RESUMO
Purpose: to determine normal values of Hertel exophthalmometry in children, teenagers, and adults in Tehran
Methods: in a population-based epidemiological study, ocular protrusion was measured in 1063 randomly selected [stratified sampling method] normal subjects of Tehran. Hertel exophthalmometry was performed in all by a single oculoplastic surgeon. Subjects were divided into 3 age groups: children [6-12 years], teenagers [13- 19 years], and adults [20-70 years]. Data were analyzed using two-tailed paired t-test, independent sample t-test and linear regression test
Results: the age range was 6 to 70 years [mean 20.3 +/- 10 .9] and 601 [56.5%] were male. Mean absolute exophthalmic value was 14.2 +/- 1.8 mm in children, 15.2 +/- 1.9 mm in teenagers, and 14.7 +/- 2.3 mm in adults. Increase in age had a statistically significant effect on the exophthalmic value [r = +0.32 for children, +0.01 for teenagers, and -0.30 for adults; P<0.01]. Relative exophthalmic value was less than 2 mm in all subjects
Conclusion: the normal exophthalmic value had positive correlation with increase in age up to 20 years old and negative correlation thereafter. There was a positive correlation between the base and increase in age of all age groups