2.03 Iritis (uveitis)
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agk's Library of Common Simple Emergencies

Presentation
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The patient usually complains of unilateral eye 
pain, blurred vision and photophobia. He may 
have had a pink eye for a few days, trauma 
during the previous day, or no overt eye 
problems. There may be tearing but there is 
ususally no discharge. Eye pain is not markedly 
relieved after instillation of a topical 
anesthetic. When you look at the junction of 
the cornea and conjunctiva (the corneal limbus) 
you will see a corcumcorneal injection which, 
on close inspection, is a tangle of fine 
ciliary vessels, visible through the white 
sclera. This limbal blush or ciliary flush is 
usually the earliest sign of iritis. A slit 
lamp with 10x magnification may help, but is 
usually evident on close inspection. As the 
iritis becomes more pronounced, the iris and 
ciliary muscles go into spasm, producing an 
irregular, poorly reactive, constricted pupil 
and a lens which will not focus. The slit lamp 
may demonstrate white blood cells or light 
reflection from a protein exudate in the clear 
aqueous humor of the anterior chamber (cells 
and flare).

What to do:
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- Perform a complete eye exam, including 
   topical anesthesia if necessary; visual 
   acuity, pupillary reflexes, funduscopy, slit 
   lamp examination of the anterior chamber 
   (including pinhole illumination to bring out 
   cells and flare) and fluorescein staining to 
   detect any corneal lesion.
- Attempt to ascertain the cause of the iritis 
   (is it generalized from a corneal insult or 
   conjunctivitis, a late sequela of blunt 
   trauma, infectious, or autoimmune?)
- Explain to the patient the potential severity 
   of the problem: this is no routine conjunct- 
   ivitis, but a process which can develop into 
   blindness.
- Arrange for ophthalmologic consultation or 
   followup, and, if acceptable to the 
   consulting ophthalmologist . . .
    o Dilate the pupil and paralyze ciliary 
      accommodation with 1% cyclopentolate 
      (Cyclogyl) drops once, which will not 
      only relieve the pain of the muscle 
      spasm, but will keep the iris away from 
      the lens, where meiosis and inflammation 
      might cause adhesions (posterior 
      synechiae). For a prolonged effect, 
      instill 1 drop of homatropine 5% before 
      discharge.
    o Suppress the inflammation with topical 
      steroids, like 1% prednisolone 
      (Inflamase) drops once;
    o Prescribe po pain medicine if needed; and
    o Ensure that the patient is seen the next 
      day in followup.

What not to do:
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- Do not let the patient shrug off his "pink 
   eye" and escape followup, even if he is 
   feeling better, because of the real possi- 
   bility of permanent visual impairment.
- Do not overlook a penetrating foreign body as 
   the cause of the inflammation.
- Avoid dilating an eye with a shallow anterior 
   chamber and precipitating acute angle 
   closure glaucoma.

Discussion
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Iritis (or anterior uveitis) always represents 
a real threat to vision which requires 
emergency treatment and expert followup. The 
inflammatory process in the anterior eye can 
opacify the anterior chamber, deform the iris 
or lens, scar them together, or extend into 
adjacent structures. Posterior synechiae can 
potentiate cataracts and glaucoma. Treatment 
with topical steroids can backfire if the 
process is caused by an infection (especially 
herpes keratitis); thus the slit lamp 
examination is especially useful.

Iritis may have no apparent cause, or be 
associated with ankylosing spondylitis, 
Reiter's syndroms, psoriatic arthritis, 
sarcoidosis and infections such as 
tuberculosis, Lyme disease and syphilis.

Sometimes an intense conjunctivitis or 
keratitis may produce some sympathetic limbal 
blush, which will resolve as the primary 
process resolves, and require no additional 
treatment. A more definite, but still mild, 
iritis, may resolve with cycloplegics, and not 
require steroids. All of these, however, 
mandate ophthalmologic consultation and 
followup.

References
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- Au YK, Henkind P: Pain elicited by consensual 
   pupillary reflex: a diagnostic test for 
   acute iritis. *Lancet* 1981;ii:1254-1255.

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