Drug-Induced Retinopathy

Overview

Drug-induced retinopathy is damage to the retina, the light-sensing layer at the back of the eye, that occurs as a side effect of certain medications. The retina converts light into signals the brain reads as vision, so damage to it can blur or distort sight, affect color vision, or reduce side or night vision, depending on which part is harmed.

A number of medicines are known to potentially affect the retina, usually with long-term use or higher doses. Well-recognized examples include hydroxychloroquine and chloroquine (used for autoimmune diseases and, historically, malaria), certain cancer treatments, and some other drugs. Because early retinal damage may cause no symptoms, people taking higher-risk medications are often monitored with regular eye exams so that any change can be caught early, when stopping or adjusting the drug can prevent further harm.

Symptoms

Symptoms depend on the drug and the part of the retina affected, and early changes are often silent. When symptoms occur, they may include:

• Blurred or hazy vision
• Difficulty reading or seeing fine detail
• Changes in color vision
• Trouble seeing in dim light
• Blind spots or missing areas in the field of vision
• Distorted vision

Because damage can begin before symptoms appear, regular eye screening is the main way to detect it early in people taking higher-risk medicines. Any new vision change while on such a medicine should be reported promptly.

Causes

Drug-induced retinopathy is caused by medications that can be toxic to the retina. Examples include:

• Hydroxychloroquine and chloroquine: Used for conditions such as lupus and rheumatoid arthritis; long-term use can damage the macula.
• Certain cancer treatments: Some chemotherapy and targeted agents can affect the retina.
• Interferon: Used for some infections and cancers, can cause retinal changes.
• Other medications: A range of drugs, including some used for other conditions, have been linked to retinal effects.

Risk generally rises with higher doses and longer duration of treatment.

Risk Factors

• Long-term or high-dose use of a retina-toxic medication
• Kidney or liver problems that affect how a drug is cleared
• Pre-existing retinal or macular disease
• Older age
• Higher cumulative dose over years of treatment

Diagnosis

Detection relies on regular eye monitoring and specialized testing:

• Dilated eye exam: Examines the retina for changes.
• Optical coherence tomography (OCT): Detailed scans that can reveal early retinal thinning or damage.
• Visual field testing: Detects subtle blind spots before they affect daily vision.
• Other tests: Such as fundus autofluorescence or an electroretinogram (ERG), used to detect early or specific patterns of toxicity.

For some medications, screening guidelines recommend a baseline exam and periodic monitoring during treatment.

Treatment

The main step is to recognize the problem early and address the responsible medication, which is done with the prescribing doctor.

• Stopping or changing the drug: When retinopathy is detected, the prescriber may stop or substitute the medication; this is the most important action and is never done without medical guidance.
• Monitoring: Continued eye follow-up to track whether damage stabilizes, since some changes can progress even after the drug is stopped.
• Supportive care: Low-vision aids and rehabilitation if vision is affected.
• Balancing risks: Decisions weigh the benefit of the medication for the underlying disease against the risk to vision.

There is often no way to reverse damage that has occurred, which is why early detection and prevention are so important.

Prevention

• Have a baseline eye exam before starting a higher-risk medication, if recommended
• Attend regular eye monitoring during treatment as advised
• Take medications at the prescribed dose and do not exceed it
• Tell your eye doctor about all medicines you take
• Report any vision change promptly rather than waiting for the next exam
• Keep kidney and liver health in check, as these affect drug levels

When to See a Doctor

If you take a medication known to affect the retina, keep your scheduled eye monitoring appointments even without symptoms. Contact your eye doctor promptly if you notice:

• Blurred vision or trouble reading
• Changes in color vision
• Blind spots or missing areas in your vision
• Difficulty seeing in dim light

Do not stop a prescribed medication on your own; instead, contact the doctor who manages it so the benefits and risks can be weighed.

Related Topics

Frequently Asked Questions

References

1. American Academy of Ophthalmology. Recommendations on screening for retinal toxicity.
2. National Eye Institute (NEI). Retinal diseases.
3. MedlinePlus, U.S. National Library of Medicine. Hydroxychloroquine.
4. Mayo Clinic. Medication side effects and the eyes.