Recession-Resection of the Vertical Rectus Muscles for Chin-up Vertical Abnormal Head Position Associated With Infantile Nystagmus Syndrome.

ABSTRACT

PURPOSE: To review the correction of chin-up abnormal head position (AHP) due to infantile nystagmus syndrome via surgery on the vertical rectus muscles, typically a combined recession-resection of these muscles. METHODS: This was a review of 6 patients who underwent surgical correction of chin-up vertical AHP in the context of infantile nystagmus syndrome at an academic institution. The correction of AHP, visual acuity, ductions, and ocular alignment were noted both preoperatively and postoperatively. The need for repeat surgery, induced strabismus, or correction of AHP were also noted. RESULTS: Six patients underwent surgery for chin-up AHP. A combined recession-resection of the vertical rectus muscles (bilateral inferior rectus muscle recession of 5 to 8 mm; bilateral superior rectus muscle resection of 7 to 8 mm) was performed in 4 of 6 patients, and isolated bilateral recession of the inferior rectus muscles was performed in the remaining 2 patients. Four of 6 patients (67%) achieved complete correction of their AHP at the last follow-up visit, with a mild residual chin-up AHP persisting in the other 2 patients. One patient developed large angle exotropia, one had restrictive hypertropia and horizontal plane null position, and another developed an incomitant horizontal strabismus with exotropia in right gaze. Reoperation was performed in the former 2 patients, with successful correction of the strabismus in each. CONCLUSIONS: Surgery on the vertical rectus muscles can reduce or eliminate a chin-up head position in patients with infantile nystagmus syndrome. Care should be taken to avoid producing a restriction of depression in abduction if the amount of resection is too large. [J Pediatr Ophthalmol Strabismus. 2022;59(6)410-415.].