Lateral Canthal Incision for Dermoid Cyst Excision

Most periocular dermoid cysts can be excised through an eyelid crease incision.  In this case, the lesion is relatively lateral and inferior.  A lateral canthal incision is used.  As in all dermoid cyst excisions, the goal is to remove the cyst without rupture. 

This is Richard Allen at oculosurg.com.  This video demonstrates the use of a lateral canthal incision for the excision of a dermoid cyst.  My preference in approaching dermoid cysts is usually to employ a lid crease incision.  In this case, the cyst was laterally located, and I thought it may be difficult to excise it through a standard eyelid crease incision.  The 15 blade is used to make a 1-centimeter lateral canthal incision.  Westcott scissors are then used to perform an upper cantholysis, taking care not to disturb the lacrimal gland ductules.  A 4-0 Silk suture is then placed through the lateral upper and lower lid margin to provide traction during the case.  The cyst is exposed and dissection is carried out around the cyst with Westcott scissors.  My goal in the excision of dermoid cysts is to remove them without rupture.  I will usually dissect until it become difficult, and then move to a different area.  It is important not to be impatient in the excision of these lesions.  Dissection is slowly performed 360 degrees around the lesion until the posterior attachments are exposed.  Once the posterior attachments are exposed, they can be transected and the cyst can be removed.  Hemostasis is assured, and the cantholysis and canthotomy are repaired.  Repair of the cantholysis is performed with a 4-0 Vicryl suture on a P-2 needle which engages the periosteum of the lateral orbital rim.  The suture then engages the lateral upper eyelid at the level of the tarsus.  The suture then engages the lateral lower eyelid at the level of the tarsus, followed by the periosteum of the lateral orbital rim.  The suture is then tied.  Inspecting the level of the lateral canthus shows that it is symmetrical to the other side.  The lateral canthotomy is then closed with a single deep 4-0 Vicryl suture placed in a buried fashion, followed by superficial 5-0 fast absorbing sutures placed in an interrupted fashion.  Antibiotic ointment is placed over the incision and into the eye, and the patient will follow up in approximately one week.