RESUMEN
PURPOSE: The purpose of this article is to describe a severe side effect presentation of a bilateral cataract after treatment with intense focused ultrasound (IFUS) and subsequent uneventful cataract surgery. OBSERVATIONS: A 43-year-old woman presented to the emergency room with decreased visual acuity several hours after undergoing an eyelid-tightening procedure using IFUS. The patient's vision was decreased (R>L), a result of an acute cataract, which had an unusual appearance and consistency. Several weeks later, visual acuity had decreased further in the right eye to 20/400 and the patient underwent uneventful laser-assisted cataract surgery with intraocular lens implantation, which resulted in full visual recovery. CONCLUSIONS AND IMPORTANCE: This case emphasizes the need for particular attention to possible side effects resulting from periocular IFUS, including severe ocular impact requiring surgical intervention.