Anterior transposition of inferior oblique for inferior rectus muscle aplasia.

Congenital absence of extraocular muscle is rare. The most common extraocular muscle found to be congenitally absent is superior oblique followed by inferior rectus. Patients with absent inferior rectus muscle can present with abnormal head posture and incomitant hypertropia with limitation of ocular motility in the field of action of the inferior rectus with or without torticollis. Microphthalmos, microcornea, coloboma, and Axenfeld-Rieger syndrome are known to be commonly associated with inferior rectus muscle aplasia. Orbital computed tomography (CT) or magnetic resonance imaging before surgery is useful for confirmation of the diagnosis and plan of management. We report satisfactory surgical outcome of anterior transposition of inferior oblique in a case of inferior rectus aplasia with iris coloboma, microcornea, and anomalous insertion of inferior oblique. The patient had right hypertropia in primary position which increased on levoversion and left tilt. Preoperative orbital CT revealed congenital absence of inferior oblique. Peroperatively, congenital absence of inferior rectus was confirmed, and inferior oblique was found to be hyperplastic and abnormally inserted to the sclera. Anterior transposition of inferior oblique was done with satisfactory outcome.

Simultaneous Superior Rectus Recession and Anterior Transposition of Inferior Oblique Muscle as a Surgical Option for Traumatically Lost Inferior Rectus Muscle.

PURPOSE: To evaluate the role of simultaneous superior rectus (SR) recession and anterior transposition of inferior oblique (ATIO) muscle in patients with traumatically lost inferior rectus (IR) muscle. METHODS: Six patients with history of ocular trauma, followed by sudden onset vertical diplopia along with marked hypertropia (HT) and limitation of depression in abduction in the affected eye suggestive of IR disinsertion, were included in this prospective study. The patients were treated by simultaneous SR recession and ATIO muscle in the affected eye by limbal conjunctival approach under local anesthesia. RESULTS: Preoperatively, primary position HT of 40-50 (mean 44.16 ± 4.91) prism diopters (PD) was present in all cases which increased to 65-70 (mean 65.83 ± 5.84) PD in down and in the ipsilateral gaze along with marked limitation of depression in abduction and A pattern. On exploration, the IR could not be traced in four cases. Fibrotic muscle sheath with retracted IR was found 10-12 mm away from the limbus in rest of the two patients. ATIO (6.5 mm from the limbus) with simultaneous recession of ipsilateral SR was done under local anesthesia. At 12 weeks postoperatively, three patients were orthophoric in primary position and vertical alignment with in 4-7 PD in primary position was achieved in rest of the three patients. CONCLUSION: Simultaneous SR recession with ATIO seems to be a good alternative to achieve satisfactory vertical alignment for patients with traumatically lost inferior rectus muscle.

Congenital cranial dysinnervation disorders.

The European Neuromuscular Centre (ENMC) derived the term Congenital Cranial Dysinnervation Disorders in 2002 at an international workshop for a group of congenital neuromuscular diseases. CCDDs are congenital, non-progressive ophthalmoplegia with restriction of globe movement in one or more fields of gaze. This group of sporadic and familial strabismus syndromes was initially referred to as the 'congenital fibrosis syndromes' because it was assumed that the primary pathologic process starts in the muscles of eye motility. Over the last few decades, evidence has accumulated to support that the primary pathologic process of these disorders is neuropathic rather than myopathic. This is believed that for normal development of extra ocular muscles and for preservation of muscle fiber anatomy, normal intra-uterine development of the innervation to these muscles is essential. Congenital dysinnervation to these EOMs can lead to abnormal muscle structure depending upon the stage and the extent of such innervational defects. Over last few years new genes responsible for CCDD have been identified, permitting a better understanding of associated phenotypes, which can further lead to better classification of these disorders. Introduction of high-resolution MRI has led to detailed study of cranial nerves courses and muscles supplied by them. Thus, due to better understanding of pathophysiology and genetics of CCDDs, various treatment modalities can be developed to ensure good ocular alignment and better quality of life for patients suffering from the same.