Inferior oblique muscle thickness in Asians

The purpose of this study was to examine the inferior oblique muscle (IOM) thickness in Asians by the quasi-sagittal plane of the orbits. Specimens were examined from 23 orbits of 18 Asians (9 orbits in males, 14 in females), aged 63 to 97 years at death. All specimens were fixed in 10% buffered formalin before use. The orbital contents were incised parallel to the optic nerve, after which the lengths of both short and long axes of the IOM were measured and the ratio of short to long axes was calculated. The mean lengths of each short or long axis of the IOM were 2.27 ± 0.49 mm and 7.23 ± 0.97 mm, respectively. The average ratio was 0.32 ± 0.07. There were no significant differences in laterality or gender. This study determined the normal IOM thickness in Asian cadavers, the outcome of which could be useful for detection of IOM involvement in Graves’ orbitopathy

Course of the vertical portion of the lower lacrimal canaliculus

The nomenclature of each part of the lacrimal canaliculus, for example the vertical portion, does not always reflect the true course. Since we have sometimes observed findings suggesting the so called vertical portion of the lower lacrimal canaliculus inclined laterally, we re-examined the course of the vertical portion. Twenty-eight postmortem lower eyelids in 16 Japanese were examined and divided into 2 groups. The first group was 14 lower eyelids of 7 cadavers. Eyelids were incised sagittally from the lower lacrimal punctum. The second group was 14 lower eyelids of 9 cadavers; these were incised from the lower lacrimal punctum with 5 degrees lateral inclination to the sagittal plane. In the first group, 10 canaliculi of 7 cadavers were interrupted at the halfway point of the vertical portion. Four canaliculi of 4 cadavers included the whole length of the vertical portion. In the second group, all specimens included the whole length of the vertical portion. Most vertical portions of the lower lacrimal canaliculus demonstrated a laterally inclined course of approximately 5 degrees, although some took a completely vertical course