Differential Diagnosis for Red Eye
The differential diagnosis for red eye is extensive and can be categorized into several groups. Here's a breakdown of the possible causes:
- Single Most Likely Diagnosis
- Conjunctivitis: This is the most common cause of red eye, often due to viral or bacterial infections. It's characterized by redness, discharge, and irritation of the conjunctiva.
- Other Likely Diagnoses
- Dry Eye Syndrome: Insufficient tear production or poor tear quality can cause redness, irritation, and discomfort.
- Blepharitis: Inflammation of the eyelids can lead to redness, itching, and swelling.
- Subconjunctival Hemorrhage: A broken blood vessel under the conjunctiva can cause sudden onset of redness.
- Allergic Conjunctivitis: An allergic reaction can cause redness, itching, and watery discharge.
- Do Not Miss Diagnoses
- Acute Angle-Closure Glaucoma: A medical emergency that can cause severe eye pain, redness, and vision loss.
- Corneal Ulcer: A bacterial or fungal infection of the cornea that can lead to severe vision loss if left untreated.
- Endophthalmitis: A rare but serious infection of the inner eye that can cause severe vision loss and pain.
- Scleritis: Inflammation of the sclera that can cause severe eye pain, redness, and vision loss.
- Rare Diagnoses
- Keratoconus: A progressive thinning of the cornea that can cause vision distortion and redness.
- Uveitis: Inflammation of the uvea that can cause eye pain, redness, and vision loss.
- Sjögren's Syndrome: An autoimmune disorder that can cause dry eye and other systemic symptoms.
- Erythema Multiforme: A skin condition that can cause red, target-shaped lesions on the eyes and skin.
Each of these diagnoses has distinct characteristics and requires a thorough medical evaluation to determine the underlying cause of the red eye.