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Episcleritis

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Overview

Episcleritis is the inflammation of the episclera and is benign and self-limiting. The episclera is a thin layer of tissue that lies between the conjunctiva and the sclera (the white part of the eye). Episcleritis is common and does not progress to scleritis. 

Epidemiology

  • Most cases are idiopathic, but some cases can be associated with systemic inflammatory disease
  • Prevalence is uncertain, but it happens most often in younger patients up to the 5th decade

Risk Factors

Presentation

Episcleritis is classically not painful, but there may be mild pain. Features are:

  • Classically painless red eye – there still may be mild pain
    • The redness may be localised or diffuse
  • Visual acuity is normal
  • Can be bilateral or unilateral
  • Mild watering
  • Mild discomfort e.g. photophobia
  • Injected vessels are mobile when gentle pressure is applied
  • Applying phenylephrine drops improves eye redness

Differential Diagnoses

Anterior uveitis

  • Pain – may be worse with use i.e. reading something close by
  • Photophobia is more prominent
  • Ciliary flush may be present
  • Pupil margins may be irregular
  • Associated autoimmune disease/infection may be present

Scleritis

  • Classically painful red eye but the pain may only be mild
  • Watering and/or photophobia may be present
  • Injected vessels are not mobile and do not move with gentle pressure
  • Phenylephrine eye drops do not improve eye redness

Acute angle-closure glaucoma

  • Severe ocular pain/headache with or without associated nausea/vomiting 
  • Blurred vision and halos around light surfaces

Optic neuritis

  • There is pain in eye movement, but no red eye
  • Colour desaturation may be seen – colours appear faded/washed-out

Investigations

Overview

  • Slit-lamp examination:
    • No scleral inflammation seen
  • Diagnosis is clinical and based on the history and examination findings
  • Consider tests if there is suspected systemic disease e.g. anti-nuclear antibody for SLE

Management

  • 1st-line: conservative management + artificial tears
  • If more severe, consider corticosteroid eyedrops under ophthalmic supervision

Patient Advice

  • Patients should be reassured that the condition is benign and resolves in 1-2 weeks
  • Patients should be made aware that episodes can occur in the other eye
  • Patients should be safety-netted on concerning features such as pain in eye movement, visual changes etc.

Complications

  • Involvement of ocular structures – very rare
  • Complications of corticosteroids – rebound inflammation on withdrawal, ocular hypertension and steroid-induced glaucoma

Prognosis

  • Usually resolves over 1-2 weeks

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