The Effect of Anterior Transposition of the Inferior Oblique Muscle with Marginal Myectomy in a Case of Lost Inferior Rectus Muscle

ABSTRACT

Although a patient with lost inferior rectus (IR) muscle woud be done infratransposition of the horizontal recti to control hypertropia, this procedure only could control ocular deviation at primary position, but could't improve the limitation of the downgaze markedly and could cause limitation of abduction and adduction. Authors tried to correct lost IR with anterior transposition of the inferior oblique muscle(IO) with marginal myectomy in the theoretical base that the anterior transposition of the IO can convert IO a depressor from an elevator. A 66 year-old female patient received trauma on her left IR muscle by sickle, then primary deviation of left eye was hypertropia of 50 prism diopters, exotropia of 35 prism diopters and secondary deviation was hypertropia 60 prism diopters, exotropia of 40 prism diopters and the degree of limitation of infraduction was -4. We performed anterior transposition of the IO with marginal myecctomy of 6.0 mm and lateral rectus (LR) 6.0 mm recession and medial rectus (MR) 4.5 mm resection of the left eye. The postoperative ocular alignment at primary position was exotropia of 10 prism diopters and degree of limitation of infraduction was -2 and limitation of supraduction was -2. The anterior transposition of IO with marginal myectomy was simple and effective in correcting the hypertropia and ocular motility in a case of lost IR.