Comparison of techniques for correction of chin-down vertical abnormal head position associated with infantile nystagmus syndrome

Abstract Purpose We evaluated the relative effectiveness of combined recession-resection of vertical rectus muscles versus superior rectus recession with inferior oblique weakening for patients who underwent surgical correction of chin-down abnormal head position (AHP) associated with infantile nystagmus syndrome (INS). Design Retrospective interventional case series. Methods Review of 22 patients who underwent surgical correction of chin-down vertical AHP associated with INS at an academic institution. The primary outcome was collapse of AHP. Unfavorable outcomes included repeat surgery, induced strabismus, in addition to failure of collapse of AHP. Results Twenty-two patients had chin-down AHP. Recession-resection (BSRc 6-9 mm; BIRs 5-9 mm) was performed in 11 cases; weakening of both elevators (BSRc 5-8 mm, BIOc or myectomy) in 11 cases. Unfavorable outcome rates were 64% (7/11) compared with 18% (2/11), respectively (P = 0.03). Re-operation was performed for 6/22 patients. Five were from the recession-resection group, namely three for induced V-pattern esotropia, one for alternating esotropia, and one to correct recurrent AHP. The last of the 6 who requied reoperation was in the elevator weakening group, and required correction of a recurrent AHP (P = 0.06). Conclusions While recession-resection of the vertical recti and weakening of both elevators each produce acceptable collapse of chin-down AHP, the former frequently induces a V-pattern esotropia requiring re-operation.