Clinical findings and surgical outcomes of patients with traumatic isolated inferior rectus muscle paresis

To evaluate clinical findings and surgical outcomes of patients with traumatic isolated inferior rectus muscle paresis. The medical records of patients with traumatic isolated inferior rectus paresis who underwent strabismus surgery at Farabi Eye Hospital between 2011 and 2018 were reviewed retrospectively. Clinical features, type of surgery, and surgical outcomes were extracted from the record for analysis. A total of 19 patients (14 males [74%]) were included. Mean patient age was 34.8 ± 14.6 years. Left eyes in 13 patients (68%) were involved. Thirteen cases (68%) underwent orbital reconstruction surgery for blow-out fracture. Preoperative limitation of duction in the gaze of the inferior rectus muscle was −2 to −3 in all cases. Four patients (21%) had a paradoxical contralateral compensatory head tilt. Inferior rectus muscle resection alone was the first surgical intervention in 12 patients (63%). At the final follow-up, 12 patients (63%) were orthotropic, without any deviation or diplopia in primary position and downgaze. Three patients (16%) had a residual hypertropia of 3Δ at distance and near without diplopia, and 4 patients (21%) required reoperation. In our patients with traumatic isolated inferior rectus paresis with persistent deviation at least 6 months after trauma, a stepwise approach based on size of the vertical deviation was employed, with good outcomes: inferior rectus resection alone for hypertropia of 6Δ-20Δ and inferior rectus resection and superior rectus recession for hypertropia of ≥20Δ or significant hypertropia in the field of the superior rectus muscle.