Prevalence of posterior vitreous detachment in high myopia.

BACKGROUND: Posterior vitreous detachment is known to develop early in high myopia. However, the prevalence of posterior vitreous detachment in relation to patient age and degree of myopia has not been studied by modern vitreous examination methods.
METHODS: The vitreous conditions of 224 eyes with high myopia (> -6 diopters [D]) were examined biomicroscopically with a +90-D present lens and a Goldmann three-mirror contact lens. The vitreous conditions of 220 eyes with emmetropia (between -1 and +1 D) also were studied and served as controls.
RESULTS: In high myopia, no patients 29 years of age or younger had posterior vitreous detachment. Thereafter, the prevalence of posterior vitreous detachment increased with age (i.e., 23%, 29%, 44%, and 72% in the fourth through seventh decades, respectively, and 100% of patients 70 years or older). Moreover, posterior vitreous detachment developed earlier in severe high myopia (> -10 D) than in moderate high myopia (> -6 to -10 D). In emmetropia, no patients 39 years of age or younger had posterior vitreous detachment, and its prevalence also increased with age (i.e., 8%, 23%, 44%, 74%, and 86% in the fifth through ninth decades, respectively).
CONCLUSION: In high myopia, posterior vitreous detachment develops increasingly with age and degree of myopia. Although the sample size in each age group was small, the results suggested that posterior vitreous detachment may develop nearly 10 years earlier in highly myopic than in emmetropic eyes.