@article {1603857,
	title = {Botulinum Toxin Injection of the Inferior Oblique Muscles for V-Pattern Strabismus and Primary Position Hypertropia},
	journal = {Am J Ophthalmol},
	volume = {235},
	year = {2022},
	month = {2022 Mar},
	pages = {32-37},
	abstract = {PURPOSE: To evaluate outcomes of botulinum toxin (BTX) injection of the inferior oblique (IO) muscle. DESIGN: Retrospective case series. METHODS: Setting: Single center, ophthalmology department at Boston Children{\textquoteright}s Hospital. STUDY POPULATION: All patients treated with IO muscle injection of BTX (onabotulinumtoxinA) between 2010 and 2020. OBSERVATION PROCEDURE: Sensorimotor evaluations at short-term (\&lt;2 months), medium-term (2-4 months), and long-term (>=4 months) intervals. OUTCOME MEASURE: Primary outcomes included median improvement in V-pattern strabismus and primary position hypertropia. Secondary outcomes included IO muscle overaction. Wilcoxon signed-rank tests were performed to identify differences before and after injection. RESULTS: Record review identified 20 patients with a median age of 4.5 (range, 1-69) years. Median BTX dose injected (31 IO muscles) was 5.0 (range, 3.0-7.0) units. Indications included V-pattern strabismus (N\&nbsp;=\&nbsp;8), hypertropia (N\&nbsp;=\&nbsp;7), or both (N\&nbsp;=\&nbsp;5). Median long-term interval was 6.4 (range, 4.1-26.6) months. Injections were concurrent with treatment of horizontal strabismus in all but 3 cases. Median V-pattern magnitude changed from 10 prism diopters (PD) preoperatively to 0 PD short-term (P\&nbsp;=\&nbsp;.006) and 3.5 PD long-term (P\&nbsp;=\&nbsp;.34). Median hypertropia changed from 8.5 PD preoperatively to 1.5 PD short-term (P\&nbsp;=\&nbsp;.01) and 8 PD long-term (P\&nbsp;=\&nbsp;.87). Median IO muscle overaction grade improved significantly at short-term (P \&lt; .001) and long-term (P\&nbsp;=\&nbsp;.007) intervals. There were no complications associated with the IO muscle injections. CONCLUSIONS: BTX injection of the IO muscles can be a useful adjunct to the management of V-pattern strabismus. Intervention for primary position hypertropia may be helpful for short-term relief with no expectation of long-term benefit.},
	issn = {1879-1891},
	doi = {10.1016/j.ajo.2021.07.003},
	author = {Oke, Isdin and Elhusseiny, Abdelrahman M and Shah, Ankoor S and Hunter, David G}
}
