What is the primary care evaluation for visual floaters?

Primary Care Evaluation for Visual Floaters

Patients with acute-onset floaters should be urgently referred to an ophthalmologist for same-day evaluation to rule out sight-threatening conditions such as retinal tears or detachment. 1

Initial Assessment in Primary Care

History

• Duration and onset of floaters (sudden vs. gradual)
• Characteristics of floaters (number, size, movement)
• Associated symptoms:
  • Flashes of light (photopsia)
  • Visual field defects or shadows
  • Subjective visual reduction (strongly associated with retinal tears, LR 5.0) 2
  • Pain
• Risk factors:
  • Age (>50 years increases risk of posterior vitreous detachment) 3
  • Myopia
  • Previous eye surgery or trauma
  • Previous retinal tears or detachment
  • Family history of retinal tears or detachment 1

Physical Examination

• Visual acuity measurement
• Pupillary assessment for relative afferent pupillary defect
• Confrontation visual fields
• Red reflex examination
• Penlight inspection of the anterior eye 1

Risk Stratification

High-Risk Features Requiring Same-Day Ophthalmology Referral:

• Sudden onset of numerous floaters
• Floaters accompanied by flashes of light
• Subjective visual reduction (LR 7.9 for urgent retinal pathology) 4
• Visual field defect or "curtain" in vision
• Recent eye trauma or surgery
• History of retinal detachment in either eye

Moderate-Risk Features:

• New-onset floaters without other symptoms
• Gradual increase in pre-existing floaters
• High myopia

Low-Risk Features:

• Long-standing stable floaters
• No associated symptoms
• Normal visual acuity

Management Algorithm

1. For high-risk features:

   • Same-day referral to ophthalmology for dilated fundoscopic examination with scleral depression 1, 2
   • Educate patient about warning signs requiring immediate attention

2. For moderate-risk features:

   • Referral to ophthalmology within 1-2 weeks
   • Clear instructions about warning signs requiring immediate re-evaluation

3. For low-risk features:

   • Routine ophthalmology referral
   • Reassurance that most isolated floaters are not sight-threatening

Follow-up Recommendations

• Patients initially diagnosed with uncomplicated posterior vitreous detachment (PVD) have a 3.4% chance of developing a retinal tear within 6 weeks 2
• Instruct patients to return immediately if they experience:
  • Significant increase in number of floaters (≥10 new floaters, LR 8.1-36 for retinal tear) 2
  • New flashes of light
  • Visual field defects
  • Decrease in visual acuity (LR 2.3-17 for retinal tear) 2

Clinical Pearls and Pitfalls

• Vitreous hemorrhage on slit-lamp examination is the strongest predictor of retinal tear (LR 10) 2
• Multiple small floaters are frequently associated with vitreous hemorrhage and retinal breaks 3
• 95% of floaters in patients over 50 years are related to acute onset of PVD 3
• Never dismiss acute-onset floaters as benign without ophthalmologic evaluation 1
• Absence of vitreous pigment on examination reduces likelihood of retinal tear (negative LR 0.23) 2
• Visual acuity assessment is essential in all patients with floaters 2

By following this structured approach to evaluating visual floaters in primary care, clinicians can appropriately triage patients and ensure timely referral for those at risk of vision-threatening complications.