Ocular toxicity in low-dose tamoxifen: a prospective study.

PURPOSE: To look at the incidence, symptomatology, course and reversibility of low-dose tamoxifen ocular toxicity.
METHODS: Sixty-five women with breast cancer, on tamoxifen oral therapy (20 mg/day), and a totally normal eye examination, were prospectively followed up. A full ophthalmic evaluation was done every 6 months, for a median of 30 months (range 4-79 months). Any sign of toxicity in the cornea, lens, retina or optic nerve was looked for, whether associated with a change in visual acuity or not.
RESULTS: Ocular toxicity was documented in 8 patients, giving an incidence of 12%. Seven patients had keratopathy in the form of subepithelial deposits, whorls and linear opacities. Three of these patients had a concurrent symptomatic bilateral pigmentary retinopathy that warranted discontinuation of therapy. One patient developed bilateral optic neuritis that left her with optic nerve pallor and a decrease in vision. The patients who had the toxicity had a significantly higher tamoxifen cumulative dose (p = 0.03), and were longer on treatment (p = 0.04), than the non-affected ones. The keratopathy changes were reversible upon discontinuation of the drug.
CONCLUSION: Prompt reporting of symptoms and yearly ophthalmic examinations are mandatory in patients on tamoxifen to detect toxic effects while these are still reversible.