Effect of oral photochemotherapy (8-methoxypsoralen + UVA) on the electrophysiologic function of retina

Methoxsalen-induced macular toxicity

Psoralen compounds such as methoxsalen are photosensitizer agents used in conjunction with ultraviolet A (UVA) radiation exposure as photochemotherapy (Psoralens and ultraviolet-A therapy [PUVA therapy]) for certain epidermal skin disorders such as psoriasis and vitiligo. Methoxsalen has been shown to be associated with premature cataract formation by forming adducts with lens proteins following oral administration and subsequent UVA exposure. Hence, the use of UV-filtering glasses is recommended during PUVA therapy sessions. Ocular tissues can be exposed to its photosensitizing effect with subsequent UV radiation exposure through sunlight if the patient was to be without protective eye glasses, potentially causing macular toxicity. Till date, there have been no reports in the literature of any posterior segment ocular toxicity arising from methoxsalen use. Here, we describe a case of a bilateral macular toxicity in a middle-aged male treated with methoxsalen for vitiligo.