Red eye

Written by cypher. Posted Thursday, January 15, 2009 @ 23:21:45 by Webmaster

The “red eye” is one of the most common ophthalmic problems presenting to the general practitioner.

An accurate history is important and should pay particular attention to vision, degree, and type of discomfort and the presence of a discharge.

The history, and a good examination, will usually permit the diagnosis to be made without specialist ophthalmic equipment.

Symptoms and signs :

The most important symptoms are pain and visual loss; these suggest serious conditions such as corneal ulceration, iritis, and acute glaucoma.

A purulent discharge suggests bacterial conjunctivitis; a clear discharge suggests a viral or allergic cause.

A gritty sensation is common in conjunctivitis, but a foreign body must be excluded, particularly if only one eye is affected.

Itching is a common symptom in allergic eye disease, blepharitis, and topical drop hypersensitivity.

Conjunctivitis :

Conjunctivitis is one of the most common causes of an uncomfortable red eye.

Conjunctivitis itself has many causes, including bacteria, viruses, Chlamydia, and allergies.

Bacterial conjunctivitis :

History The patient usually has discomfort and a purulent discharge in one eye that characteristically spreads to the other eye.

The eye may be difficult to open in the morning because the discharge sticks the lashes together.

There may be a history of contact with a person with similar symptoms.

Examination The vision should be normal after the discharge has been blinked clear of the cornea.

The discharge usually is mucopurulent and there is uniform engorgement of all the conjunctival blood vessels.

When fluorescein drops are instilled in the eye there is no staining of the cornea.

Management Topical antibiotic eye drops (for example, chloramphenicol) should be instilled every two hours for the first 24 hours to hasten recovery, decreasing to four times a day for one week.

Chloramphenicol ointment applied at night may also increase comfort and reduce the stickiness of the eyelids in the morning.

Patients should be advised about general hygiene measures; for example, not sharing face towels.

Viral conjunctivitis :

Viral conjunctivitis commonly is associated with upper respiratory tract infections and is usually caused by an adenovirus.

This is the type of conjunctivitis that occurs in epidemics of “pink eye.”

History The patient normally complains of both eyes being gritty and uncomfortable, although symptoms may begin in one eye.

There may be associated symptoms of a cold and a cough.

The discharge is usually watery.

Viral conjunctivitis usually lasts longer than bacterial conjunctivitis and may go on for many weeks; patients need to be informed of this. Photophobia and discomfort may be severe if the patient goes on to develop discrete corneal opacities.

Examination Both eyes are red with diffuse conjunctival injection (engorged conjunctival vessels) and there may be a clear discharge.

Small white lymphoid aggregations may be present on the conjunctiva (follicles).

Small focal areas of corneal inflammation with erosions and associated opacities may give rise to pronounced symptoms, but these are difficult to see without high magnification.

There may be associated head and neck lymphadenopathy with marked pre-auricular lymphadenopathy.

Management Viral conjunctivitis is generally a self limiting condition, but antibiotic eye drops (for example, chloramphenicol) provide symptomatic relief and help prevent secondary bacterial infection.

Viral conjunctivitis is extremely contagious, and strict hygiene measures are important for both the patient and the doctor; for example, washing of hands and sterilising of instruments.

The period of infection is often longer than with bacterial pathogens and patients should be warned that symptoms may be present for several weeks.

In some patients the infection may have a chronic, protracted course and steroid eye drops may be indicated if the corneal lesions and symptoms are persistent.

Steroids must only be prescribed with ophthalmological supervision, because of the real danger of causing cataract or irreversible glaucomatous damage.

Furthermore, if long term steroids are required, patients should remain under continuous ophthalmological supervision.

Chlamydial conjunctivitis :

History Patients usually are young with a history of a chronic bilateral conjunctivitis with a mucopurulent discharge. There may be associated symptoms of venereal disease.

