Yearly eye checks should be given to patients receiving tamoxifen for breast cancer, even at low doses. This is the conclusion of Dr Bahaan Noureddin and colleagues (American university of Beirut, Lebanon) who assessed 65 patients and found that the drug may cause initially asymptomatic eye damage.
Writing in Eye (1999;13:729), they say that all subjects were taking 10mg of tamoxifen twice daily. Ocular toxicity was found in eight of these patients (12 per cent). It took the form of keratopathy in four, concurrent keratopathy and retinopathy in three and optic neuritis in one patient. The authors conclude that "there is a need for a detailed ophthalmic evaluation in patients before starting tamoxifen therapy, followed by clear instructions to report even subtle visual symptoms. Finally, yearly evaluations seem to be in order as some of the changes are initially asymptomatic".
Dr Ian Jackson (clinical specialist, Astra Zeneca) told The Journal on January 26 that Astra Zeneca, the manufacturer of Nolvadex, had 11m patient years of experience with tamoxifen. While the company had reports of retinopathy, keratopathy and optic neuritis associated with tamoxifen on file, they were few. He added that any visual problems experienced by patients should be investigated thoroughly.