Results after graded recession of inferior oblique muscle in strabismus sursoadductorius

Abstract

Introduction: Idiopathic strabismus sursoadductorius is characterized by an overaction of the inferior oblique (IO) muscle, with elevation of the eye in adduction. This can result in chronic headache, eye pain, diplopia and abnormal head posture. Aim: Presentation of clinical results after graded recession of inferior oblique overaction (IOOA) in strabismus sursoadductorius. Method: During a period of 6 years (2012–2017) we performed a dosed transposition of IO muscle in 53 patients in the Department of Ophthalmology of the Semmelweis University and analyzed the clinical results retrospectively. The mean age was 12.8, min–max: 2–51 years. The transposition of the muscle (8 mm, 10 mm or maximal) was performed because of IOOA and was planned depending on the vertical deviation (VD) in maximal adduction. In case of maximal transposition, the insertion of IO was placed under the lateral part of the lower rectus muscle. We evaluated the squint angle in five positions of gaze preoperatively and postoperative 1 week, 1 month and 3–6 months. We examined best corrected visual acuity, binocular vision and complications after surgery. Results: Postoperatively 25 patients had acceptable stereopsis (Titmus 5). Visual acuity remained stable after surgery in all cases. The VD measured in maximal adduction changed with a decrease of 7.5° when 8 mm transposition was performed, and changed with a decrease to 12°, when maximal recession was performed. The mean reduction of VD was 17.8 prism dioptres (PD) after 1 week (p<0.01), 20.5 PD after 1 month and remained stable during a followup of 3–6 months. Conclusion: Graded recession of inferior oblique muscle is a suitable proposed procedure in patients with marked strabismus sursoadductorius. The rates of functional under or overcorrection or other complications are low.