Q My friend thought she had conjunctivitis, but it was actually uveitis. What’s the difference?
A The conjunctiva is the thin transparent membrane covering the front of the eye. It’s very sensitive and warns/defends our eyes against external threats; blinking spreads tears to clean and lubricate it. Dust, allergens (pollen, pets), bacterial/virus infections, and dry eyes can produce generalised pinky redness, watering, a yellowy discharge and/or itching/ irritation, with blurred vision that can be blinked away. Conjunctivitis can be treated with eye-drops from your pharmacy if necessary. However, conjunctival scratches and ulcers produce severe pain, and need immediate medical attention.
Uveitis means inflammation of deeper tissues in and around the iris (coloured part of the eye). It produces severe pain, and light intolerance, with difficulty opening the eye, which waters profusely. The black pupil shrinks, blurred vision won’t clear, and you may have a headache. Uveitis can be recurrent or affect both eyes, and can be triggered by immune-system disorders, infections, trauma and other conditions; it may penetrate deeper tissues and put sight at risk. So your GP or emergency department would refer you immediately to an eye specialist for tests and treatment, usually steroidal medication and/ or anti-inflammatory eye-drops, and follow-up.