Types of injections of the eyeball and types of corneal vascularization
Last updated: October 2026
Key points in 60 seconds
- Conjunctival injection: bright red, worst at the fornices, moves with the conjunctiva and blanches with phenylephrine.
- Ciliary injection: dusky, around the limbus, does not move or blanch: think keratitis, iritis, angle closure, scleritis.
- A red eye that does not blanch should be treated as serious until proven otherwise.
- Superficial corneal vessels branch from the conjunctiva and regress; deep vessels run straight in the stroma (interstitial keratitis).
- Deep vascularisation is a risk factor for graft rejection after keratoplasty.
- superficial (conjunctival) injection
- deep (pericorneal) injection
- mixed injection
- superficial vascularization of the cornea
- deep vascularization of the cornea
- mixed corneal vascularization
Distinguishing the injection patterns
| Pattern | Appearance | Suggests |
|---|---|---|
| Superficial (conjunctival) | Bright red, most pronounced toward the fornices, moves freely with conjunctiva, blanches with topical phenylephrine | Conjunctivitis, superficial irritation, dry eye, allergic conjunctivitis |
| Deep (pericorneal/ciliary) | Violaceous/dusky red, concentrated around the limbus, does not move with conjunctiva, does not blanch with phenylephrine | Keratitis, iritis/anterior uveitis, acute angle closure, scleritis — treat as serious until proven otherwise |
| Mixed | Both patterns together | Often more severe or combined anterior segment disease |
Practical bedside tip: the phenylephrine blanching test is useful for rapid triage — superficial vessels blanch, deep ciliary vessels do not. A red eye that fails to blanch should be treated as a sign of potentially serious disease.
Corneal vascularization patterns
- Superficial: vessels continuous with conjunctival vessels, crossing the limbus superficially in a branching, tree-like pattern — seen in chronic contact lens wear, superficial keratitis, phlyctenular disease. Tends to regress once the cause is treated
- Deep: vessels from the anterior ciliary/episcleral circulation, running straight and parallel in the deep stroma — classic for interstitial keratitis (congenital syphilis, herpes). More persistent, and a recognised risk factor for graft rejection if keratoplasty is later needed
- Mixed: both patterns together, seen in more severe or longstanding corneal disease
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Key sources
- American Academy of Ophthalmology. Basic and Clinical Science Course, Section 12: Retina and Vitreous (current edition)
- Avery RL, et al. Intravitreal injection technique and monitoring: updated guidelines of an expert panel. Retina. 2014;34(Suppl 12):S1-S18
📘 Want the exam-ready deep dive? This topic is covered in iNotes 2027: Basic Science & Optics (Ophthalmology Postgraduate Exam Notes) — available on Kindle. See all my books.
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