Hydroxychloroquine Retinal Toxicity: Protecting Your Vision
Understanding Hydroxychloroquine Retinal Toxicity
Hydroxychloroquine retinal toxicity is a form of drug-induced retinopathy (retinal damage caused by a medication). Hydroxychloroquine was approved for medical use in the United States in 1955. It has been used for decades to treat autoimmune diseases. Over time, the drug can accumulate in the retina and cause lasting damage to the cells responsible for central and color vision.
When detected early, the damage may be limited. If toxicity is not caught in time, it can progress to a pattern known as bull's-eye maculopathy. This pattern appears as a ring of damaged tissue surrounding the center of the macula. The macula is the part of the retina responsible for sharp, detailed vision.
Hydroxychloroquine affects the retina through several related processes. The drug binds to melanin in the retinal pigment epithelium (RPE). The RPE is a layer of cells that supports the photoreceptors (the cells that detect light). This binding may explain why toxicity can continue even after the medication is stopped.
Research has shown that hydroxychloroquine disrupts RPE cell metabolism by damaging lysosomes. Lysosomes are structures inside cells that break down waste. It also reduces the ability of RPE cells to clean up shed photoreceptor outer segments. When this debris accumulates, it leads to RPE degeneration and photoreceptor loss. Modern imaging studies suggest that photoreceptors most likely degenerate first, with RPE damage developing afterward.
One of the most concerning aspects of hydroxychloroquine toxicity is that retinal damage can continue to worsen even after the medication is discontinued. This happens because the drug binds tightly to melanin in the RPE and remains in retinal tissue for an extended period. In some cases, worsening can occur in the year following cessation of the drug. This progression can potentially lead to central vision loss.
Who Is Affected and Risk Factors
The single most important risk factor for hydroxychloroquine retinal toxicity is how long a person takes the medication. At recommended doses, the risk of toxicity within the first five years is below 1% (AAO, 2016). It stays below 2% even after 10 years of use (AAO, 2016). However, the risk rises sharply with longer use. Overall frequency of retinopathy has been measured at 4.3% (PMC, 2020). Risk increases from 1% in the first five years to 11.5% between 16 and 20 years of use (PMC, 2020). Some studies report that prevalence can reach 20% to 50% after 20 years of exposure (PMC, 2023).
Taking more than the recommended dose significantly raises the risk of retinal damage. Current guidelines from the American Academy of Ophthalmology (AAO) recommend keeping the daily dose below 5.0 mg per kilogram of actual body weight. When dosage stays below this threshold, the likelihood of toxicity within five years is below 1% (AAO, 2016). Patients who exceed this dosing limit face a meaningfully higher risk.
Kidney function plays a direct role in how the body clears hydroxychloroquine. Patients with stage 3 kidney disease or worse face an increased risk. Stage 3 kidney disease is defined by a glomerular filtration rate (GFR) of less than 60 mL/min/1.73 m2. These patients have an odds ratio of 2.08 for developing toxic retinopathy (AAO, 2016). Because the kidneys help remove the drug from the body, reduced kidney function allows it to accumulate to higher levels.
Tamoxifen, a medication commonly used in the management of breast cancer, is a significant risk factor when taken alongside hydroxychloroquine. Research has identified up to a five-fold increased risk of developing retinopathy when the two medications are taken together (AAO, 2016). Patients taking both drugs should discuss this increased risk with their prescribing physician and retina specialist.
Additional factors that may increase the chance of retinal toxicity include:
- Pre-existing macular disease, which may make the retina more vulnerable to drug-related damage
- Higher cumulative dose over the lifetime of use
- Genetic factors that may influence how the retina responds to the drug
Signs and Symptoms
In the early stages of hydroxychloroquine retinal toxicity, most patients do not experience any noticeable changes in their vision. This is one of the most important reasons why regular screening is critical. The retina can sustain measurable damage before a person is aware of any problem.
In rare cases, a patient in the early stage may notice a paracentral scotoma. This is a small blind spot near the center of vision that can cause difficulty with reading. Some patients may also notice subtle changes in color vision.
