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Conjunctivitis

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Conjunctiva is a mucous membrane covering the inner surface of the eye lids and extends to the limbus on the surface of the eye globe.

Patients usually present for care with ocular redness and discharge.

Major functions are to produce mucus for the tear film layer and provides immune cells and antimicrobial chemicals to protect the ocular surface.

Divided into three anatomic areas: palpebral, forniceal and bulbar.

It is loosely attached to the eye and allows free movement.

Has an epithelial layer and a deep substantia propia.

Associated with infectious and non-infectious causes of inflammation referred to as conjunctivitis.

Conjunctivitis accountsvfor 1% of primary care office visits.

It is estimated that viral conjunctivitis mat account for up to 20 million cases per year in the US.

Conjunctivitis accounts were approximately half of all eye related visits to general practitioners and an estimated 1/3 of all related eye related emergency department visits.

Conjunctivitis results in more than $300 million in annual costs.

Non-infectious causes of conjunctivitis: allergies, immunologic and toxic.

Infectious causes of conjunctivitis: bacterial, viral and chlamydial.

The conjuntiva lines the inner part of the eyelids from the eyelashes around to the sclera of the eyeball.

The conjunctiva is transparent, but when inflamed becomes thickened, red and weeps fluid.

Fluid that is formed can be clear, cloudy yellow or green and as thick as pus.

Drying of the fluid on the eye lashes causes crusty appearance.

The entire sclera can be inflamed.

It must be determined whether the red eye president is caused by serious eye disease such as uveitis, corneal abrasion, scleritis, or keratitis, or a more benign process such as conjunctivitis, episcleritis or sub conjunctival hemorrhage.

Other common causes of red eye include allergic conjunctivitis, subconjunctival hemorrhage, and dry eye disease.

More serious causes of red eye disease include foreign body, corneal abrasion, corneal infection, scleritis, iritis, and glaucoma.

The presence of red eye with discharge indicates infectious conjunctivitis in the majority of cases, and requires an assessment of the likelihood of a viral versus bacterial etiology.

Three findings indicate a serious eye disorder with conjunctivitis: significant eye pain, visual blurring, and photophobia.

Viral conjunctivitis is the most common infectious conjunctivitis and requires no treatment.

Viruses cause, approximately 80% of cases of acute infectious conjunctivitis in adults, but fewer than 20% of pediatric cases.

Watery discharge is typical of viral conjunctivitis, but is seen in 1/4 of bacterial cases.

Associated findings of pharyngitis, preauricular lymph node enlargement, and contact with a person with a red eye suggests  a viral cause.

Adenoviruses cause 65 to 90% of cases of viral conjunctivitis.

Treatment for viral conjunctivitis is supportive.

Adenovirus types 8, 37, and 64 can cause epidemic keratoconjunctivitis, which is a highly contagious, severe conjunctivitis in which the cornea may be involved.

Virus can be recovered on the hands in nearly have of patients, and can survive more than one month on plastic and metal objects.

Herpes simplex, varicella, zoster, enterovirus, measles virus, mumps virus, rubella virus, acute respiratory syndrome coronavirus 2, Ebola and pox virus, and other viruses can also cause conjunctivitis.

Bacteria are the second most common cause of conjunctivitis.

Non-bacterial conjunctivitis is more likely if the patient presents during the summer or there is watery discharge.

Bacterial conjunctivitis is more likely to occur during winter months.

Bacterial conjunctivitis associated with conjunctival injection, mucopurulent discharge, and often bilateral involvement.

Bacterial conjunctivitis associated with preserved vision.

Bacterial conjunctivitis May be associated with eyelid edema.

Bacterial conjunctivitis can be treated with topical antibiotics and warm compresses.

The most common bacterial pathogens associated with acute conjunctivitis in adults is Staphylococcus aureus.

Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are common bacterial pathogens in children.

Excessive prescribing of antibiotics has potential adverse effects including bacterial resistance,  the possibility of toxic or allergic reactions and increased cost.

Clinical findings associated with a higher likelihood of viral conjunctivitis include: pharyngitis, preauricular lymphadenopathy, and contact with an individual with a redeye; clinical findings associated with a higher likelihood of bacterial conjunctivitis include mucopurulent discharge and otitis media.

Allergic conjunctivitis can be treated with topical antihistamines.

Ophthalmic administration of antibacterial agents is much like less likely to cause adverse effects than systemic administration.

Ophthalmic formulations of antibacterial drugs achieve high concentrations on the eye surface and can be effective in treating ocular surface infections, even when the organisms are reported to be resistant.

Sulfacetamide is not a highly effective ophthalmic antibacterial, can be sensitizing and can really cause Stevens‘s-Johnson syndrome.

Neomycin ophthalmic can cause sensitization and other local adverse reactions in about 5-10% of patients.

Bacitracin and erythromycin ophthalmic are not active against Gram negative organisms that cause a small percentage of acute conjunctival Infections in adults.

Polymyxin B ophthalmic is only active against Gram-negative organisms.

Trimethoprim ophthalmic has broad spectrum of activity, including methicillin-resistant staphylococcus.

Ophthalmic azithromycin has activity primarily against gram-positive microbes, but also against H. influenzae.

A single oral dose of azithromycin is effective to treat Chlamydia trachomatis and gonococcal conjunctivitis.

Conjunctivitis caused by chlamydia and gonorrhea requires systemic treatment.

All fluoroquinolones are active against most bacteria associated with conjunctivitis.

