| EM guidemap - Red eye |
Click on any of the headings or subheadings to rapidly navigate to the relevant section of the guidemap
Introduction and general principles
Causes of a red eye - brief background material
- viral conjunctivitis
- bacterial conjunctivitis
- chlamydial conjunctivitis
- allergic conjunctivitis
- vernal conjunctivitis
- atopic keratoconjunctivitis
- giant papillary conjunctivitis
- Parinaud's oculoglandular conjunctivitis
- superior limbic conjunctivitis
- ocular rosacea
- systemic diseases
Cavernous venous sinus thrombosis and orbital cellulitis
Appendix - links to emedicine.com chapters
| Introduction and general principles |
- this guidemap only provides a brief overview of the different causes of a "red eye" and it may help an emergency physician differentiate serious causes of a red eye (cavernous sinus thrombosis, orbital cellulitis, acute angle-closure glaucoma, necrotizing scleritis, herpetic keratitis) from less serious causes (allergic or viral conjunctivitis, corneal abrasion, episcleritis) => an emergency physician should consult textbooks (eg. the many ophthalmology textbook chapters at emedicine.com) for more details about the different disease entities and their specific treatment after determining the likely cause of the "red eye"
- the guidemap is mainly focused on the diagnosis of acute causes of a "red eye", and it may allow an emergency physician to make appropriate triage decisions regarding the need for immediate versus elective ophthalmologist consultation
(* an emergency physician should be able to diagnose and treat "red eye" conditions such as corneal abrasion, corneal FB, conjunctivitis, mild keratitis and episcleritis - without an immediate need to always consult an ophthalmologist => the patient can follow-up with an ophthalmologist as an outpatient within 24 - 48 hours)
- conjunctivitis is probably the most common cause of a non-traumatic "red eye", but more serious causes of a "red eye" must always be excluded by a systematic approach to the history and examination
- there is no "fixed" problem-solving approach to the clinical problem of a "red eye", and I use the following simple problem-solving approach
I conceptually divide "red eye" patients into three major groups - those who are likely to have external eye disease (eg. allergic or infectious conjunctivitis, or corneal abrasion or FB) versus serious internal eye disease (eg. iritis, acute angle-closure glaucoma, scleritis) versus serious extraocular disease (cavernous sinus thrombosis, orbital cellulitis)
External eye disease causing a red eye
- clinical features that suggest an external eye disease causing a red eye:-
- pain sensation is usually described as itching, gritty, scratching, or burning rather a deep-seated ache
- the pain is significantly improved by the application of topical anesthetics
- eye discharge is common, and can vary from watery => mucoid => purulent dependent on the etiology
- photophobia and blepharospasm may be present to varying degrees
- vision may be blurred, but visual acuity is usually normal or near-normal
- preauricular lymphadenopathy may be present, and suggests viral or chlamydial conjunctivitis
(* see the description of vernal conjunctivitis and giant papillary conjunctivitis to obtain greater detail on differentiating clinical features)
- patients with infectious conjunctivitis often have a gritty FB sensation and a watery-mucoid (viral) or muco-purulent (bacterial) discharge => see the conjunctivitis section to obtain greater detail on the differentiating clinical features between viral vs bacterial vs chlamydial conjunctival infection
(* the presence of preauricular lymphadenopathy strongly suggests a viral or chlamydial conjunctivitis and makes allergic conjunctivitis unlikely)
- patients with traumatic or chemical or toxic conjunctivitis/keratitis usually also have surface symptoms (FB sensation, mild photophobia, tearing) and the diagnosis is often readily apparent based on a specific history of exposure and characteristic clinical signs
- some patients with chemical or infectious conjunctivitis may also develop a severe keratitis or a secondary iritis, and they often have more severe eye pain that is unrelieved by topical anesthetics; those patients also have characteristic signs of severe keratitis or iritis on slit lamp examination (see keratitis and iritis)
- scleritis can usually be differentiated from conjunctivitis by using the clinical features listed in the scleritis section
- a subconjunctival hemorrhage of spontaneous onset is usually asymptomatic and the clinical signs are readily apparent; fundoscopy must be performed in patients with symptomatic subconjunctival hemorrhage to exclude occult globe injury and/or an intraocular FB
- a checklist of additional (negative) clinical signs that should be present if the etiological cause of the "red eye" is only related to non-traumatic disorders of the external eye, and not due to more serious causes (internal eye disease or extraocular disease)
- the cornea should be clear
- the anterior chamber should be clear
- the pupils shoud be normal in size and reactivity
- visual acuity should be normal or near-normal
- extraocular eye movements should be normal
- proptosis should be absent
- the eyeball should not be painful on palpation
- usually suggested by severe eye pain (unrelieved by topical anesthetics), impaired vision, poorly reactive pupils and an abnormal slit lamp examination +/- abnormal IOP
- it should be possible to differentiate iritis from acute angle-closure glaucoma based on their clinical features
- mid-dilated, unreactive pupil + steamy cornea + peri-orbital pain +/- nausea/vomiting + increased IOP => angle closure glaucoma
