Red eye

Overview
A red eye refers to the appearance of redness on the white part of the eye (sclera), caused by dilated or broken blood vessels. It can result from minor, harmless conditions like irritation or dryness, but it may also signal serious eye problems such as infection, glaucoma, or trauma. The severity and associated symptoms (pain, vision changes, discharge) help determine whether urgent medical evaluation is needed.

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Common Causes

• Conjunctivitis (pink eye): Viral, bacterial, or allergic inflammation of the conjunctiva.

• Dry eye syndrome: Insufficient tear production or poor tear quality.

• Blepharitis: Inflammation of the eyelids.

• Subconjunctival hemorrhage: Burst blood vessel causing a bright red patch, usually painless.

• Corneal injury or ulcer: From trauma, contact lenses, or infections.

• Uveitis: Inflammation inside the eye, often painful and associated with systemic conditions.

• Glaucoma (acute angle-closure): Sudden eye pain, halos around lights, nausea, and vision loss (medical emergency).

• Foreign body or chemical irritation.

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Associated Symptoms

• Itchiness, tearing, or burning (allergies, dryness)

• Discharge (watery in viral conjunctivitis, sticky/yellow-green in bacterial)

• Photophobia (light sensitivity)

• Blurred vision or vision loss (serious concern)

• Headache and nausea (possible acute glaucoma)

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Treatment
Treatment depends on the cause:

• Conjunctivitis:

  • Viral: Self-limiting, supportive care (cool compresses, lubricating eye drops).

  • Bacterial: Topical antibiotics such as chloramphenicol eye drops/ointment or fusidic acid gel (per clinical guidance).

  • Allergic: Antihistamine or mast-cell stabilizer eye drops (e.g., olopatadine, sodium cromoglicate).

• Dry eyes: Artificial tears (carboxymethylcellulose, hypromellose).

• Blepharitis: Warm compresses, lid hygiene, topical antibiotics if secondary infection.

• Subconjunctival hemorrhage: Usually resolves in 1–2 weeks without treatment.

• Corneal ulcer/injury or uveitis: Requires urgent ophthalmology referral, may need topical antibiotics, antivirals, corticosteroids (specialist use only).

• Acute angle-closure glaucoma: Medical emergency; treated in hospital with agents like acetazolamide, topical beta-blockers (timolol), pilocarpine, or surgery.

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Precautions

• Avoid rubbing the eyes.

• Do not self-use steroid eye drops, as they can worsen infections or glaucoma.

• Remove contact lenses until cleared by a doctor.

• Maintain good hand hygiene to prevent spreading conjunctivitis.

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When to Seek Urgent Medical Help

• Sudden, severe eye pain.

• Vision loss or changes.

• Sensitivity to light with redness.

• Associated headache and nausea.

• Eye injury or chemical exposure.

• Red eye in a newborn or infant.

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Drug Interactions

• Topical antibiotics (e.g., chloramphenicol) have minimal systemic interactions, but chloramphenicol may rarely interact with bone marrow-suppressive drugs.

• Antihistamine drops may have additive sedative effects if used with oral antihistamines.

• Glaucoma treatments like beta-blocker drops (timolol) can interact with systemic beta-blockers, calcium channel blockers, and antiarrhythmics, increasing risk of bradycardia or hypotension.

• Carbonic anhydrase inhibitors (acetazolamide) interact with salicylates, lithium, and diuretics, requiring monitoring.