Estimation of the Eyeball and Orbital Volume Using the Cavalieri Principle on Computed Tomography Images

Objective: The volumes of the eyeball and orbit have been the subject of a few studies, yet none of them have used stereological methods to estimate the volume. In the present study, we estimated the volumes of the eyeball and orbita in normal healthy men and women using the stereological method. Material and Methods: We estimated the volume of the eyeball (VE) and the volume of the orbit (VO) in normal men and women using the Cavalieri principle as a combination of a point-counting technique. We used computed tomography scans taken from 31 subjects (12 men and 19 women). Results: The mean (±SD) VO in the female subjects was 18.47±2.52 cm3 on the right side and 18.16±2.52 cm3 on the left side. The VE was 7.45±1.19 cm3 and 7.45±1.25 cm3 on the right and left sides, respectively. The mean (±SD) VO in the male subjects was 22.35±3.05 cm3 on the right side and 22.71±2.80 cm3 on the left side. The VE was 7.32±0.74 cm3 and 7.61±1.04 cm3 on the right and left sides, respectively. Conclusion: Measurement by the technique described is an easy, and quick method of assessing the volumes of the eyeball and orbit.