Morphometric analysis of eyelid fissure in patients with eyelid retraction in acute stage of dysthyroid orbitopathy after treatment with botulinum toxin type A

Purpose: To compare morphometric data of eyelid fissure using computerized image analysis before and after application of botulinum toxin type A in patients with eyelid retraction caused by dysthyroid orbitopathy in acute stage. Methods: This was a prospective study with 12 individuals that received transcutaneous 5 UI/0.1 ml injection of botulinum toxin in the upper eyelid. They were examined periodically for 6 months. Clinical eyelid examination was performed and recorded using a video camera connected to a microcomputer. Results: Vertical eyelid fissure, upper eyelid margin to reflex distance and the eyelid area showed reduction in the treated eye. A decrease in the levator function of the upper eyelid was observed, and also, a reduction in the difference between the lateral and medial areas. The lower eyelid margin reflex distance did not show any significant differences after the application. Measurements of the contralateral eye increased up to 2 weeks after the application. Conclusions: These results showed a reduction in eyelid retraction and improving the upper eyelid contour, without changes in the lower eyelid position.