Yes, anastrozole can cause dry eyes.
Clinicians should inform women taking anastrozole about the possibility of dry eyes as a recognized side effect of this medication. 1
Evidence from Guidelines
The 2019 ASCO Clinical Practice Guideline explicitly states that dry eyes are a known adverse effect of anastrozole that should be discussed with patients before initiating therapy 1. This recommendation carries a strong strength of recommendation with high-quality evidence 1. The guideline specifically instructs clinicians to inform women of the possibility of dry eyes (along with joint stiffness, arthralgias, vasomotor symptoms, hypertension, and vaginal dryness) when prescribing anastrozole for breast cancer risk reduction or treatment.
The FDA drug label does not explicitly list dry eyes in the common side effects section 2, though this may reflect underreporting rather than absence of the effect.
Clinical Evidence and Prevalence
Research data supports the guideline recommendations with substantial evidence:
- Prevalence is high: A 2024 study found that 69.6% of patients on aromatase inhibitors developed dry eye disease 3
- Duration matters: Longer treatment duration (>24 months) significantly increases dry eye risk (OR 3.53,95% CI 1.47-9.21) 3
- A 2013 retrospective study found dry eye symptoms in aromatase inhibitor users were substantially higher than the 9.5% prevalence in age-matched controls 4
Mechanism and Clinical Features
The dry eye associated with anastrozole appears to be evaporative in nature, characterized by:
- Increased tear osmolarity (323 vs 307 mOsm/L in symptomatic vs asymptomatic patients) 5
- Meibomian gland dysfunction and dropout 5
- Reduced tear break-up time 6
- Decreased tear production (Schirmer test scores) 6
This occurs because aromatase inhibitors cause profound estrogen deprivation, which disrupts tear film homeostasis and affects meibomian gland function 6.
Clinical Management Approach
When prescribing anastrozole:
Pre-treatment counseling: Explicitly warn patients about dry eye symptoms as part of informed consent 1
Monitor for symptoms: Ask about blurred vision, irritation, foreign body sensation, redness, tearing, and photosensitivity 4
Risk stratification: Patients receiving concurrent radiotherapy have additional increased risk (OR 3.31) 3
Duration awareness: Risk increases significantly after 24 months of therapy 3, 5
Common Pitfall
The FDA label's omission of dry eyes from the common side effects list may lead clinicians to dismiss this complaint. However, guideline-level evidence clearly establishes dry eyes as a recognized and relatively common adverse effect that warrants proactive discussion and management 1.