As toxicity progresses, symptoms become more apparent. These may include:
- Reduced central vision or blurry vision
- Paracentral scotomas (blind spots near the center of the visual field)
- Photopsia (flashes of light)
- Increased sensitivity to glare
- Difficulty reading or recognizing faces
When hydroxychloroquine retinal toxicity advances to later stages, it can lead to the loss of visual acuity (sharpness of vision), peripheral vision, and night vision. By the time patients notice significant symptoms, substantial and often irreversible damage has occurred.
The classic sign of advanced hydroxychloroquine toxicity is bull's-eye maculopathy. This is a pattern of damage visible on imaging or examination. A ring of damaged RPE and photoreceptor cells surrounds a relatively preserved central area of the macula. This pattern indicates that significant retinal damage has already taken place. The goal of screening is to detect toxicity well before this stage develops.
Diagnosis and Testing
The AAO recommends that all patients starting hydroxychloroquine receive a baseline eye examination within the first year. This baseline exam should include best corrected distance visual acuity (BCVA). It should also include an automated threshold visual field (VF) of the central 10 degrees, with retesting if an abnormality is noted. Spectral domain optical coherence tomography (SD-OCT) is also part of the baseline evaluation. These results serve as a reference point for future comparison.
After the baseline exam, annual screening is recommended after five years of hydroxychloroquine use for patients without significant risk factors. For individuals with significant risk factors, monitoring should include annual examinations from the start of treatment. Risk factors that call for earlier screening include a daily dose above 5.0 mg/kg of actual body weight (AAO, 2016), reduced kidney function, use of tamoxifen, or concurrent macular disease.
Several tests are used to detect early signs of toxicity before symptoms appear:
- Spectral domain optical coherence tomography (SD-OCT) can reveal thinning or disruption of the outer retinal layers
- Automated visual field testing of the central 10 degrees can identify paracentral scotomas the patient may not yet notice
- Multifocal electroretinography (mfERG) measures the electrical response of the retina in specific areas
- Fundus autofluorescence (FAF) imaging can show patterns of RPE damage
Research has shown that Asian patients are more likely to have retinal damage that extends beyond the central macula. Because of this pattern, wider visual field testing may be needed for these patients. Standard central 10-degree testing alone may miss toxicity in wider retinal areas. A retina specialist familiar with these patterns can adjust the screening approach accordingly.
Treatment Options
There is currently no treatment that can reverse retinal damage caused by hydroxychloroquine. No medication, laser treatment, or surgical procedure can repair photoreceptors or RPE cells destroyed by the drug. This is why early detection through regular screening is the most important strategy for preserving vision.
When a retina specialist detects signs of toxicity, the primary recommendation is to stop hydroxychloroquine. The patient should then switch to an alternative medication for the underlying autoimmune condition. This decision should be made in coordination with the prescribing rheumatologist or other physician. Stopping the drug does not ensure that the damage will stop progressing, but it removes the ongoing source of toxicity.
Patients who must discontinue hydroxychloroquine due to retinal toxicity will need to work with their prescribing physician. Several other immunomodulatory and immunosuppressive medications are available. The choice of alternative depends on the specific autoimmune condition and the patient's overall health profile.
What to Expect
When toxicity is caught at an early stage, before significant photoreceptor loss has occurred, the outlook is generally more favorable. Mild damage may stabilize or show some improvement after the medication is stopped. However, patients should understand that the retina has limited capacity to repair itself. Some degree of damage may remain even after the drug is discontinued.
When toxicity is detected at an advanced stage, or when bull's-eye maculopathy has already developed, the prognosis is more concerning. Vision loss at this stage is typically irreversible. Retinal damage may also continue progressing for a year or more after hydroxychloroquine is discontinued. This occurs because the drug remains bound to retinal tissue. Patients in this situation may experience worsening central vision, expanding scotomas, or further loss of night vision.
