Anteronasal transposition: A new twist on the inferior oblique muscle
In patients with severe superior oblique palsy with a large degree of excyclotorsion, anteronasal transposition of the inferior oblique muscle can be considered as the primary procedure of choice.
Take-Home Message: In patients with severe superior oblique palsy with a large degree of excyclotorsion, anteronasal transposition of the inferior oblique muscle can be considered as the primary procedure of choice.
By Lynda Charters; Reviewed by Sonal R. Farzavandi, FRCS
Singapore-Anteronasal transposition of the inferior oblique muscle can be considered as the primary procedure of choice in patients with severe superior oblique palsy with a large degree of excyclotorsion.
Sonal R. Farzavandi, FRCS, described a surgical technique with a “twist” on the oblique muscle in an 11-year-old girl. Dr. Farzavandi is senior consultant, Pediatric Ophthalmology and Strabismus Service, Singapore National Eye Centre, Singapore.
Case report
The only remarkable finding in this child was a Marcus Gunn jaw winking ptosis of the left eye. Vision in each eye was 20/20 with excellent binocular function and no strabismus.
The oculoplastics team planned to perform a left eye extirpation of the levator palpebrae superioris and fascia lata brow suspension. Intraoperatively, the levator muscle was isolated and cut.
However, the superior oblique muscle was also cut inadvertently and the cut ends were identified and sutured with 5-0 Mersilene. After the repair, the surgery continued with the fascia lata brow suspension, Dr. Farzavandi said.
Three weeks postoperatively, the child presented with symptomatic torsional diplopia that was worse in downgaze. She reported difficulty in reading and could fuse the images with reasonable stereopsis with a head tilt to the right.
In the nine gaze positions, Dr. Farzavandi described that the patient has a classical left superior oblique palsy. There was a left hypertropia of 20 prism diopters (PD) in the primary position that increased to 25 PD in right gaze and worsened in dextrodepression, a small esotropia in downgaze, and excyclotorsion 8 degrees in primary gaze increasing to 13 degrees in downgaze (Figures 1 and 2).
The head tilt test showed orthophoria on right head tilt, but with left head tilt, there was a 25 PD left hypertropia.
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