Prevalence of dissociated strabismus in children with ocular misalignment: A population-based study

Purpose The purpose of this study was to report the prevalence of dissociated strabismus among a population-based cohort of children diagnosed with all forms of ocular misalignment. Methods The medical records of all children (<19 years of age) identified by the resources of the Rochester Epidemiology Project who were diagnosed with strabismus while residing in Olmsted County, Minnesota, from January 1, 1985, through December 31, 1994, were retrospectively reviewed for the prevalence of dissociated vertical (DVD) or horizontal (DHD) deviations. Results Of 627 children with strabismus, 12 (1.9%) were found to have DVD at their initial diagnosis at a mean age of 52 months (range, 3.5-206 months). During a mean follow-up of 10.4 years (range, 1-20 years), an additional 44 children were diagnosed with DVD, yielding a total of 50 children (7.9%). The common strabismus subtypes with the highest prevalence of DVD were, in declining order, congenital esotropia (53%), esotropia in the setting of a developmental deficit (25%), and accommodative esotropia (3.4%). None of the subjects were recorded as having DHD. Conclusions In this patient cohort, DVD was relatively uncommon and occurred most frequently among those with early-onset strabismus and strabismus in the setting of a developmental deficit.