Corneal Ulcer: A Microbial Disease of the Eye Ameen Jafferie

Biomedical Careers Program I

Outer Layer of the Eye

Inner Layers of the Eye

Anatomy of the HumanEye

Corneal Ulcer Symptoms

Corneal Ulcer Treatments

Eye Defense Mechanisms

Bacteria in Eye Niche

Common Eye Infections

Outer most layer: Sclera• Tough fibrous layer• Transparent• Forms cornea• Refracts light to focus image• Protected by thin conjunctiva layer• Mucous membrane• Aqueous humor connects cornea

to lens

Middle layer: Choroid• Contains vessels• Forms cilliary body in anterior part• Iris regulates amount of light

entering eye• Light passes through pupil

Inner most layer: Retina

• Contains photoreceptors• Rods• Cones• Signal Transduction• Neurons of retina relay info. from

photoreceptors to optic nerve

• Blurry or hazy vision• Photophobia• Severe pain and soreness• Sensation of large foreign body in eye• Itching and discharge• Red eyes• White patch on cornea

• Lacrimal apparatus protects the eyefrom microorganisms andsubstances

• Lacrimal glands secrete tears• Lysozyme in tears• Capable of breaking gram positive

bacteria• Lesser extent gram negative• Blink reflex• Conjunctiva kept moist• Protective barriers• Cornea• Conjunctiva

(

• Bacteria in conjuctiva• Chlamydia trachomatis

Chlamydophila pneumoniaeHaemophilus aegyptiusHaemophilus influenzaeStaphylococcus aureus

• Native flora of the lids and mucoussurface limit pathogeniccolonization

• Pathogenic microorganismsoutcompeting normal flora cancause disease

• Conjunctivitis is inflammation ofconjunctiva

• Most commonly caused by virus• Keratitis is inflammation of the

cornea• Corneal Ulcer• Multiple causes• Bacterial infection from an injury

or contact lenses• Pseudomonas aeruginosa

digests the cornea

Corneal Ulcer• Open sore in the outer layer of the

cornea• Erodes the surface of the eye• Caused by bacteria, virus, fungi, or

parasite• Pseudomonas and Staphylococcus• Fusarium• Acanthamoeba• Herpes simplex• Abrasions on the eye surface• Severely dry eyes• Foreign bodies in the eye• Bell’s palsy

• Antibiotics, antifungal, and antiviral eyedrops are the mainstay of treatment

• Pain medication may be prescribed toreduce pain

• Steroid or anti-inflammatory eyedropsused to reduce swelling

• Corneal transplant if not treated withmedication