Abstract
Abstract: :
Purpose: Birds and lizards have a third eyelid called "nictitans". In mammalians semi-lunar fold represents the third eyelid atrophic remnant. In human anatomy, semi lunar fold has a fibrous skeleton connected with the posterior recessus of Tenon's capsule through the orbital fascia. The aim of this study is the evaluation of a deep posterior subtenon injection technique according to this special anatomy and derived from Ripart's method. Methods: Technique: The needle was placed under the semi-lunar fold tangentially to the globe. Then the eye was turn in adduction and the needle was verticalized and moved inward. Then the needle perforated orbital fascia and Tenon's capsule before injection in Tenon's capsule posterior recessus. Two evaluations was done: 1) Subtenon anesthesia in 40 patients, versus Greenbaum's cannula in 40 other patients. 2) 101 triamcinolone acetonamide subtenon injections in 12 eyes of 10 patients (7 posterior uveitis, 2 Irvine-Gass syndrome, and 1 optic neuritis). Results: 1) Analgesia was excellent without akinesia in the two techniques. There were less chemosis and conjunctival hemorrhages in deep posterior subtenon injections than with the Greenbaum cannula. 2) In 11 eyes: visual acuity was increased and biomicroscopy was qualitatively improved after triamcinolone injections. 1 eye worsened a previous cataract. No glaucoma nor subconjunctival deposits and orbital fat atrophy was observed. Conclusion: Anatomical characteristics of the semi-lunar fold allow safe and useful deep posterior sub-tenon injections.
Keywords: 315 anatomy • 365 conjunctiva