Surgical management of superior oblique paresis using inferior oblique anterior transposition.

Background: Inferior oblique anterior transposition (IOAT) is an effective surgical procedure for weakening the inferior oblique muscle. The purpose of this study was to assess the effectiveness and complications of IOAT for superior oblique paresis at a single center over a period of 11 years.

Methods: The medical records of consecutive patients treated for congenital and acquired fourth nerve paresis with IOAT procedures at Addenbrookes Hospital, Cambridge, from 2001 to 2012 were retrospectively reviewed. All patients were examined before and after surgery: the vertical deviation in primary position and on contralateral gaze was measured, as were versions. The data collected included patient sex and age, presenting complaint, follow-up period, abnormal head position before and after surgery, postoperative complications, and further operative procedures.

Results: A total of 98 IOAT procedures were reviewed, with a mean follow-up of 5.8 months. The technique produced a mean correction of 9.5(Δ) in primary position and 17(Δ) in contralateral gaze. Inferior oblique overaction was reduced in all cases, with 20% having a residual overaction and 47% having an underaction. No patients had symptomatic antielevation syndrome.

Conclusions: In this patient cohort, IOAT effectively managed appropriately selected patients with superior oblique paresis, improving the vertical deviation in primary position and contralateral gaze. The procedure induced limitation of elevation in some patients. No patient experienced major postoperative symptoms.