What Are the Symptoms of Hydroxychloroquine Retinopathy?

Hydroxychloroquine, often recognized by its brand name Plaquenil, is a medication frequently prescribed for autoimmune conditions such as lupus and rheumatoid arthritis. This drug helps manage inflammation and disease activity. While generally considered safe and effective for long-term use, it carries a rare but serious potential eye side effect. This complication, known as retinopathy, impacts the retina, the light-sensitive tissue at the back of the eye.

Understanding Hydroxychloroquine Retinopathy

Hydroxychloroquine retinopathy involves damage to the retina, specifically targeting the macula, a small, central area responsible for sharp, detailed vision and color perception. The drug accumulates over time in the retinal pigment epithelium (RPE), a layer of cells that supports the light-sensing photoreceptors. This accumulation disrupts the RPE’s normal functions, leading to cellular damage and atrophy.

Several factors can increase the likelihood of developing this condition. A daily dose exceeding 5.0 mg/kg of real body weight significantly elevates the risk. The duration of treatment also plays a role, with risk remaining low for the first five years (under 1%) but rising to nearly 20% after 20 years of continuous use. Other contributing factors include pre-existing kidney or liver disease, concomitant use of certain medications like tamoxifen, and advanced age (over 60 or 65 years). Pre-existing retinal conditions can also predispose individuals to toxicity.

Recognizing the Symptoms

Symptoms of hydroxychloroquine retinopathy often begin subtly or are absent in the early stages, which underscores the importance of regular eye screenings. Patients might not notice any issues until the condition has progressed to affect the central macula, the area responsible for detailed vision needed for tasks like reading.

As the retinopathy advances, individuals may experience painless, progressive blurring or distortion of central vision. They might find it increasingly difficult to read fine print or discern small details. Blind spots (scotomas) can develop in the central or paracentral areas of their vision.

Changes in color perception, such as difficulty distinguishing between blue and green hues, can also occur. Some individuals report challenges with night vision or adapting to low-light environments, along with seeing halos around lights. Peripheral vision is preserved until the very late stages of the disease. These visual disturbances can affect one eye or both.

Diagnosis and Monitoring

Diagnosing hydroxychloroquine retinopathy involves regular, comprehensive eye examinations for patients taking the medication. These screenings aim to detect early signs of retinal damage before symptoms become noticeable. A baseline eye exam is often recommended within the first few months of starting hydroxychloroquine therapy. For patients without additional risk factors, annual follow-up exams are recommended after five years of treatment.

Specific diagnostic tests are employed to assess retinal health. Visual acuity testing measures the sharpness of vision, while a fundus examination allows the ophthalmologist to view the back of the eye. Optical Coherence Tomography (OCT) is a non-invasive imaging technique that provides detailed cross-sectional views of the retina, allowing for the detection of subtle structural changes in retinal layers.

Visual field testing, such as automated perimetry, assesses the sensitivity of different parts of the retina and can reveal blind spots. Fundus autofluorescence (FAF) can highlight cellular stress or loss in the retinal pigment epithelium. In some cases, multifocal electroretinogram (mfERG) may be used to objectively measure the electrical responses of the macula to light, providing functional evidence of retinal dysfunction. A combination of these tests offers the most accurate assessment for diagnosis.

Management and Outlook

Once hydroxychloroquine retinopathy is diagnosed, the primary management step involves discontinuing the medication. This decision is made in consultation with the prescribing physician, weighing the benefits of the drug against the risk of further vision loss. The retinal damage caused by hydroxychloroquine can be irreversible, especially if detected at a late stage. This emphasizes the importance of early detection through regular eye screenings.

Even after stopping the drug, some progression of retinal damage may occur for a period, usually within the first year after cessation. However, the damage generally stabilizes over time. There are currently no specific treatments available to reverse the existing retinal damage from hydroxychloroquine. The goal of management is to prevent further deterioration of vision by removing the causative agent.

What is Anhidrotic Ectodermal Dysplasia?

Statin Induced Myopathy: Causes, Symptoms, and Treatment

Occipital Nerve Stimulation for Chronic Pain Relief