Differential Diagnosis of Red Eye

Differential Diagnosis of Red Eye

• Red eye may include a wide range of disorders from mild self-limiting disorders to sight-threatening conditions.
• Optometrist must determine whether management is appropriate in optometric practice or if referral is necessary.

History Taking for Red Eye Cases

• A good history and symptoms is essential to diagnose the underlying cause of red eye.
• Consider all possibilities, e.g., red eye caused by allergic reaction to preservative in eye drops.
• Factors to consider:
  • General health and medication
  • Previous ocular history
  • Duration and onset of symptoms
  • Other symptoms associated with red eye

Other Symptoms Associated with Red Eye

• Discharge:
  • Viral and acute allergic reactions: watery discharge
  • Bacterial infections: purulent or mucopurulent discharge
  • Vernal or atopic condition: mucous discharge
• Photophobia:
  • Corneal involvement, e.g., abrasions, oedema
  • Ciliary spasm, e.g., anterior uveitis
• Pain:
  • Mild to moderate: conjunctivitis, episcleritis, corneal foreign body
  • Moderate to severe: corneal abrasions/erosions, anterior uveitis, scleritis, acute angle-closure glaucoma
• Itching:
  • Associated with a large number of conditions, e.g., conjunctivitis, contact lens associated papillary conjunctivitis

Signs

• Distribution of redness:
  • Diffuse and maximum involvement at fornix with associated papillae or follicles: conjunctivitis
  • Circumlimbal injection: iritis
  • Diffuse or nodular hyperaemia: scleritis or episcleritis
  • Segmental injection: marginal keratitis, corneal foreign body
• Papillae and follicles:
  • Papillae: allergic eye conditions, contact lens associated conjunctivitis, bacterial infections, chronic blepharitis, superior limbic keratoconjunctivitis
  • Follicles: viral and chlamydial conjunctivitis

Conditions which Present with Red Eye

• Subconjunctival haemorrhage:
  • Usually unilateral, painless, and sudden
  • More likely in older individuals
  • May be associated with an episode of vigorous coughing, sneezing, or vomiting
• Conjunctival inflammation:
  • Allergic: vernal, atopic, hay fever
  • Bacterial: Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae
  • Viral: Herpes simplex, Epidemic keratoconjunctivitis, Pharyngoconjunctival fever
  • Chlamydial
  • Toxic: Contact lenses
• Acute allergic conjunctivitis:
  • Self-limiting reaction to an allergen which produces an immediate response
  • Symptoms: conjunctival injection and oedema, lid oedema, itching, and watery discharge
  • Treatment: cold compresses, identify and remove the allergen, topical anti-histamine
• Acute bacterial conjunctivitis:
  • Symptoms: acute onset of red, gritty, sticky eyes, may be history of recent respiratory infection
  • Signs: diffuse conjunctival injection and oedema, mucous and crusting on lids and lashes
  • Treatment: broad-spectrum antibiotic drops or ointment, good hygiene measures
• Viral conjunctivitis:
  • Symptoms: acute onset of watering, burning, itchy eyes, may follow an upper respiratory tract infection
  • Signs: diffuse conjunctival injection and oedema, epiphora, lid oedema
  • Treatment: cold compresses, may use topical antibiotic to prevent secondary infection, advise on hygiene measures
• Vernal keratoconjunctivitis (VKC):
  • Potentially serious condition affecting children
  • Symptoms: itching, photophobia, mucous discharge
  • Signs: conjunctival injection, large papillae, white Trantas’ spots along the limbus, corneal epithelial erosions
  • Treatment: topical mast cell stabiliser and topical steroid, sometimes requires immunosuppressant
• Atopic conjunctivitis:
  • Seen in adult atopic patients
  • Symptoms: itching and redness
  • Signs: lid eczema, anterior blepharitis, conjunctival/limbal injection and oedema with dense small papillae
  • Treatment: similar to VKC
• Chlamydial conjunctivitis:
  • Most common amongst young sexually active patients
  • Symptoms: conjunctivitis with large follicles, mucopurulent discharge and often with corneal signs
  • Treatment: topical antibiotic, referral to genito-urinary clinic input required to confirm diagnosis and administer systemic treatment
• Contact lens associated papillary conjunctivitis:
  • Combined hypersensitivity reaction to some element of contact lens wear
  • Symptoms: mucous discharge, reduced lens comfort, itching, blurred vision
  • Treatment: modify contact lens wear, change/reinforce cleaning regime, change CL material
• Episcleritis:
  • Common, benign, and self-limiting
  • Symptoms: rapid onset, unilateral mild discomfort, irritation, tenderness to touch, and watering
  • Signs: sectoral or diffuse redness, congestion of superficial episcleral vessels
  • Treatment: symptoms usually progress over 3-5 days and then resolve, may benefit from artificial tears, topical vasoconstrictor/antihistamine combination
• Scleritis:
  • Less common than episcleritis
  • Symptoms: severe boring orbital pain which may radiate to the face
  • Signs: severe inflammation of scleral, episcleral, and conjunctival vessels
  • Treatment: urgent referral to hospital eye service, initially treatment with oral NSAIDs, systemic immunosuppression
• Anterior uveitis:
  • Symptoms: usually unilateral, red eye, dull aching pain, previous episodes, pain on attempted accommodation
  • Signs: ciliary flush, cells and flare in anterior chamber, posterior synechiae, keratic precipitates
  • Treatment: depending on the level of prescribing qualification, may direct referral to hospital eye service, topical steroidal treatment to reduce inflammation and prevent complications, cycloplegics to reduce ciliary spasm
• Herpes simplex virus (conjunctivitis):
  • 90% population history of infection (seropositive)
  • Symptoms: blepharoconjunctivitis, watery discharge, tender preauricular lymphadenopathy
  • Treatment: usually self-limiting but anti-viral therapy recommended
• HSV – Dendritic ulcers:
  • Found in recurrent HSV corneal disease
  • Symptoms: unilateral red eye, mild to moderate pain, gritty or foreign body feeling, and photophobia
  • Signs: branching ulcer, may coalesce to geographic ulcer
  • Treatment: referral – soon (if stroma is involved, in children, CL wearers, or bilateral – emergency same day referral)
• Microbial keratitis:
  • May be associated with contact lens wear, ocular surface disease, and topical steroid use
  • Symptoms: red eye, mild to severe ocular pain, photophobia, reduced vision, and discharge
  • Signs: white focal infiltrate in stroma, conjunctival injection, infiltrates around the margins, stromal oedema, anterior chamber cells +/- Hypopyon
  • Treatment: immediate referral to hospital eye service, medical treatment – broad-spectrum antibiotic e.g., ciprofloxacin 0.3%
• Microbial keratitis - Acanthamoeba:
  • Protozoan infection, normally derived from nonsterile sources in contact lens wearers
  • Symptoms: severe pain, may be bilateral, redness, reduced vision, photophobia
  • Treatment: emergency same day referral, assume that all dendritic type ulcers in contact lens wearers are acanthamoeba until proved otherwise### Marginal Keratitis
• Multiple bilateral peripheral corneal stromal infiltrates with clear cornea separating them from limbus by an area of normal cornea
• Stains with fluorescein
• Redness and oedema of conjunctiva (only affected quadrant injected)
• Anterior chamber usually quiet
• If bilateral, consider underlying conditions such as Wegener's granulomatosis

