Endoscopic Transconjunctival Surgical Approach to the Optic Nerve and Medial Intraconal Space: A Cadaver Study

Abstract

AbstractObjective:Surgical approaches to the orbit require great precision and care because of the functional and aesthetic importance of this region. Conventional approaches to the posterior orbit often require bone removal, may disrupt extraocular muscles, and may create external surgical scars. We conceived a transconjunctival surgical approach to the medial intraconal space that is aided by a minimally invasive endoscopic technique and avoids muscle transection.Methods:Assisted by a rigid endoscope measuring 2.7 mm in diameter, with 0- and 30-degree lenses, we made a medial conjunctival incision along the limbus to approach the medial intraconal space and optic nerve in 7 fresh cadaver heads (a total of 9 procedures).Results:This approach provided direct and quick access to the medial intraconal space and intraorbital optic nerve with the use of endoscopes via an aesthetically acceptable conjunctival incision, and it provided an excellent view of the operative area. Unlike conventional techniques, this approach left the anatomy relatively undisturbed and did not require detachment of the medial rectus muscle.Conclusion:The endoscopic medial transconjunctival surgical approach provides minimally invasive direct access to the medial intraconal space and the intraorbital optic nerve. The approach is easy; minimally disturbs structures; and lends itself to biopsy, drainage, and even excision of selected lesions in this region without muscle transection and with aesthetically acceptable anatomic closure.