Purchase this article with an account.
A. Eisner, J.P. O'Malley, L.J. Incognito, M.D. Toomey, J.R. Samples; Differential Effects of Adjuvant Breast Cancer Medications on Optic Cup Size . Invest. Ophthalmol. Vis. Sci. 2006;47(13):3648.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The selective–estrogen–receptor–modulator tamoxifen has long been the adjuvant medication of choice for early–stage hormone–positive breast cancer, but aromatase inhibitors such as anastrozole may become the adjuvant medication of choice for post–menopausal women. Because cup dimensions have been reported to depend on gender and/or hormonal status, and because tamoxifen may block swelling–activated chloride channels in astrocytes, cup dimensions may be affected differently by tamoxifen and anastrozole. This study compares effects of these two medications.
The Heidelberg Retina Tomograph II was used for measuring cup dimensions for 3 groups of women ages 51–69 years: (1) short–term tamoxifen users (4–24 months), (2) short–term anastrozole users (4–24 months), and (3) healthy control subjects. All subjects were amenorrheic, all had 20/20 or better acuity, and all were considered to be free of eye disease. All tamoxifen and anastrozole users had been treated for early–stage breast cancer, and none were known to have cancer at the time of testing. No subjects were using hormonal medications other than tamoxifen or anastrozole, and no subject had previously used an adjuvant therapy other than the one presently used. There were 12 anastrozole users, 24 tamoxifen users, and 36 control subjects. Between–group comparisons were made using Kruskal–Wallis non–parametric analyses of variance; p–values are unadjusted for multiple comparisons.
Cup volumes, cup areas, maximum cup depths and cup/disk ratios all differed significantly between groups (each p < .0009). Every tamoxifen vs. anastrozole comparison was significant (each p < .004) whereas no anastrozole vs. control comparison was significant (each p–value between 0.10 and 0.20). For tamoxifen vs. control comparisons, only the p–value for the maximum cup depth (p = .025) was weaker than p = .002. The median values for all 4 indices were: (1) cup volume = 0.104 mm3 for anatrozole users, 0.055 mm3 for control subjects, and 0.009 mm3 for tamoxifen users; (2) cup area = 0.481 mm2 for anastrozole users, 0.334 mm2 for control subjects, and 0.126 mm2 for tamoxifen users; (3) maximum cup depth = 0.615 mm for anastrozole users, 0.569 mm for control subjects, and 0.392 mm for tamoxifen users; and (4) cup/disk ratio = 0.261 for anastrozole users, 0.200 for control subjects, and 0.078 for tamoxifen users.
Short–term tamoxifen use appears to cause subclinical optic–cup swelling whereas short–term anastrozole use does not. It is not known whether anastrozole affects the cup.
This PDF is available to Subscribers Only