Ophthalmologists Miss Claire Daniel and Miss Dania Qatarneh continue our series on common eye problems
A 35-year-old man presents to his GP with a painful, red and photophobic right eye. It has been gradually getting worse over the past week and is associated with a watery discharge. He is otherwise well and denies any past ocular history – including contact-lens wear or trauma. On examination, his visual acuity is 6/6 unaided. He has bilateral lid margin disease (blepharitis), crusty lid margins with hyperaemia and telangiectatic changes. He has right inferior conjunctival hyperaemia and a peripheral small corneal white infiltrate, which stains with fluorescein.
Differential diagnosis
The main two diagnoses to consider here are microbial keratitis and marginal keratitis. The absence of contact-lens wear and trauma, with the presence of blepharitis, makes microbial keratitis less likely. The peripheral location of the infiltrate and relatively long duration of symptoms also support a diagnosis of marginal keratitis.
The problem
Marginal keratitis is an immune-mediated inflammatory condition of the peripheral cornea, secondary to lid-margin disease. It is self-limiting, though treatment can relieve symptoms and shorten the clinical course. Marginal keratitis occurs most frequently in patients suffering from chronic staphylococcal keratitis or blepharitis.
Features
Symptoms include a red, painful eye and photophobia that develops over days. Examination reveals evidence of blepharitis with localised conjunctival injection and a peripheral corneal white infiltrate.
Referral and treatment
Treatment should target both the keratitis and blepharitis as the source of inflammation. Lid hygiene should be encouraged to treat the blepharitis, with the addition of staphylococcal cover with fusidic acid or chloramphenicol. This patient was started on fusidic acid twice a day. Given that the mainstay of treatment for keratitis is topical steroids, a referral to the local eye emergency services is needed before starting steroid treatment.
The patient was seen the next day in his local eye unit, where the diagnosis was confirmed and prednisolone 0.5% was added to his treatment – four times a day for the first week and twice a day for the second. Follow-up was arranged in the eye clinic two weeks later to ensure resolution of the disease, and to check for potential side-effects of topical steroid use – mainly elevation of intraocular pressure.
Prognosis is good, but patients should be warned about the risk of recurrence, particularly given the chronicity of blepharitis. Regular lid hygiene can help to limit the frequency of recurrences.
Miss Claire Daniel is a consultant ophthalmic surgeon and Miss Dania Qatarneh is a specialist registrar at Moorfields Eye Hospital London
