What should be done for tearing and swelling after an intravitreal anti‑VEGF injection?

Management of Tearing and Swelling After Intravitreal Anti-VEGF Injection

For tearing and swelling after intravitreal anti-VEGF injection, immediately assess for infectious endophthalmitis versus sterile inflammation by examining for pain severity, hypopyon, fibrin reaction, and visual acuity—then treat with topical corticosteroids for sterile inflammation or urgent vitreous tap with intravitreal antibiotics if infection is suspected.

Immediate Clinical Assessment Algorithm

When a patient presents with tearing and swelling post-injection, you must rapidly differentiate between three main entities:

1. Sterile Intraocular Inflammation (Most Common)

• Presents with mild anterior chamber reaction (Tyndall +1 to +3) and vitritis
• Critically: NO severe pain, NO hypopyon, NO fibrin reaction 1
• Tearing and mild discomfort are common
• Visual acuity typically preserved or mildly reduced
• Occurs after mean of 7 injections, more common with aflibercept 1

2. Infectious Endophthalmitis (Most Dangerous)

• Represents 8.5% of endophthalmitis cases at tertiary centers 2
• Key distinguishing features: severe pain, rapid progression, hypopyon, fibrin, marked vision loss
• Coagulase-negative Staphylococcus most common (75% culture-positive rate) 2
• Streptococcus viridans shows particularly rapid, aggressive onset 2

3. Posterior Scleritis (Rare but Important)

• Severe pain, photophobia, and tearing as presenting symptoms 3
• More common with frequent biweekly injections
• B-scan ultrasound shows scleral thickening and choroidal folds 3

Treatment Protocol

For Sterile Inflammation (Most Likely Scenario):

• Initiate topical corticosteroid therapy immediately 1
• Expect visual recovery to baseline within 28 days
• Vitritis resolves in approximately 40 days 1
• You can safely continue the same anti-VEGF agent after resolution—no recurrence observed in patients who resumed treatment 1
• No systemic antibiotics needed

For Suspected Endophthalmitis:

• Perform immediate vitreous tap and inject intravitreal antibiotics 2
• Do NOT wait for culture results
• If vitritis persists despite initial treatment, suspect unusual organisms (Enterobacter cloacae, Lactococcus garvieae) and proceed to vitrectomy 2
• Long-term visual outcomes can return to baseline even after endophthalmitis if treated promptly 2

For Posterior Scleritis:

• Combination topical AND systemic corticosteroids 3
• Consider reducing injection frequency once resolved

Critical Pitfalls to Avoid

Do not assume all post-injection inflammation is infectious. The vast majority of inflammatory reactions are sterile and respond to topical steroids alone 1, 4. Overtreatment with antibiotics contributes to resistant organisms 5.

Do not discontinue anti-VEGF therapy permanently after sterile inflammation. Evidence shows safe resumption of the same agent without recurrence 1.

Do not miss the "red flags" for endophthalmitis: severe pain, hypopyon, fibrin, and rapid visual decline distinguish infection from sterile inflammation 1, 2.

Monitoring Strategy

• Sterile inflammation: Follow every 3-7 days until resolution
• Suspected endophthalmitis: Daily monitoring initially, then as clinically indicated
• Document baseline visual acuity to track recovery trajectory (should return to baseline within 4 weeks for sterile cases) 1

The evidence strongly supports that sterile inflammation is far more common than infectious endophthalmitis 1, 4, 6, making topical corticosteroids the appropriate first-line treatment for mild-to-moderate post-injection inflammation without severe pain or hypopyon.