Adherence syndrome following inferior oblique anteropositioning - a case report.

Introduction: We report a case of inferior oblique (IO) muscle adherence with fat adherence, which developed following unilateral IO anteriorization (IOAT).

Methods: A 14-year-old child with V pattern left exotropia, bilateral IO overaction, bilateral dissociated vertical deviation (DVD), and strabismic amblyopia (OS) underwent recess/resect procedure along with IOAT. He developed consecutive esotropia and drooping of upper eyelid with marked limitation of levoelevation (-4). Differential diagnoses of antielevation syndrome and adherence syndrome were considered. On surgical exploration, forced duction test (FDT) was positive for elevation, left inferior oblique (LIO) muscle insertion was found anterior to the inferior rectus (IR) insertion along with fat adhesions which were released and IO muscle was reattached 3 mm behind and 2 mm lateral to IR insertion, along with advancement of left lateral rectus.

Results: Following resurgery, the patient had six prisms left esophoria and a hypotropia 9 prisms, with minimal limitation of levoelevation (-1). One month later, it was seen that the hypotropia had increased to 18 prism diopters and limitation of elevation was -2.

Conclusions: Adherence syndrome is a rare and severe complication of IO weakening procedures. The initial postoperative improvement achieved in elevation and hypotropia in primary position was not maintained over subsequent follow-ups.