TY - JOUR
T1 - Sustained improvement of reading symptoms following botulinum toxin A injection for convergence insufficiency
AU - Saunte, Jon Peiter
AU - Holmes, Jonathan M.
N1 - Funding Information:
Financial Support: This study was funded by Dagny Johansens Fond, Hillerød Hospital, DK, (JPS), Oda Pedersens Fond v/Dansk Oftalmologisk Selskab, Copenhagen, DK, (JPS), National Institutes of Health Grant EY018810 (JMH), Research to Prevent Blindness, New York, NY (JMH as Olga Keith Weiss Scholar and an unrestricted grant to the Department of Ophthalmology, Mayo Clinic), and Mayo Foundation, Rochester, MN.
Funding Information:
†Supported by: Dagny Johansens Fond, Oda Pedersens Fond v/Dansk Oftalmologisk Selskab, Copenhagen, DK, (JPS), National Institutes of Health Grant EY018810 (JMH), Research to Prevent Blindness, New York, NY (JMH as Olga Keith Weiss Scholar and an unrestricted grant to the Department of Ophthalmology, Mayo Clinic), and Mayo Foundation, Rochester, MN. Received 13 December 2013; Revised 10 February 2014; Accepted 12 February 2014; Published online 30 April 2014 Correspondence: Dr. Jonathan M. Holmes, Ophthalmology E4, Mayo Clinic, Rochester, MN 55905. Tel: (507) 284-3760. Fax: (507) 284-8566. E-mail: holmes.jonathan@mayo.edu
PY - 2014/9
Y1 - 2014/9
N2 - Introduction: We evaluated the use of botulinum toxin A in adults with convergence insufficiency in whom prior treatment had failed. Methods: We studied 8 patients (median age 36 years, range 17 to 77 years) with reading symptoms due to convergence insufficiency defined as an exodeviation greater at near, not exceeding 10 PD in the distance measured by prism and alternate cover test, and either convergence near point >6cm or reduced fusional amplitudes. All patients were still symptomatic after prior treatment by convergence exercises (n=8), base-in prism glasses (n=5) or strabismus surgery (n=2). Five patients received injection of 5IU botulinum toxin in 0.1ml saline to one lateral rectus muscle, two received 2.5IU, and one received 2.5IU to both lateral rectus muscles. Results: At 1 month post injection, all patients had an initial reduction of exodeviation from baseline (median 9 PD, p=0.008) at near, although 2 patients had a temporary intermittent esotropia in the distance with diplopia associated with difficulty driving. At 6 months, when the pharmacological effect of botulinum toxin had completely worn off, patients still maintained a small reduction of exodeviation (median 4 PD, p=0.3) at near. Reading symptoms improved in 7 of 8 patients at 1-month post injection, and in all patients at 6 months. Two patients had health-related quality of life assessed with the Adult Strabismus 20 Questionnaire, showing improved Reading Function scores at 6 months. Interestingly, 3 patients reported improved reading despite returning to the baseline angle at 6 months, and 2 of 4 with 12-month follow-up still reported improvement. Conclusions: In adult convergence insufficiency, botulinum toxin injection to a lateral rectus muscle improves reading symptoms beyond the duration of the pure pharmacological effect. Botulinum toxin injection may be useful in management of adult convergence insufficiency, although repeat injections may be needed.
AB - Introduction: We evaluated the use of botulinum toxin A in adults with convergence insufficiency in whom prior treatment had failed. Methods: We studied 8 patients (median age 36 years, range 17 to 77 years) with reading symptoms due to convergence insufficiency defined as an exodeviation greater at near, not exceeding 10 PD in the distance measured by prism and alternate cover test, and either convergence near point >6cm or reduced fusional amplitudes. All patients were still symptomatic after prior treatment by convergence exercises (n=8), base-in prism glasses (n=5) or strabismus surgery (n=2). Five patients received injection of 5IU botulinum toxin in 0.1ml saline to one lateral rectus muscle, two received 2.5IU, and one received 2.5IU to both lateral rectus muscles. Results: At 1 month post injection, all patients had an initial reduction of exodeviation from baseline (median 9 PD, p=0.008) at near, although 2 patients had a temporary intermittent esotropia in the distance with diplopia associated with difficulty driving. At 6 months, when the pharmacological effect of botulinum toxin had completely worn off, patients still maintained a small reduction of exodeviation (median 4 PD, p=0.3) at near. Reading symptoms improved in 7 of 8 patients at 1-month post injection, and in all patients at 6 months. Two patients had health-related quality of life assessed with the Adult Strabismus 20 Questionnaire, showing improved Reading Function scores at 6 months. Interestingly, 3 patients reported improved reading despite returning to the baseline angle at 6 months, and 2 of 4 with 12-month follow-up still reported improvement. Conclusions: In adult convergence insufficiency, botulinum toxin injection to a lateral rectus muscle improves reading symptoms beyond the duration of the pure pharmacological effect. Botulinum toxin injection may be useful in management of adult convergence insufficiency, although repeat injections may be needed.
KW - Botox
KW - Botulinum toxin
KW - Convergence insufficiency
KW - Reading function
KW - Strabismus
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U2 - 10.3109/09273972.2014.907815
DO - 10.3109/09273972.2014.907815
M3 - Article
C2 - 24786379
AN - SCOPUS:84905583482
SN - 0927-3972
VL - 22
SP - 95
EP - 99
JO - Strabismus
JF - Strabismus
IS - 3
ER -