- small, irregular pupil + deep-seated eye pain that is worse on eye movement or accomodation + consensual photophobia + positive slit lamp signs of flare and cells => iritis
- deep-seated eye pain that is worse at rest and at night + pain on palpation of the eye + violaceous appearance of the sclera => scleritis
Orbital or extra-orbital disease causing a red eye
- an orbital cellulitis or cavernous
sinus thrombosis is suggested by the presence of proptosis + congested
chemosis + painful, external ophthalmoplegia + visual loss with a relative
afferent pupillary defect
| Clinical clue table suggesting the possibility of serious eye disease causing the "red eye" --- clinical features that may necessitate immediate ophthalmologist consultation |
| Clinical feature | Suggests |
| Severe eye aching | Iritis, keratitis, acute angle-closure glaucoma, scleritis, orbital cellulitis, cavernous sinus thrombosis (CST) |
| Prominent photophobia | Iritis, keratitis |
| Impaired vision | Iritis, keratitis, acute angle-closure glaucoma, orbital cellulitis, CST |
| Cloudy cornea | Keratitis, acute angle-closure glaucoma |
| Corneal opacification | Keratitis - chemical or infectious |
| Circumcorneal conjunctival injection | Iritis, keratitis |
| Cloudy anterior chamber | Iritis |
| Pain on eyeball palpation | Scleritis (+++), orbital cellulitis, CST |
| Proptosis | Orbital cellulitis, CST, posterior scleritis |
| Impaired, or painful, extraocular eye movements | Orbital cellulitis |
| Fever, toxic appearance | Orbital cellulitis (+), CST (++) |
| Hyperpurulent discharge from an "angry" eye | Gonococcal conjunctivitis/endophthalmitis |
| Prominent nausea and vomiting | Acute angle-closure glaucoma |
| Small, irregular, poorly-reactive pupil | Iritis |
| Fixed mid-dilated pupil | Acute angle-closure glaucoma |
| Increased intra-ocular pressure | Acute angle-closure glaucoma, iritis (secondary complication) |
| History of connective tissue disease, or granulomatous disease | Iritis, scleritis |
| Causes of a red eye - brief background material |
- there are many causes of a red eye, and the listed disease-causes are presented in an arbitrary sequence - roughly based on their clinical likelihood in an ED setting - conjunctivitis, corneal FB or abrasion, subconjunctival hemorrhage > keratitis > iritis > scleritis > acute angle-closure glaucoma > orbital cellulitis or cavernous sinus thrombosis
- characterized by inflammation of the surface membrane overlying the anterior sclera (bulbar conjunctiva) and tarsal surface of the eyelids (palpebral conjunctiva)
- acute conjunctivitis (< 4 weeks duration) is characterized by symptoms of surface eye discomfort (foreign body sensation, grittiness, burning, stinging), eye discharge (watery => mucoid => purulent), mild photophobia and diffuse conjunctival injection
(* the conjunctival vessels can usually be moved by manual pressure from a Q tip, and they blanch in response to the application of 2.5% phenylephrine eyedrops; deep sceral vessels are radially oriented, do not blanch in response to phenylephrine eyedrops and may cause a bluish discoloration of the normally white sclera when vasodilated)
- muco-purulent eye discharge may cause the eyelids to mat together, and eyelid matting on awakening suggests a purulent bacterial conjunctivitis
- a thick discharge may produce a pseudomembrane in the conjunctival fornices, and it must be differentiated from a true membrane, which causes localized conjunctival bleeding when it is manually scraped away
- pseudomembranes can be seen in both viral and bacterial conjunctivitis, but are more common in bacterial conjunctivitis
- chemosis (conjunctival edema) and eyelid edema may be present
- deep-seated eye pain (eye pain not relieved by topical anesthetic eyedrops) and/or marked photophobia should not be present in acute conjunctivitis, and they suggests iritis, scleritis, acute angle-closure glaucoma or the possibility of peri-orbital disease (eg. orbital cellulitis, cavernous sinus thrombosis)
- the presence of consensual photophobia, cells and flare seen on slit lamp examination of the anterior chamber, impaired pupillary response to light, increased conjunctival injection around the limbus, and deep-seated pain unrelieved by topical anesthetics suggests iritis; a fixed mid-dilated pupil and steamy cornea and severe peri-orbital pain suggests acute angle closure glaucoma: the presence of congested chemosis and proptosis suggests orbital cellulitis or cavernous sinus thrombosis
- vision is usually normal, or the slightly impaired vision clears with a blink (impaired vision due to a conjunctival discharge overlying the cornea)
- the presence of preauricular lymphadenopathy suggests certain types of infectious conjunctivitis - benign adenoviral, or chlamydia, or herpes simplex (which is suggested by the presence of eyelid vesicles or an associated dendritic keratitis), or rare bacterial causes of conjunctivitis (cat scratch fever, tularemia)
- follicles (raised whitish-grey structures with overlying branching conjunctival blood vesseles) may be present on the palpebral conjunctiva of the superior and inferior conjunctival fornix, and their presence suggests an allergic or viral conjunctivitis
- it is not always possible to differentiate viral from bacterial conjunctivitis (and the degree of conjunctival injection is often moderate-severe in both conditions), and the empiric use of antibiotic eyedrops is often recommended when the diagnosis is not clear-cut => lab tests (gram stain and C&S of conjunctival scrapings) are usually reserved for conjunctivitis that does not respond within 72 hours or if Neisseria gonorrhoeae is supected
