Modified Muscle Transposition Procedure for a Case of Inferior Rectus Muscle Aplasia

PURPOSE: We report a case of inferior rectus muscle aplasia in a 65-year-old woman. METHODS: Images were obtained using ocular motility photography and magnetic resonance imaging (MRI), and operative findings were analyzed. RESULTS: A 65-year-old woman presented with marked right hypertropia. The right eye also had microcornea, iris coloboma, and completely restricted downward movement. MRI showed absence of the inferior rectus muscle in both eyes. During surgery, it was confirmed that the right inferior rectus muscle was absent. The patient underwent a muscle transposition procedure without tenotomy or muscle splitting. A superior rectus muscle tenotomy was also performed. Postoperatively, the right eye showed hypotropia and improved downward movement. CONCLUSION: Muscle transposition without tenotomy or tendon splitting is a surgical option for the unusual abnormality presented in this paper.