CLASSIFICATION AND MANAGEMENT OF CONJUNCTIVITIS
Introduction:
•Conjunctivitis or pink eye is the inflammation of the outermost layer of the white part of the eye and inner surface of the eyelid.
•Common triad in all forms of conjunctivitis
– Itching is more common in allergic cases
– Most common infectious (contagious) causes are viral followed by bacterial.
– Conjunctivitis may occur unilaterally or bilaterally.
– Diagnosis is often based on signs & symptoms and occasionally on microbial culture.
– Viral causes are common in adults while in children bacterial.
– Examination of the palpebral conjunctiva (that overlying the inner aspect of the eyelids) is usually more diagnostics than examination of bulbar conjunctiva (that overlying the sclera).
-In conjunctivitis, pupillary reaction and VA are normal.
CLASSIFICATION
Causes:
Allergy
•Usually bilateral
•Itching is the most common complain in allergic conjunctivas
•Specific allergens differ among patients; viz perfumes, cosmetics, mites, pollens, hair of animals, irritants such as smoke, dust e.t.c
• The most frequent cause of conjunctivitis is allergic conjunctivitis •Reaction to allergens results in release of histamine by mast cells.
•Hence; vasodilatation of peripheral blood vessels causing swelling of conjunctiva, itching and tearing. Types of Allergic Conjunctivitis
•Hay fever conjunctivitis
•Vernal conjunctivitis
•Atopic conjunctivitis
•Giant papillary conjunctivitis
Bacteria:
•Rapid onset of redness, swelling of the eyelid and sticky discharge.
•Conjunctivitis due to common pus producing bacteria causes marked grittiness, irritation and a stingy opaque, grayish or yellowish discharge.
•Non-acute bacterial conjunctivitis is caused by staphylococcus, streptococcus and haemophilus species.
Bacteria such as Chlamydia trachomatis or moraxella spp. Can cause nonexudative but persistent conjunctivitis with much redness. Bacteria conjunctivitis involving the production of membranes or pseudomembranes are associated with Neisseria gonorrhoeae, B-hemolytic streptococci and corynebacterium diphtheria.
Most common cause of acute bacterial conjunctivitis are staphylocous aureus, streptococci pneumonia, and Haemophilus influenza while: hyperacute cases are caused by Neisseriae gonorrhoeae or meningitidis
Chronic cases which last longer than 3 weeks are caused by staph. Aureus, moraxella leannata or gram-ve enteric flora.
Viruses:
•Viral conjunctivitis is self limiting and treated symptomatically.
•Adenoviruses are most common cause of viral conjunctivitis-a.k.a adenoviral kerato conjunctivitis.
•Herptic keratoconjnctivitis caused by herpes simplex viruses.
•Acute haemorrhagic conjunctivitis is a highly contagious disease caused by one of two enteroviruses, enterovirus 70 and coxsackievirus A24 – First identified in an outbreak in Ghana in 1969 and have spread worldwide since then.
•Others include; varicela zoster – virus, Epstein – Barr virus, rubeola, rubella, mumps etc.
Chemicals, Irritants or toxic
•Results when acidic or alkaline substance gets in the eye; worse in alkali burns than acidic burns.
•Mild burns produce conjunctivitis while more severe burns may cause the cornea to turn white.
•Chemical splash is often observed only in the lower conjunctival sac.
•Caustic alkalis such as sodium hydroxide may result in marked deceptively white eye, followed by sloughing off of the dead epithelium due to vascular closure.
•Individuals who wear contact lens may experience irritations
•Slit lamp biomicroscopy may reveal evidence of anterior
leveitis
Autoimmune
•Conjunctivitis is a triad of reactive arthritis though to be cause by antoimmune cross reactivity and associated with autoimmune disease relapsing polychondritis
•Also seen in Graft-versus- Host fisease stevens-Johnsons syndrome, Reiters syndrome & Kawasaki disease.
Neonatal Conjunctivitis (Epidemiology & Demography)
•Occurs in 1.6% to 12% of all new borns
•Most common and acute causes is Ophthalmia neonatorum;
•Usually diagnosed by time of onset:
•First 24 hours of life – caused by chemical most likely
•Silver nitrate
•Between 2 and 5days of life: gonocoecal
•Between 5 and 23 days of life: chlamydial.
By Extent of Involvement:
•Blepharo – conjunctivitis •Kerato-conjunctivitis •Blepharokeratoconjunctivitis: This is marked by •Changes of the lid margin •Meibornian gland dysfuntion •Redness of the eye •Conjunctival chemosis and •Inflammation of the cornea.
TREATMENT
Your doctor may prescribe Antibiotics to you, this may help shorten the length of infection, reduce complications, and reduce the spread to others. Antibiotics may be necessary in the following cases:
- With discharge
- When conjunctivitis occurs in people whose immune system is compromised
- When certain bacteria are suspected