Changes in eye position during growth and adult life as based on exophthalmometry, interpupillary distance, and orbital distance measurements.

The association between eye position and age is analysed in a material comprising 267 subjects aged 5-20 years and 187 aged 21-80. The study was prompted by a previous longitudinal finding of a 3 mm increase in exophthalmometry value from age of 10 to 18 years, and by a literature almost devoid of similar investigations in young age groups. The increase in Hertel value during growth could be confirmed. An adult mean value of 16.0 mm in females and 16.6 mm in males was achieved in late teen-age years, the level being stable after that. The adult range was 11-23 mm. After a similar marked increase in the young, interpupillary distance and orbital width also showed some slight trends in adults. A suggested decrease in orbital width towards old age was consistent with a secular trend, while a concomitant increase in interpupillary distance was unexpected, the combined result being a more divergent (relative) eye position with age (P less than 0.01). There was no significant correlation between exophthalmometry and refractive value. Fixed upper Hertel value limits of normal are hard to give; clinically it is the changes that matter. Modelling of facial bony structures and soft tissue contours is discussed.