Patients generally do not volunteer genitourinary symptoms when presenting with conjunctivitis; these need to be elicited through questioning.

Examination There is bilateral diffuse conjunctival injection with a mucopurulent discharge. There are many lymphoid aggregates in the conjunctiva (follicles).

The cornea usually is involved (keratitis) and an infiltrate of the upper cornea (pannus) may be seen.

Management The diagnosis is often difficult and special bacteriological tests may be necessary to confirm the clinical suspicions.

Treatment with oral tetracycline or a derivative for at least one month can eradicate the problem, but poor compliance can lead to a recurrence of symptoms.

Systemic tetracycline can affect developing teeth and bones and should not be used in children or pregnant women.

Associated venereal disease should also be treated, and it is important to check the partner for symptoms or signs of venereal disease (affected females may be asymptomatic).

It often is helpful to discuss cases with a genitourinary specialist before commencing treatment, so that all relevant microbiological tests can be performed at an early stage.

In developing countries, infection by Chlamydia trachomatis results in severe scarring of the conjunctiva and the underlying tarsal plate.

These cicatricial changes cause the upper eyelids to turn in (entropion) and permanently scar the already damaged cornea.

Worldwide, trachoma is still one of the major causes of blindness.

Conjunctivitis in infants :

Conjunctivitis in young children is extremely important because the eye defences are immature and a severe conjunctivitis with membrane formation and bleeding may occur. Serious corneal disease and blindness may result.

Conjunctivitis in an infant less than one month old (ophthalmia neonatorum) is a notifiable disease.

Such babies must be seen in an eye department so that special cultures can be taken and appropriate treatment given.

Venereal disease in the parents must be excluded.

Allergic conjunctivitis :

History The main feature of allergic conjunctivitis is itching.

Both eyes usually are affected and there may be a clear discharge.

There may be a family history of atopy or recent contact with chemicals or eye drops. Similar symptoms may have occurred in the same season in previous years.

It is important to differentiate between an acute allergic reaction and a more long term chronic allergic eye disease.

Examination The conjunctivae are diffusely injected and may be oedematous (chemosis).

The discharge is clear and stringy.

Because of the fibrous septa that tether the eyelid (tarsal) conjunctivae, oedema results in round swellings (papillae).

When these are large they are referred to as cobblestones.

Management Topical antihistamine and vasoconstrictor eye drops provide short term relief.

Eye drops that prevent degranulation of mast cells also are useful, but they may need to be used for several weeks or months to achieve maximal effect.

Oral antihistamines may also be used, particularly the newer compounds that cause less sedation.

Topical steroids are effective but should not be used without regular ophthalmological supervision because of the risk of steroid induced cataracts and glaucoma, which may irreversibly damage vision.

Cases of allergic eye disease in association with severe eczema will often need careful combined ophthalmological and dermatological management.

Episcleritis and scleritis :

Episcleritis and scleritis usually present as a localised area of inflammation.

The episclera lies just beneath the conjunctiva and adjacent to the tough white scleral coat of the eye.

Both the sclera and episclera may become inflamed, particularly in rheumatoid arthritis and other autoimmune conditions, but no cause is found for most cases of episcleritis.

History The patient complains of a red and sore eye that may also be tender.

There may be reflex lacrimation but usually there is no discharge.

Scleritis is much more painful than episcleritis.

The pain of scleritis often is sufficiently severe to wake the patient at night.

Examination There is a localised area of inflammation that is tender to the touch.

The episcleral and scleral vessels are larger than the conjunctival vessels.

The signs of inflammation are usually more florid in scleritis.

Management Any underlying cause should be identified.

Episcleritis is essentially self limiting, but steroid eye drops hasten recovery and provide symptomatic relief.

Scleritis is much more serious, and all patients need ophthalmological review.

Serious systemic disorders need to be excluded, and systemic immunosuppressive treatment may be required.

