[Insertion anomalies of the horizontal muscles and dysfunctions of the oblique muscles in the A-V patterns].
Insertion anomalies of the horizontal rectus muscles and dysfunctions of the oblique muscles were studied in 141 cases with A-V patterns of 824 patients with horizontal strabisums. The frequency of insertion anomaly among all cases of A-V pattern studied was 49.6%, there were more V pattern insertion anomalies than in those of A pattern, but the ratio of insertion anomalies in each type of A-V pattern was more in the A pattern than in the V pattern. In the oblique muscles, overaction of the inferior oblique muscle in the V pattern and of the superior oblique muscle in the A pattern were frequently encountered and insufficient action of the oblique muscles occurred more frequently in cases A-V esotropia than in cases of exotropia. In cases of combination of insertion anomaly of the horizontal rectus muscles with dysfunction of the oblique muscles, insertion anomaly was involved in 91.3% of cases of overaction of the superior oblique muscles, but only in 37.4% of cases of overaction of the inferior oblique muscles. The combination of insertion anomalies with dysfunction of the oblique muscles suggests a possible existence of simulated dysfunction of the oblique muscles in some cases of dysfunction of the oblique muscles diagnosed preoperatively. At the choice of a procedure in surgical correction, a confirmation of insertions of the horizontal muscles during operations is needed, and for this purpose the perilimbal incision is more appropriate than the fornix incision.
Eye Clinic, Inuyama Central Hospital, Japan.
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Nakamura
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Awaya
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Miyake
D005133:Eye Movements; D006801:Humans; D009801:Oculomotor Muscles / Q000503:physiopathology*; D013285:Strabismus / Q000503:physiopathology* / Q000601:surgery