Lamotrigine‐associated macular phototoxicity in Asperger syndrome

Abstract

Purpose: Asperger's syndrome is a neurodevelopmental disorder that falls within the autism spectrum disorder family. Comorbid conditions such as depression and anxiety are commonly associated, and lamotrigine is often prescribed off‐label for treatment. It has the capacity to absorb ultraviolet (UV) light and generate free oxygen radicals, which can potentially cause cellular damage. In this case report, we present multimodal imaging findings in a patient diagnosed with solar maculopathy.Methods: A young patient was referred to our department for bilateral visual decline and central scotoma. The patient was examined with multimodal imaging including fundus photography, fundus autofluorescence (FAF), swept‐source optical coherence tomography (SS‐OCT) and multifocal electroretinogram.Results: A 25‐year‐old patient with Asperger's syndrome treated with lamotrigine was referred to our department for bilateral visual decline and central scotoma. Best corrected visual acuity (BCVA) was 0.40 in both eyes. Dilated fundus examination revealed a bilateral yellow foveal lesion. Fundus autofluorescence (FAF) imaging showed foveal hyperautofluorescence. SS‐OCT in the macular region of both eyes showed a disruption of the ellipsoid zone and the external limiting membrane. Upon further questioning, the patient disclosed history of repeatedly gazing at the sun. The diagnosis of solar maculopathy associated with lamotrigine was established.Conclusion: This is the second report of lamotrigine associated retinal phototoxicity. Lamotrigine, recognized as a photosensitizer, may induce a photochemical response, with retinal phototoxicity. Caution must be exercised to educate patients about the importance of not gazing directly at the sun, as it van cause irreversible retinal impairment.