日本人下眼瞼の組織所見

Anatomical structure of lower eyelid in the Japanese

目的：眼窩前半部を含む日本人の下眼瞼組織の検討。対象：4屍体の8下眼瞼。男性3人と女性1人，年齢は64～90歳。所見：眼窩隔膜はまず前方に向かい，次いで眼輪筋の後面に沿って下眼瞼縁へと上行する。上眼瞼と異なり，両者間に線維脂肪組織はない。眼輪筋前瞼板部と前隔膜部の間を通り真皮に向かう囊眼瞼筋膜があるが，下眼瞼溝の形成はない。眼輪筋の前瞼板部と瞼板間に囊眼瞼筋膜はない。眼窩隔膜は途中で囊眼瞼筋膜と合流し，瞼板には付かない。全症例で下円蓋部下内方の膠原線維の大きな集塊内にMuller筋の小片が散在する。さらに2例でこの集塊と瞼板下縁との間に平滑筋の小片が散在する。結論：眼窩隔膜と眼輪筋との間には線維脂肪組織は存在せず，明確な下眼瞼溝もない。下眼瞼のMuller筋の形態は上眼瞼とは異なり，瞼板下縁に達していない。

Purpose：To describe the structure of lower eyelid and anterior orbit in the Japanese. Material：Eight lower eyelids of 4 cadavers from 3 males and 1 female aged 64 to 90 years. Findings：The orbital septum,located posterior to orbicularis muscle,ascends toward the lower lid margin. As different from the upper eyelid,no fibroadipose tissue exists between the orbital septum and orbicularis muscle. Some capsulopalpebral fascia（CPF）is located among pretarsal part of orbicularis muscle without forming the inferior palpebral sulcus. No CPF is present between the lower tarsus and pretarsal part of orbicularis musle. Orbital septum joins CPF without communicating the lower tarsus. Small fragments of Muller muscle are scattered in large clumps of collagenous fibers inferior nasal to the lower fornix. In 2 out of 4 specimens,fragments of Muller muscle were present between the clumps and inferior border of lower tarsus. Conclusion：No fibroadipose tissue exists between the orbital septum and orbicularis muscle. There is no explicit inferior palpebral sulcus. As different from upper eyelid,Muller muscle in lower eyelid does not reach inferior margin of lower eyelid.