高度近視を伴う固定内斜視の手術前後のMRI所見

Magnetic resonance imaging of strabismus fixus with high myopia before and after surgery

　高度近視を伴う3例の固定内斜視を対象に，斜視手術の前後に眼窩部MRIを行い，眼球運動障害の矯正と，MRI画像上の外直筋走行の変化との関係を検討した。その結果3例中2例に外直筋の下方偏位がみられ，そのうち1例は術後に外直筋の走行が正常化された。しかしながら，2例とも外転障害の著明な改善は得られなかった。一方，外直筋の下方偏位がみられなかった1例については，外転障害の改善が得られた。結果として，外直筋の下方偏位の改善は必ずしも外転運動の改善を説明するものではないと推論される。

Three cases of convergent strabismus fixus with high myopia were examined by magnetic resonance imaging (MRI) of the orbit before and after strabismus surgery. We paid particular attention to the relation between corrected ocular motility and changes in the lateral rectus muscle. The course of lateral rectus was dislocated downward in two cases, of which the course became normal after surgery. No marked improvement set in the abduction disturbance in these two cases. The abduction disturbance improved postoperatively in the other case which showed no downward deviation of the course of lateral rectus. The findings suggest that improvement in downward deviation of the lateral rectus in strabismus fixus is not necessarily associated with improvement of abduction disturbance.