Can amlodipine cause glaucoma? Unpacking the evidence on calcium channel blockers and eye health

October 10, 2025 •

4 min read

According to a large 2023 study in JAMA Ophthalmology, users of calcium channel blockers (CCBs), including amlodipine, had an almost 40% higher odds of developing glaucoma compared to non-users. This surprising finding raises important questions about whether can amlodipine cause glaucoma and the nature of this potential connection.

Quick Summary

Recent studies indicate a link between amlodipine and an increased risk of primary open-angle glaucoma, with the association potentially driven by an intraocular pressure-independent mechanism.

Key Points

Emerging Evidence: Recent large-scale studies show a statistically significant association between calcium channel blockers (CCBs) like amlodipine and an increased risk of developing primary open-angle glaucoma (POAG).
IOP-Independent Mechanism: The glaucoma link does not appear to be caused by an increase in intraocular pressure, the traditional risk factor. Instead, the mechanism is believed to be IOP-independent.
Retinal Nerve Thinning: Researchers have found that CCB use correlates with thinner retinal nerve fiber and ganglion cell layers, suggesting a potential neurodegenerative pathway.
Genetic Factors: Some research indicates the risk may be limited to a specific population with certain genetic markers, meaning not all amlodipine users face the same level of risk.
Conflicting Past Research: Early studies on CCBs and eye health yielded conflicting results, with some suggesting a protective effect due to increased ocular blood flow, contrasting with recent findings.
Consult a Professional: Patients with glaucoma or risk factors should discuss their medication with their ophthalmologist and primary care physician, as alternative medications might be considered.
Other Ocular Side Effects: Beyond glaucoma risk, amlodipine has less common ocular side effects, including blurred vision, swelling around the eyes, and dry or irritated eyes.

Understanding Amlodipine and Its Primary Function

Amlodipine is a widely prescribed medication belonging to a class of drugs known as calcium channel blockers (CCBs). Its primary function is to treat hypertension (high blood pressure) and angina (chest pain). It works by relaxing the blood vessels, which in turn lowers blood pressure and improves blood flow throughout the body. Given its prevalence and long-term use in millions of patients, any potential side effects warrant careful examination, especially concerning vision.

The Emerging Link Between Amlodipine and Glaucoma

Historically, the relationship between CCBs and glaucoma was a topic of debate, with some theories suggesting a neuroprotective effect due to improved ocular blood flow. However, recent large-scale observational studies paint a more complex and potentially concerning picture.

Findings from the UK Biobank Study

One of the most significant pieces of evidence comes from a population-based, cross-sectional study published in JAMA Ophthalmology. The study analyzed data from over 400,000 UK Biobank participants and revealed a statistically significant association between CCB use and glaucoma.

Increased Odds: Participants taking CCBs showed a 39% higher odds of developing glaucoma compared to those not on the medication.
Retinal Thinning: The study also found that CCB users had thinner macular retinal nerve fiber layer (mRNFL) and macular ganglion cell–inner plexiform layer (mGCIPL) thicknesses. These are key structural markers used to diagnose and monitor glaucoma progression.
Amlodipine Specifics: A follow-up analysis using UK Biobank and MedWatch data explicitly looked at amlodipine and found that it increased the risk of primary open-angle glaucoma (POAG) by 16.1%.

The IOP-Independent Mechanism

Crucially, these large-scale studies found no significant association between CCB use and elevated intraocular pressure (IOP), which is the most common risk factor for glaucoma. This suggests an IOP-independent mechanism for glaucomatous neurodegeneration. Researchers hypothesize that the drug's effect on the eye's vascular system, separate from its systemic blood pressure-lowering effect, may contribute to nerve damage.

How Do the Findings Affect Patients?

For most individuals taking amlodipine, the risk is statistically small. However, the findings are particularly important for specific patient groups. A 2024 study suggests that while an eye exam before starting amlodipine might not be necessary for everyone, it is advisable for hypertensive patients with a family history of glaucoma or other risk factors.

