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Painful red eye

Dr Tanvir Jamil discusses a common problem

Dr Tanvir Jamil discusses a common problem

Case history
Christine presents on Monday morning and complains of a painful red eye for the last two days. The eye is very watery, slightly painful and feels like there is something stuck under the eyelid. Her vision is slightly blurred.

What kind of conditions cause a red eye and how is the 'redness' different?
Eye complaints account for almost 60 in 1,000 consultations in general practice. Ten to 15 of these will be conjunctivitis.

A unilateral painful red eye accompanied by even mild visual loss must be treated with suspicion. Look out for:

  • bacterial conjunctivitis – redness is peripheral and bilateral with central sparing
  • episcleritis – condition is unilateral and segmental
  • scleritis – the whole eyeball looks purplish-red with accompanying visual loss and pain
  • acute iritis – redness is around the cornea and unilateral, corneal surface is dull, small occasionally irregular pupils
  • glaucoma – redness is unilateral, around the cornea, corneal surface is dull, oval shape pupils, no light response
  • corneal ulcer – redness around the cornea and unilateral corneal surface is dull
  • subconjunctival haemorrhage – there is localised haemorrhage with posterior limit present

What about discharge, discomfort and photophobia?
A watery red eye is often associated with viral conjunctivitis, allergic conjunctivitis, a foreign body and a corneal ulcer. Bacterial conjunctivitis will cause a purulent sticky discharge with crusting around the eyelids.

Conjunctivitis (bacterial or viral) will often cause a burning discomfort in the eyes. Allergic conjunctivitis feels gritty or itchy. Anterior uveitis causes moderate pain but glaucoma often causes severe pain accompanied by nausea, vomiting and headache. Patients often complain of severe photophobia in keratitis (such as arc eye or corneal ulcer).

Arc eye usually develops some hours after exposure. The discomfort feels like 'sand in the eye' and lasts 12 to 24 hours. It typically occurs in welders and sunbed users who do not use adequate eye protection.

What kind of questions do I need to ask in the history?

  • When did the symptoms begin?
  • Was there a precipitant: pollen, injury?
  • Is the eye sore or itchy?
  • Is there a discharge?
  • Do you have any problems with your vision?
  • Past medical history – anterior uveitis tends to affect the young and middle-aged. In almost half of people who present it is associated with systemic conditions such as Reiter's syndrome, ankylosing spondylitis, Still's disease, TB, sarcoid, Crohn's, syphilis and carcinomatosis
  • Do you wear contact lenses?
  • Are you on any medication? Anticholinergics or sympathomimetics can precipitate acute glaucoma
  • Have you had this before? Patients who have anterior uveitis tend to present periodically

What kind of eye examination would you consider in the general practice setting?

  • Look for purulent discharge. If it is obvious and bilateral, diagnosis is bacterial conjunctivitis. Give antibiotic eye drops and send home. If not present or not bilateral, examine the eye more closely
  • Bilateral eyelid oedema – allergic conditions such as hay fever or pet allergies
  • Herpes zoster lesions on the eyelid usually means that the eye is also involved. Give antiviral eye drops and refer to ophthalmology clinic to check surface of eye
  • Pattern of redness in eye
  • Assess pupillary reactions – a fixed, dilated, occasionally ovoid pupil means glaucoma. Miosis (a small, occasionally irregular pupil) may indicate anterior uveitis
  • Look under the eyelids to exclude foreign bodies – removal of which will give the patient instant relief
  • Examine the cornea and iris. A hazy cornea indicates acute glaucoma. Instilling a drop of fluorescein will reveal corneal lesions when inspected under a (preferably) blue light. Lesions appear green – abrasions as streaks, herpetic ulcers as dendritic and UV exposure as multiple punctuate lesions. Fungal lesions (candida, aspergillus) may show up as grey indolent ulcers
  • If you suspect glaucoma, a shallow anterior chamber may be noticed in the other eye. Raised intra-ocular pressure may also make the eyeball feel hard to digital pressure. The mean value for intraocular pressure is 15-16mmHg with a standard deviation of +/-2.5. The upper limit of normal is 21mmHg
  • Use an ophthalmoscope to detect corneal foreign bodies. A hypopyon (a fluid level of exudates) may also be seen in the anterior chamber, caused by leakage of proteins into the aqueous humour during an attack of anterior uveitis
  • Lastly, if the patient complains of visual impairment, measure the visual acuity with a Snellen chart

When would you refer to the eye clinic?

  • Impairment of visual acuity
  • Abnormal pupillary reactions – this could be acute glaucoma or severe iritis
  • If conjunctival infection is most marked around the pupil (suggestive of keratitis, corneal ulcer or intraocular pathology)
  • Corneal ulceration
  • Possible penetrating injury – may need CT scan
  • Cloudy fundus – acute glaucoma

I'm happy treating conjunctivitis and foreign bodies but what about trickier eye conditions?
Remember to refer corneal metallic foreign bodies as they can leave a 'rust ring'. All fungal infections and herpes zoster should be referred. The latter is usually treated with long-term steroids and topical aciclovir.

Acute closed-angle glaucoma is an ophthalmic emergency and inpatient treatment involves 2-4% pilocarpine to induce miosis (which opens up the closed angle) and acetazolamide. Once stable the patient undergoes a peripheral iridectomy (at the 12 o'clock position) in both eyes to allow free aqueous flow. Episcleritis is usually self-limiting. Treatment, if required, is usually with oral NSAIDs and steroid eye drops. Scleritis is a medical emergency and immediate referral is warranted for IV steroids.

Should GPs ever initiate steroid eye drops?
Almost never. The one exception is patients with a history of anterior uveitis who present with a unilateral red eye and ask you for their usual steroids. Prolonged anterior uveitis can lead to glaucoma (from disruption of aqueous flow), cataracts (from interference of lens metabolism), retinal detachment (from traction on the retina by vitreous strands) and macular oedema and degeneration. Therapy involves steroid eye drops and cyclopegic medication. Patients are best followed by an ophthalmologist.

Dr Tanvir Jamil is a GP trainer in Burnham, Buckinghamshire

Using an ophthalmoscope can detect corneal foreign bodies Using an ophthalmoscope can detect corneal foreign bodies

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