Study On The Growth Of Orbital During Childhood By CT And Epidemic Survey

Part Ⅰ Measurement of Orbital Volume by CT during ChildhoodObjective: The aim of this study was to construct a curve of changes in orbitalvolume that occur throughout childhood from the age of 1 to 15 years, and toanalyze the rule of its development.Methods: Using the technology of spiral CT images obtained in 110 children,orbital volume was measured and plotted against age.Results: By the time the child is 1 year old, orbital volume is on average 13.77 ±1.93 cm3 in boys and 13.10±0.23 cm3 in girls;these volumes increase to 21.51 ±3. 30 cm~3 and 19.45 ± 0. 82 cm~3, respectively, by the time the child reaches 15 yearsof age. This represents an overall increase in orbital volume by a factor of 1.6 inboys and 1.5 in girls. The differences between the two sides are not statisticallysignificant for either sex (t=0.151, P> 0.05). The change in orbital volume that isassociated with age in general displays a linear pattern (r=0.706, P<0.05) .Throughout childhood, orbital volumes are larger in boys than in girls, but share asimilar growth pattern. The difference between the two sexes tends toward statisticalsignificance after 13 years old (t=4. 871, P<0.05) .Conclusions: During childhood, the development of the orbital volume is inaccordance with the growing an developing mode of neurological system. The orbitshowed rapid growth in the first 3 years of life.Part II Development of exophthalmos degree and interorbital distance of normal children by Epidemic SurveyObjective: To investigate the developing rule of exophthalmos, interorbital distanceduring childhood. And to study their mutual relationships with orbital volume.Methods: Random sampling was performed among 3000 healthy children from theage of 1 to 15years old. Adopting epidemic survey, we used a Hertelexophthalmometer to measure the degree of exophthlamos and interorbital distance(IOD).Results: No statistically significant different is observed between boys and girls orbetween right and left eyes about the degree of exophthalmos (respectively, t=0.613,P>0. 05;*=0.673, P>0. 05). The changes of exophthalmos degree and interorbitaldistance that are both associated with age(respectively, r=0.291, P<0.05;r=\ .589,P<0.05 ) . They increase with the increase of age.Conclusions: By and large, the curves of development of exophthalmos is similarbetween boys and girls. But the sex point of intersection is found by the time thechild reaches 12 years old. The development of interorbital distance will slower after10 years old. Their development results relates close with the development of orbitalvolume.