Corneal ulceration :

Corneal ulcers may be caused by bacterial, viral, or fungal infections; these may occur as primary events or may be secondary to an event that has compromised the eye for example, abrasion, wearing contact lenses, or use of topical steroids.

History Pain usually is a prominent feature as the cornea is an exquisitely sensitive structure, although this is not so when corneal sensation is impaired; for example, after herpes zoster ophthalmicus. Indeed, this lack of sensory innervation may be the cause of the ulceration.

There may be clues such as similar past attacks, facial cold sores, a recent abrasion, or the wearing of contact lenses.

Examination Visual acuity depends on the location and size of the ulcer, and normal visual acuity does not exclude an ulcer.

There may be a watery discharge due to reflex lacrimation or a mucopurulent discharge in bacterial ulcers.

Conjunctival injection may be generalised or localised if the ulcer is peripheral, giving a clue to its presence.

Fluorescein must be used or an ulcer easily may be missed.

Certain types of corneal ulceration are characteristic; for example, dendritic lesions of the corneal epithelium usually are caused by infection with the herpes simplex virus.

If there is inflammation in the anterior chamber there may be a collection of pus present (hypopyon). The upper eyelid must be everted or a subtarsal foreign body causing corneal ulceration may be missed.

Patients with subtarsal foreign bodies sometimes do not recollect anything entering the eye.

Management Patients with corneal ulceration should be referred urgently to an eye department or the eye may be lost.

Management depends on the cause of the ulceration. The diagnosis usually will be made on the clinical appearance.

The appropriate swabs and cultures should be arranged to try to identify the causative organism.

Intensive treatment then is started with drops and ointment of broad spectrum antibiotics until the organisms and their sensitivities to various antibiotics are known.

Injections of antibiotics into the subconjunctival space may be given to increase local concentrations of the drugs.

Topical antiviral therapy should be used for herpetic infections of the cornea.

Cycloplegic drops are used to relieve pain resulting from spasm of the ciliary muscle, and as they are also mydriatics they prevent adhesion of the iris to the lens (posterior synechiae).

Topical steroids may be used to reduce local inflammatory damage not caused by direct infection, but the indications for their use are specific and they should not be used without ophthalmological supervision.

Iritis, iridocyclitis, anterior uveitis, and panuveitis :

The iris, ciliary body, and choroid are similar embryologically and are known as the uveal tract.

Inflammation of the iris (iritis) does not occur without inflammation of the ciliary body (cyclitis) and together these are referred to as iridocyclitis or anterior uveitis.

Thus the terms are synonymous.

It is important to consider diabetes mellitus in any patient with recent onset anterior uveitis.

Several groups of patients are at risk of developing anterior uveitis, including those who have had past attacks of iritis and those with a seronegative arthropathy, particularly if they are positive for the HLA B27 histocompatibility antigen; for example, a young man with ankylosing spondylitis.

Children with seronegative arthritis are also at high risk, particularly if only a few joints (pauciarticular) are affected by the arthritis.

Uveitis in children with juvenile chronic arthritis may be relatively asymptomatic and they may suffer serious ocular damage if they are not screened.

Sarcoidosis also causes chronic anterior uveitis, as do several other conditions including herpes zoster ophthalmicus, syphilis, and tuberculosis.

In panuveitis both the anterior and posterior segments of the eyes are inflamed and patients may have evidence of an associated systemic disease (for example, sarcoidosis, Behçet’s syndrome, systemic lupus erythematosus, polyarteritis nodosa, Wegener’s granulomatosis, or toxoplasmosis).

History The patient who has had past attacks can often feel an attack coming on even before physical signs are present.

There is often pain in the later stages, with photophobia due to inflammation and ciliary spasm.

The pain may be worse when the patient is reading and contracting the ciliary muscle.

Examination The vision initially may be normal but later it may be impaired.

Accommodation, and hence reading vision, may be affected.

There may be inflammatory cells in the anterior chamber, cataracts may form, and adhesions may develop between the iris and lens.

