Canthaxanthin is a naturally occurring chemical, which is most commonly utilized as a colorant for food and dyes or a skin bronzing agent. Its most prevalent impact on human health is canthaxanthin retinopathy, which appears as birefringent, yellow to red crystals surrounding the macula. This occurs with increasing, dose-dependent exposure. Generally, patients remain asymptomatic and findings may only be evident on funduscopic examination. Cessation of canthaxanthin ingestion appears to reverse the retinopathy, but the time until crystal disappearance is variable. Despite a usually favorable outcome, long-standing visual changes may occur. We report a case of an 84-year-old woman with significant visual loss secondary to canthaxanthin retinopathy that ultimately improved upon cessation of the drug. 1. Introduction Canthaxanthin is a naturally occurring carotenoid pigment which is synthesized by microorganisms and plants. It can be found in fruits, vegetables, and fish and primarily occurs in human tissue as a result of dietary ingestion. Like other carotenoids, it is fat-soluble and intensely colored. Canthaxanthin carries a red to orange hue and is used as an agent for coloring foods, dyes, and for skin bronzing. Experimental use has been successful for photoprotection for erythropoietic protoporphyria and cosmetic improvement in vitiligo [1]. The bronzing effect is achieved through carotenoid deposition in the dermis and subcutaneous tissue. Past reports have concluded that this chemical does not carry genotoxic, reproductive, or carcinogenic risks and does not have allergic potential as an oral medication and that acceptable daily intake is 0.03？mg/kg/day [2]. However, there have been reports of adverse impacts on human health, mainly canthaxanthin retinopathy, which manifests as birefringent, yellow to red crystals in the macula [3, 4]. In addition, a case of aplastic anemia has been reported in association with canthaxanthin ingestion [5]. We present a case of an elderly woman with visual loss from canthaxanthin retinopathy following years of use of the drug. 2. Case Report An 84-year-old woman presented with a two-month history of worsening vision in both eyes. She had a 10-year history of canthaxanthin use for tanning, at variable dosages. Estimated total dosage is greater than 100？g. She had undergone bilateral cataract extractions in the past and had no other known ocular diseases. Visual acuity was 20/200？OD and 20/300？OS. Funduscopic examination demonstrated bilateral macular pigmentary changes and gold crystalline deposits (Figure 1).
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