Lateral canthal support system in Japanese.
The present study aimed to elucidate microscopically the precise structure of the generally termed 'lateral canthal tendon' (LCT). Specimens from 9 post-mortem lower eyelids of 6 Japanese aged from 72 to 91 years old at death were fixed in 10% buffered formalin, and microscopically examined. Specimens were excised as exenterated samples including an area 5 mm wider than the orbital aperture. The removed contents were further incised longitudinally on the central eyelid and also incised parallel to the upper eyelid margin on the site 3 mm from its margin. After the preparation of microscopical examination, sections of all 9 eyelids were stained with Hematoxylin and Eosin. We found that the structure generally termed LCT consisted of two definitive different layers microscopically. The superficial layer was only an orbital septum (septal band). It was mainly constituted of thick fibers between adipose-rich tissues. The deep layer continued from the tarsus and projected posteriorly; which was a ligament (tarsoligamentous band). This tissue was constituted by thin, minute fibers with little adipose tissues. The structure generally termed LCT is not a tendon but a complex constitution of an orbital septum and a ligament; which we named, in a mass, 'lateral canthal bands', cooperatively supporting the lateral canthus.
Kakizaki
Hirohiko
H
Department of Ophthalmology, Aichi Medical University, Nagakute-cho, Aichi-gun, Aichi-ken 480-1195, Japan. cosme@d1.dion.ne.jp
Zako
Masahiro
M
Nakano
Takashi
T
Asamoto
Ken
K
Miyaishi
Osamu
O
Miyagawa
Toshiaki
T
Iwaki
Masayoshi
M
D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D002102:Cadaver; D005143:Eyelids / Q000033:anatomy & histology*; D006801:Humans; D008022:Ligaments / Q000648:ultrastructure*; D008853:Microscopy; D009801:Oculomotor Muscles / Q000648:ultrastructure; D009915:Orbit