Small-angle hypertropia in a case of inferior rectus aplasia: an intraoperative surprise.

Introduction: The clinical features of congenital inferior rectus (IR) aplasia are similar to IR paresis/palsy, and they include hypertropia, limitation of downgaze - especially in abduction, incyclotorsion, A-pattern strabismus, and abnormal head posture.Case report: A 22-year-old man presented with a right face turn, small-angle hypertropia (14 prism diopters) in the right eye, and limitation of downgaze that passed the midline; no diplopia was present and supraduction was normal in that eye. Double Maddox rod revealed 12 degrees of incyclotorsion for the right eye. The Titmus test revealed a stereo acuity of 400 seconds of arc. Based on the preoperative clinical findings, a presumptive diagnosis of IR paresis was made and a surgical plan for performing superior rectus muscle recession and IR muscle resection was devised. Intraoperatively, forced duction test was positive in depression. To our surprise, after performing a 4 mm recession of the superior rectus muscle, we found that the IR muscle was absent. We then revised the surgical plan and performed a 6 mm resection and anterior transposition of the inferior oblique (IO) muscle. Post-operatively, the patient was orthophoric in the primary position without diplopia, and his abnormal head posture was significantly improved.Conclusion: The amount of primary position hypertropia and severity of downgaze limitation are not adequate for differentiating congenital IR aplasia from IR paresis/palsy. Orbital imaging including CT, MRI or anterior segment optical coherence tomography (AS-OCT, UBM) is helpful to distinguish these two entities preoperatively.

The effect of systemic erythropoietin and oral prednisolone on recent-onset non-arteritic anterior ischemic optic neuropathy: a randomized clinical trial.

BACKGROUND: To evaluate the effect of systemic erythropoietin, as well as oral steroids, in the management of recent-onset non-arteritic anterior ischemic optic neuropathy (NAION). METHOD: Patients diagnosed with NAION within 5 days were randomized into group A (systemic erythropoietin), group B (oral steroids), and group C (control). Group A received 10,000 units of erythropoietin twice a day for 3 days. Group B received oral prednisone 75 mg daily tapered off in 6 weeks. RESULTS: The mean best-corrected visual acuity (± SD) at the time of presentation was 1 ± 0.56, 1.01 ± 0.6, and 0.94 ± 0.47 logMAR in groups A, B, and C, respectively (P = 0.140); corresponding values at 6-month follow-up were 0.70 ± 0.44, 0.73 ± 0.35, and 0.75 ± 0.39 logMAR, respectively (P = 0.597). Fifty-five percent of patients in group A versus 34.3% in group B and 31.2% in group C had an improvement of at least 3 lines in the best-corrected visual acuity values at the 6th month of follow-up visit (P = 0.04). Peripapillary retinal nerve fiber layers at presentation were 189 ± 58, 193 ± 64, and 199 ± 62 micrometers, respectively (P = 0.779), which decreased to 88 ± 12, 74 ± 25, and 71 ± 18, respectively at 6-month follow-up (P = 0.041). CONCLUSION: The findings of our study indicate the beneficial effects of systemic erythropoietin in preserving the function and structure of the optic nerve in recent-onset NAION. TRIAL REGISTRATION: Clinical registration number: IR.SBMU.ORC.REC.1397.18.