Differential Diagnosis for Red Eye
Single Most Likely Diagnosis
- Conjunctivitis: This is the most common cause of red eye, often presenting with discharge, itching, and sometimes a foreign body sensation. It can be viral, bacterial, or allergic in nature.
Other Likely Diagnoses
- Dry Eye Syndrome: Characterized by insufficient tear production or poor tear quality, leading to irritation, redness, and sometimes a gritty sensation in the eyes.
- Blepharitis: Inflammation of the eyelids, often associated with redness, itching, and swelling, which can be caused by bacterial or demodex mite infestations.
- Corneal Abrasion: A scratch on the cornea, usually resulting from trauma, which can cause pain, redness, and sensitivity to light.
- Uveitis: Inflammation of the uvea, the middle layer of the eye, which can cause redness, pain, and sensitivity to light, often associated with systemic diseases.
Do Not Miss Diagnoses
- Acute Angle-Closure Glaucoma: A medical emergency characterized by sudden, severe eye pain, redness, blurred vision, and sometimes nausea and vomiting. It requires immediate treatment to prevent permanent vision loss.
- Endophthalmitis: A severe infection within the eye, usually following surgery or trauma, which can lead to vision loss if not promptly treated.
- Retinal Detachment: A condition where the retina separates from the back of the eye, causing sudden flashes of light, floaters, and a curtain or shadow descending over the field of vision. It is a medical emergency.
- Orbital Cellulitis: An infection of the tissues surrounding the eye, which can cause redness, swelling, and pain, and may lead to serious complications if not treated promptly.
Rare Diagnoses
- Scleritis: Inflammation of the sclera, the white part of the eye, which can cause severe pain, redness, and tenderness, often associated with systemic autoimmune diseases.
- Keratitis: Inflammation of the cornea, which can be caused by infection, injury, or systemic diseases, leading to pain, redness, and vision problems.
- Sympathetic Ophthalmia: A rare, inflammatory condition that can occur in one eye after trauma or surgery in the other eye, potentially leading to severe vision loss.
- Carotid Artery-Cavernous Sinus Fistula: An abnormal connection between the carotid artery and cavernous sinus, which can cause redness, swelling, and vision changes due to increased pressure in the eye.