What should I do if I still see a negative image of the flash over a week after retinography (retinal photography)?

Management of Persistent Flash Afterimage Following Retinography

If you are experiencing a negative image of the flash for over a week after retinal photography, you should promptly consult an ophthalmologist for evaluation, as this persistent afterimage could indicate underlying retinal pathology that requires assessment.

Understanding Flash Afterimages

Persistent afterimages following retinal photography (retinography) are not normal when they last more than a week. While brief afterimages are common immediately after flash exposure, prolonged afterimages may indicate:

• Potential retinal damage
• Posterior vitreous detachment (PVD)
• Retinal breaks or tears
• Early signs of retinal detachment

Recommended Evaluation

Immediate Assessment

An ophthalmologic evaluation should include:

• Visual acuity testing 1
• Slit-lamp biomicroscopy 1
• Dilated fundus examination with scleral depression 1
• Examination of the vitreous for hemorrhage, detachment, and pigmented cells 1
• Assessment for relative afferent pupillary defect 1

Additional Testing

Based on initial findings, your ophthalmologist may recommend:

• Optical coherence tomography (OCT) to evaluate retinal architecture 1
• Fluorescein angiography to assess retinal circulation 1
• B-scan ultrasonography if media opacity prevents adequate examination 1, 2
• Visual field testing to map any scotoma 2

Clinical Significance

Persistent visual phenomena after flash exposure require attention because:

1. They may represent early signs of retinal pathology that could progress to vision-threatening conditions 1, 3
2. Studies show that 10.5% of patients presenting with new visual symptoms (flashes/floaters) have flat retinal tears, and 16.6% have retinal detachments 3
3. Even if initial examination is normal, approximately 2% of patients with acute PVD may develop retinal breaks in the following weeks 1

Follow-up Recommendations

If no pathology is identified at the initial examination:

• A follow-up examination within 6 weeks is recommended, particularly if there is any vitreous pigment, hemorrhage, or visible vitreoretinal traction 1
• Patients should be instructed to return immediately if they experience new or worsening symptoms such as:
  • Increased floaters
  • Flashes of light
  • Visual field loss
  • Decreased visual acuity 1, 2

Important Considerations

• Recovery from flash exposure is typically quick, with electroretinography showing faster recovery than neural visual pathways 4
• Persistent afterimages beyond a week are not part of normal recovery and warrant investigation
• Patients with high myopia or previous eye surgery are at increased risk for retinal complications and should be monitored more closely 1, 2

Remember that early detection and treatment of any underlying retinal pathology is crucial for preserving vision. Do not dismiss persistent afterimages as they may be an important warning sign of retinal problems requiring intervention.