INFECTIOUS DISEASES OF THE EYES MAJID MOHIUDDIN
INFORMATION:• CONJUCTIVA: The thin, tough lining that covers the inner wall of the eyelid and the sclera (the white of the eye).• CONJUNCTIVITIS: An infection or inflammation of the conjunctiva.• KARATITIS: An infection or inflammation of the cornea – the domed covering over the iris and lens.• KERATOCONJUNCTIVITIS: An infection that involves both the cornea and
BACTERIAL CONJUCTIVITIS (Pinkeye)• Irritation• Reddening of conjunctiva,• Edema of eyelids,• Mucopurulent discharge,• Sensitivity to light,• Highly contagious.
ETIOLOGIC AGENT:• Haemophilus influenzae biogroup aegyptius and Streptococcus pneumoniae. And others.RESERVOIRRS AND MODE OF TRANSMISSION:• Infected humans,• Human to human via, eye and respiratory discharge, contaminated fingers, facial tissues, clothing, eye makeup, eye medications, ophthalmic instruments and contact lens-wetting and lens cleaning agents.DIAGNOSIS:• Microscopic examination
CHLAMYDIAL CONJUNCTIVITIS, INCLUSION CONJUCTIVITIS, PARATRACHOMA• Mucopurulent discharge in neonates, result in mild scarring of conjunctivae and cornea.• May concurrent with chlamydial nasopharyngitis or pneumonia.• In adults, may be concurrent with nongonococcal urethritis or cervicitis.
ETIOLOGIC AGENT:• Serotypes (serovars) of Chlamydia trachomatis.RESERVOIRS AND MODE OF TRANSMISSION:• Infected humans.• Contact with genital discharges of infected people.• Contaminated fingers to eye.• Infection in newborns via infected birth canal.• Nonchlorinated swimming pools.DIAGNOSIS:• Chlamydias cannot grow on artificial media.• Diagnosis by cell culture
TRACHOMA, CHLAMYDIA KERATOCONJUNCTIVITS• Highly contagious• Acute or chronic conjunctival inflammation• Scarring of cornea and conjunctiva• Deformation of eyelids and blindness.• Trachoma is most common in poverty stricken areas of the hot, dry Mediterranean Countries and the Far East. Leading blindness in the World.
ETIOLOGIC AGENT:• Serotypes (serovars) of Chlamydia trachomatisRESERVOIRS AND MODE OF TRANSMISSION:• Infected humans• Direct contact with infectious ocular or nasal secretions• Contaminated articles• Also spread by flies.DIAGNOSIS:• Microscopic observation of intracellular chlamydial elementary bodies in epithelial cells of Giemsa stained conjunctival scrapings.
ETIOLOGIC AGENT:• Neisseria gonorrhoeae (G-ve, kidney-bean shaped diplococci) also known as gonococcus.RESERVOIRS AND MODE OF TRANSMISSION:• Infected humans• Contact with the infected birth canal during delivery.• Adult infection from finger to eye contact with infected genital secretions.Diagnosis:• Culture media (Chocolate agar, Thayer Martin agar, Martin Lewis agar, New York City agar
AMEBIC CONJUCTIVITIS AND KERATOCONJUCTIVITIS• Inflammation of the conjunctiva• Corneal ulcers• Pus formation• Severe pain• Loss of vision
ETIOLOGIC AGENT:• Several species of amebae – genus Acanthamoeba.RESERVOIRS AND MODE OF TRANSMISSON:• Ameba contaminated water.• Unsterile contact lens• Cleaning and wetting solutionsDIAGNOSIS:• Microscopic examination of scrapings, swabs.
TOXOPLASMOSIS• Systemic sporozoal infection• Immunocompetent persons• Serious disease, even death, may occur in immunodeficient persons• Infection during early pregnancy may lead to fetal infection, causing death of the fetus or serious birth defects.(eg brain damage).
ETIOLOGIC AGENT:• Toxoplasma gondii; an intracelluar sporozoan.RESERVOIRS AND MODE OF TRANSMISSION:• Cats and other felines that usually acquire infection by eating infected rodents or birds.• Intermediate hosts include rodents, birds, sheep, goats, swine and cattle.• Humans usually become infected by eating raw or under cooked meat.DIAGNOSIS:• Immunodiagnostic procedures• Demonstration of the pathogen in body tissues or fluids by biopsy or necropsy• Isolation of the pathogen in animals or cell