Nearpoint phoria changes associated with the cessation of childhood myopia progression.

BACKGROUND: A convergent (eso) shift in near phoria associated with the onset of myopia has been reported.

METHODS: Data from two Midwestern United States optometry practices were used to assess whether the near phoria shifted back in the divergent (exo) direction after the cessation of childhood myopia progression. Data were collected for myopic children who had three or more examinations before the age of 15 years and at least one examination after the age of 17 years.

RESULTS: Refractive error data were used to calculate an index of the age of cessation of childhood myopia progression. The phoria at the first examination after the cessation age was designated as the baseline and was normalized to zero. For all previous and subsequent examinations, the changes in phoria with respect to the baseline phoria were calculated. The phoria at the examination just after the cessation age was significantly more divergent than those at the first, third, and fourth examinations prior to the cessation age (1.1, 1.4, and 1.7 prism diopters, respectively). The third visit after the cessation age was 1.8 prism diopters more divergent than the first visit after the cessation age. Thus, these data showed an exo shift in near phoria after the cessation of childhood myopia progression.