Objective: To investigate the normal value of six parameters of head and eye in Chinese children, including interorbit distance (IOD), interpupillary distance (IPD), superior otobasion-ectocochion distance (obs-ec), intersuperior otobasion distance (obs-obs), exophthalmos and nasal basis angle, for stipulating the sizes of children spectacle frames.
Methods: The value of these six parameters in 10 171 children ages 5 to 17 years old were measured with caliper in four cities and the results were analyzed.
Results: The IOD, IPD, obs-ec and obs-obs were increased and positively correlated with the age. The differences of these parameters among different ages were statistically significant (F = 0.97, P < 0.01), especially in IPD before 15, IOD before 13, obs-ec and obs-obs before 12 and exophthalmos before 12 years old. The fastest growth age in IPD, IOD, exophthalmos, obs-ec and obs-obs was 10, 11, 5, 7 and 11 years old, respectively. The growth period of IPD, IOD, exophthalmos, obs-ec and obs-obs was 5 - 15, 5 - 13, 5 - 8, 5 - 12 and 5 - 15 years old. The difference of these six parameters among children in 4 cities were statistically significant (t = 3.1, P < 0.01).
Conclusions: The most active growth period of IPD, IOD, obs-obs, obs-ec and exophthalmos lies between 5-15 years old in Chinese children 5-17 years old. Although the differences of these six parameters between male and female and among children in four cities are statistically significant, practically they are not important for stipulating the sizes of children's spectacle frames.