Management of Marginal Keratitis

• Treat blepharitis with warm compresses, lid hygiene, and topical antibiotic
• Ocular lubricants for symptomatic relief
• Oral painkillers for symptoms if required (e.g. paracetamol)
• Self-limiting condition, but treatment may be prescribed to shorten the clinical course and reduce symptoms
• If severe, refer (soon) and prescribe topical antibiotics to reduce bacterial load and topical steroids to reduce inflammation
• May require oral doxycycline in severe cases (for blepharitis)

Acute Closed-Angle Glaucoma (ACAG)

• Rare condition, unlikely to present to practice
• Incidence increases with age (average 60 years)
• Moderate to high hypermetropes most at risk – may have had previous sub-acute episodes (haloes around lights, blurred, HA, painful eyes, nausea)
• Signs: very painful red eye, severely reduced vision, headache, and nausea
• Symptoms: hyperaemic eye, pupil fixed (mid-dilated position), oedematous cornea, anterior chamber shallow, drainage angle closed, IOP very high (>50mmHg)
• Immediate referral to ophthalmologist (same day) - Treatment aims to lower IOP before damage occurs to optic nerves

Post-operative Red Eye – Cataract Operation

• Majority of cases will be following cataract surgery
• Early: range of red eye conditions possible following surgery, including subconjunctival haemorrhage, anterior uveitis, or endophthalmitis
• Late: persistent anterior uveitis or reaction to topical post-op drops
• Management: Examination of the anterior chamber, mainly to detect any cells and flare, and to rule out any hypopyon
• IOP measurement – this can be raised as response to steroids or the inflammation itself
• Dilated fundal examination also recommended for any posterior chamber inflammation
• If any significant inflammation detected, consult with ophthalmologist/ refer back to hospital eye department promptly

Post-operative Red Eye – Other Operations

• Glaucoma surgery: inflammation, blebitis can lead to failure of the bleb
• Also risk of endophthalmitis
• Corneal surgery: endophthalmitis risk, risk of graft rejection
• Any patient presenting with a red eye in either of these contexts should be referred back to their consultant ophthalmologist promptly (emergency referral – no intervention)

Photokeratitis

• Delayed onset reaction to intense exposure of UV light from a welder, sun lamp, etc.
• Severe cases can result in a red, sore eye with blurred vision, watering, and photophobia
• Caused by absorption of the UV radiation of the corneal epithelium causing areas of erosion
• Other signs may include conjunctival oedema and injection, lid swelling, and skin burns in some cases
• Management: Primary goal is to improve comfort
• Sunglasses, oral pain relief
• Topical cycloplegics to reduce pain
• Topical ocular lubricants
• Normally resolves in around 48hrs

Thyroid Eye Disease

• Occurs in patients diagnosed with thyroid dysfunction/Ophthalmic Graves' Disease
• Painful red eye due to soft tissue inflammation
• Occurs in first 3 years of systemic disease
• Unilateral or bilateral
• Symptoms: photophobia, grittiness, lacrimation, and discomfort
• Signs: Periorbital and lid swelling, conjunctival hyperaemia, chemosis, superior limbic conjunctivitis, KCS
• Urgency of referral depends on signs and symptoms present

Preseptal Cellulitis

• Infection of lids and soft tissue around the eye
• Usually unilateral
• Pre-septal cellulitis does not penetrate the orbital septum and is most commonly secondary to a skin laceration or bite
• Periorbital swelling, erythema, tenderness
• Lid may be difficult to open
• VA, pupils, CV, and ocular motility normal
• Requires direct immediate referral to HES to differentiate from orbital cellulitis
• Medical treatment: Requires oral antibiotics

Orbital Cellulitis

• Infection of soft tissue behind the septum
• Usually associated with sinus disease
• Unilateral swollen, tender erythematous lid, chemosis, proptosis, restricted motility
• If severe, reduced VA, RAPD, colour vision defect
• If severe, patient may be systemically unwell
• Emergency admission to HES – IV antibiotics
• Surgical drainage for abscesses