Clozapine-induced maculopathy

A 57-year-old man was treated for schizophrenia with clozapine 900 mg daily over 22 years. His history included epilepsy, hypertension and hypercholesterolaemia, which was treated with clonazepam, clonidine and atorvastatin. Examination showed acuity 6/5 bilaterally, corneal and macular pigmentation (Figure, A, arrow, compared with B, which is normal macula), with subfoveal atrophy and disruption of the photoreceptor-retinal pigment epithelium junction on optical coherence tomography scan ([OCT]; Figure, C compared with D, which is a normal OCT, arrows), and left eye macular dysfunction on multifocal electroretinography ([ERG]; Figure, E compared with F, which is a normal ERG). These changes were similar to previously described clozapine-associated retinopathy.1 Clonazepam is associated with depigmentary retinopathy and normal ERG responses.2 Clonidine and atorvastatin have no documented retinopathy. The patient’s hyperpigmentation may be due to clozapine absorption via the choroid, binding to retinal pigment epithelium and interrupting photoreceptor phagocytosis.3 High dose clozapine warrants ophthalmic follow-up.

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