After hydroxychloroquine is stopped due to detected toxicity, continued monitoring by a retina specialist is important. Follow-up visits allow the specialist to track whether the damage has stabilized or is continuing to progress. OCT imaging and visual field testing are typically repeated at regular intervals to document any changes over time.
Living With Hydroxychloroquine Retinal Toxicity
Patients who have experienced retinal damage from hydroxychloroquine can take steps to make the most of their remaining vision. Wearing UV-protective sunglasses outdoors helps protect the retina from additional light-related stress. Maintaining overall eye health through regular comprehensive eye exams is also important. Other conditions such as cataracts or glaucoma could compound existing vision challenges.
For patients who have experienced significant vision loss, low vision rehabilitation can help maximize the use of remaining sight. Low vision specialists can recommend magnifying devices, specialized lighting, large-print materials, and assistive technology. These tools can help people continue to read, work, and maintain independence even with reduced central vision.
Living with hydroxychloroquine retinal toxicity requires ongoing communication between the patient, the retina specialist, and the physician managing the autoimmune condition. Patients should keep all members of their medical team informed about any changes in vision or medication adjustments. This coordinated approach helps ensure that both the autoimmune disease and the retinal condition are managed effectively.
When to See a Retina Specialist
Any patient who is about to begin hydroxychloroquine therapy should have a baseline eye examination. This exam should include the tests described in this article. It establishes a reference point that will be used in future screenings to detect subtle changes in the retina.
Patients on hydroxychloroquine should follow the screening schedule recommended by the AAO. Those without additional risk factors should begin annual screening after five years of use. Those with risk factors such as high dosage, kidney disease, tamoxifen use, or existing macular disease should be screened annually from the beginning of treatment.
Any patient taking hydroxychloroquine who notices new visual symptoms should see a retina specialist promptly. This applies regardless of when the next screening is scheduled. Symptoms such as new blind spots, difficulty reading, changes in color vision, or increased glare sensitivity may indicate developing toxicity. These symptoms should not be dismissed or attributed to normal aging without a thorough examination.
Questions and Answers
If your retina specialist finds no signs of toxicity during screening, you can typically continue taking hydroxychloroquine as prescribed. The purpose of regular screening is to catch early damage so that the medication can be stopped before significant vision loss occurs. As long as your exams remain normal, the benefits of the medication for your autoimmune condition generally outweigh the risk of retinal damage. This is especially true if your daily dose stays below 5.0 mg/kg of actual body weight.
Retinal toxicity from hydroxychloroquine is uncommon in the first several years of use. For patients taking the recommended dose, the risk remains below 1% during the first five years (AAO, 2016). It stays below 2% through 10 years (AAO, 2016). The risk increases more substantially after 10 to 15 years of continuous use. Because individual risk varies based on dosage, kidney function, and other factors, baseline and follow-up screening remain important.
The response varies depending on how early the toxicity is detected. If damage is caught at a very early stage, mild changes may stabilize or show modest improvement after the medication is discontinued. However, in many cases, retinal damage from hydroxychloroquine is irreversible. In some patients, vision may continue to worsen for a year or more after stopping the drug. This occurs because hydroxychloroquine remains bound to retinal tissue. Early detection through regular screening is critical for this reason.
There are currently no eye drops, supplements, or preventive treatments proven to protect the retina from hydroxychloroquine toxicity. The most effective strategies for reducing risk are keeping the daily dose at or below 5.0 mg/kg of actual body weight and following the recommended screening schedule. Promptly discontinuing the medication if early signs of toxicity are detected is also essential. Patients should not rely on any over-the-counter products as a substitute for proper medical screening.
Short-term use of hydroxychloroquine carries a very low risk of retinal toxicity. The medication is sometimes prescribed for brief courses, such as during certain infections or short-term inflammatory flares. In these situations, the cumulative dose is too small to cause meaningful retinal damage in the vast majority of patients. The risk of toxicity is primarily associated with continuous use over many years. If you have concerns about any duration of use, a retina specialist can provide guidance based on your specific situation.