Cornea
Marginal Keratitis
Also known as: marginal keratitis, staphylococcal marginal keratitis, peripheral corneal infiltrate, blepharitis keratitis, catarrhal ulcer, marginal ulcer, staphylococcal hypersensitivity keratitis, peripheral corneal opacity
Filed as: Soon
Source-cited from the record's own evidence list. Clinical content programme led by Dr Ankit Mathur, PhD, Grad Cert Ocu Thera, B.S. Optom. How the clinical content is governed
Clinical decision support only
Overview
A hypersensitivity reaction to staphylococcal antigens in chronic staphylococcal blepharitis (immune-complex and cell-mediated mechanisms have both been described). Presents as peripheral corneal infiltrates separated from the limbus by a clear zone. Common in patients with chronic lid margin disease. Distinct from bacterial keratitis — the infiltrates are sterile and stain minimally or not at all with fluorescein.
Recognition
Symptoms: what patients report
- Unilateral eye pain or irritation.
- Redness.
- Photophobia — variable.
- Tearing.
- Symptoms are typically less severe than microbial keratitis.
- Background history of blepharitis, lid margin disease, or chronic dry eye.
Signs: what the examination shows
- Peripheral (marginal) corneal infiltrates: grey-white opacities at the peripheral cornea, typically at 2, 4, 8, or 10 o'clock (lid margin contact zones).
- Clear zone between the infiltrate and the limbus — the defining sign; infiltrates do not extend to the limbus.
- Minimal or no fluorescein staining — sterile infiltrate with largely intact epithelium.
- Conjunctival injection, especially adjacent to the infiltrate.
- Underlying blepharitis: staphylococcal (anterior) signs — crusting, hard scales or collarettes at the lash base, lash loss; posterior (meibomian gland) signs — capped or plugged orifices, lid-margin telangiectasia.
- Multiple infiltrates in different quadrants in recurrent or bilateral disease.
What OptoGuide™ covers for marginal keratitis
- Pattern reasoning: what this combination of findings points to, and its differentiators
- Don't-miss risks and escalation triggers
- Management tiers with linked New Zealand therapeutics
- Referral urgency, specialty, and letter drafting
Sources
- Keratitis (marginal) — College of Optometrists CMG
- Marginal Keratitis — EyeWiki
- Anterior Eye Disease and Therapeutics A-Z (Bruce & Loughnan) — standard reference text
- Eye Infections. Durand ML, Barshak MB, Sobrin L. The New England Journal of Medicine. 2023;389(25):2363-2375.
- Peripheral Ulcerative Keratitis: Pathogenesis, Diagnosis, and Multimodal Management. Guerrero-Acosta JC, Ortiz-Morales G, Vera-Duarte GR, et al. Journal of Clinical Medicine. 2026;15(3):1264.
- Inflammatory Diseases of the Peripheral Cornea. Mondino BJ. Ophthalmology. 1988;95(4):463-72.
- CLEAR – Contact lens complications. Stapleton F, Bakkar M, Carnt N, et al. Contact Lens and Anterior Eye. 2021;44(2):330-367.
- Differential diagnosis of microbial keratitis and contact lens-induced peripheral ulcer. Aasuri MK, Venkata N, Kumar VM. Eye & Contact Lens. 2003;29(1 Suppl):S60-2.
- Staphylococcal infection and the limbus: study of the cell-mediated immune response. Ficker L, Seal D, Wright P. Eye. 1989;3(Pt 2):190-3.
- Blepharitis Preferred Practice Pattern. Amescua G, Akpek EK, Farid M, et al. Ophthalmology. 2019;126(1):P56-P93.
Standard texts: Kanski's Clinical Ophthalmology: A Systematic Approach, The Wills Eye Manual, Oxford Handbook of Ophthalmology, Oxford American Handbook of Ophthalmology, Signs in Ophthalmology: Causes & Differential Diagnosis.