What is the risk of blindness associated with liquid threading?

Risk of Blindness Associated with Liquid Threading

Liquid threading carries a significant risk of blindness due to vascular occlusion, with no consistently successful treatments available for vision recovery once blindness occurs.

Mechanism of Vision Loss with Liquid Threading

Liquid threading (filler injections) can cause blindness through vascular complications, primarily through:

1. Vascular occlusion: Filler material can enter the ophthalmic arterial system through:

   • Retrograde flow into the ophthalmic artery
   • Embolization of filler material into retinal circulation
   • Compression of vessels supplying the eye

2. High-risk anatomical areas:

   • Nose (40.6%)
   • Forehead (27.7%)
   • Glabella (38.8%)
   • Nasolabial fold (13.3%) 1, 2

Incidence and Prognosis

The risk of blindness from filler injections is rare but devastating:

• Recovery rates are extremely poor:

  • 68.2% of cases have no vision recovery
  • 25.8% experience partial improvement
  • Only 6.0% achieve complete vision recovery 1

• Associated complications:

  • Ptosis (56.2%)
  • Ophthalmoplegia (44.1%)
  • Pain (31.2%)
  • Skin changes (73.2%)
  • Stroke-like features (19.2%) 1

Risk Factors

The risk of blindness is influenced by:

1. Filler type:

   • Autologous fat (47.9%) carries the highest risk
   • Hyaluronic acid (79.6% of recent cases) is also commonly implicated 1, 2

2. Injection technique:

   • Rapid, high-pressure injections
   • Large bolus injections
   • Deep injections near vascular structures

3. Patient factors:

   • Previous facial surgeries
   • Anatomical variations in vasculature

Prevention Strategies

To minimize the risk of blindness:

1. Anatomical knowledge:

   • Thorough understanding of facial vascular anatomy is essential
   • Recognize danger zones (glabella, nasal region, nasolabial fold)

2. Injection technique:

   • Use small-gauge needles or cannulas
   • Inject slowly with minimal pressure
   • Aspirate before injection
   • Use small volumes per injection site
   • Consider blunt-tipped cannulas in high-risk areas

3. Procedural considerations:

   • Avoid bolus injections in high-risk areas
   • Consider using vasoconstrictors to reduce vascular flow
   • Have hyaluronidase immediately available when using hyaluronic acid fillers

Management of Vascular Complications

If vision changes occur during or immediately after injection:

1. Immediate actions:

   • Stop injection immediately
   • For hyaluronic acid fillers, inject high-dose hyaluronidase at the site of injection
   • Consider retrobulbar or peribulbar hyaluronidase injection (by ophthalmologist)
   • Massage the area to potentially dislodge emboli

2. Medical interventions:

   • Systemic steroids to reduce inflammation
   • Consider intraarterial thrombolytic therapy
   • Ocular massage
   • Topical nitroglycerin
   • Carbogen therapy (95% oxygen, 5% carbon dioxide)

3. Urgent referral:

   • Immediate ophthalmology consultation
   • Consider emergency department evaluation for possible stroke symptoms

Treatment Effectiveness

Unfortunately, no treatments have been found to be consistently successful in treating blindness once it occurs:

• No specific treatments were significantly associated with visual improvement (P > .05) 1
• Partially preserved visual acuity at onset was the only significant predictor of visual improvement (P < .001) 1

Conclusion

The risk of blindness from liquid threading, while rare, represents a devastating complication with poor recovery prospects. Prevention through thorough anatomical knowledge, proper injection techniques, and immediate recognition of complications is paramount, as no treatment has proven consistently effective once vision loss occurs.