Medial and lateral canthal ligaments shown in P45 sheet plastination and dissection

PURPOSE: Ocular suspensory ligament is an important part of the lower eyelid retractors. However, there is a scarcity of studies examining detailed en-block histologies of ocular suspensory ligaments. METHODS: In this study, we included the cadavers of Chinese adults as subjects. These cadavers of Chinese adults were processed using P45 plastination techniques. The polymer resulted in transparent plastination, and the P45 sheet-plastinated sections of the lower eyelid were observed. The gross anatomy results of three Chinese adult heads (six hemifaces) were included as gross dissection data. All photographic documentation was performed via a Canon EOS 7D Mark camera. RESULTS: The results showed that the inferior rectus muscle, inferior oblique muscle, ocular suspensory ligament, and its arcuate expansion are under the eyeball. The medial and lateral parts of the ocular suspensory ligament end at the medial and lateral canthal ligament. The middle part, a hammock-like shape, is slightly lower. The ocular suspensory ligament holds up the inferior oblique muscle, inferior rectus muscle, and the eyeball. As the inferior oblique muscle passes through the sheath of the inferior rectus, the fascia is thickened, forming the ocular suspensory ligament. The ocular suspensory ligament connects to the intermuscular septum, the inferior tarsal muscle, and the medial and lateral check ligaments. CONCLUSION: This study observed the ocular suspensory ligament and arcuate expansion through P45 sheet plastination for the first time and identified the distribution of the lower eyelid ligaments, thus laying the foundation for further research.