Red Eye Differential Diagnosis
The differential diagnosis for a red eye can be organized into the following categories:
- Single Most Likely Diagnosis
- Conjunctivitis: This is the most common cause of a red eye, often presenting with discharge, itching, and tearing. It can be viral, bacterial, or allergic in nature.
- Other Likely Diagnoses
- Dry eye syndrome: Characterized by a lack of sufficient lubrication on the surface of the eye, leading to redness, irritation, and sometimes a gritty sensation.
- Blepharitis: Inflammation of the eyelids, often associated with redness, itching, and crusting around the eyelashes.
- Corneal abrasion: A scratch on the surface of the cornea, which can cause redness, pain, and sensitivity to light.
- Uveitis: Inflammation of the uvea, the middle layer of the eye, which can cause redness, pain, and sensitivity to light.
- Do Not Miss Diagnoses
- Acute angle-closure glaucoma: A medical emergency characterized by sudden onset of severe eye pain, redness, and vision loss. If missed, it can lead to permanent vision loss.
- Endophthalmitis: A severe infection within the eye, often following surgery or trauma, which can cause redness, pain, and vision loss. Prompt treatment is essential to preserve vision.
- Orbital cellulitis: An infection of the tissues surrounding the eye, which can cause redness, swelling, and vision loss. If left untreated, it can lead to serious complications, including cavernous sinus thrombosis.
- Rare Diagnoses
- Scleritis: Inflammation of the sclera, the white part of the eye, which can cause redness, pain, and tenderness.
- Episcleritis: Inflammation of the episclera, a thin layer of tissue on top of the sclera, which can cause redness and mild pain.
- Keratitis: Inflammation of the cornea, which can cause redness, pain, and vision loss. It can be caused by infection, trauma, or other factors.
- Carotid-cavernous fistula: An abnormal connection between the carotid artery and the cavernous sinus, which can cause redness, swelling, and vision loss.