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Xanthopsia (Phototherapy Side Effect)

What is Xanthopsia (phototherapy side effect)?

Xanthopsia is a visual disturbance in which objects appear yellow‑tinted or “golden.” The term comes from the Greek words xanthos (yellow) and opsis (appearance). While rare, xanthopsia can occur as an adverse effect of phototherapy—​the therapeutic use of specific wavelengths of light to treat skin disorders such as psoriasis, vitiligo, or neonatal jaundice. The intense light exposure can temporarily alter the retinal pigment epithelium or interfere with cone cell function, leading to a yellow hue over the visual field.

Most cases are transient and resolve after the light exposure ends, but persistent xanthopsia may indicate underlying retinal or neurological involvement that requires further evaluation.

Sources: Mayo Clinic; National Institutes of Health (NIH); Cleveland Clinic.

Common Causes

Besides phototherapy, a variety of medical conditions, medications, and environmental factors can produce xanthopsia. The most frequently reported causes include:

• Phototherapy – narrow‑band UVB, broadband UVB, or UVA exposure for skin diseases.
• Medications – digoxin, quinidine, thioridazine, and certain antibiotics (e.g., chlorpromazine).
• Retinal diseases – macular degeneration, retinal detachment, or central serous chorioretinopathy.
• Liver dysfunction – jaundice or bilirubin accumulation can tint the visual field.
• Vitamin A toxicity – hypervitaminosis A may alter cone photoreceptor activity.
• Neurological disorders – migraine aura, epilepsy, or occipital lobe lesions.
• Metabolic disturbances – hypoglycemia or electrolyte imbalance.
• Heavy metal poisoning – lead or mercury exposure.
• Age‑related changes – cataracts can scatter short‑wavelength light, making yellow appear more prominent.
• Psychiatric medications – certain antipsychotics and antidepressants are linked to color‑vision changes.

When phototherapy is the suspected trigger, the timing of symptom onset (usually during or shortly after treatment sessions) is a key clue.

Associated Symptoms

Patients with xanthopsia often report additional visual or systemic findings, such as:

• Reduced contrast sensitivity
• Glare or halos around lights
• Blurry or hazy vision
• Photophobia (light sensitivity)
• Headache or eye strain, especially after prolonged light exposure
• Accompanying skin irritation or burns at the phototherapy site
• Systemic signs of medication toxicity (nausea, fatigue, cardiac arrhythmia with digoxin)
• Yellowing of the skin or sclera (indicative of jaundice)

When to See a Doctor

Because xanthopsia can signal eye or systemic disease, prompt medical attention is advised if any of the following occur:

• Visual changes persist more than 24–48 hours after the last phototherapy session.
• Sudden onset of double vision, loss of peripheral vision, or “curtain‑like” visual loss.
• Severe headache, nausea, or vomiting accompanying the color distortion.
• History of heart medication (e.g., digoxin) with new visual changes.
• Signs of liver disease: dark urine, pale stools, abdominal pain, or yellow skin.
• Any eye pain, redness, or discharge.
• Difficulty performing daily tasks (reading, driving) due to the yellow tint.

Early evaluation helps rule out serious retinal or neurological pathology, and it may prevent permanent visual impairment.

Diagnosis

Healthcare providers use a stepwise approach to identify the cause of xanthopsia:

1. Detailed History

• Timing relative to phototherapy sessions or medication changes.
• Dosage and type of phototherapy (UVB vs. UVA, session length).
• Concurrent drugs, liver disease, or metabolic disorders.
• Family history of eye disease.

2. Comprehensive Eye Examination

• Visual acuity test – baseline measurement of clarity.
• Color vision testing – Ishihara plates, Farnsworth-Munsell 100‑Hue test.
• Fundoscopy – inspection of the retina, macula, and optic nerve for pathology.
• Optical coherence tomography (OCT) – high‑resolution imaging of retinal layers.
• Fluorescein angiography (if vascular lesions suspected).

3. Laboratory Work‑up

• Complete metabolic panel (liver enzymes, bilirubin).
• Serum digoxin level (if on cardiac glycosides).
• Vitamin A level, heavy‑metal screen (lead, mercury).
• Blood glucose and electrolytes.

4. Neurological Assessment

If retinal work‑up is unrevealing, a neurologist may order MRI of the brain/orbital region to exclude occipital lobe lesions or demyelinating disease.

Treatment Options

Management targets the underlying cause and relieves symptoms. Options include:

1. Discontinuation or Adjustment of the Offending Agent

• Temporarily stop phototherapy; switch to a lower‑intensity protocol if treatment is essential.
• Review medication list with a pharmacist—dose reduction or alternative drug may be needed (e.g., replace digoxin with a beta‑blocker).

2. Pharmacologic Interventions

• Ocular lubricants – artificial tears relieve dryness and photophobia.
• Systemic steroids – short courses can reduce inflammation in cases of central serous chorioretinopathy.
• Antioxidant supplements – lutein, zeaxanthin, and vitamin C may support retinal health (consult a physician first).

3. Visual Rehabilitation

• Prescription of tinted lenses (e.g., yellow‑filter glasses) to normalize color perception.
• Low‑vision therapy for persistent contrast deficits.

4. Addressing Systemic Issues

• Treat underlying liver disease (e.g., antiviral therapy for hepatitis, lifestyle modification).
• Correct vitamin A toxicity by stopping supplements and monitoring serum levels.
• Manage metabolic derangements (e.g., insulin for hypoglycemia).

5. Follow‑up Care

Most phototherapy‑related xanthopsia resolves within days to weeks after cessation. Follow‑up eye exams at 1‑month intervals are recommended until visual fields return to normal.

Prevention Tips

While some cases are unavoidable, patients and clinicians can reduce risk through the following measures:

• Customize phototherapy protocols – use the lowest effective UV dose, limit session time, and monitor skin response.
• Wear protective eyewear (UV‑blocking goggles) approved for the specific wavelength used.
• Schedule treatment sessions early in the day to avoid additional ambient sunlight exposure.
• Maintain up‑to‑date medication reviews; avoid known culprits when possible.
• Screen for liver disease before initiating long‑term phototherapy, especially in patients with alcohol use or hepatitis history.
• Educate patients about early visual symptoms and encourage prompt reporting.
• Ensure proper hydration and use of moisturizers to protect ocular surface during intense light exposure.
• Consider alternative therapies (topical agents, systemic biologics) for skin conditions when a patient shows high sensitivity to light.

Emergency Warning Signs

Key Take‑aways

Xanthopsia is a yellow‑tint visual disturbance that can arise after phototherapy or from a wide range of systemic and ocular conditions. While often transient, persistent or severe cases warrant thorough evaluation to exclude retinal disease, medication toxicity, or systemic illness. Prompt recognition, appropriate eye protection, and collaboration between dermatologists, ophthalmologists, and primary‑care providers are essential for safe management and prevention.

For further reading, consult reputable sources such as the Mayo Clinic, CDC, NIH, and the Cleveland Clinic.

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