The affected eye is red with the injection particularly being pronounced over the area that covers the inflamed ciliary body (ciliary flush).

The pupil is small because of spasm of the sphincter, or irregular because of adhesions of the iris to the lens (posterior synechiae).

An abnormal pupil in a red eye usually indicates serious ocular disease.

Inflammatory cells may be deposited on the back of the cornea (keratitic precipitates) or may settle to form a collection of cells in the anterior chamber of the eye (hypopyon).

Management If there is an underlying cause it must be treated, but in many cases no cause is found.

It is important to ensure there is no disease in the rest of the eye that is giving rise to signs of an anterior uveitis, such as more posterior inflammation, a retinal detachment, or an intraocular tumour.

Treatment is with topical steroids to reduce the inflammation and prevent adhesions within the eye.

The ciliary body is paralysed to relieve pain, and the associated dilation of the pupil also prevents the development of adhesions between the iris and the lens that can cause “pupil block” glaucoma.

The intraocular pressure may also rise because inflammatory cells block the trabecular meshwork, and antiglaucoma treatment may be needed if this occurs.

Continued inflammation may lead to permanent damage of the trabecular meshwork and secondary glaucoma, cataracts, and oedema of the macula.

Patients with panuveitis will need systemic investigation and possibly systemic immunosuppression.

Acute angle closure glaucoma :

Acute angle closure glaucoma always should be considered in a patient over the age of 50 with a painful red eye.

The diagnosis must not be missed or the eye will be damaged permanently.

History The attack usually comes on quite quickly, characteristically in the evening, when the pupil becomes semidilated.

There is pain in one eye, which can be extremely severe and may be accompanied by vomiting.

The patient complains of impaired vision and haloes around lights due to oedema of the cornea.

The patient may have had similar attacks in the past which were relieved by going to sleep (the pupil constricts during sleep, so relieving the attack).

The patient may have needed reading glasses earlier in life.

A patient with acute angle closure glaucoma may be systemically unwell, with severe headache, nausea, and vomiting, and can be misdiagnosed as an acute abdominal or neurosurgical emergency.

Acute angle closure glaucoma also may present in patients immediately postoperatively after general anaesthesia, and in patients receiving nebulised drugs (salbutamol and ipratropium bromide) for pulmonary disease.

Examination The eye is inflamed and tender.

The cornea is hazy and the pupil is semidilated and fixed. Vision is impaired according to the state of the cornea.

On gentle palpation the eye feels harder than the other eye.

The anterior chamber seems shallower than usual, with the iris being close to the cornea.

If the patient is seen after the resolution of an attack the signs may have disappeared, hence the importance of the history.

Management Urgent referral to hospital is required.

Emergency treatment is needed if the sight of the eye is to be preserved.

If it is not possible to get the patient to hospital straight away, intravenous acetazolamide 500 mg should be given, and pilocarpine 4% should be instilled in the eye to constrict the pupil.

First the pressure must be brought down medically and then a hole made in the iris with a laser (iridotomy) or surgically (iridectomy) to restore normal aqueous flow.

The other eye should be treated prophylactically in a similar way. If treatment is delayed, adhesions may form between the iris and the cornea (peripheral anterior synechiae) or the trabecular meshwork may be irreversibly damaged necessitating a full surgical drainage procedure.

Subconjunctival haemorrhage :

History The patient usually presents with a red eye which is comfortable and without any visual disturbance. It is usually the appearance of the eye that has made the patient seek attention.

If there is a history of trauma, or a red eye after hammering or chiselling, then ocular injury and an intraocular foreign body must be excluded.

Subconjunctival haemorrhages are often seen on the labour ward post partum.

Examination

There is a localised area of subconjunctival blood that is usually relatively well demarcated.

There is no discharge or conjunctival reaction.

Look for skin bruising and evidence of a blood dyscrasia.

