Delirium caused by topical administration of cyclopentolate for cataract surgery in mild cognitive impairment due to Alzheimer's disease

Abstract Rationales: Cholinergic modification by anticholinergic medication can produce adverse effects in central nervous system (CNS) and cyclopentolate is an antimuscarinic agent widely used for ophthalmologic management. We demonstrate a rare case of hyperactive delirium caused by topical administration of cyclopentolate in a patient with amnestic mild cognitive impairment (MCI) due to Alzheimer's disease (AD). Patient concerns: A 74-year-old man showed acute confusion after preparation for cataract operation in day surgery clinic. The patient became confused and agitated after instillation of topical cyclopentolate drop into the eye and the symptoms persisted over several hours. Diagnosis: Previously the patient had been diagnosed with amnestic MCI with the finding of bilateral medial temporal atrophy on brain magnetic resonance imaging. 18 F-flutemetamol positron emission tomography scan demonstrated multifocal amyloid deposition in the brain. Interventions: The patient was closely observed with the supportive management. Outcomes: The patient began to recover 5 h after the onset of symptoms and the cognitive function was reverted to previous state within 24 h. Lessons: It is well known that several drugs with anticholinergic effects used in perioperative periods make the patients susceptible to delirium, but even the topical administration of cyclopentolate for cataract surgery also produce adverse CNS effects in a vulnerable patient who is diagnosed with MCI due to AD in this case.