2
- Higher rates (5.8% for whites and 2.9% for African Americans) were observed in children 60-71 months of age 2
- National projections suggest approximately 677,000 cases of manifest strabismus among US children 6-71 months 2
Adults
- The estimated incidence is 4% in the adult population 1
- New-onset adult strabismus has an annual incidence of 6.0 per 100,000 people, with divergence insufficiency representing 10.6% of these cases 1
- Sagging eye syndrome as a cause of acquired diplopia increases with age:
- Less than 5% under age 50
- Up to 60% over age 90 1
Global Prevalence
A comprehensive systematic review and meta-analysis of global strabismus prevalence found:
- Pooled global prevalence of any strabismus: 1.93% (1.64-2.21%) 3
- Exotropia prevalence: 1.23% (1.00-1.46%) 3
- Esotropia prevalence: 0.77% (0.59-0.95%) 3
Regional Variations
- Significant regional differences exist in strabismus prevalence worldwide 3
- In Japan, strabismus fixus has been estimated at 2.65% among high myopes 1
- The prevalence varies by WHO region, which was identified as a significant factor affecting heterogeneity in strabismus rates 3
Age and Demographic Factors
- Age significantly affects the prevalence of exotropia 3
- Divergence insufficiency typically presents after age 50 and increases with age 1
- Median age of presentation for divergence insufficiency is 74 years 1
- Divergence insufficiency is significantly more common among Caucasian women 1
- Sagging eye syndrome occurs more frequently in females (54%) and myopes, with most patients presenting between 60-80 years of age 1
Common Types of Strabismus
In a population-based study in Olmsted County, Minnesota, the most common forms of childhood strabismus were:
- Accommodative esotropia (27.9%)
- Intermittent exotropia (16.9%)
- Acquired nonaccommodative esotropia (10.2%)
- Esotropia in children with abnormal central nervous system (7.0%)
- Convergence insufficiency (6.4%) 4
Clinical Implications
Strabismus has significant impacts on quality of life:
- Children with strabismus show reduced functional vision and eye-related quality of life 5
- Parents of children with strabismus also experience reduced quality of life 5
- The greatest differences between children with strabismus and visually normal controls were in functional vision domains 5
Important Considerations
- Prevalence estimates vary based on study methodology, definitions of strabismus, and populations studied
- Publication year affects heterogeneity in exotropia prevalence, suggesting changing patterns over time 3
- Early identification and treatment are important as strabismus can impact visual function, binocularity, and psychosocial development
- Strabismus in adults often does not resolve spontaneously and may be progressive, particularly strabismus fixus 1