Ophthalmological examination after hemispherotomy

Introduction: Functional hemispheric disconnection (hemispherotomy) is an established surgical treatment for drug-resistant epilepsy. We aimed to describe visual function, including refractive errors, amblyopia, visual field defects, and oculomotor abnormalities, in a French cohort of patients who underwent hemispherotomy. Methods: We retrospectively reviewed the ophthalmological records of all patients who underwent hemispherotomy at the Hopital Fondation Adolphe de Rothschild between November 1987 and September 2024. Results: Among the 368 patients who underwent hemispherotomy, 122 had a comprehensive ophthalmological assessment. Refractive errors were identified in 78 patients (66.7%). Amblyopia was diagnosed in 27 of the 89 patients in whom it could be assessed (30.3%). Of the 38 patients with reliable visual field testing, 37 (97.4%) had a homonymous hemianopia contralateral to the operated hemisphere. Oculomotor abnormalities were observed in 83 patients (68.0%), while 52 (42.6%) exhibited an abnormal head posture, suggesting compensatory mechanisms for visual field loss. Conclusions: Ophthalmological abnormalities are highly prevalent following hemispherotomy. Systematic ophthalmological screening and appropriate management of treatable conditions, particularly refractive errors and amblyopia, appear warranted in this population. Patients also seem to develop compensatory oculomotor strategies and abnormal head postures in response to contralateral homonymous hemianopia.