Author: Claude (AI), from PubMed abstracts · Reviewed by: Dr Mina Abdelmseih · Reviewed: 2026-11-15 · Review due: 2027-11-15

Educational content only. Not personalised medical advice. Clinical decisions remain the responsibility of the treating clinician.

Safety of intravitreal drugs: inflammation, vasculitis and endophthalmitis

Intravitreal injection is one of the most commonly performed procedures in ophthalmology [S7] [S9]. Injections are generally well tolerated, but sight-threatening complications can occur, including endophthalmitis, retinal detachment and retinal vasculitis [S7]. Some newer anti-VEGF drugs carry higher rates of intraocular inflammation and occlusive vasculitis than established agents [S5] [S12].

Key points - The three inflammatory adverse events after anti-VEGF injection are sterile intraocular inflammation, brolucizumab-associated retinal vasculitis and post-injection endophthalmitis; their overlapping features can make them hard to tell apart [S6]. - Across phase 3 nAMD trials, abicipar pegol and brolucizumab had more intraocular inflammation, retinal vasculitis and retinal artery occlusion than established agents [S12]. - Intravitreal vancomycin can cause haemorrhagic occlusive retinal vasculitis with severe vision loss [S7]. - Endophthalmitis is the most feared complication; povidone-iodine effectively reduces its risk [S4] [S8]. - Systemic adverse events (cardiovascular, renal, neurological) are possible despite intraocular delivery, especially in people with diabetes and older patients with multimorbidity [S11].

Evidence last checked: 2026-10-17 (PubMed abstracts).

Red flags

• Pain, worsening vision or increasing inflammation after an injection: consider endophthalmitis first, as it is the most concerning complication [S7] [S4].
• Vision loss with inflammation after brolucizumab: occlusive retinal vasculitis has been reported in the setting of intraocular inflammation [S5].
• Severe vision loss after intravitreal vancomycin (haemorrhagic occlusive retinal vasculitis) [S7].
• Recent or multiple strokes in a patient starting anti-VEGF therapy [S1].

Recognise it

• Anterior segment complications include hyphaema, sterile anterior segment inflammation (incidence 0.05 to 1.1% depending on the drug), implant migration with corneal decompensation (0.43%), lens damage (0.07%) and accelerated cataract (up to 50% with steroids and 10.9% with anti-VEGF) [S9]. Most occur immediately and have a good prognosis if treated correctly [S9].
• Later surgery. Each injection is associated with an increased complication rate in subsequent cataract surgery (up to 4% per injection) [S9].
• Diabetes. People with diabetes may be at higher risk of adverse events because of cardiovascular and renal comorbidity and greater susceptibility to infection [S2].
• Systemic risk. In patients at high arteriothrombotic risk with high exposure (for example monthly aflibercept or ranibizumab for DMO), studies show increased all-cause mortality vs randomised controls; overall the evidence is inconsistent [S1].

Confirm it

• A narrative review describes distinguishing features of sterile inflammation, brolucizumab vasculitis and endophthalmitis [S6]; details are in the full text, not the abstract.
• Endophthalmitis is the most concerning complication, so keep it at the top of the differential for any post-injection inflammation [S7].

Manage it: safe injection practice

Before acting on this section, check the national and local guidelines, product information and regulatory approvals that apply where you practise. See the medical disclaimer.

Tier A (primary care / no specialist)

• Tier A staff do not give injections. Teach injected patients to report pain, redness or reduced vision promptly after any injection, and refer at once (see Refer when) [S7].
• Ask injected patients about recent stroke and cardiovascular events and pass this to the eye team [S1] [S11].

Tier B (general eye clinic, injecting service)

• Antisepsis. Povidone-iodine reduces endophthalmitis after intravitreal injection [S8]. If it is poorly tolerated, lower concentrations or chlorhexidine are alternatives [S8]. Povidone-iodine can cause eye pain, persistent epithelial defects and inflammation [S8].
• Technique. Topical antisepsis, hand hygiene, gloves, masks and drapes have been proposed, with significant variation in protocols [S4]. Face mask use by patient and physician is not associated with increased endophthalmitis and may reduce culture-positive cases [S7].
• Drug choice. Weigh the benefits of brolucizumab and abicipar pegol against their higher ocular adverse event rates [S12]. In HAWK and HARRIER, overall safety of brolucizumab looked similar to aflibercept at 48 weeks [S3]; inflammation and vasculitis signals emerged in later analyses [S5] [S12].
• Doses are not covered here: follow product labelling and local protocols.

Tier C (specialist centre)

• Manage suspected endophthalmitis, vasculitis and retinal artery occlusion as vitreoretinal emergencies [S7] [S12].
• Consider special measures for patients at higher systemic risk, such as those with recent or multiple strokes [S1].
• Monitor real-world safety of newly approved agents, including faricimab, aflibercept 8 mg, the ranibizumab port delivery system and complement inhibitors for geographic atrophy [S10].
• Report suspected adverse events to pharmacovigilance systems; early identification of systemic adverse effects can lessen severity [S11].

Refer when

Pitfalls

• Treating post-injection inflammation as sterile without considering endophthalmitis [S6].
• Assuming all anti-VEGF drugs have the same safety profile [S5] [S12].
• Relying only on registration trial safety data [S3] [S10].
• Forgetting the systemic effects of intraocular drugs in frail and diabetic patients [S2] [S11].

Evidence notes

• Conflict: the registration trials reported brolucizumab safety similar to aflibercept [S3], whereas pooled phase 3 data and later reviews found more inflammation, vasculitis and artery occlusion [S5] [S12].
• Evidence on systemic risk is inconsistent, partly because trials exclude high-risk patients and are underpowered for rare events [S1].
• Incidence figures in [S9] come from a narrative review, not a systematic one.
• Not covered by these sources: treatment protocols for post-injection endophthalmitis, intravitreal steroid implant complications in detail, compounding and repackaging of bevacizumab, and injection safety in low-resource settings.

Related articles

• Post-operative endophthalmitis
• Anti-VEGF biosimilars and off-label bevacizumab
• Next-Generation Anti-VEGF and Long-Acting Retinal Drugs

References

See the numbered source list below. Each marker [S#] links to its PubMed and DOI record.