- traumatic conjunctivitis or toxic conjunctivitis is suggested by the history of mechanical injury, or chemical exposure, or UV light exposure (arc welding - solar keratitis), or exposure to ocular medications (eg. neomycin) that could worsen the original degree of conjunctivitis by adding a component of allergic conjunctivitis
Clinical clues suggesting different types of conjunctivitis
- itching, burning pain and sparse/moderate watery-stringy eye discharge +/- mild photophobia
- diffuse conjunctival injection +/- follicles in the inferior conjunctival fornix +/- preauricular lymphadenopathy +/- pseudomembranes (rare)
- generally starts in eye one and then involves the other eye within days (a persistent unilateral infectious conjunctivitis suggests a bacterial etiology)
- there is often a history of contact with a person with "pink eye", or history of a recent URI with constitutional symptoms of fever and myalgia
- may last 2 - 4 weeks (longer than bacterial conjunctivitis); viral cultures are not required and treatment is symptomatic
- patients are highly contagious for the first week, and careful hygiene is important to prevent spread to other people (emergency physicians should wear disposable gloves during patient examination and wash their hands vigorously afterwards); patients can return to work after approximately one week when the risk of spread is less
- certain viral subtypes (adenovirus or enterovirus E70 or Cox-Sackie virus A24 or picornavirus) may produce an explosive-onset acute hemorrhagic conjunctivitis with multiple pinpoint conjunctival petechiae, that can coalesce to form patchy subconjunctival hemorrhages +/- chemosis +/- eyelid edema and induration; epithelial punctate corneal keratopathy can occur, but subepithelial deposits are rare; symptoms usually resolve within 3 - 7 days; seen mainly in developing countries and tends to occur in epidemics
- pharyngo-conjunctival fever (adenovirus types 3, 4 and 7) is seen in children and is suggested by the combination of fever + pharyngitis + mild follicular conjunctivitis (+ preauricular lymphadenopathy +/- punctate keratopathy), and it's a transient disease lasting < 14 days
- epidemic keratoconjunctivitis (adenovirus types 8 and 19) produces a more intense conjunctivitis +/- conjunctival petechia +/- diffuse subconjunctival hemorrhages, ipsilateral preauricular lymphadenopathy, +/- associated keratitis with widely scattered subepithelial corneal infiltrates (characterized by intense pain and photophobia) +/- pseudomembranes in the conjunctival fornices
- epidemic keratoconjunctivitis (EKC) is very contagious and usually occurs in closed institutions; EKC resolves with symptomatic treatment (cool compresses, topical vasoconstrictors, +/- sulfacetamide antibiotic eyedrops to prevent secondary infection) within 2 - 3 weeks
- the incubation period of EKC is 2 - 14 days and the patient is infectious for 10 - 14 days after symptoms develop
- the adenovirus can be spread through the medical profession (direct contact with contaminated diagnostic ophthalmic instruments - the virus, which is resistant to standard disinfectants such as 70% isopropyl alcohol, remains viable for 5 weeks)
- EKC is endemic in East Asia, accounts for > 50% of viral conjunctivitis, and is not thought to be spread by the medical profession
- EKC usually starts with symptoms of sudden eye irritation, soreness, photophobia and watery tearing
- EKC starts with signs of inferior follicular conjunctivitis, conjunctival hyperemia, eyelid edema and ipsilateral preauricular lymphadenopathy => diffuse punctate epithelial keratitis develops 3 - 7 days later ( producing intense photophobia and increased pain) and lasts 2 - 3 weeks => subepithelial corneal deposits may subsequently develop within the next few weeks, and persist for months-years before spontaneously disappearing (they may be visually disabling and require topical steroid therapy)
- severe cases of EKC may develop pseudomembranes or true membranes in the conjunctical fornices resulting in conjunctival scarring and secondary symblepharon formation
- the second eye becomes involved in 50% of cases, and the involvement is less severe
- herpes simplex conjunctivitis - most frequently due to reactivation disease secondary to sunlight, UV light, menses, stress, trauma, immunosupression - is suggested by the presence of eyelid vesicles, preauricular lymphadenopathy +/- a dendritic keratitis (isolated conjunctivitis usually resolves spontaneously, but the presence of keratitis requires a stat ophthalmology consultation and appropriate anti-viral eyedrop therapy + strict avoidance of steroid eyedrops)
- typically produces a mucopurulent conjunctivitis with papillary conjunctivitis of the upper and lower eyelids (producing a velvety red appearance of the tarsal surface of the upper and lower eyelids) => morning awakening with agglutination of the eyelids (matting) is common
Severe bacterial conjunctivitis with markedly inflammed inferior conjunctival fornix
- the most common bacterial cause is Streptoccus pneumonia followed by Staphyloccus aureus; Hemophilus influenzae is less frequent; other gram negative infections are even less common and are a result of poor hygiene in elderly diabetics or immunocompromized patients; Pseudomonas infection is associated with contact lens-induced infection or swimming pools
- surface irritation of the eye (keratitis sicca - dry eyes, blepharitis - eye margin inflammation, trichiasis - inturned eyelashes, phthiriasis - eyelash pupic lice infestation) may predispose the patient to secondary bacterial infection
- pseudomembranes and true membranes may form in the conjunctival fornices (especially with N gonorrhoeae, C diptheriae, and beta-hemolytic streptococci)
