TY - CHAP M1 - Book, Section TI - Introduction to Autonomic Pharmacology A1 - Katzung, Bertram G. A2 - Katzung, Bertram G. A2 - Vanderah, Todd W. PY - 2021 T2 - Basic & Clinical Pharmacology, 15e AB - CASE STUDYA 56-year-old woman is brought to the university eye center with a complaint of “loss of vision.” Because of visual impairment, she has lost her driver’s license and has fallen several times in her home. Examination reveals that her eyelids close involuntarily with a frequency and duration sufficient to prevent her from seeing her surroundings for more than brief moments at a time. When she holds her eyelids open with her fingers, she can see normally. She has no other muscle dysfunction. A diagnosis of blepharospasm is made. Using a fine needle, several injections of botulinum toxin type A are made in the orbicularis oculi muscle of each eyelid. After observation in the waiting area, she is sent home. Two days later, she reports by telephone that her vision has improved dramatically. How did botulinum toxin improve her vision? How long can her vision be expected to remain normal after this single treatment? SN - PB - McGraw-Hill CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=1203377600 ER -