Laboratory investigationMeasurement of Orbital Volume by Computed Tomography: Especially on the Growth of the Orbit
Introduction
Not only changes in the limited volume of tissue in the orbit, but also changes in the shape and size of the orbit, cause exophthalmos and enophthalmos.1, 2, 3 Oono4 studied the orbital volume of Japanese by actual anatomical measurement and reported it to be 26.0 cm3 and 25.9 cm3 for the right and left eyes in men and 23.1 cm3 and 23.2 cm3 in women. A figure between 25 cm3 and 30 cm3 is widely accepted. As is generally known, the orbital volume varies with race and sex.5
Attempts at measuring the orbital volume by x-ray computed tomography (CT) have been made for a long time, but results of these studies have yet to be utilized clinically.1, 6, 7 There has as yet been no report on the growth of orbital volume. Actual in vivo measurement, radiographs, and x-ray CT have been used merely as a method of one-dimensional measurement. So a great deal was expected of clinically applicable methods to measure the orbital volume and studies of basic data.8, 9, 10, 11
Using reconstructed x-ray CT images of serial coronal sections, we measured the orbital volume and studied its changes with aging. The results made it clear that a more reliable measurement of orbital volume can be made by this method. Additionally, we studied the relation between the orbital volume and age by comparing parameters that can easily be obtained in the clinical practice of ophthalmology. This article is a report of our findings.
Section snippets
Subjects
The subjects were represented by 129 radiographs from 109 patients (74 male, 35 female) who had undergone x-ray CT for the orbit mainly because of injury and whose orbit was normal on one side. There are few cases of injury in infants and not enough cases are available. So cases not likely to affect the growth of the orbit on the normal side, such as a case of retinoblastoma involving one eye, were added to the subjects. CT was performed twice at intervals of about 2 weeks after surgery on a
Reproducibility of Orbital Volume and Laterality
Table 1 represents the results of measurements of the orbital volume on the normal side before and after surgery in the fracture group, and the orbital volume on both sides in the normal group. The difference between the two measurements in the fracture group stood at 0.09 ± 0.69 (mean value ± SD) cm3 and no significant difference was found, which showed the reproducibility of this measurement to be good. The laterality in the normal group stood at 0.06 ± 0.56 (mean value ± SD) cm3; the
Discussion
Studies on the orbital volume using CT images have been reported since the mid-1980s, and the diagnostic and clinical usefulness of the data obtained has been recognized. However, most of the reports dealt with eyes with a blowout fracture of the orbit or thyroid ophthalmopathy,13, 14 and studies on the normal orbit are few.6 With the measurement of orbital volume using sections of CT images, the extent of measurement anterior to the orbit differs from one section to another according to the
Conclusions
- 1.
Using x-ray CT images of 109 cases, 129 examinations, we measured the volume of the normal orbit and charted its growth.
- 2.
Serial coronal sections in 2-mm thick slices ranging from the lacrimal fossa to the optic canal were used in the measurement of orbital volume.
- 3.
The reproducibility of the measurements was good.
- 4.
No laterality of the orbital volume was found.
- 5.
Orbital volume strongly correlated with height and interlateral orbital rim distance, suggesting the possibility that orbital volume can be
Acknowledgements
This paper was published in Japanese in the Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 2000;104:724–30. It appears here in a modified form after peer review and editing for the Japanese Journal of Ophthalmology.
References (16)
- et al.
Diagnostic imaging of craniofacial fractures
Radiol Clin North Am
(1989) - et al.
Orbital volume measurements in enophthalmos using three-dimensional CT imaging
Ophthalmic Plast Reconstr Surg
(1984) - et al.
Studies on enophthalmos. The measurement of orbital injuries and their treatment by quantitative computed tomography
Ophthalmic Plast Reconstr Surg
(1986) Untersuchungen über die orbita von Japanern
Jpn J Med Sci
(1927)- Albert DM, Jakobiec FA. Principles and practice of ophthalmology clinical practice. Philadelphia: WB Saunders,...
- et al.
Volume measurements of normal orbital structures by computed tomographic analysis
AJR Am J Roentgenol
(1985) - et al.
Measurement of orbital volumes following trauma using low dose computed tomography
Eur Radiol
(1993) - et al.
Growth patterns in the orbital regiona morphometric study
Cleft Palate-Craniofac J
(1992)
Cited by (111)
Quantitative assessment of bony orbital volume symmetry: CT analysis in the uninjured caucasian population
2022, British Journal of Oral and Maxillofacial SurgeryDo Racial Differences in Orbital Volume Influence the Reconstruction of Orbital Trauma
2022, Journal of Oral and Maxillofacial SurgeryCitation Excerpt :Similarly, Japanese males have also been shown to have larger OV than females.45 The findings from this study appear to support current literature.20,45 The reasons for the differences in OV between genders is unclear.
Influence of eye movement on lens dose and optic nerve target coverage during craniospinal irradiation
2021, Clinical and Translational Radiation OncologyThree-dimensional periorbital asymmetry assessment of congenital microphthalmia children with a structured light 3D scanning system
2021, Journal of Cranio-Maxillofacial SurgeryAging of the facial skeleton
2021, Aesthetic Surgery of the Facial SkeletonComparative radiological assessment of orbital volume restoration following management of zygomatic complex fractures
2020, Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology