Normal canthal index and intercanthal dimensions in Saudi Arabian young men and boys of semitic origin

ABSTRACT

Knowledge of the normal dimensions of interocular and intercanthal distances in the local population could be helpful in syndrome diagnosis. In order to establish baseline standard values, we measured interpupillary distance [IPD], inter-inner-canthal and inter-outer-canthal distances, and calculated the canthal index [CI] in 200 boys [age 6 to 15 years] and 200 young men [age 16 to 22 years], phenotypically normal and of Saudi Arabian Semitic [as opposed to African] descent. A projected photographic technique was used. Average IPD for boys was 53.3 mm [range 50.6 to 60.1 mm; standard error of mean [SEM] 2.7 mm], and for young men 63.6 mm [range 62.1 to 65.2 mm; SEM 1.2 mm]. Average CI for boys was 39.1 [range 32.1 to 45.2; SEM 2.5], and for young men 36.9 [range 27.3 to 43.9; SEM 2.9]; this was higher than in comparative populations of North American Caucasian, African American, and Japanese descent. The underlying reason was found to be a relative ocular hypotelorism in the examined local population. Regression equations for the measured variables are offered. We also found that physically measured IPD was not significantly different from the IPD calculated mathematically