- the conjunctival injection is usually diffuse and intense, and the mucoid or purulent discharge moderate-severe; subconjunctival hemorrhages, chemosis and eyelid edema may occur
- may occur in epidemic form, and referred to as "pink eye" by laypersons
- treatment is empiric, and gram stain and C&S is not routinely acquired - unless the onset is hyperacute and suggestive of gonorrhoea, or if the 72-hour response to topical antibiotic therapy is inadequate
- the presence of an associated blepharitis suggests staphylococcal infection; marginal ulcers (small superficial corneal ulcers) alongside the limbus suggest a superimposed staphylococcal allergic conjunctivitis due to the staphylococcal toxin
Staphylococcal conjunctivitis with a ring of marginal corneal ulcers
- a hyperacute onset (12 - 24 hours) of a hyperpurulent (purulent discharge is so copious that it re-accumulates immediately after been wiped away) conjunctivitis in a sexually active young adult, followed by the rapid development of an "angry" eye with chemosis and eyelid swelling +/- keratitis with severe eye pain, suggests Neisseria gonorrhoeae => requires gram staining of conjunctival scrapings + culture on blood and chocolate agar + parenteral antibiotics + immediate ophthalmological consultation +/- admission; a history of auto-inoculation from the dominant hand of a sexually active male, or known infected sexual contacts, or known venereal disease (urethritis or vaginitis) may be present
- most cases of bacterial infection are self-limiting within 5 - 10 days, and should respond to topical antibiotics within 72 hours; a failure to respond suggests a non-bacterial etiology or an unresponsive bacterial infection => ophthalmological follow-up consultation is mandatory in all cases; the presence of complications - keratitis, corneal opacities (corneal abscess), peripheral corneal thinning, frank corneal ulceration or hypopyon - mandate an immediate ophthalmological consultation
- called inclusion conjunctivitis
- adult inclusion conjunctivitis often presents similarly to a viral conjunctivitis with diffuse conjunctival injection and watery/stringy mucopurulent discharge +/- chemosis +/- lid edema +/- palpebral conjunctival follicles +/- preauricular lymphadenopathy in a sexually active patient with a history of genitourinary symptoms (vaginitis, cervicitis or urethritis), or a history of chronic conjunctivitis unresponsive to antibiotic eyedrops, or a history of swimmming in poorly chlorinated swimming pools
- neonatal inclusion conjunctivitis is usually secondary to infection acquired during vaginal delivery through an infected birth canal (incubation period of 5 - 14 days)
- adult chlamydial conjunctivitis should be suspected if an "assumed" viral/bacterial conjunctivitis doesn't respond within 14 days in patients at risk of harboring sexually transmitted diseases; a tendency to chronicity with exacerbations and remissions is common
- mimics viral conjunctivitis and produces diffuse conjunctival injection, watery or mucoid discharge, and pre-auricular lymphadenopathy
- untreated disease may result in inferior conjunctival follicles (within 2-3 weeks), marked eyelid edema and pseudoptosis, epithelial keratitis and pseudomembrane formation
- treatment requires systemic antibiotics (macrolides or tetracyclines) for a few weeks in addition to topical erythromicin antibiotic ointment
- chronic chlamydial infection (trachoma) may result in conjunctival scarring and cicatrix formation
- the patient often has bilaterally itchy eyes following exposure to an inciting allergen
- seasonal allergic conjunctivitis may be due to tree pollen (spring), grass pollen (summer) or weed pollen (fall) and the patient may have no symptoms during the winter months
- perennial allergic conjunctivitis is a year-round condition and may be caused by animal dander, dust mites or cockroaches
- the conjunctiva is milky white or pink in color, +/- edematous (glassy chemosis)
- the discharge is clear and watery initially and may become white and stringy later
Severe allergic conjunctivitis with chemosis
- the eyelids may be edematous; rhinitis, sneezing and pharyngeal irritation are often present in hayfever
- a conjunctival smear for eosinophils may be useful if the diagnosis is in doubt
- acute allergic conjunctivitis can also be secondary to topical eyedrops eg. neomycin (10 - 15% of patients) or insect protein (insects or gnats flying into the eyes during the summer months - the severe allergic conjunctivitis only affects one eye, which is a tip off to the etiology)
(* other common causes of acute allergic conjunctivitis include cosmetics, hair sprays, detergents, and contact lens solutions)
- chronic bilateral, recurrent hypersensitivity conjunctivitis seen in preadolescent children (male > female) in the warmer months of the year
- often a personal/family history of atopy (atopic eczema, asthma, seasonal allergic conjunctivitis)
- bilateral itchy tearing is present, and a ropy thick strand of material can be pulled from the conjunctival fornices a few times per day
- giant, flat-topped cobblestone follicles (5 - 8mm in size) can be seen on the tarsal surface of the everted upper eyelids and they are often covered by a milky discharge; the inferior palpebral conjunctiva is usually not involved
Conjunctival follicles on the palpebral surface of the everted upper eyelid
- the limbal form is characterized by a broad, gelatinous opacification of the superior limbus that can override the cornea (vernal catarrh); occasional chalk-white conjunctival nodules (Horner -Tranta's dots), containing eosinophils and degenerated epithelial cells, can be seen alongside the corneal limbus for short periods of < 1 week
Vernal catarrh
