Ophthalmic changes from age of 10 to 18 years. A longitudinal study of sequels to low birth weight. II. Visual acuity.

Re-examination of corrected visual acuity was done in 137 18-year-old Danes, who were originally examined at the age of 10 years, as part of a study of sequels to low birth weight (LBW) (Fledelius 1976). Median values indicate that most adolescents are able visually to discriminate considerably above the customary 6/6 limit. As compared with low-birth-weighters (n=70), full-terms (n=67) show a significantly higher cumulated visual acuity score. Similarly, binocular median visual acuities are 1.2 (LBW) and 1.4 (in FT). The difference is neither explained by the ex-prematures' higher frequency of heterotropia, nor by their (minor) share of eyes with subnormal vision. The latter occurred especially in the subgroup of 'myopia of prematurity'. The exceptional cases with RLF-blindness were discarded from follow-up. Concerning visual acuity, the previously reported lagging behind of ex-prematures in childhood has proven to be not only a temporary delay, but a permanent (adult) feature.