Normal Ocular Protrusion Values in South Indian Population and Effect of Age, Gender and Refractive Status on Ocular Protrusion

AIM: To determine the absolute and relative ocular protrusion values in normal south Indian population, and its relation to age, gender and type of refractive error. METHODS: A total of 387 subjects aged 7–70 years were included in this study. Both right and left absolute ocular protrusion values were measured by a single physician using Luedde exophthalmometer in primary gaze. Right eye ocular protrusion data were used for reporting the absolute ocular protrusion values, and difference between right and left eye absolute ocular protrusion values of the same individual was used to report the relative ocular protrusion values. Subject age was grouped as decades. Measurement values were evaluated by descriptive and inferential statistics. RESULTS: The mean absolute ocular protrusion of right eye was 14.67 ± 1.70 mm and left eye was 14.32 ± 1.75 mm. The mean right absolute ocular protrusion values from 1st to 7th decade were 12.73 ± 1.21 mm, 14.8 ± 1.25 mm, 15.79 ± 1.31 mm, 15.77 ± 1.36 mm, 15.87 ± 1.28 mm, 15 ± 1.03 mm and 14.36 ± 0.88 mm respectively. One-way analysis of variance showed that there was a significant difference in the ocular protrusion among the age groups (p < 0.005). The mean relative ocular protrusion was 0.35 ± 0.64 mm. The type of refractive error (up to ±6.00D) has no significant effect on the absolute ocular protrusion values and showed a weak correlation between magnitude of myopia and hyperopia on absolute ocular protrusion. There was a statistically significant difference in absolute ocular protrusion among the female and male subjects. CONCLUSION: Age and gender seems to significantly influence the absolute ocular protrusion and need to be considered for clinical evaluation of bilateral proptosis. The refractive error up to ±6.00D seems to have no significant effect on the absolute ocular protrusion.