- epithelial punctate keratitis occurs in 50% of cases, and the areas of punctate epithelial keratopathy may coalesce => shield ulcers (superficial, horizontal irregular corneal ulcers); keratoconus may occur as a complication and may be due to chronic eye rubbing
- vernal conjunctivitis gradually subsides after 5 years and is rare after age 20 years
- can be associated with facial and eyelid skin eczema (95% of cases) and asthma (85% prevalence), and often affects the inferior tarsal conjunctiva (in contrast to vernal conjunctivitis, which affects the superior tarsal conjunctiva)
- has no sex predilection, is perennial rather than seasonal, rarely produces a ropy discharge or Horner-Tranta's dots, and is more likely to cause the complications of conjunctival scarring and deep corneal neovascularization
- blindness can occur secondary to the chronic superficial punctate keratitis, corneal thinning and scarring, shield ulcers, keratoconus and cataracts (anterior and posterior subcapsular shield-shaped)
Giant papillary conjunctivitis
- mimics vernal conjunctivitis in that macropapillae (0.3mm - 1mm) and moderately-sized (1 - 2 mm) creamy-white papillary follicles are seen on the superior tarsal conjunctiva
Papillary follicles on the palpebral surface of the upper eyelid
- bilateral itchy red eyes are present with a small amount of mucoid or ropy discharge with no seasonal variation
- seen in contact lens wearers (especially soft lenses), and thought to be a hypersensitivity reaction
- patients first complain of itching after removing their contact lenses => then patients complain of increased lens awareness and increased lens movement (their contact lenses tend to be more mobile and ride higher) => eventually the patients cannot tolerate wearing their contact lenses for prolonged periods of time
- the contact lenses may be covered with a whitish mucoid protein deposit, especially along the superior border as they ride higher under the upper eyelids
- Tranta's dots and gelatinous nodules may develop at the limbus; cloudy vision can be secondary to corneal deposits
- disappears if contact lenses are not worn; other helpful measures include reduced contact lens wearing time, more thorough cleansing of the lenses, different cleansing solutions not containing preservatives, and a switch to alternative type lenses (disposable daily-wear soft contact lenses, hard or gas-permeable type lenses)
- rarely due to ocular prostheses, protruding ocular nylon sutures or cyanoacrylate adhesive exposure
Clinical clues suggesting rare causes of conjunctivitis
Parinaud's oculoglandular conjunctivitis
- red eye + mucopurulent discharge + FB gritty sensation + granulomatous nodules of the palpebral conjunctiva + preauricular or submandibular lymphadenopathy
- causes include cat scratch disease, tularemia, tuberculosis and rarely syphilis, mumps, mononucleosis, fungi and sarcoidosis
Superior limbic conjunctivitis
- red eye + FB sensation + tearing + mild photophobia + frequent blinking; chronic or recurrent course; typically bilateral but often asymmetric
- characterized by sectoral conjunctival thickening and conjunctival inflammation localised to the superior conjunctiva, especially alongside the limbus
Superior limbic conjunctivitis
- fine punctate staining and filaments may be seen on the superior cornea, +/- fine papilla of the superior tarsal conjunctiva
- thought to be due to mechanical irritation of the superior conjunctiva due to proptosis and/or a tight upper eyelid (50% of patients have thyroid exophthalmos) +/- local tear deficiency; an auto-immune etiology is also theorized
- a similar condition may be seen in contact lens users (contact lens-induced superior limbic keratoconjunctivitis) that is characterized by increasing contact lens intolerance, superior tarsal and bulbar injection, and significant superior corneal staining with stromal haziness
- bilateral chronic conjunctival redness + burning FB sensation in middle-aged patient with rosacea
- rosacea of the eyelids and cheeks and rhinophyma of the nose is present
- superficial punctate keratitis, peri-limbral infiltrates and frank corneal ulceration may occur
Conjunctivitis associated with systemic diseases
- many systemic diseases may be associated with conjunctival injection and include infectious diseases (cat scratch fever, tularemia, leptospirosis, rubeola, Kawasaki disease) and skin diseases (erythema multiforme, Stevens Johnson syndrome, pemphigus)
Corneal abrasion or foreign body
- usually associated with a history of trauma or foreign body exposure (eg. fingernail, comb, tree branch twig, flying insects)
- symptoms include FB sensation, tearing and mild photophobia, increased pain on blinking or eye movements, +/- blepharospasm
(* severe photophobia or severe aching suggests a secondary traumatic iritis, or penetrating globe injury; the superficial pain due to a corneal abrasion usually disappears after the instillation of topical anesthetic eyedrops)
- a corneal abrasion or FB is easily diagnosed by slit lamp examination +/- fluorescein staining; may be associated with prominent circumcorneal injection
- multiple linear abrasions across the cornea ("ice-rink" pattern) suggest an entrapped FB beneath the upper eyelid => always check for a FB in the superior conjunctival fornix and under the everted upper eyelid
- inferior abrasions occur secondary to manual contact lens removal, or prolonged contact lens use without blinking (lens becomes dehydrated and abrades the eye)
- it is essential that corneal perforation is excluded (by slit lamp examination +/- Seidel's test to look for aqueous leakage) in all patients with a traumatic corneal injury
