Abstract
Purpose To investigate the efficacy and complications associated with dose increments of botulinum toxin-A (BTA) for comitant horizontal strabismus patients.
Methods Twenty-five esotropic (ET) and 45 exotropic (XT) patients received 2.5–20 U of BTA injection. Parameters for achieving less than 10 prism dioptres (pd) of horizontal deviation and percentage correction of the pretreatment deviation were assessed for injections of less than 10 U and more than 10 U of BTA. Induced ptosis and vertical deviation were examined within and after 6 months of follow-up.
Results The mean pretreatment deviations were 38.6 ± 2.5 pd and 37.6 ± 1.9 pd for the ET and XT groups, respectively. After receiving 1.6 and 1.5 injections on average, improvement to less than 10 pd at the primary position occurred in 32% of ET and 22% of XT patients; the difference was not statistically significant. The percentage corrections of the ET patients were 41.4 ± 9.3% and 36.9 ± 5.6% in those treated with less than 10 U and more than 10 U of BTA respectively; the difference between the two groups was insignificant. For the XT patients the values were 42.1 ± 7.4% and 28.9 ± 3.5% respectively, which also were not statistically significantly different. Frequency of induced ptosis was more common in ET than XT patients (p = 0.01) and this difference was more pronounced with increased doses of BTA (7.7% in ET and 5.3% in XT patients with less than 10 U of BTA, and 24.0% in ET and 4.3% in XT patients with more than 10 U of BTA). Ptosis resolved completely within 6 weeks in all cases. Induced vertical deviation with less than 10 U of BTA was encountered in one case of ET (11.1%, 9 pd) and in another case of XT (8.3%, 4 pd), increasing to 60.0% (2–20 pd) and 38.8% (4–16 pd) respectively with more than 10 U of BTA injection. In about a year, induced vertical deviation resolved in approximately 40%, and decreased in 30% of the cases.
Conclusion Increasing the dose of BTA is clinically effective in larger deviations, although statistically indifferent, especially in ET compared with XT. However, an increased dose is accompanied by increased incidence of induced ptosis and vertical deviation. Ptosis is temporary, but vertical deviation may persist for a long time and may present a cosmetic problem for some patients when more than 10 U of BTA is used.
Similar content being viewed by others
Article PDF
References
Scott AB, Rosenbaum A, Collins CC . Pharmacological weakening of extraocular muscles. Invest Ophthalmol 1973;12:924–7.
Scott AB . Botulinum toxin injection of eye muscles to correct strabismus. Trans Am Ophthalmol Soc 1981;79:734–70.
Scott AB . Botulinum toxin injection into extraocular muscles as an alternative to strabismus surgery. J Pediatr Ophthalmol Strabismus 1980;17:21–5.
Elston JS, Lee JP, Powell CM, Hogg C, Clark P . Treatment of strabismus in adults with botulinum toxin A. Br J Ophthalmol 1985;69:718–24.
Lee JP, Elston JS, Vickers S, Powell C, Kelly J, Hogg C . Botulinum toxin therapy for squint. Eye 1988;2:24–8.
Horgan SE, Lee JP, Bruce C . The long term use of botulinum toxin for adult strabismus. J Pediatr Ophthalmol Strabismus 1998;35:9–16.
Scott AB . Botulinum toxin treatment of strabismus. Focal points 1989: Clinical modules for ophthalmologists, vol VII, module 12. San Francisco: American Academy of Ophthalmology, 1989.
Biglan AW, Burnstine RA, Rogers GL, Saunders RA . Management of strabismus with botulinum A toxin. Ophthalmology 1989;96:935–43.
Carruthers JD, Kennedy RA, Bagaric D . Botulinum toxin vs adjustable suture surgery in the treatment of horizontal misalignment in adult patients lacking fusion. Arch Ophthalmol 1990;108:1432–5.
Osako M, Keltner JL . Botulinum A toxin (Oculinum) in ophthalmology. Surv Ophthalmol 1991;36:28–46.
Abbasoglu OE, Sener EC, Sanaç AS . Factors influencing success and relation of botulinum A treatment. Eye 1996;10:385–91.
Spencer FR, McNeer KW . Botulinum toxic paralysis of adult monkey extraocular muscle. Arch Ophthalmol 1987;105:1703–11.
Apt L . An anatomical reevaluation of rectus muscle insertions. Trans Am Ophthalmol Soc 1980;78:365–75.
Souza-Dias C, Prieto-Diaz J, Vesugui CF . Topographical aspects of the insertions of the extraocular muscles. J Pediatr Ophthalmol Strabismus 1986;23:183–9.
Gammon JA, Gemmill M, Tiggers J, Leiman S . Botulinum chemodenervation treatment of strabismus. J Pediatr Ophthalmol Strabismus 1985;22:221–6.
Scott AB, Magoon EH, McNeer KW, Stager DR . Botulinum treatment of childhood strabismus. Ophthalmology 1990;97:1434–8.
Jankovic J, Brin MF . Therapeutic uses of botulinum toxin. N Engl J Med 1991;324:1186–94.
Brin MF, Blitzer A . Botulinum toxin: dangerous terminology errors [letter]. J R Soc Med 1993;86:494.
Burns CL, Gammon JA, Gemmill MC Ptosis associated with botulinum toxin treatment of stabismus and blepharospasm. Ophthalmology 1986;93:1621–7.
Shippman S, Weseley AC, Cohen KR, Wang F . Secondary vertical deviations after Oculinum injection. Am Orthoptic J 1986;36:120–3.
Lingua RW . Sequelae of botulinum toxin injection. Am J Ophthalmol 1985;100:305–7.
Scott AB . Antitoxin reduces botulinum side effects. Eye 1988;2:29–32.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Şener, E., Sanaç, A. Efficacy and complications of dose increments of botulinum toxin-A in the treatment of horizontal comitant strabismus. Eye 14, 873–878 (2000). https://doi.org/10.1038/eye.2000.240
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1038/eye.2000.240
Keywords
This article is cited by
-
Botulinumtoxin-Injektionen zur Behandlung von Strabismus
Der Ophthalmologe (2007)
-
Botulinumtoxin-Injektionen zur Behandlung von Strabismus
Spektrum der Augenheilkunde (2007)
-
Reversible pupillary dilation following botulinum toxin injection to the lateral rectus
Eye (2006)