title: The lower eyelid retractor consists of definite double layers.
abstract: OBJECTIVE
  To examine whether the lower eyelid retractor consists of a single layer or multiple layers.
  
  
  METHODS
  Retrospective clinical case series and dissectional study.
  
  
  METHODS
  Fifty-one lower eyelid retractors (31 right, 20 left) of 44 patients (ages, 63-95 years) during entropion surgeries and 10 lower eyelids (5 right, 5 left) of 5 Oriental cadavers (73-91 years old at death) were observed macroscopically. Specimens from 20 postmortem lower eyelids of 12 Orientals (11 right, 9 left; 66-96 years old at death) were used for microscopic observations.
  
  
  METHODS
  Macroscopically, we bluntly or, in parts, sharply dissected lower eyelid retractors into 2 layers during entropion surgeries. Cadaveric lower eyelids also were used to investigate relationships between the lower eyelid retractor and the Lockwood ligament. Cadaveric lower eyelids with sagittal full-thickness sections of the central part were examined microscopically using Masson trichrome staining.
  
  
  METHODS
  Anatomical findings in the lower eyelid retractor.
  
  
  RESULTS
  Lower eyelid retractors easily were detached into 2 layers. Macroscopically, the anterior layer was defined as a coarse tissue continuing from the Lockwood ligament, which joined with the lower orbital septum, and constituted the lower conjoined fascia. The posterior layer appeared to be a dense fibrous sheet with a lustrous surface. Microscopically, the lower eyelid retractor consisted of a definite double layer. The anterior layer, a coarse fibrous tissue, consisted of the suborbicularis fascial layer, orbital septum, and superficial part of the capsulopalpebral fascia, which continued to the anterior lamellae of the lower eyelids. The posterior layer consisted of dense fibers of the capsulopalpebral fascia with smooth muscle continuing to the tarsus.
  
  
  CONCLUSIONS
  The lower eyelid retractor consists of a definite double layer. The posterior dense layer containing smooth muscle is the main tractional component of the lower eyelid retractor.
authors.affiliation: Department of Ophthalmology, Aichi Medical University, Nagakute, Japan. cosme@d1.dion.ne.jp
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Kakizaki
authors.forename: Jinsong
authors.initials: J
authors.lastname: Zhao
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakano
authors.forename: Ken
authors.initials: K
authors.lastname: Asamoto
authors.forename: Masahiro
authors.initials: M
authors.lastname: Zako
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Iwaki
authors.forename: Osamu
authors.initials: O
authors.lastname: Miyaishi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000718:Anatomy, Regional; D004774:Entropion / Q000601:surgery; D005143:Eyelids / Q000033:anatomy & histology*; D005205:Fascia / Q000033:anatomy & histology; D006801:Humans; D008022:Ligaments / Q000033:anatomy & histology; D008875:Middle Aged; D009130:Muscle, Smooth / Q000033:anatomy & histology*; D009801:Oculomotor Muscles / Q000033:anatomy & histology*; D012189:Retrospective Studies