(* Seidel's test is performed by administering a concentrated solution of fluorescein to the site of the potential corneal perforation => a constant swirling dilution or clearing of the concentrated fluorescein solution suggests a leakage of anterior chamber aqueous fluid)
- patching is no longer recommended as part of the treatment regimen of corneal abrasions; treatment involves topical NSAIDs for a few days, potent oral narcotic analgesics, +/- a short-acting cycloplegic for any associated ciliary spasm
- the external eye has a homogeneous red area (subconjunctival hemorrhage) alongside the cornea resembling a splash of bright red paint on the surface of the eye
- often asymptomatic if spontaneous and unassociated with trauma
- may occur secondary to increased intra-orbital pressure, or following coughing or straining
- rarely due to a bleeding diathesis when present as an isolated finding
- usually resolves spontaneously in 14 days and no treatment is required beyond reassurance
- there is considerable overlap in the acute conditions that cause conjunctivitis and keratitis, and patients with keratitis often have more severe pain secondary to ciliary muscle spasm +/- secondary iritis
- occurs in response to arc welding or sunlamp exposure without protective glasses, or exposure to bright sunlight (eg. snowblindness)
- there is often a delay of 6 - 12 hours before symptoms (foreign body sensation, tearing, photophobia, blepharospasm) develop
- usually presents with a superficial punctate keratitis, which covers the entire corneal surface and which may result in diffuse epithelial desquamation if severe => usually heals in 48 - 72 hours
- a diffuse corneal haze can be seen in severe cases
- treatment often involves a short acting cycloplegic (cyclopentolate 1%) to relieve ciliary spasm, prophylactic antibiotic eyedrops, liberal oral analgesic medication +/- temporary patching for 24 hours
(* topical anesthetic eyedrops should not be prescribed for long-term use - because they impair corneal healing and the constantly anethetized eye will be more susceptible to ongoing damage from dust FB's, and vigorous eye rubbing, or too tight an eye patch)
- the extent of the injury is dependent on the toxicity of the chemical agent => consult a poison control center for targeted advice after initiating eye irrigation
Any opacification of the cornea is an ophthalmological emergency and requires immediate ophthalmological consultation
- predisposing factors include factors that disrupt the surface corneal epithelium eg. recent corneal injury or eye surgery, dry eyes (keratoconjunctivitis sicca), Bell's palsy or ophthalmic nerve neuropathy, prolonged contact lens wear
- may present with punctate epithelial lesions of the corneal surface, or a corneal infiltrate or corneal ulcer
- a corneal infiltrate is recognized as a focal white opacity in the corneal stroma, while a corneal ulcer exists if there is stromal loss with an overlying epithelial defect that stains intensely with fluorescein
- bacteria are the most common etiology of a corneal infiltrate or ulcer
- fungi should be considered if there was a traumatic injury, especially from vegetable matter like a tree branch, or if the corneal lesion has feathery borders with satellite lesions, or if the corneal lesion is rough with raised borders and brown pigmentation
- acanthamoeba should be considered if the patient wears contact lenses, especially if he was swimming or hot-tubbing while wearing his contact lens, or if he manifests poor contact lens hygiene, or if there is less evidence of corneal inflammation or anterior chamber reaction than expected relative to the degree of pain, or if the corneal infiltrate has a ring-appearance
- herpes simplex should be suspected if there are eyelid vesicles or peri-orbital vesicles, or if the pattern of keratitis has a dendritic appearance, or if a corneal ulcer has a geographic or stellate appearance - especially if it has a scalloped border with branching terminal bulbs, or if the edges of the ulcer are slightly heaped up with swollen epithelial cells that stain with rose bengal, or if there is a history of previous herpetic episodes, or if there is relative corneal hyposensitivity (pain less than expected)
Herpes dendritic keratitis (fluoroscein stain) with hypopyon
- HSV may also produce a necrotizing stromal inflammation (with no overlying ulcer) or endothellitis (keratic precipitates on the corneal endothelial surface)
Any opacification of the cornea is an ophthalmologic emergency and is presumed to be due to a corneal bacterial infection until proved otherwise => consult an ophthalmologist immediately
- the ophthalmologist may choose to treat the corneal infiltrate/corneal ulcer as bacterial until proved otherwise
- a common management approach is to first obtain corneal infiltrate/ulcers scrapings for immediate gram stain and C&S, followed by aggressive antibiotic therapy
- the degree of aggressiveness of antibiotic therapy may depend on the degree of threat of visual loss
- low risk of visual loss (small non-staining peripheral infiltrate with no/minimal anterior chamber reaction and minimal discharge) => tobramycin or fluoroquinolone antibiotic therapy q 4 - 6 hourly
- borderline risk of visual loss (1 - 1.5mm peripheral infiltrate, or any peripheral infiltrate with a positive fluoroscein test, or mild anterior chamber reaction, or moderate discharge) => fluoroquinolone antibiotic eyedrops q 1 hourly around the clock
- vision threatening (> 1.5mm corneal infiltrate or ulcer, moderate-severe anterior chamber reaction, purulent discharge, or infiltrate/ulcer in the visual axis) => fluoroquinolone antibiotic eyedrops q 5 minutes for 3 doses, then q 15 minutes for 2 - 6 hours, then q 30 minutes around the clock +/- subconjunctival antibiotics + oral quinolones
