Emergency Medicine

PAINFUL, RED EYE

Ophthalmic Emergencies 421

Acute iritis

DIAGNOSIS

1 Although most cases are idiopathic, iritis is occasionally due to exogenous
infection from a perforating wound or corneal ulcer.

2 Otherwise, ill-understood endogenous mechanisms, some linked with
HLA-B27 and seronegative arthropathy, may be causally related such as
ankylosing spondylitis, Reiter’s syndrome, ulcerative colitis, Crohn’s disease,
and Still’s disease.
(i) Rarer causes include sarcoidosis, toxoplasmosis, Behçet’s,
tuberculosis (TB) and herpes zoster ophthalmicus.

3 There is circumcorneal ciliary injection, constant pain, photophobia and
impaired vision.

4 The pupil contracts, and tiny aggregates of cells, known as keratic precipi-
tates (KPs) may be seen on the inner surface of the cornea.

5 Pus forms in the anterior chamber causing a hypopyon in severe cases,
and the iris may adhere to the anterior lens surface causing posterior
synechiae.

MANAGEMENT

1 Refer the patient immediately to the ophthalmology team for treatment with
steroid drops and a cycloplegic such as homatropine.

2 Attacks may become recurrent and progress to secondary glaucoma.

Acute episcleritis and scleritis

DIAGNOSIS

1 Episcleritis is localized inf lammation beneath the conjunctiva adjacent to
the sclera that resolves spontaneously in 1–2 weeks.

2 Scleritis is a more painful inf lammation of the sclera itself. Rheumatoid
arthritis, systemic lupus erythematosus (SLE), Wegener’s, polyarteritis and
other systemic illnesses such as sarcoid and TB may be associated.

3 The eye is locally red in episcleritis, and diffusely red and tender with ref lex
watering but no discharge in scleritis.
(i) Progression to scleral thickening and discolouration then eyeball
perforation may occur in scleritis.

4 Send blood for full blood count (FBC), erythrocyte sedimentation rate
(ESR), rheumatoid factor, antinuclear antibody (ANA) and DNA antibodies.
Commence an NSAID such as ibuprofen 200–400 mg orally t.d.s. or
naproxen 250 mg ora lly t.d.s.