Normal values for inner intercanthal, interpupillary, and outer intercanthal distances in the Indian population

The purpose of this study was to establish a set of normal values for inner intercanthal distance (IICD), interpupillary distance (IPD) and outer intercanthal distance (OICD) in a normal Indian population aged 3-80 years and to find whether the difference between the values of these parameters is statistically significant. We also aimed to compute a regression equation for calculating these. Two thousand five hundred clinically normal Indians were enrolled in the study. A millimeter scale was used to measure IPD and IICD. OICD was measured from the bar reading of Hertel's exophthalmometer. Statistical methods were used to calculate the mean and standard deviation values for these parameters. T-test was applied to determine whether difference between the mean values for these parameters in both sexes was statistically significant or not. A regression equation was also computed to find the values for these parameters in both sexes. The IICD, IPD and OICD ranges for males were 20-36 mm, 46-70 mm and 76-105 mm, and for females 20-36 mm, 46-75 mm and 71-105 mm, respectively The difference between the mean values for these parameters was statistically significant in some age groups but not in others. Gender did not usually influence the normal values for IICD, IPD and OICD in the Indian population. The normal values of these parameters were usually lower than those observed for other races. A knowledge of normal values in this population subgroup can help in studying orbito-cranial growth patterns, syndrome diagnosis, surgical management of cranio-facial deformities and trauma, and manufacture of spectacles.