Hydroxychloroquine toxicity: when treatment for lupus or arthritis leads to sight loss

Imagine taking medication for years to control a painful, debilitating condition, only to discover that the treatment itself has permanently damaged your eyesight.

This is a recognised risk of hydroxychloroquine, also sold under the brand name Plaquenil. Most patients will never experience serious eye problems, but those who do may suffer permanent damage. That’s why appropriate prescribing and regular monitoring matter so much.

Hydroxychloroquine can gradually damage the retina, the light-sensitive tissue at the back of the eye. The risk is greater in patients who have been taking the medication for many years, particularly those prescribed higher doses.

This condition is known as hydroxychloroquine retinopathy, or HCQ toxicity.

The difficulty is that retinal damage can develop without any noticeable symptoms. By the time someone experiences blurred vision, difficulty reading or missing areas in their field of vision, the condition may already be advanced.

Unfortunately, the damage is generally irreversible and can sometimes continue to progress even after the medication has been stopped.

Because patients may not notice the early signs of toxicity, specialist retinal monitoring can identify damage before significant sight loss occurs. Monitoring includes specialist retinal imaging, such as optical coherence tomography (OCT) and fundus autofluorescence (FAF), which can reveal damage before changes to eyesight become noticeable.

The Royal College of Ophthalmologists recommends annual monitoring after five years of hydroxychloroquine treatment. For patients at greater risk, including those with impaired kidney function, those taking higher doses or those also taking tamoxifen, annual monitoring may begin after just one year.

A patient’s weight is an important consideration when deciding how much hydroxychloroquine to prescribe. Taking more than 5 mg per kilogram of actual body weight each day increases the risk of retinal damage. A dose that was appropriate when treatment began may also need reviewing if the patient’s weight or kidney function changes.

The prescribing clinician is responsible for ensuring that patients are referred for appropriate monitoring and that the results are acted upon.

Problems can arise when patients are not referred for recommended eye monitoring, are prescribed an inappropriate dosage or have abnormalities identified during examinations that are not properly followed up.

Sometimes, the difficulty lies in communication between the GP, prescribing specialist and ophthalmology department. A patient may assume that someone is keeping an eye on the risks associated with their medication, without realising that essential monitoring has not taken place.

We have seen the consequences of inadequate long-term medication monitoring in other cases, including a £150,000 settlement following a GP’s failure to review a patient’s treatment.

If the warning signs are missed, the damage may be considerably worse by the time the patient receives a diagnosis.

Through my work with clients affected by hydroxychloroquine toxicity, I’ve seen how losing your sight can change almost everything. Reading, driving or simply getting around independently may become difficult or impossible. For someone already living with a long-term medical condition, having to rely on other people for everyday tasks can be especially hard.

Developing hydroxychloroquine retinopathy does not necessarily mean that medical negligence has occurred. Retinal toxicity is a recognised risk of treatment and can develop even when appropriate precautions have been taken.

However, there may be grounds for a medical negligence claim if failures in prescribing, monitoring or responding to test results caused avoidable injury. Establishing a claim involves proving both a breach of duty and causation.

When investigating these claims, we look closely at how the medication was prescribed, whether the patient received appropriate eye monitoring and what happened when concerns were raised. We also need to establish whether earlier action would have prevented or reduced the sight loss.

Where negligence has caused permanent sight loss, compensation can help meet the cost of specialist equipment, care, adaptations and lost earnings, as well as recognising the wider impact on someone’s life. Check out our guide to calculating future financial losses.

If you take hydroxychloroquine and notice changes to your vision, seek urgent medical advice. If you are concerned about whether you are receiving appropriate eye monitoring, speak to your treating clinician. Do not stop taking prescribed medication without medical advice.

If you have suffered sight loss and believe that problems with your hydroxychloroquine treatment or monitoring may have contributed to it, our specialist clinical negligence solicitors can help. We can review your medical records, investigate the care you received and advise you on whether you may have a claim for compensation.