Patients already diagnosed with glaucoma, or those at high risk, should discuss their medication with their ophthalmologist and primary care physician. In cases where glaucoma is progressing despite controlled IOP, considering an alternative antihypertensive medication, such as a diuretic or beta-blocker, may be a relevant discussion point.

Comparison of Research Findings: CCBs and Glaucoma


Research Study	Data Source	Main Finding	Key Mechanism	IOP Effect	Clinical Takeaway
Kastner et al. (JAMA Ophthalmol 2023)	UK Biobank (over 400k participants)	39% increased odds of glaucoma with CCB use.	Thinner mRNFL and mGCIPL layers (neurodegeneration).	No significant increase or association.	Association is IOP-independent; relevant for patients with worsening glaucoma despite controlled IOP.
Lehrer & Rheinstein (Clin Hypertens 2024)	MedWatch & UK Biobank (amlodipine specific)	16.1% increased risk of POAG with amlodipine use.	IOP-independent mechanism, potentially genetic or vascular.	No significant increase or association.	Amlodipine has a potentially hazardous relationship with POAG; consider alternatives for high-risk patients.
Asefa et al. (Arch Ophthalmol 2008) (cited in)	US insurance billing data	26% increased glaucoma risk with CCB use.	Not explicitly studied, assumed IOP-independent.	Not explicitly studied.	Earlier support for a link between CCBs and glaucoma, though study design differs.
Paul & Zuckerman (2015)	Retrospective cataract surgery review	Marginal pupil dilation correlation with amlodipine.	Effect on iris function.	Not studied.	Amlodipine may complicate cataract surgery by affecting pupil dilation.

Potential Ocular Side Effects of Amlodipine

While the association with glaucoma is a key area of research, amlodipine is known to have other less common ocular side effects. Patients should be aware of these potential symptoms:

Visual disturbances: Blurred or double vision (diplopia) are among the uncommon side effects reported.
Swelling: Peripheral edema, a common side effect of amlodipine, can sometimes affect the area around the eyes.
Dry or irritated eyes: Some individuals report burning, dry, or itching eyes.
Conjunctivitis: Inflammation of the conjunctiva (conjunctivitis) has also been reported in rare cases.

Conclusion

In conclusion, while the overall risk for most patients is small, emerging evidence suggests a potential link between amlodipine and an increased risk of primary open-angle glaucoma. The mechanism appears to be independent of intraocular pressure, potentially involving neurodegenerative changes in the retina. This marks a shift from older, more optimistic hypotheses regarding calcium channel blockers and eye health. For individuals with existing glaucoma or other risk factors, this association warrants a thorough discussion with healthcare providers to assess whether amlodipine remains the optimal treatment. Continued research is essential to fully understand the underlying biological mechanisms and clinical implications of this finding.

For more detailed information on the 2023 UK Biobank study, you can review the original publication in JAMA Ophthalmology.

Frequently Asked Questions

Recent large-scale studies have shown a statistical association between amlodipine and an increased risk of developing primary open-angle glaucoma (POAG). The exact causal relationship is still under investigation, and the increased risk is considered minor for the general population.

No, most studies suggest that the link between amlodipine and glaucoma is not due to an increase in intraocular pressure (IOP). In fact, large studies have not found a significant effect of amlodipine on IOP.

Research suggests an IOP-independent mechanism involving neurodegeneration. Studies have found that amlodipine use is associated with thinner macular retinal nerve fiber layers, a key indicator of glaucomatous damage.

You should not stop taking amlodipine without consulting your doctor. The decision to change medication should be made in consultation with your prescribing physician and an ophthalmologist, who can weigh the benefits of controlling your blood pressure against the potential risks to your eye health.

In addition to the potential glaucoma link, amlodipine can cause other, less common eye-related side effects, including blurred vision, double vision (diplopia), eye pain, swelling around the eyes, and dry or irritated eyes.

Individuals with pre-existing risk factors for glaucoma, such as a family history of the disease, are at greater potential risk and should be particularly vigilant about regular eye examinations.

If you are concerned about your eye health or have a family history of glaucoma, you should inform your doctor. An ophthalmological examination before or during amlodipine treatment may be recommended in high-risk cases.