Keratitis : DEFINITION
Keratitis is a condition in which the eye's cornea, the front part of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves impaired eyesight. Deep keratitis involves deeper layers of the cornea, and the natural course leaves a scar upon healing that impairs vision if on or near the visual axis. This can be reduced or avoided with the use of topical steroideyedrops.
PATHOPHYSIOLOGY
Amoebic keratitis. Amoebic infection of the cornea is the most serious corneal infection, usually affecting contact lens wearers.[2] It is usually caused by Acanthamoeba. On May 25, 2007, the CDC issued a health advisory due to increased risk of Acanthamoeba keratitis (AK)infection associated with use of Advanced Medical Optics (AMO) Complete Moisture Plus Multi-Purpose eye solution.
Bacterial keratitis. Bacterial infection of the cornea can follow from an injury or from wearing contact lenses. The bacteriums usually involved are Staphylococcus aureus and for contact lens wearers Pseudomonas aeruginosa.
Fungal keratitis (cf. Fusarium, causing recent incidences of keratitis through the possible vector of Bausch & LombReNu with MoistureLoccontact lens solution)
Viral keratitis
Herpes simplex keratitis. Viral infection of the cornea is often caused by the herpes simplex virus which frequently leaves what is called a 'dendritic ulcer'.
Herpes zoster keratitis
Onchocercal keratitis -- for which reason onchocerciasis is also named "river blindness"
Conjunctivitis ( pinkeye ) : Conjunctivitis, also known as pinkeye, is an inflammation of the conjunctiva. The conjunctiva is the thin clear tissue that lies over the white part of the eye and lines the inside of the eyelid. Pinkeye has a number of different causes, including:
• Viruses
• Bacteria (such as gonorrhea or chlamydia)
• Irritants such as shampoos, dirt, smoke, and pool chlorine
• Allergies, like dust, pollen, or a special type of allergy that affects some contact lens wearers
Pinkeye caused by some bacteria and viruses can spread easily from person to person, but is not a serious health risk if diagnosed promptly. Pinkeye in newborn babies, however, should be reported to a doctor immediately, as it could be a vision-threatening infection.
Symptoms
• Blurred vision
• Crusts that form on the eyelid overnight
• Eye pain
• Gritty feeling in the eyes
• Increased tearing
• Itching of the eye
• Redness in the eyes
• Sensitivity to light
Treatment
• Treatment of conjunctivitis depends on the cause.
• Allergic conjunctivitis may respond to allergy treatment. It may disappear on its own when you avoid your allergy triggers. Cool compresses may help soothe allergic conjunctivitis.
• Antibiotic medication, usually eye drops, is effective for bacterial conjunctivitis. Viral conjunctivitis will disappear on its own. Many doctors give a mild antibiotic eyedrops for pink eye to prevent bacterial conjunctivitis.