DETERMINATION OF THE NORMAL RANGE OF EXOPHTHALMOMETRIC VALUES FOR BLACK AND WHITE ADULTS MICHAEL E. MIGLIORI, M.D., AND GEOFFREY J. GLADSTONE, M.D. Detroit, Michigan We used the Hertel exophthalmometer to measure the degree of protrusion in 681 adults, ranging in age from 18 to 91 years. The 327 white and 354 black subjects had no history of orbital or endocrine disease, severe myopia (more than —7 diopters), or buphthalmos. The mean normal protrusion values were 16.5 mm in white men, 18.5 mm in black men, 15.4 mm in white women, and 17.8 mm in black women. Although protrusion values above 21 mm are usually considered abnor- mal, we found that the upper limits of normal were 21.7 mm for white men, 24.7 mm for black men, 20.1 mm for white women, and 23.0 mm for black women. These differences were statistically significant (P <.025). No individual had more than 2 mm of asymmetry between eyes. The orbit is a rigid box capable of expanding only anteriorly. Therefore, any increase in intraorbital volume re- sults in forward displacement of the eye or exophthalmos. The degree of protru- sion of the eye is an important clinical sign in orbital disease. For the purposes of this study, we used the term protru- sion when referring to the normal amount of protrusion of the eye, and the term exophthalmos when referring to abnor- mal forward displacement of the globe. Protrusion is usually measured from the deepest part of the lateral orbital rim to the apex of the cornea. The absolute value is the amount of protrusion com- pared to a given standard. The relative value is the asymmetry of protrusion be- tween the two eyes of the same individu- al. The comparative value is the change in an individual over a period of time. Accepted for publication Aug. 1, 1984. From the Department of Ophthalmology, Sinai Hospital of Detroit, Detroit, Michigan. Reprint requests to Geoffrey J. Gladstone, M.D., 29275 Northwestern Highway, Suite 100, Southfield, MI 48034. The normal limit of protrusion is tradi- tionally considered to be 21 mm. 1 This does not take into account racial or sexual differences in orbital anatomy. Several reports 2,3 have stated that blacks have a higher mean protrusion value than whites, but these studies have either been limited in scope or lacking in good statistical analysis. We undertook a study to determine the normal ranges of protru- sion in white and black adults of both sexes. We also looked at the asymmetry of protrusion between the eyes of each indi- vidual to determine the upper limit of normal for the relative value. SUBJECTS AND METHODS We used the Hertel exophthalmometer to measure the degree of protrusion in 681 consecutive, randomly selected adults, ranging in age from 18 to 91 years. There were 127 white men, 113 black men, 200 white women, and 241 black women. None had orbital disease, trau- ma, surgery, endocrine disease, myopia (of more than —7 diopters), buphthalmos, or any obvious external ocular disease. We took all readings with the same in- 438 ©AMERICAN JOURNAL OF OPHTHALMOLOGY 98:438^142, 1984