Measurements of orbital volume using cone-beam computed tomography in eye movement abnormalities.

PURPOSE: To measure the orbital volume in adult patients with unilateral eye movement abnormalities originating in childhood.

METHODS

Cone-beam computed tomography was performed in 2 patients with eye movement abnormalities. A 28-year-old woman was treated because of right divergent squint originating at 8 years of age after penetrating corneal trauma. A 38-year-old man was examined because of abnormal head posture caused by left superior oblique underaction originating at 6 years of age. Orbital scans were analyzed with Cranioviewer 3D craniofacial cephalometric program. We measured bony orbital area in 6 slices (in ventro-dorsal direction per 4.8 mm) in every orbit on coronal scans.

RESULTS

The volume was more in the orbit with unilateral divergent squint and less in the orbit with unilateral superior oblique underaction compared to the contralateral orbital volume measurements.

CONCLUSION

Cranioviewer 3D craniofacial cephalometric program is suitable for volumetric analysis of the bony orbit on cone-beam computed tomography files. The development of the orbit can be influenced by extraocular muscle movements.