Nummular Thioridazine Retinopathy

Incidental retinal phototoxicity associated with ingestion of photosensitizing drugs

“…Humans treated with thiazide diuretics suffered unusual and frequent skin erythemal reactions without any abnormal exposure to sunlight [19]. A few studies on the possible association of thioridazine and fluphenazine ingestion with enhanced susceptibility to retinal phototoxic damage have been reported [5,6,12,14,17]. The phototoxicity, as observed in the six eyes described in this report, is a clear indication of the potential harmful effects of ambient light in patients treated with photosensitizing medications.…”

Retinal Phototoxicity Induced by Hydrochlorothiazide After Exposure to a UV Tanning Device

“…Once excited to reactive states by UV or visible light, these compounds produce damage throughout mechanisms mediated by free radical or, directly, by oxygen (14). Thiazide and its derivates, such as hydrochlorothiazide, are able to induce photosensitization by both systems (15), and the retinal phototoxic damage induced by these compounds represents a well-recognized clinical condition (5)(6)(7)(8)(9)(10)(11)(12). Recently, Mauget-Fa et al have described four cases of incidental retinal phototoxicity in patients receiving photosensitizing drugs, after exposure to a light sources usually known to be harmless, such as camera flash, electric welding arc light and microscope light.…”

“…Once excited to reactive states by UV or visible light, these compounds produce damage throughout mechanisms mediated by free radical or, directly, by oxygen (14). Thiazide and its derivates, such as hydrochlorothiazide, are able to induce photosensitization by both systems (15), and the retinal phototoxic damage induced by these compounds represents a well‐recognized clinical condition (5–12). Recently, Mauget‐Fa et al.…”

“…Both the anterior and the posterior segment of the eye may be affected (7). However, when the “sensitized” eye is exposed to an intense and/or extensive light source, the target is represented by the macular region (7–11). The phototoxic effects range from minor histologic/chemical changes, which do not impact the quality of vision, to pigmentary retinal lesions, which could potentially cause the loss of sight (10–12).…”

Clinical Case Notes

“…Two of these patients had also received chlorpromazine 7,8 , which may also cause a pigmentary retinopathy 4,9 , and had been on thioridazine for at least 7 months. The other three cases had all been on thioridazine for between 13 and 17 years 10−12 .…”