- hospital admission may be warranted - especially if the patient is likely to be non-compliant, if Neisseria gonorrhoeae or fungi or acathamoeba is suspected, if corneal perforation is imminent, or if the infection is vision threatening
- herpes simplex is often diagnosed by giemsa stain of the corneal lesion (multinucleated giant cells) or viral culture using a cotton-tipped applicator to swab the unroofed vesicle => antiviral therapy per ophthalmologist after immediate consultation (eg. topical trifluridine 1% solution 8 - 9 times daily or vidarabine 3% ointment 5 times daily and/or oral acyclovir 2g per day => response to topical therapy usually occurs in 2 - 4 days, with complete resolution in 1 - 2 weeks)
See the herpes keratitis chapter at emedicine.com for greater detail and many great photographs
- inflammation of the iris is called iritis, while inflammation of the iris and ciliary body is called iridocyclitis (both are classified as anterior uveitis)
- often unilateral, and presents with a painful red eye without discharge
- associated with deep-seated pain, which may radiate to the peri-orbital area or temple; pain is often worse with eye movements and during accomodation
- the pain is associated with direct and consensual photophobia (due to ciliary spasm), a small, irregular and poorly reactive pupil, and blurred vision due to the hazy aqueous in the anterior chamber
- characterized by a peri-limbal flush due to dilatation of the radial vessels; the degree of vascular engorgement increases in the region of the limbus forming a dense ring of dilated conjunctival blood vessels surrounding the cornea with lesser degrees of peripheral conjunctival injection (opposite pattern to conjunctivitis)
Ciliary flush with prominent peri-limbal conjunctival injection
- cells and flare are present on slit lamp exam; keratic precipitates on the corneal endothelium and posterior synechiae between the iris and lens may also be present
Keratic precipitates on the corneal endothelium
- the presence of "cells and flare" is the "essential" clinical sign in iritis (anterior uveitis) and the flare is best seen when using a narrow slit lamp beam directed at the eye from a 30 - 40 degrees angle (the flare appears between the cornea and the iris like a "foglight beam seen in a fog")
- one semi-quantification grading system for flare:-
- 1+ = faint/barely visible haze
- 2+ = moderate haze, but iris/lens details clearly visible
- 3+ = hazy iris and lens details
- 4+ = cloudy aqueous with keratic deposits on the corneal endothelium
- trace = 1 - 5 cells
- 1+ = 6 - 15 cells
- 2+ = 16 - 25 cells
- 3+ = 26 - 50 cells
- 4+ = more than 50 cells
- can be associated with HLA-B27-associated diseases, sarcoidosis, syphilis, tuberculosis, juvenile rheumatoid arthritis, syphilis, brucellosis, herpes simplex and Lyme disease; idiopathic in 50% of cases
- workup can be performed by the ophthalmologist in an outpatient setting in 24 hours, and may include a CBC, sed rate, ANA, RPR, VDRL, PPD skin testing, lyme titre etc.
- also seen following blunt or penetrating eye injury or following lens injury/surgery ("sympathetic" iritis can occur in the eye contralateral to the injured eye, and both the "excited" and the "sympathetic" eyes are usually involved)
- toxoplasmosis, CMV and histoplasmosis may cause posterior uveitis (choroiditis), which doesn't produce a red eye
- patients with iritis should be referred to an ophthalmologist within 24 hours; topical steroids are the cornerstone of therapy + intermediate-acting cycloplegics for the ciliary spasm
- scleritis (destructive inflammation of the sclera) can be localised or diffuse, and either anterior or posterior
- scleritis may rarely be rapidly necrotizing with inflammation, or rapidly necrotizing without inflammation (scleromalacia perforans)
- common causes of scleritis include rheumatoid arthritis, Wegeners granulomatosis, SLE, progressive systemic sclerosis, Reiter syndrome, inflammatory bowel disease, Behcets diseases, polyarteritis nodosa, gouty arthritis, psoriatic arthritis, or relapsing chondritis
- scleritis may also be due to chronic granulomatous infections eg. tuberculosis, brucellosis, leprosy, syphilis or sarcoid
- complications (especially with necrotizing scleritis) include peripheral ulcerative keratitis, uveitis or glaucoma
- scleritis is usually associated with deep-seated pain, and/or pain radiating to the forehead, brow or jaw, which is poorly relieved by simple analgesics and worse with eye movements and eye palpation; the pain, which is boring in nature, may be so severe as to wake the patient from sleep; necrotizing inflammatory scleritis is particularly painful and and may present with avascular "porcelain-like" areas of sclera (best seen with a green light)
- scleritis is usually associated with a bluish discoloration of the sclera due to vasodilatation of deep-seated scleral vessels and thinning of the sclera, and the deep-seated scleral vessels may not vasoconstrict in response to topical 2.5% phenylephrine eyedrops (in contrast to the blanching of superficial episcleral vessels and conjunctival vessels in response to topical vasoconstrictors); the sclera is often swollen and it may cause the slit lamp light beam to be displaced forwards in the area of maximal swelling (see accompanying photograph)
Scleritis with sectoral scleral edema
- scleritis may be unilateral, bilateral or alternating
- posterior scleritis may present with pain without redness, and secondary retinal or choroidal exudative changes and detachments
- necrotizing or chronic scleritis may result in destruction of the sclera => dark-pigmented choroid may be visible through the translucent sclera, and produce a dark blue-black color
