Age of first distance prescription and final myopic refractive error.

PURPOSE: This study explores the relationship between the recalled age of first distance prescription and the final myopic refractive error developed in adults.

METHODS

Adult office workers, sent for a general health check-up without refractive selection, completed a questionnaire about age of first distance prescription, years of university study, and parental history of myopia, and were subjectively refracted by an ophthalmologist.

RESULTS

Average age of the 397 consecutive myopic subjects was 42.6 +/- 9.6 years and 80.6% were males. The median age of first prescription was 20 years. In the group with earlier first distance prescription (ages 3 to 10), 25.6% developed low final refractive errors (-0.50 to -3.0 diopters), 38.5% developed moderate myopia (< -3.0 to -6.0 diopters), and 35.9% developed high myopia (< -6.0 diopters), while in the groups with later first distance prescription (ages 23 to 30), 90-100% developed low final refractive errors.

CONCLUSIONS

Subjects developing myopia after age 20 had low myopia. Those subjects with an early recalled age of first prescription had a broad spectrum of myopic refractive errors, including a high proportion (approximately 2/3) of moderate to high myopia, and approximately 1/3 of low myopia.