Abstract
Purpose:
The purpose of this study was to describe the clinical characteristics and natural history of convergence insufficiency (CI) in a population-based cohort of adults.
Methods:
The medical records of all adult (>18 years of age) residents of a well-defined population diagnosed with CI over a 20-year period, were retrospectively reviewed.
Results:
A total of 118 adults (annual incidence of 8.44 per 100 000 patients older than 18 years) were diagnosed with CI during the 20-year period, comprising 15.6% of all forms of adult-onset strabismus observed in this population. The mean age at diagnosis was 63 years (range, 21.7 to 97.1 years) and 68 (57.6%) were female. There was a significant increase in incidence (p < 0.001) with increasing age. The mean initial exodeviation was 14 PD at near and 1.7 PD at distance. The Kaplan Meier probability of the near exodeviation increasing by 5 PD or more was 10.7% at 5 years, 19.3% at 10 years, and 22.8% at 15 years. Approximately 75% were managed with prisms while less than 5% underwent surgical correction.
Conclusions:
Adult-onset convergence insufficiency comprised approximately 1 in 6 adults who were newly diagnosed with strabismus in this 20-year cohort. There was a significant increase in incidence with increasing age. Nearly one-fourth had an increase of their near exodeviation of at least 5 PD by 15 years after their diagnosis and most patients were managed conservatively.