Purpose
To report the prevalence and causes of amblyopia among children with ptosis diagnosed in a well-defined population over a 40-year period.
Design
Retrospective, population-based cohort study.
Methods
We retrospectively reviewed the charts of one hundred and seven patients (< 19 years) for the prevalence and causes of amblyopia who were diagnosed with childhood ptosis as residents of Olmsted County, Minnesota, from January 1, 1965, through December 31, 2004.
Results
Amblyopia was diagnosed in 16 (14.9%) of the 107 patients with childhood ptosis. Fourteen (14.6%) of 96 patients diagnosed with a congenital form of ptosis demonstrated amblyopia. Twelve (14.8%) of the 81 patients diagnosed with simple congenital ptosis had amblyopia, 7 (8.6%) of which were due solely to eyelid occlusion of the visual axis. The causes of amblyopia in the remaining 5 patients were due to significant refractive error in 3 patients and strabismus in 2 patients.
Conclusions
Amblyopia occurred in 1 in 7 children diagnosed with ptosis in this population-based cohort. Approximately half of those with amblyopia, or less than 10% of all patients, were due solely to eyelid occlusion of the visual axis.