Erythromycin ophthalmic ointment or trimethoprim/polymyxin B ophthalmic solution are reasonable choices for first line treatment of acute bacterial conjunctivitis.

Alternatives include bacitracin or bacitracin/polymyxin B ointment or a topical fluoroquinolone.

Affects about 1% of patients.

In general, withholding antibiotics, even if bacterial conjunctivitis is present, unless it is caused by chlamydia or gonorrhea, is not hazardous, as it will resolve on its own.

Antibiotics will shorten the duration of a bacterial conjunctivitis.

The presence of red and itchy eyes, suggests an allergic process and the use of an ophthalmic antihistamine such as azelastine or olopatadine, or a mast-cell stabilizer such as cromolyn.

Watery discharge is likely viral.

The presence of discharge and mattering with no itching suggests bacterial conjunctivitis.

All ophthalmic antibiotics appear to be efficacious for bacterial conjunctivitis.

Gentamicin ophthalmic drops, which do not burn as much as other antibiotics.

Neomycin preparations have a high risk of hypersensitivity.

Conjunctivitis with excessive mucopurulent discharge are seen with chlamydia and gonorrhea.

Chlamydia conjunctivitis often occurs in young adults, and should be considered in sexually active adults in whom treatment for acute bacterial conjunctivitis fails.

Chlamydia conjunctivitis treatment includes topical erythromycin and oral antibiotics for genital infection.

Viral conjunctivitis is the most common overall cause of infectious conjunctivitis.

Viral conjunctivitis usually does not require treatment.

Viral conjunctivitis highly contagious.

Viral conjunctivitis offten caused by adenovirus.

Viral conjunctivitis often occurs bilaterally., with watery discharge.

Viral conjunctivitis usually associated with normal visual acuity, and may be associated with preauricular lymphadenopathy.

Viral conjunctivitis may be associated with upper respiratory infection.

Viral conjunctivitis usually mild and resolve within 2 weeks.

Severe viral conjunctivitis may be associated with sub epithelial corneal opacity es and pseudomembrane formation.

Viral conjunctivitis treatment is usually supportive, with artificial tears and compresses.

Viral conjunctivitis that is severe may be benefited from steroid eye drops.

Bacterial conjunctivitis is the second most common cause of infectious conjunctivitis.

Most uncomplicated cases of bacterial conjunctivitis resolves in 1 to 2 weeks.

Bacterial conjunctivitis associated with mattering and adherence of the eyelids on waking, lack of itching, and absence of a history of conjunctivitis are major associated factors.

Topical antibiotics decrease the duration of bacterial conjunctivitis.

Conjunctivitis secondary to sexually transmitted diseases such as chlamydia and gonorrhea require the use of systemic antibiotics in addition to topical antibiotic therapy.

Allergic conjunctivitis occurs in up to 40% of the population.

Itching is the most consistent sign in allergic conjunctivitis.

Treatment of allergic conjunctivitis consists of topical antihistamines and mast cell inhibitors.

Symptoms include itching, burning, discharge, and often experience the sensation of having a foreign body in the eye.

Severe pain is uncommon.

Generally does not impair vision, but with severe inflammation some cloudiness of vision may occur.

May be caused by environmental irritates, allergies or infections.

Most clinically significant cases attributed to an infectious process.

Two main infectious kinds of agents include, bacterial and viruses.

Approximately half of infectious cases caused by viruses and half by bacteria.

Bacterial cases may be more common among young children, and viral agents the cause more commonly in older persons.

Usual bacterial agents involved are pneumococci, Hemophilus or Moraxella, all inhabitants of the respiratory tract.

All infections are spread by direct contact.

Eye drainage form an infected patient is highly infectious, with a high attack rate.

Living close together is responsible for epidemics.

Newborns may become infected with Chlamydia during passage through the birth canal of a woman with an infection.

Untreated gonorrhea in a mother can lead to infection of an infant, this is prevented by the use of eye antibiotics in newborns.

Contact lens use can lead to giant papillary conjunctivitis, secondary to chronic irritation, especially if the lenses are not cleaned regularly.

Clinical diagnosis.

No specific test exists to confirm the diagnosis.

Allergic and irritative causes generally produce less redness and less discharge than conjunctivitis from infectious causes.

Discharge from non-infectious cases clearer and thinner and yellower than fluid from those with infections.

Rietveld scoring for bacterial conjunctivitis:

Two glue eyes in the morning = five points

One glued eye in the morning = 2 points

Eye itching =-1 point

History of conjunctivitis = -2 points

In the above scoring a score of +4 or more increases probability of bacterial conjunctivitis, where is the score of zero or less decreases that probability.

Allergic disease often associated with other allergic symptoms.

Allergic and irritative type of involvement generally affect both eyes equally.

Allergic conjunctivitis associated with 5 categories: seasonal allergic, vernal keratoconjunctivits, giant papillary type, atopic keratoconjunctivitis and contact conjunctivitis.

Affects about 10% of the population.

Most patients have a family history of allergic conjunctivitis.

Symptoms present in childhood.

Seasonal allergic conjunctivits is an acute IgE mediated process as a result of pollen, dander, mold and housedust which are airborne. and

Infectious disease related disease frequently begins in one eye and spreads to the other.

Many viruses may be responsible, but the adenoviruses are the usual viral agents involved.

All cases of resistant conjunctivitis require a slit-lamp examination and it is best to avoid topical steroids.

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