Dopamine dilemma: case report of treating psychosis in patient with retinitis pigmentosa

Retinitis Pigmentosa is a rare inherited degenerative eye disease affecting the retinal pigment epithelium (RPE), in which mutation of rhodopsin leads to severe visual impairment, and legal blindness. The D4 receptors are abundant within the rods of the retina and dopamine release is the primary feedback mechanism preventing retinal degeneration by the unopposed action of melatonin. Here, we present a 50-year-old female patient with schizophrenia and retinitis pigmentosa who was admitted to an inpatient unit for an acute psychotic exacerbation with agitation and persecutory delusions. Patient initially was administered IM haloperidol since she refused oral form, but she eventually was compliant to oral Haloperidol with eventual reduction in daily dose to 5mg/d with treatment response and good tolerability including no change in visual acuity. The treatment of psychosis in patients with retinitis pigmentosa is challenging and requires consideration of the potential D4 receptor effects associated with an antipsychotic medication to prevent further retinal damage.