Surgical Anatomy of Deep Lateral Wall by Adults Cadavers and Computed Tomography

Abstract

Purpose:We investigated the surgical anatomy of the deep lateral orbital wall via dissection of Korean cadavers and analysis of the orbit in normal adults using computed tomography. Methods: Twelve cadavers were used to determine the exact anatomic index of the orbital lateral wall, and computed tomography images of 20 patients were used for surgical anatomic measurements during deep lateral orbital wall decompression. Additionally, the anatomic indexes measured in the cadavers and in the computed tomography study were compared and analyzed. Results: In the cadaver study, the mean distance from the orbital rim to the end of the superior orbital fissure was 36.7 ± 1.98 mm, to the rim of the frontosphendoial suture was 18.2 ± 1.92 mm, and from the end of the superior orbital fissure to the inferior orbital fissure was 17.1 ± 1.19 mm. In the computed tomography study, the mean value from the orbital rim to the end of the superior orbital fissure was 39.2 ± 2.46 mm, and from the rim to the frontosphenoidal suture was 17.8 ± 1.56 mm. Conclusions: The present study regarding the surgical index of the lateral orbital wall in Koreans will assist surgeons to safely and confidently perform deep lateral orbital wall decompression. J Korean Ophthalmol Soc 2011;52(8):964-969

Position and size of the sphenoid door jamb in the lateral orbital wall for the orbital decompression

“…In the present study, the distance from the LOM to the anterior margin of the SDJ at the level of the SOF was 17.4 mm, which is very close to the value of 18.2 mm obtained for dried skulls from the same racial group [19]. That previous study used the frontosphenoidal suture as a landmark for the anterior margin of the SDJ.…”

“…The measured SDJ volume has differed somewhat among studies using CT. Values both larger (2.9 cm 3 [12] and 2.84 cm 3 [19]) and smaller (1.24 cm 3 [13] and 0.428 cm 3 [20]) than that found in the present study (2.0 cm 3 ) have been reported. These discrepancies may have been due to methodological differences such as in the slice thickness and different decisions about the SDJ outline.…”

“…The width of the SDJ demonstrated the morphological difference between the anterior and posterior margins of the SDJ, being 18.2 mm at the level of the SOF, 23.4 mm at the intermediate level of the SDJ, and 24.3 mm at the level of the IOF. The location of the posterior margin of the SDJ has been previously reported to vary between 26.0 and 36.9 mm [192223]. The present study identified the SDJ as a triangular prism with a height of about 2 cm and whose bottom is wider than its top.…”

“…The volume of the SDJ is calculated by multiplying the area of the outlined structure by the thickness of each scan slice. Goldberg et al [12] scanned nine patients and 11 normal subjects with slice thicknesses of 1.5–3.0 mm, Beden et al [13] and Oh and Lee [19] used 0.5-mmthick CT sections of 20 normal patients, and Kim et al [20] scanned 20 patients using a slice thickness of 2.5 mm. These differences in scan thickness among the different studies may have greatly influenced the calculated volumes of the SDJ.…”