What causes black spots in my vision and how are they treated?

Black Spots in Vision: Causes and Treatment

Black spots in vision most commonly represent floaters from posterior vitreous detachment (PVD), which affects 14% of patients presenting with acute-onset floaters and carries a significant risk of retinal tear requiring urgent ophthalmologic evaluation. 1

Immediate Risk Stratification

When a patient presents with black spots in vision, you must immediately assess for retinal tear or detachment, which can cause permanent vision loss if untreated. 1, 2

High-Risk Features Requiring Urgent Ophthalmology Referral:

• Subjective visual reduction (most important symptom; increases retinal tear likelihood 5-fold) 1
• New onset of ≥10 floaters (increases risk 8-36 fold) 1
• Flashing lights accompanying the floaters 1, 2
• Vitreous hemorrhage on examination (increases retinal tear likelihood 10-fold) 1
• Curtain or shadow in peripheral vision 2, 3

Assessment Protocol:

• Always measure visual acuity in any patient with acute-onset floaters or black spots 1
• Examine for vitreous pigment on slit-lamp biomicroscopy if available (absence reduces retinal tear likelihood to 23% of baseline) 1
• Document whether symptoms are monocular or binocular 1
• Assess timing: acute onset (hours to days) versus gradual 1

Common Causes of Black Spots

1. Posterior Vitreous Detachment (Most Common)

PVD is the most likely diagnosis in patients presenting with acute monocular floaters. 1 The vitreous gel separates from the retina, creating shadows perceived as black spots or floaters.

• Prevalence of retinal tear in acute PVD: 14% (95% CI, 12%-16%) 1
• Even patients initially diagnosed with uncomplicated PVD have a 3.4% chance of developing retinal tear within 6 weeks 1
• Any change in symptoms during follow-up period warrants re-evaluation 1

2. Retinal Tear or Detachment

This is a vision-threatening emergency requiring same-day ophthalmology referral. 2, 3

• Presents with sudden onset of floaters, flashes, and/or visual field defects 2
• Delay in treatment results in permanent vision loss 2, 3

3. Vitreous Hemorrhage

• Appears as sudden onset of multiple black spots or "shower of floaters" 1
• Most strongly associated with retinal tear (LR 10; 95% CI, 5.1-20) 1
• Requires urgent ophthalmologic assessment 2

4. Age-Related Macular Degeneration (AMD)

Black spots in central vision may represent scotomas from geographic atrophy or choroidal neovascularization. 4

• Typically bilateral and gradual in onset 4
• Associated with drusen, retinal pigment epithelial changes, or subretinal hemorrhage 4
• Risk factors: age >60, smoking, family history, white race 4

5. Glaucoma-Related Visual Field Defects

Advanced glaucoma can cause black spots in peripheral vision from optic nerve damage. 5, 3

• Black patients present with more extensive optic nerve damage and require higher medication concentrations 5
• Often asymptomatic until advanced stages 3
• Requires funduscopic examination for optic disc cupping 3

6. Surgical Complications (Context-Specific)

In patients who have undergone refractive surgery, "black spots" may refer to areas where femtosecond laser failed to cut effectively. 4

• Incidence: 0.3% in keratorefractive surgery 4
• Not relevant to typical patient presenting with visual symptoms 4

Management Algorithm

Step 1: Triage for Emergency Referral

Refer urgently (same day) to ophthalmology if ANY of the following:

• Subjective vision reduction 1
• ≥10 new floaters 1
• Flashing lights 1, 2
• Visual field defect (shadow/curtain) 2, 3
• Vitreous hemorrhage 1

Step 2: For Lower-Risk Presentations

If patient has isolated floaters without high-risk features:

• Document visual acuity 1
• Provide patient education about warning signs 1
• Schedule ophthalmology evaluation within 1-2 weeks 1
• Instruct patient to return immediately if symptoms worsen or new symptoms develop 1

Step 3: Follow-Up Monitoring

Even patients with initially uncomplicated PVD require monitoring, as 3.4% develop retinal tears within 6 weeks. 1

Return immediately if:

• New onset of ≥10 floaters (LR 8.1-36 for retinal tear) 1
• Subjective visual reduction (LR 2.3-17 for retinal tear) 1
• Any new flashing lights 1

Critical Pitfalls to Avoid

• Never reassure a patient with subjective vision loss that floaters are benign without ophthalmologic examination 1
• Do not delay referral for patients with high-risk features, as retinal detachment treatment outcomes worsen with time 2, 3
• Do not assume bilateral symptoms are benign—assess each eye separately 1
• Black patients with glaucoma require more aggressive screening and treatment due to higher rates of blindness and more advanced disease at presentation 5
• In patients over 60 with gradual onset central black spots, consider AMD and evaluate for drusen and retinal pigment epithelial changes 4