Correlation Between Height and Width of Orbital Opening Among the Igbo Ethnic Group of Nigeria: A Radiologic Study

The orbit is roughly pyramidal in shape with the apex located posteriorly forming the optic canal and the base located anteriorly forming the orbital margin. The orbital margin has the form of a quadrilateral with rounded corners. The aim of this study was to investigate the correlation between orbital height and width among the Igbo ethnic group of Nigeria. A total number of 350 radiographic films of subjects aged between less than one year and seventy nine years (<1year – 79years) were collected, comprising of 217 males and 133 females, from the National Orthopaedic Hospital, Enugu, Nigeria. The orbital height was measured from the frontal film as the maximal distance between the superior and inferior orbital margins. The orbital width was also measured from the same frontal film as the maximal distance between the medial and lateral orbital margins. The data gathered were presented in scattergrams and analyzed using Microsoft excel, version 2007. The coefficients of correlation and determination were determined. The significance of correlation was also calculated and was considered statistically significant at 95% confidence level (that is when P<0.05). The result showed that there is a strong positive correlation between orbital height and width with correlation coefficient of 0.7 which was statistically significant (P<0.05). For the first time, it was shown that when one of the parameters of the orbital opening (orbital height or width) is known, a rough estimate could be made of the other parameter with some degree of accuracy. It is recommended that since there are racial discrepancies in orbital dimensions, similar study be carried out in other populations so as to assist surgeons in their practice.

Key Words: orbital height, orbital width, correlation, Igbo ethnic group