Can retinal photography cause phototoxicity?

Phototoxicity from Retinal Photography: Risk Assessment and Prevention

Yes, retinal photography can cause phototoxicity, particularly when combined with photosensitizing medications or with prolonged exposure times. 1

Mechanism and Risk Factors

Phototoxic maculopathy can occur from exposure to strong light sources used in ophthalmic procedures, including retinal photography. The risk increases with:

• Photosensitizing medications: Tetracyclines, retinoids, amiodarone, hydrochlorothiazide, furosemide, allopurinol, and benzodiazepines significantly increase phototoxicity risk 1, 2
• Exposure duration: Longer exposure times and multiple flashes increase risk 1, 3
• Light intensity: More powerful light sources used in modern imaging equipment increase potential damage 3
• Wavelength: Blue-violet light (425-445 nm) is particularly toxic to cone photoreceptors 4

Clinical Presentation

Patients with phototoxic maculopathy may present with:

• Scotomas (blind spots)
• Visual loss
• Yellow-gray sub-retinal lesions visible on fundus examination
• Hypofluorescent spots surrounded by hyperfluorescent window defects on fluorescein angiography 2

Prevention Strategies

To minimize the risk of phototoxicity during retinal photography:

1. Screen for photosensitizing medications before retinal photography 1
2. Minimize exposure time and number of flashes used during imaging 1
3. Use appropriate filters to reduce harmful wavelengths
4. Consider protective eyewear with UV filtering for patients at higher risk 1
5. Shield uninvolved areas similar to recommendations for phototherapy (e.g., covering face if not being imaged) 5

Management of Suspected Phototoxicity

If phototoxicity is suspected following retinal photography:

1. Perform OCT imaging to detect structural changes in the retina 1
2. Document baseline findings including comprehensive OCT scan
3. Conduct visual field testing if symptoms persist 1
4. Schedule follow-up in 1-3 months to confirm resolution and repeat OCT 1

Prognosis

The prognosis for phototoxicity from retinal photography is generally favorable:

• Complete visual recovery typically occurs within a few months
• Even with visual recovery, subtle retinal pigment epithelial disturbances may persist but usually without functional impact 1, 2
• Early detection and intervention before structural damage develops allows for the best outcomes 1

Special Considerations

• Patients with pre-existing retinal conditions may have increased susceptibility to phototoxicity
• The risk of permanent vision loss is significantly lower when initial OCT is normal 1
• Persistence of symptoms beyond 3-4 months or development of OCT abnormalities requires close monitoring 1

Retinal phototoxicity from diagnostic imaging represents a balance between obtaining necessary clinical information and minimizing risk to the patient. With proper precautions and awareness of risk factors, the likelihood of significant phototoxic damage can be substantially reduced.