Eye: Conjuctivitis

Conjunctivitis  

Is an infection or inflammation of the conjunctiva.

Causes

• Microbial infection (exogenous microbes -bacteria (eg, Chlamydia), viruses, fungus, and parasites)
• Allergy
• Irritating-toxic stimuli
• Existing ocular infection or can be a manifestation of a systemic disease

Clinical Manifestations

Conjunctivitis may be unilateral or bilateral, but the infection usually starts in one eye and then spreads to the other eye by hand contact.   

General symptoms include

• Foreign body sensation
• Scratching or burning sensation
• Itching
• Photophobia

Types:

l. MICROBIAL CONJUNCTIVITIS

a.Bacterial conjunctivitis:  

• can be acute or chronic
• Signs and smptoms-vary from mild to severe

Common causative microorganism-

• Streptococcus pneumonia

• Haemophilus influeze
• Saphylococcus aureus

Chronic bacterial conjunctivitis –

• seen in patients with lacrimal duct obstruction, chronic dacryocystitis, and chronic blepharitis.
• c/f- an acute onset of redness, burning, and discharge.
• Conjunctival irritation  
• The exudates are variable but are usually present on waking in the morning (The eyes may be difficult to open because of adhesions caused by the exudate)  Purulent discharge occurs in severe acute bacterial infections, whereas mucopurulent discharge appears in mild cases.

b. Viral

• Acute and chronic
• The discharge is watery, and follicles are prominent. Severe cases include pseudomembranes.
• Causative organisms- adenovirus (highly contagious) and herpes simplex virus.  
• Symptoms —extreme tearing, redness, and foreign sensation that can involve one or both eyes.
• The condition is usually preceded by symptoms of upper respiratory infection.  
• Corneal involvement causes extreme photophobia.
• There is lid edema, ptosis,conjunctival hyperemia (i.e. dilation of the conjunctival blood vessels), watery discharge, follicles, and papillae.
• These signs and symptoms vary from mild to severe and may last for 2 weeks.  
• Viral conjunctivitis, although self-limited, tends to last longer than bacterial conjunctivitis.

c. Epidemic keratoconjunctivites (EKC)

• EKC –often accompanied by periauricular lymphadenopathy  and occasionally periorbital pain.
• There are marked follicular and papillary formations.
• EKC can lead to keratopathy
• EKC is a highly contagious viral conjunctivitis that is easily transmitted from one person to another among household members, school children, and health care workers

d. Chlamydial conjunctivitis  

• Includes trachoma and inclusion conjunctivitis
• Trachoma is an ancient disease and is the leading cause of preventable blindness in the world.
• It is prevalent in areas with hot, dry, and dusty climates and in  conditionswith poor living.
• It is spread by direct contact or fomites, and the vectors can be insects such as flies  and ants.
• Inclusion conjunctivitis affects sexually active who have genital chlamydial infection.
• Transmission - oral genital sex or hand-to-eye transmission.
• Indirect transmission -inadequately chlorinated swimming pools.
• The discharge is mucopurulent, follicles are present and there is lymphadenopathy

2. ALLERGIC CONJUNCTIVITIS

• Immunologic or allergic conjunctivitis is a hypersensitivity reaction as a part of allergic rhinitis, or it can be an independent allergic reaction.
• The patient usually has a history of an allergy to pollens and other environmental allergens.
• There is extreme itching, epiphora (i.e, excessive secretion of tears) and usually severe photophobia.
• The string like mucoid discharge is usually associated with rubbing the eyes because of severe itching.

3. TOXIC CONJUNCTIVITIS

Causes

• Medications
• Chlorine from swimming pools (more common during the summer)
• Exposure to toxic fumes among industrial workers
• Exposure to other irritants such as smoke, hair sprays, acids, and alkalis

Diagnosis

Evaluate the four main clinical features

• Type of discharge (ie, watery, mucoid, purulent, or mucopurulent)
• Type of conjunctival reaction (ie, follicular or papillary)
• Presence of pseudomembranes or true membranes
• Presence or absence of lymphadenopathy (ie, enlargement of the preauricular and submandibular lymph nodes where the eyelids drain)
• Pseudomembranes consist of coagulated exudate that adheres to the surface of the inflamed conjunctiva. True membranes form when the exudate adheres to the superficial layer of the conjunctiva, and removal results in bleeding.
• Follicles are multiple, slightly elevated lesions encircled by tiny blood vessels; they look like grains of rice.
• Papillae are hyperplastic conjunctival epithelium in numerous projections that are  usually seen as a fine mosaic pattern under slit-lamp examination.
• Diagnosis is based on the distinctive characteristics of ocular signs, acute or chronic presentation, and identification of any precipitating events.
• Positive results of swab smear preparations and cultures- confirm the diagnosis

Management

• Depends on the type.
• Benign conditions -may not require treatment and laboratory procedures.
• For more severe cases, topical antibiotics, eye drops, or ointment are prescribed.
• Gonococcal conjunctivitis- require antibiotic therapy
• Acute bacterial conjunctivitis is almost always self-limiting.

• If left untreated- fòllows a 2-week course with resolution of symptoms.
• If treated with appropriate antibiotics, it may last for a few days, with the exception of gonococcal and staphylococcal conjunctivitis.
• Viral conjunctivitis is not responsive to any treatment.   
• Cold compresses - alleviate some symptoms.
• Patients must be made aware of the contagious nature of the disease, and adequate instructions must be given.
• An emphasis on hand washing and avoiding sharing hand towels, face cloths, and eye drops.
• Tissues should be directly discarded into a trashcan.
• Proper steps must be taken to avoid nosocomial infections.
• Frequent hand hygiene, procedures for environmental cleaning, and disinfection of equipment used for eye examination must be strictly followed at all times  
• All forms of tonometry must be avoided unless medically indicated.
• All multidose medications must be discarded at the end of each day or when contaminated.
• Infected employees and others must not be allowed to work or attend school until symptoms have resolved which can take 3 to 7 days.
• Allergic conjunctivitis -corticosteroids in ophthalmic preparations.
• Depending on the severity of the disease, they may be given oral preparations.   
• Use of vasoconstrictors, such as topical epinephrine solution, cold compresses, ice packs, and cool ventilation usually provide comfort by decreasing swelling.

For trachoma –

• broad-spectrum antibiotics administered topically and systemically.
• Surgical management - correction of trichiasis to prevent conjunctival scarring   

Toxic conjunctivitis-

• chemical irritants must be irrigated immediately and profusely with saline or sterile water.

Complications

• Corneal perforation
• Blindness
• The systemic complications –Meningitis, Generalized septicaemia