Microscopic anatomy of Asian lower eyelids

To elucidate the microscopic anatomy of the Asian lower eyelid.

Specimens (full-thickness sections of lower eyelids from 19 postmortem lower eyelids) from 11 Asians aged 73 to 96 years at death were fixed in 10% buffered formalin and microscopically examined. After pretreatment, sagittal sliced sections of the central part were stained with Masson trichrome.

The distinct junction of the orbital septum to the capsulopalpebral fascia (CPF) was confirmed in 7 eyelids in which orbital septum was clearly stained, with an average distance from the tarsus to the junction of 2.38 mm. The other 12 eyelids did not show a distinct junction, and the orbital septum was poorly defined anteriorly and indistinct posteriorly. There was a distinct layer between the orbicularis oculi muscle and the orbital septum. The inferior and the posterior attachments of the CPF to the tarsus were seen in all eyelids. Seventeen of the 19 eyelids had attachment of the CPF on the anterior aspect of the tarsus, from which an extension of the CPF through the pretarsal orbicularis oculi muscle was observed. All eyelids had anterior extension of the CPF through the preseptal orbicularis oculi muscle, which was overridden on the pretarsal orbicularis oculi muscle.

The microscopic findings of Asian lower eyelids, especially fascial components, were mostly similar to those of non-Asian eyelids, but differences existed in higher or indistinct septum fusion, anterior and superior orbital fat projection, and the overriding of the preseptal orbicularis oculi muscle.