Abstract
Purpose: :
Although strabismus is a commonly recognized disorder of childhood, there are few population-based data on new-onset strabismus in adults. The purpose of this study was to report the incidence of adult-onset strabismus in a geographically defined population.
Methods: :
The medical records of all adults (>18 years) residing in Olmsted County, Minnesota when newly diagnosed with any form of strabismus from January 1, 1985, through December 31, 2004, were retrospectively reviewed.
Results: :
A total of 754 adults were identified as being newly diagnosed with strabismus during the twenty-year period, yielding an overall age- and sex-adjusted annual incidence of 54.2 per 100,000 persons (95% CI 50.2, 58.1). The median age at diagnosis was 65.2 years (range, 19.2-99.6 years) and 413 (54.8%) were female. The predominant deviation was esotropia in 266 (35.3%), exotropia in 248 (32.9%), and hypertropia in 240 (31.8%) individuals. The four most common types of new-onset strabismus were paralytic strabismus (39.3%), convergence insufficiency (15.6%), unspecified hypertropia (12.9%), and divergence insufficiency (10.6%). For the paralytic group (n=296), 145 (49.0%) had 6th nerve palsy, 90 (30.4%) had 4th nerve palsy, 51 (17.2%) had 3rd nerve palsy, and 10 (3.4%) had another paralytic deviation. Using Poisson regression models, the overall incidence of strabismus and of its four most common types increased with age (p < 0.001 for all comparisons).
Conclusions: :
The incidence of adult strabismus increases significantly with age and paralytic strabismus is the most common form. In contrast to childhood strabismus, in which esotropia predominates over other forms, esotropia, exotropia, and hypertropia were equally represented among newly presenting adult strabismus cases in this population.
Keywords: strabismus: etiology • neuro-ophthalmology: diagnosis