What is the appropriate management within the first 12 hours after an intravitreal anti‑VEGF injection for a patient who presents with tearing and swelling?

Management of Tearing and Swelling Within 12 Hours Post-Intravitreal Anti-VEGF Injection

Immediately assess for infectious endophthalmitis versus sterile inflammation by examining for pain severity, visual acuity loss, hypopyon, and vitritis—if infectious endophthalmitis is suspected, perform urgent vitreous tap with intravitreal antibiotics (vancomycin and ceftazidime) within hours of presentation.

Algorithmic Approach to Early Post-Injection Complications

Step 1: Rapid Clinical Assessment (Within Hours)

Distinguish between three primary diagnoses based on specific clinical features:

Infectious Endophthalmitis:

• Timing: Typically 2-8 days post-injection (mean 4.3 days) 1, 2
• Key features: Severe pain, rapid vision loss (often to counting fingers or worse), hypopyon, dense vitritis preventing fundus view
• Pupil: May be sluggish or have relative afferent pupillary defect
• Conjunctiva: Marked hyperemia and chemosis

Sterile Endophthalmitis:

• Timing: 24-48 hours post-injection 3, 4
• Key features: Minimal to NO pain (critical distinguishing feature), vitreous haze, anterior chamber reaction
• Vision: Decreased but often better than infectious cases
• Presentation: Less severe overall inflammatory response

Simple Post-Injection Reaction:

• Timing: Within 12-24 hours
• Key features: Mild tearing, lid swelling, minimal conjunctival injection
• Vision: Preserved or minimally affected
• No vitritis or anterior chamber reaction

Step 2: Immediate Management Based on Diagnosis

If Infectious Endophthalmitis is Suspected:

The guidelines emphasize that severe adverse effects require urgent intervention 5. Perform immediate vitreous tap and intravitreal antibiotic injection 1:

• Vancomycin 1.0 mg in 0.1 mL
• Ceftazidime 2.25 mg in 0.1 mL
• Consider adding intravitreal dexamethasone 0.4 mg 6
• Send vitreous sample for culture and sensitivity
• Time is critical: delay worsens visual outcomes 1

Consider core vitrectomy if 2, 3:

• Dense vitritis preventing visualization
• No improvement within 24-48 hours
• Persistent inflammation despite antibiotics

If Sterile Endophthalmitis is Suspected:

Recent evidence supports early vitrectomy for rapid resolution 3:

• Complete and early vitrectomy (CEVE protocol) with antibiotic infusion
• Intraoperative cultures (will be negative)
• Intravitreal dexamethasone
• Resolution typically occurs within 30 days with return to baseline vision 3

If Simple Post-Injection Reaction:

Conservative management:

• Topical corticosteroids (prednisolone acetate 1% four times daily)
• Artificial tears for surface irritation
• Close observation at 24-48 hours
• No antibiotics needed if no infection suspected 5

Step 3: Critical Pitfalls to Avoid

Do NOT:

• Delay treatment while awaiting culture results if endophthalmitis is suspected—treat empirically 1
• Use routine prophylactic antibiotics post-injection, as they do not reduce endophthalmitis risk and may promote resistance 5, 7
• Assume all inflammation is sterile—infectious endophthalmitis requires immediate intervention 8, 4
• Patch the eye or use therapeutic contact lenses, which increase infection risk 9

DO:

• Examine the fellow eye for sympathetic inflammation (rare but reported) 10
• Check intraocular pressure, as transient elevation is common 11, 12
• Document baseline visual acuity and pupillary response 5
• Perform gonioscopy if IOP elevated or anterior chamber reaction present 5

Step 4: Follow-Up Timing

Infectious endophthalmitis: Daily examination until improving, then every 2-3 days 1

Sterile endophthalmitis: Examine at 24-48 hours post-vitrectomy, then weekly until resolved 3

Simple reaction: Re-examine at 24-48 hours; if worsening, escalate to endophthalmitis protocol 4

Key Evidence Considerations

The guidelines consistently emphasize that topical povidone-iodine before injection is mandatory, but routine antibiotic drops are not recommended and may be harmful 5, 7. In the DRCR.net studies, all five endophthalmitis cases occurred in patients using topical antibiotics, while zero cases occurred among 2,500 injections without antibiotics 7.

The distinction between infectious and sterile endophthalmitis is critical: infectious cases have culture-positive rates of 75% (predominantly coagulase-negative Staphylococcus) 1, while sterile cases have negative cultures but may present with severe inflammation requiring vitrectomy 3, 6.

Visual outcomes are generally favorable if treated promptly: patients can return to baseline vision and resume anti-VEGF therapy after resolution 1, 2. However, delayed treatment significantly worsens prognosis 1.