Short wavelength automated perimetry and tamoxifen use

Abstract

Background/aims: Oestrogen receptors (ORs) have been reported to be present in the retina, and the selective oestrogen receptor modulator tamoxifen has been reported to affect colour vision. This study aimed, therefore, to determine whether standard doses of tamoxifen affect visual sensitivities mediated via short wavelength sensitive (SWS) cones. Methods: Two types of visual fields were measured for middle aged women who were being treated with 20 mg of tamoxifen daily as adjuvant therapy for early stage breast cancer. Visual fields were measured using short wavelength automated perimetry (SWAP) and frequency doubling perimetry (FDP). For SWAP, 24-2 visual fields were analysed. No subjects had tamoxifen retinopathy or other eye disease. For each type of visual field, mean deviations (MDs) were assessed as a function of the duration of tamoxifen use, using a cross sectional design. In addition, the difference between the two types of MDs was computed after standardisation of each type of MD separately, and this difference itself was evaluated as a function of the duration of tamoxifen use. Duration dependent changes for SWAP were further evaluated as a function of eccentricity within the visual field, and the visual field data were compared with foveal data obtained psychophysically. Results: SWAP sensitivities depended on the duration of tamoxifen use. Subjects who used tamoxifen for about 2 years or less were significantly more likely than subjects who had longer use to have high MDs. The difference between the standardised SWAP and FDP MDs likewise was significantly related to the duration of use, whereas duration of use effects for FDP itself were reduced or absent. Although the duration of use effect observed for SWAP was strongest in the peripheral portion of the visual field, there was evidence of changes in SWS cone mediated vision even at the fovea. Conclusion: Standard dosages of tamoxifen can affect SWAP visual fields. The effects of tamoxifen are not equivalent for SWAP and FDP, indicating that tamoxifen affects some types of visual pathways preferentially or selectively. SWS cone pathways, in particular, are affected. SWAP appears able to reveal effects of tamoxifen occurring years before completion of the standard 5 year regimen of use.

Oestrogen, ocular function and low-level vision: a review

“…It may cause optic neuritis (Noureddin et al 1999, Colley & Elston 2004 and reduce the size of the optic cup, which has been attributed to astrocytic swelling caused by tamoxifen-induced oestrogen reductions (Eisner et al 2007). Some women undergoing tamoxifen treatment exhibit anomalous colour sensitivity (Eisner et al 2004, Eisner & Incognito 2006, Salomao et al 2007. Aromatase inhibitors are also used to treat early-stage breast cancer.…”

The Effects of Chemotherapy on the Contrast Sensitivity Function of Breast Cancer Patients

“…According to the authors, modern treatment regimes such as those involving cyclophosphamide, methotrexate, and combinations of 5-fluorouracil, may have considerable side effects on the visual system, reported in 18-42% of patients. Eisner and Austin (2004) conducted a study to determine whether standard doses of antineoplastic drugs would affect visual sensations mediated by small wavelengths. To do this, they measured two types of visual fields (30-20 and 24-20) in women under daily treatment for breast cancer, using short wavelength automated perimeter (SWAP) and the psychophysical test of frequency doubling perimeter, observing the wavelength via cones (SWS).…”

Retinal function in patients treated with tamoxifen

“…Psychophysical tests for color vision [20] and visual fields [33] had been useful to assess subtle clinical abnormalities as well as to follow them up. Ocular alterations due to tamoxifen are not always easily distinguishable from other eye diseases.…”