Management It is worth checking the blood pressure to exclude hypertension. If there are no other abnormalities the patient should be reassured and told the redness may take several weeks to fade.

If patients are anticoagulated with warfarin then the coagulation profile (international normalised ratio, INR) should be checked.

If abnormal bruising of the skin is present then consider checking the full blood count and platelets.

Inflamed pterygium and pingueculum :

History The patient complains of a focal red area or lump in the interpalpebral area. There may have been a pre-existing lesion in the area that the patient may have noticed before.

Examination Pinguecula are degenerative areas on the conjunctiva found in the 4 and 8 o’clock positions adjacent to, but not invading, the cornea.

These common lesions may be related to sun and wind exposure.

Occasionally they become inflamed or ulcerated.

A pterygium is a non-malignant fibrovascular growth that encroaches onto the cornea.

Management If the pingueculum is ulcerated, antibiotics may be indicated. For a pterygium, surgical excision is indicated if it is a cosmetic problem, causes irritation, or is encroaching on the visual axis.

Symptomatic relief from the associated tear-film irregularities are often helped by the use of topical artificial tear eye drops.

Red eye that does not get better :

Red eyes are so common that every doctor will be faced with a patient whose red eye does not improve with basic management.

It is important to be aware of some of the more common differential diagnoses.

Many of the conditions described below will need a detailed ophthalmic assessment to make the diagnosis.

Consider early ophthalmic referral when patients present with red eyes and atypical clinical features or fail to improve with basic management.

Orbital problems :

It is easy to miss someone with early thyroid eye disease and patients can present with one or both eyes affected.

Look for associated ocular (for example, lid retraction) and systemic features of thyroid disease.

There are several rare but important orbital causes of chronic red eyes, including caroticocavernous fistula, orbital inflammatory disease, and lymphoproliferative diseases.

Eyelid problems :

Malpositions of the eyelids such as entropion and ectropion often cause chronic conjunctival injection.

Nasolacrimal obstruction presents with a watery eye but there can be chronic ocular injection if the cause is lacrimal canaliculitis or a lacrimal sac abscess.

A periocular lid malignancy such as basal cell carcinoma or sebaceous (meibomian) gland carcinoma may rarely present as a unilateral chronic red eye.

Conjunctival problems :

If a patient has a history of an infective conjunctivitis that does not improve, then you should always exclude chlamydial conjunctivitis, particularly if there are also genitourinary symptoms.

Giant papillary conjunctivitis may occur in patients with ocular allergic disease or in contact lens wearers.

If someone is on long term topical drug therapy (for example, for glaucoma) then drug hypersensitivity should be considered, especially if drug instillation causes marked itching or the eyelids have an eczematous appearance.

Other causes of chronic red eyes !include! a subtarsal foreign body, dry eyes, and cicatricial ocular pemphigoid.

Corneal problems :

Corneal causes of a chronically red and irritated eye !include! loose corneal sutures (previous cataract or corneal graft surgery), herpetic keratitis, exposure keratitis (for example, in Bell’s palsy), contact lens related keratitis, marginal keratitis (for example, in patients with blepharitis or rosacea), and corneal abscess.

Fluorescein drops will reveal corneal staining in patients whose red eye syndrome is caused by a corneal problem.

Viral infection :

Adenoviral keratoconjunctivitis may lead to a red, painful eye for many weeks and patients should be warned of this.

Patients with refractory adenoviral keratitis may occasionally need topical steroid therapy.

This should only be undertaken with close ophthalmological supervision as it can be hard to wean patients off steroids.

Scleral problems :

Episcleritis and scleritis present with red eyes that do not respond to topical antibiotic therapy.

Think of scleritis in any patient presenting with marked ocular pain and injection.

Anterior chamber problems :

Failure to consider uveitis in a patient with a red eye, photophobia, and pain can result in delays that make subsequent management more difficult.

Angle closure glaucoma has a very characteristic clinical presentation that is easy to miss.