- scleritis is frequently associated with a secondary uveitis - either iridocylitis or posterior choroiditis
- episcleritis (localized inflammation of the elastic membrane overlying the sclera and beneath the conjunctiva) is usually localised and nodular, rather than diffuse, and it's a painless/near-painless condition that is often self-limiting in a few days (only 30% of cases have an identifiable cause) - in marked contrast to scleritis, which is not a benign condition, and which is more likely to be associated with an underlying rheumatological, granulomatous or infectious condition
Nodular episcleritis - sectoral involvement with nodule
- nodular episcleritis (tender scleral nodule that does not move when the overlying conjunctiva is moved with a Q tip) is slightly more uncomfortable than simple episcleritis without nodule formation, and has a more prolonged course
- a patient with episcleritis, which is usually a self-limiting condition often treated with oral NSAIDs, should be referred electively to an ophthalmologist for outpatient evaluation; however, a prompt opthalmological consult should be obtained for a patient with severe scleritis or necrotizing scleritis
- risk factors include a shallow anterior chamber, older age, female sex, a history of farsightedness, Eskimo or Asian extraction
- usually presents with the sudden onset of monocular eye pain +/- peri-orbital pain, nausea and vomiting, and blurred vision +/- haloes around lights (due to corneal edema)
- often precipitated by sudden pupillary dilatation in patients with a shallow anterior chamber and/or thickened lens eg. dark enviroment of a cinema, mydriatic eyedrops used for an ophthalmological examination, nebulised beta-sympathomimetics or anticholinergics used for asthma therapy, intranasal cocaine used for epistaxis or recreational use
- the intraocular pressure is elevated and often 40 - 80 mmHg (normal pressure is 10 - 20 mmHg)
- there is diffuse or peri-limbal conjunctival injection, corneal edema, a fixed mid-dilated pupil +/- iris bombe (iris bulges forwards secondary to pupillary block and secondary increased pressure in the posterior chamber - the laxity of the peripheral iris and the degree of relative pupilllary block is usually greatest when the pupil is in the mid-dilated position)
Acute angle-closure glaucoma with corneal clouding and diffuse conjunctival injection
- evidence of a previous attack of acute glaucoma may be visible - peripheral anterior synechia between iris and lens, iris atrophy and glaucoma flecks on the anterior surface of the lens
- acute angle-closure glaucoma requires immediate therapy and immediate ophthalmologist consultation
(* see the visual loss guidemap for brief details on the treatment of acute angle-closure glaucoma)
Cavernous sinus thrombosis and orbital cellulitis
- cavernous sinus thrombosis (CST) is usually secondary to spread of infection from the paranasal sinuses or localized mid-face infection
- CST presents with headache and fever and retro-orbital pain + congested chemosis and eyelid/peri-orbital edema and proptosis +/- external ophthalmoplegia (secondary to 3rd, 4th and 6th nerve palsies)
- mild papilledema, peri-orbital swelling and violaceous hue of the upper eyelid may also be present in CST
- decreased visual acuity may be secondary to traction or compression of the optic nerve
- untreated cases of CST may develop similar physical signs in the contralateral eye in 24 - 48 hours, and signs of meningism/sepsis
- orbital cellulitis presents with fever + pre-existent signs of sinusitis + orbital and periorbital swelling/erythema + chemosis + painful proptosis + painful limited ROM of the eyes + increased intra-ocular pressure +/- decreased vision
(* pre-septal cellulitis presents with a red, painful swollen upper eyelid - but no painful proptosis, and no painful or limited extraocular movement, and no limited visual acuity)
- an early onset of decreased sensation in the area supplied by the ophthlamic and maxillary division of the trigeminal nerve may help differentiate CST from orbital cellulitis; later - the presence of bilateral eye involvement and positive CSF examination (which suggest CST) may also help differentiate the two entities
- an acute onset of massive exophthalmos + external ophthalmoplegia + binocular incomitant diplopia + sudden visual loss + congestive chemosis suggests a spontaneous rupture of a carotid-cavernous aneurysm
- a pulsating proptosis + audible bruit + arteriolization of the
conjunctival and episcleral vessels suggests a carotid-cavernous fistula
| Appendix |
- instead of providing details about the specific therapy of the different causes of a red eye, I have provided direct links to a select number of chapters of the emedicine.com online textbook
Bacterial conjunctivitis
Allergic conjunctivitis
Viral conjunctivitis
Giant papillary
conjunctivitis
Chlamydial conjunctivitis
Gonococcal conjunctivitis
Herpes simplex
keratoconjunctivitis
Anterior uveitis
Episcleritis
Scleritis
Acute angle-closure
glaucoma
Orbital cellulitis
Disclaimer: My EM guidemaps reflect my personal approach to problem-solving/managing clinical cases in an ED setting and they should not be regarded as the standard of care. They merely represent the personal opinions of the author and they should only be used in clinical practice if the reader-user has substantial reason to believe that the clinical advice contained in the guidemaps is valid and accurate. The guidemaps are not meant to be "authoritative" and the reader-user should consult standard medical textbooks and expert opinion articles/guidelines for more authoritative advice. The reader-user should particularly confirm all drug doses, their indications and contra-indications, prior to their use.