What are the risks of vision loss associated with Tamoxifen (tamoxifen citrate) therapy?

From the Guidelines

Tamoxifen therapy is associated with a significant risk of vision loss, particularly due to the development of cataracts, with a risk ratio of 1.14 (95% CI, 1.01-1.29) compared to placebo 1. The most common eye-related side effects of tamoxifen include cataracts, with 24.82% of patients developing cataracts compared to 21.72% in the placebo group 1. More serious but less common visual complications include corneal changes, optic neuritis, and macular edema, which could potentially lead to vision loss if not addressed. Key points to consider when evaluating the risks of vision loss associated with tamoxifen therapy include:

• The risk of cataracts is significantly higher in patients taking tamoxifen, with a risk ratio of 1.14 (95% CI, 1.01-1.29) compared to placebo 1
• The risk of undergoing cataract surgery is also higher in patients taking tamoxifen, with a risk ratio of 1.57 (95% CI, 1.16-2.14) compared to placebo 1
• Regular eye exams are recommended for patients on tamoxifen therapy, typically annually or more frequently if you have pre-existing eye conditions
• Patients taking tamoxifen should be aware of the potential risks of vision loss and should contact their healthcare provider immediately if they experience any vision changes, such as blurriness, decreased visual acuity, or changes in color perception. The benefits of tamoxifen in treating or preventing breast cancer typically outweigh these risks, but monitoring is essential to catch any problems early 1.

From the FDA Drug Label

Ocular disturbances, including corneal changes, decrement in color vision perception, retinal vein thrombosis, and retinopathy have been reported in patients receiving tamoxifen An increased incidence of cataracts and the need for cataract surgery have been reported in patients receiving tamoxifen. In the NSABP P-1 trial, an increased risk of borderline significance of developing cataracts among those women without cataracts at baseline (540 tamoxifen; 483 placebo; RR = 1.13, 95% CI: 1.00 to 1. 28) was observed. Among these same women, tamoxifen was associated with an increased risk of having cataract surgery (101 tamoxifen; 63 placebo; RR = 1.62, 95% CI: 1.18 to 2.22) Tamoxifen citrate tablets increased the risk of getting cataracts (clouding of the lens of the eye) or needing cataract surgery. The risks of vision loss associated with Tamoxifen (tamoxifen citrate) therapy include:

• Ocular disturbances: corneal changes, decrement in color vision perception, retinal vein thrombosis, and retinopathy
• Cataracts: increased incidence and need for cataract surgery, with a relative risk of 1.13 (95% CI: 1.00 to 1.28) for developing cataracts and 1.62 (95% CI: 1.18 to 2.22) for having cataract surgery 2
• Vision problems: slow blurring of vision due to cataracts 3

From the Research

Risks of Vision Loss Associated with Tamoxifen Therapy

The risks of vision loss associated with Tamoxifen (tamoxifen citrate) therapy include:

• Ocular toxicity, which occurs in approximately 0.6-12% of patients, characterized by severe loss of visual acuity, crystalline retinal deposits, macular edema, and crystalline deposits in the peripheral retina 4, 5, 6
• Retinopathy, which appears to occur in as many as 12% of patients taking 20 mg tamoxifen a day for over 2 years, with symptomatic changes in visual acuity in half of these cases 6
• Crystalline deposits, cystoid macular edema, hyperreflective deposits in the inner retinal layers, and telangiectasia, which are common retinal changes associated with tamoxifen retinopathy 6
• Increased risk of posterior subcapsular cataract, optic nerve head changes, and foveal cystoid spaces, which may increase the risk for macular holes 7

Prevalence and Detection of Vision Loss

• The prevalence of vision loss associated with tamoxifen therapy is relatively rare, but it is essential to monitor patients for retinal changes, particularly those who have been on tamoxifen therapy for 2 years or more 6
• Optical coherence tomography (OCT) screening for retinal changes should be performed every 6 months for patients who have been on tamoxifen therapy for 2 years or more 6
• Multifocal electroretinography (ERG) and color discrimination testing may not be sufficiently sensitive to detect tamoxifen-associated changes, but they can be used to monitor retinal function and color vision 8

Management of Vision Loss

• Discontinuing tamoxifen therapy is currently the primary management strategy for tamoxifen retinopathy, but it may not improve visual acuity once changes have taken place 6
• Intravitreal injections of steroids or antivascular endothelial growth factor therapy have been performed, but require further studying before conclusions can be made 6