Can a scotoma be caused by a hole in the retina, such as a retinal tear or macular hole?

Retinal Holes Can Cause Scotomas

Yes, a hole in the retina can definitely cause a scotoma, with the specific visual field defect depending on the location and size of the retinal defect. 1, 2

Types of Retinal Holes and Associated Scotomas

Full-Thickness Macular Holes

• When located in the macula (central retina), retinal holes cause central scotomas that directly affect central vision
• Patients typically experience metamorphopsia (distorted vision) and decreased visual acuity, which may progress to a central scotoma as the macular hole enlarges 1
• Macular holes are anatomic discontinuities of the neurosensory retina that develop in the center of the macula or fovea 1

Peripheral Retinal Holes/Breaks

• Full-thickness defects in the peripheral retina can cause peripheral scotomas
• Retinal breaks are classified as:
  • Tears (caused by vitreoretinal traction)
  • Holes (round and unassociated with vitreoretinal traction) 1
  • Retinal dialysis (crescentic peripheral break at the ora serrata, usually from trauma) 1

Microholes of the Macula

• These are smaller full-thickness holes (50-133 micrometers) that cause acute onset of central scotoma with mild to moderate visual acuity loss 3
• Distinguished from larger idiopathic macular holes by their smaller size and better prognosis

Mechanism of Scotoma Formation

1. Direct Tissue Loss: The scotoma directly corresponds to the area where retinal tissue is absent (the hole itself)
2. Surrounding Retinal Detachment: If fluid passes through the hole and causes surrounding retinal detachment, the scotoma may be larger than the hole itself 1, 2
3. Progression Risk: Untreated retinal holes, especially those with persistent vitreoretinal traction, can lead to rhegmatogenous retinal detachment with expanding scotomas 2

Clinical Presentation and Diagnosis

• Patients with macular holes typically report:
  • Metamorphopsia (distorted vision)
  • Decreased visual acuity
  • Central scotoma (as the hole enlarges) 1
• Patients with peripheral retinal holes may be asymptomatic or report:
  • Floaters
  • Flashes of light
  • Peripheral visual field defects if detachment occurs 2

Diagnostic Approach

• Dilated funduscopic examination is the gold standard for diagnosis 2
• Optical Coherence Tomography (OCT) provides high-resolution imaging of the retinal architecture and can confirm the presence and extent of retinal holes 1, 2
• Visual field testing can map the scotoma and correlate with the anatomical defect 4, 5

Treatment Considerations

• Macular Holes: Vitrectomy surgery with internal limiting membrane peeling has approximately 90% success rate for holes <400 μm 1

  • Early detection is associated with higher closure rates and better visual outcomes 1
  • Potential complication: Paracentral scotomas may develop after surgery in some cases 4, 5

• Peripheral Retinal Breaks: Prompt treatment of symptomatic retinal breaks with laser photocoagulation or cryotherapy reduces risk of retinal detachment to less than 5% 2

Important Clinical Pearls

• Not all retinal holes cause symptomatic scotomas - peripheral holes may be asymptomatic until they progress to retinal detachment
• The location of the scotoma corresponds to the location of the retinal defect - macular holes cause central scotomas, while peripheral holes cause peripheral field defects
• Early detection and treatment of retinal holes is crucial to prevent progression to retinal detachment and permanent vision loss 2
• Post-surgical scotomas can occur as a complication of vitrectomy for macular holes, typically in the temporal and lower periphery of the visual field 4