Red eye

Resident Survival Guide

Red eye Microchapters
Patient Information
Overview
Classification
Causes
Differentiating Red eye from other Diseases
Treatment

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief:

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Synonyms and keywords: Bloodshot eye

Overview

Red eye is one of the most common complaints managed by primary care physicians though in some cases it heralds a serious and life-threatening condition needing urgent referral to ophthalmologist. The etiology of red eye can be infectious, traumatic, inflammatory, allergic, autoimmune and rarely secondary to tumors. Red eye stems from pathologies of eye lid, conjunctiva, cornea, sclera and uvea. Doctors must always document the history and findings of an eye examination (including negative findings). Pain, photophobia, visual acuity, and whether the condition is unilateral or bilateral, are the essential elements to be documented. The clinician should refer the patient for same-day specialist assessment by an ophthalmologist if any red flag features are present.

Classification

There is no established system for the classification of red eye.

Causes

• The cause of red eye is diagnosed through a comprehensive eye examination and patient's history. The most common cause of red eye is conjunctivitis. Other common causes include blepharitis, corneal abrasion, foreign body, subconjunctival hemorrhage, keratitis, iritis, glaucoma, chemical burn, and scleritis.
• Conjunctivitis, episcleritis and subconjunctival haemorrhage make up about 70% of the primary care red eye consultations.

Sight-threatening causes

The most common causes of sight-threatening causes of red eye include

• keratitis
• scleritis
• acute glaucoma
• orbital cellulitis
• foreign body trauma
• chemical burns

Differentiating Red eye from other Diseases

In patients with red eye it is important to distinguish between benign and sight-threatening diagnoses. This can be evaluate by asking historical questions about associated symptoms and performing a complete ocular examination. Associated symptoms include:

• Pain
• Photophobia
• Visual acuity
• History of trauma or exposure
• History of secretion
• History of systemic symptoms

Differential diagnosis of red eye

Condition	Signs	Symptoms	Causes	Treatment
Viral conjunctivitis	Normal vision Normal pupil size Diffuse conjunctival injections Preauricular lymphadenopathy	Mild to no pain Diffuse hyperemia Mild itching Watery to serous discharge Photophobia Subepithelial corneal opacities	Adenovirus VZV HSV	Supportive care and preservative-free artificial tears
Bacterial conjunctivitis	Eyelid oedema Normal pupil size Normal visual acuity	Mild to moderate pain Foreign body sensation Mucopurulent secretions with bilateral glued eyes	Staphylococcus aureus Streptococcus pneumoniae Haemophilus influenzae	Topical anitbiotics
Allergic conjunctivitis	Normal visual aciuty and pupil reactin Red eye	painless tearing Watery discharge Intense itching	Environmental antigens	Supportive care and topical antihystamines
Blepharitis	Swollen eyelids Dandruff-like scaling on eyelashes	Irritated eyes Itching	Chronic inflammation of eyelids (staphyloccocal infections)	Supportive cares Topical [[antibiotics] Steroids eyedrops
Subconjunctival hemorrhage	Bright red patch on sclera	Mild pain No discharge No visual disturbance	Hypertension Atherosclerotic vessels Traumatic causes	Refer for further investigation
Episcleritis	Dilated episcleral blood Oedema of episclera	Mild pain Watery discharge	Idiopathic inflammation	Topical lubricants Oral NSAIDs
Keratitis	Decreased visual acuity Corneal opacity Eyelid oedema	Severe pain Photophobia Mucopurulent discharge Foreign body sensation	Bacterial Staphylococcus Streptococcus Viral VZV HSV	Bacterial Topical antibiotics Viral Topical or/and oral anti-virals Topical steroids
Iritis	Constricted and irregular pupil reaction Decreased visual acuity	Moderate to severe pain Photophobia Watery discharge	Idiopathic inflamation	Topical steroids
Acute Angle Closure Glaucoma	Reduced visual acuity Non-reactive pupils Dilated pupils	Severe and throbbing pain Photophobia Halos when looking at light	Elevated intraocular pressure Optic nerve damage	Topical parasympathomimetics Topical beta-blockers Carbonic anhydrase inhibitors Alpha agnoists
Scleritis	Decreased visual acuity Sclera oedema	Severe pain radiating to periorbital area Increased pain with eye movement Photophobia Watery discharge	Systemic diseases Rheumatoid arthritis Wegener granulomatosis Sarcoidosis Inflammatory bowel disease	Refer urgently

Treatment

For more information on treatment click here.

Related Chapters

• List of eye diseases and disorders