Exophthalmometric values in a normal Indian population.

PURPOSE. The purpose of this study was to establish a set of exophthalmometric values in a normal Indian population and to compute a regression equation for calculating these values. METHODS. Twenty-five-hundred clinically normal Indians of both sexes in the age group of 3-80 years, who did not have local or systemic disease likely to affect orbital or ocular structures, were enrolled in this study. Hertel's exophthalmometer was used to measure the degree of protrusion of the eyes. Statistical methods were used to calculate the mean values in the right and left eye in either sex and to compute a regression equation for calculating the exophthalmometric values. RESULTS. The range of exophthalmometric values in a normal Indian population aged 3-80 years was 7-19 mm for males and 7-21 mm for females. The exophthalmometric values were higher in the first decade, decreased in the second decade, and increased again in the third decade. They then remained stable for the next three to four decades. The peak was reached in the seventh decade in males and in the sixth decade in females. The lowest values in both sexes were attained in the eighth decade. The regression equations for the calculation of the exophthalmometric values are: In males for the right eye: Exophthalmometric value = 12.43 + 0.25 x age; In males for the left eye: Exophthalmometric value = 12.30 + 0.029 x age; In females for the right eye: Exophthalmometric value = 13.30 - 0.003 x age; In females for the left eye: Exophthalmometric value = 13.17 - 0.0003 x age. CONCLUSIONS. The trend of the normal exophthalmometric values for Indian subjects, by and large, was found to be similar to that quoted for other races. A knowledge of the normal values for this population subgroup can help clinicians in the early diagnosis and follow-up of patients with endocrine diseases, orbital tumors, craniofacial trauma and deformities and severe myopia.