A comparison of interpupillary distances between Turkish and Azerbaijani populations

Abstract

Background: Differences in far interpupillary distance (IPD) in Turkish and Azerbaijani adults of the same ethnic background from different age groups were examined to investigate the effects of ethnicity, genetics, geography, and environmental factors on IPD. Methods: A total of 1,400 healthy individuals aged ≥18 years were enrolled. The far IPD of each individual was determined in both communities. IPD data for 700 subjects in Azerbaijan and 700 subjects in Turkey was analyzed. Males and females were divided into six age ranges: 18–24, 25–34, 35–44, 45–54, 55–64, and ≥65 years. Far IPD data in Turkey and Azerbaijan was collected using two types of autorefractometers: Topcon RM 8800 and Topcon TRK-2P.Results: The mean age of the 700 subjects in Turkey was 44.5 ± 17.6 years. The mean IPD was 62.1 ± 3.7 mm. The mean IPD in females was 61 mm, which was less than males (63 mm) (P < 0.05). The mean age of the 700 Azerbaijani subjects was 44.0 ± 15.6 years. The mean IPD of the subjects was 65.0 ± 3.1 mm. The mean IPD (64 mm) in females was significantly lower than the mean IPD (66 mm) in males (P < 0.05). Differences in IPD between age groups in both communities were statistically significant (P < 0.05). The mean IPD in all age groups in the Azerbaijani population was greater than that of the Turkish population. Compared with other ethnic groups, the mean IPD in the Azerbaijani population was remarkably high.Conclusions: When mean far IPD values in individuals aged ≥18 years in the Azerbaijani and Turkish populations were compared, statistically significant differences were observed. In Azerbaijani Turks, mean IPD values in both males and females were greater than those observed in the Turkish population in all age groups. The mean IPD values of the Azerbaijani population were greater than those of other ethnic groups when classified by both age and sex. As well as ethnicity, geographical and environmental factors influenced far IPD values.