Lani
02-14-2007, 12:21 AM
The eye is an extension of the brain--the only part of it that can be seen without opening the skull. This information was presented at a poster session at San Antonio in December
Tamoxifen Linked to Swelling Within the Eye
Allison Gandey
February 13, 2007 –- A new study has found that tamoxifen use may lead to eye problems among middle-aged women older than 50 years. Researchers reporting online January 27 in Breast Cancer Research and Treatment observed physical changes within the eye, including a reduction in optic cup size. "Clinicians need to be aware that if patients on tamoxifen are complaining of vision problems, these concerns need to be taken seriously," lead author Alvin Eisner, PhD, from the Oregon Health and Science University Neurological Sciences Institute and the Casey Eye Institute, in Portland, told Medscape.
"Although tamoxifen has been used for decades, new technologies for precisely assessing intraocular structure have emerged recently," Dr. Eisner noted in a news release. "The eye may provide a window for quantifying responses to tamoxifen that otherwise may not be measurable." The researchers had previously documented the presence of subtle visual perception changes among tamoxifen users, and a survey by another group found that about 13% of tamoxifen users report vision changes.
The purpose of the present study, funded by grants from the National Institutes of Health and from Research to Prevent Blindness, was to determine whether the optic cups of tamoxifen and anastrozole users differ in size. The optic cup is the depression in the eye nearest to where the optic nerve exits on its way to the brain. The researchers measured optic nerve head topography using a commercially available confocal scanning laser ophthalmoscope.
They looked at 3 populations of amenorrheic women ages 40 to 69 years. Subjects were using tamoxifen 20 mg per day or anastrozole 1 mg per day for up to 2 years as adjuvant therapy after successful primary treatment for breast cancer. Control subjects had no breast cancer histories and were not using any hormonal medication. All subjects had excellent visual acuity and healthy eyes based on conventional photographic assessment.
Optic Cup Size Smaller in Tamoxifen Users
The investigators found that the optical cup volumes of the tamoxifen users were significantly smaller than the cup volumes of the anastrozole users, which were indistinguishable from normal. Because the cup volumes of the tamoxifen users decreased markedly with age at about 50 years and because anastrozole is indicated only for postmenopausal women, the group assessed comparisons for subjects older than 50 years.
"For these subjects," the group writes, "the cup volumes of the tamoxifen users averaged less than half of the volumes for each of the other 2 subject groups, and significant between-group differences existed in both the lateral (cup area) and axial (cup depth) directions. In contrast, any between-group differences at the optic nerve head margin were small and not significant."
"We stopped short in our paper of providing actual clinical advice," Dr. Eisner told Medscape during an interview. "And we certainly don't want to scare people. But we do feel it's important that patients with vision complaints who are on tamoxifen are thoroughly assessed."
The researchers recommend that the optic nerve head be examined biomorphometrically for tamoxifen users reporting visual change that cannot be attributed to non–drug-related causes. They write, "The ability of modern intraocular imaging techniques to reveal anatomic change on the order of tens of microns may be useful for assessing tamoxifen-induced effects occurring simultaneously elsewhere in the brain, particularly since the presence of small cups is consistent with the possibility of tamoxifen-induced astrocytic swelling."
Breast Cancer Res Treat. Published online January 27, 2007.
Tamoxifen Linked to Swelling Within the Eye
Allison Gandey
February 13, 2007 –- A new study has found that tamoxifen use may lead to eye problems among middle-aged women older than 50 years. Researchers reporting online January 27 in Breast Cancer Research and Treatment observed physical changes within the eye, including a reduction in optic cup size. "Clinicians need to be aware that if patients on tamoxifen are complaining of vision problems, these concerns need to be taken seriously," lead author Alvin Eisner, PhD, from the Oregon Health and Science University Neurological Sciences Institute and the Casey Eye Institute, in Portland, told Medscape.
"Although tamoxifen has been used for decades, new technologies for precisely assessing intraocular structure have emerged recently," Dr. Eisner noted in a news release. "The eye may provide a window for quantifying responses to tamoxifen that otherwise may not be measurable." The researchers had previously documented the presence of subtle visual perception changes among tamoxifen users, and a survey by another group found that about 13% of tamoxifen users report vision changes.
The purpose of the present study, funded by grants from the National Institutes of Health and from Research to Prevent Blindness, was to determine whether the optic cups of tamoxifen and anastrozole users differ in size. The optic cup is the depression in the eye nearest to where the optic nerve exits on its way to the brain. The researchers measured optic nerve head topography using a commercially available confocal scanning laser ophthalmoscope.
They looked at 3 populations of amenorrheic women ages 40 to 69 years. Subjects were using tamoxifen 20 mg per day or anastrozole 1 mg per day for up to 2 years as adjuvant therapy after successful primary treatment for breast cancer. Control subjects had no breast cancer histories and were not using any hormonal medication. All subjects had excellent visual acuity and healthy eyes based on conventional photographic assessment.
Optic Cup Size Smaller in Tamoxifen Users
The investigators found that the optical cup volumes of the tamoxifen users were significantly smaller than the cup volumes of the anastrozole users, which were indistinguishable from normal. Because the cup volumes of the tamoxifen users decreased markedly with age at about 50 years and because anastrozole is indicated only for postmenopausal women, the group assessed comparisons for subjects older than 50 years.
"For these subjects," the group writes, "the cup volumes of the tamoxifen users averaged less than half of the volumes for each of the other 2 subject groups, and significant between-group differences existed in both the lateral (cup area) and axial (cup depth) directions. In contrast, any between-group differences at the optic nerve head margin were small and not significant."
"We stopped short in our paper of providing actual clinical advice," Dr. Eisner told Medscape during an interview. "And we certainly don't want to scare people. But we do feel it's important that patients with vision complaints who are on tamoxifen are thoroughly assessed."
The researchers recommend that the optic nerve head be examined biomorphometrically for tamoxifen users reporting visual change that cannot be attributed to non–drug-related causes. They write, "The ability of modern intraocular imaging techniques to reveal anatomic change on the order of tens of microns may be useful for assessing tamoxifen-induced effects occurring simultaneously elsewhere in the brain, particularly since the presence of small cups is consistent with the possibility of tamoxifen-induced astrocytic swelling."
Breast Cancer Res Treat. Published online January 27, 2007.