Corneal ulcer
- 1. By; ASWIN.AK SRI RAMACHANDRA MEDICAL COLLEGE AND RESEARCH INSTITUTE
- 2. The cornea is the transparent front part of the eye which resembles a ‘watch glass’ and consists of different layers and regions: Epithelium Bowman’s membrane Stroma (substantia propria) Dua’s layer (pre-Descemet’s layer) Descemet’s membrane Endothelium.
- 3. Keratitis-The descriptive term used for any type of Corneal inflammation. Keratitis is classified based on the involvement of corneal layer.(Superficial keratitis, SPK, Deep keratitis) Corneal abrasion-Superficial epithelial defect without inflammation and it usually heal within 12-24hr by regeneration of the epithelial cell from the periphery. Corneal Ulcer-It is a manifestation of infective keratitis due to organisms that causes tissue death(necrosis) and pus formation in the corneal tissue. Corneal scar-Final outcome of any corneal inflammation.(white and opaque) CORNEAL ULCER WITH FEATHERY MARGIN
- 4. Corneal epithelium-MECHAICAL BARRIER Conjunctiva-CELLULAR AND CHEMICAL COMPONENTS Tear film-BIOLOGICAL PROTECTIVE SYSTEM All the above part forms a major component of ocular defence system…. Once the corneal epithelium gets disturbed as a result of corneal ulcer, the organisms gains access to the interior of the eye and can cause endophthalmitis, etc…
- 5. Complications of corneal ulcer can be explained under two headings; i)Before perforation ii)After perforation… BEFORE PERFORATION AFTER PERFORATION ⬇︎ ⬇︎ i)Keratectasia i)Anterior synechia ii)Hypopyon ii)Iris prolapse iii)Secondary glaucoma iii)Anterior capsular cataract iv)Keratocoele iv)Anterior staphyloma v)Corneal scarrinng v)Spontaneous expulsion of lens vi)Haemorrhage vii)Endophthalmitis
- 6. KERATECTASIA-Superficial ulcerations commonly heal with varying degrees of scarring but if the ulcer is deep, the loss of tissue may lead to a marked thinning of the entire cornea at the site of the ulcer so that it bulges under the influence of the normal intraocular pressure. As the cicatrix becomes consolidated the bulging may disappear, or it may remain permanently as secondary keratectasia, an ectatic cicatrix. It differs from a staphyloma as the iris is not incarcerated. HYPOPYON-Hypopyon is a medical condition involving inflammatory cells in the anterior chamber of the eye. It is an exudate rich in WBC, seen in the anterior chamber, usually accompanied by redness of the conjunctiva and the underlying epi-sclera. It occurs due to the release of toxins and not by the actual invasion of pathogens. The toxins secreted by the pathogens mediate the outpouring of leukocytes that settle in the anterior chamber of the eye.
- 7. SECONDARY GLAUCOMA-Secondary glaucoma refers to any form of glaucoma in which there is an identifiable cause of increased eye pressure, resulting in optic nerve damage and vision loss. As with primary glaucoma, secondary glaucoma can be of the open-angle or angle-closure type and it can occur in one or both eyes. Secondary glaucoma may be caused by an eye injury, inflammation, certain drugs such as steroids and advanced cases of cataract or diabetes. The type of treatment will depend on the underlying cause, but usually includes medications, laser surgery, or conventional surgery. KERATOCOELE-Some ulcers, especially those due to pneumococci and septic organisms, extend rapidly in depth so that the whole thickness of the cornea, except Descemet’s membrane and a few corneal lamellae, may be destroyed. Descemet’s membrane, like other elastic membranes, offers great resistance to inflammatory processes. It is, however, unable to support the intraocular pressure by itself and, therefore, herniates through the ulcer as a transparent membrane called a keratocele or descemetocele. This may persist, surrounded by a white cicatricial ring, or it may eventually rupture.
- 8. CORNEAL SCARRING-The cornea is resilient and can typically heal from minor abrasions. However, major corneal damage can result in a corneal scar. The three words - nebula, macula, and leukoma are the words used to describe the appearance of a corneal scar. Nebula (fog or mist) describes a hard-to-see corneal scar - one where slit-lamp detection is required. Macula (stain or spot) is typified by the scar in the photo. It can be seen with proper illumination. Leucoma (white) is a white scar that is easily seen just by looking at the eye.
- 9. Complication based on perforation; ANTERIOR SYNECHIA-If the perforation is small the iris becomes gummed down to the opening, the adhesion organizes forming a layer of scar tissue over the adherent iris which is referred to as a ‘pseudo-cornea’ and an anterior synechia is formed. The blocking of the perforation with the iris allows the anterior chamber to be reformed as fresh aqueous is rapidly secreted. IRIS PROLAPSE-If the perforation is large, a portion of the iris is carried not only into the opening but through it causing a prolapse of the iris. The colour of the iris soon becomes obscured by the deposition of grey or yellow exudate upon the surface, but eventually the iris stroma becomes thinned and the black pigmentary epithelium becomes visible.
- 10. CATARACT-If the perforation happens to be opposite the pupil, the pupillary margin of the iris often becomes adherent to the edges and the aperture becomes filled with exudate. The anterior chamber is then reformed very slowly; if the lens remains in contact with the ulcer for a long time, a permanent opacity may occur forming an anterior capsular cataract. ANTERIOR STAPHYLOMA-An ectatic cicatrix in which the iris is incarcerated is called an anterior staphyloma which, depending on its extent, may be either partial or total. The bands of scar tissue on the staphyloma vary in breadth and thickness, producing a lobulated surface often blackened with pigment; hence the name.
- 11. SPONTANEOUS EXPULSION OF LENS-If the perforation takes place suddenly the suspensory ligament of the lens is stretched or ruptured, causing subluxation of the lens, or even anterior dislocation and spontaneous expulsion of the lens and vitreous through the perforation. HAEMORRHAGE-The sudden reduction of intraocular pressure when perforation occurs dilates the intraocular blood vessels, which may rupture causing an intraocular haemorrhage. Rupture of the retinal vessels gives rise to a vitreous haemorrhage; choroidal, a subretinal or subchoroidal haemorrhage. It may indeed be so profuse that the contents of the globe are extruded along with the out- flowing blood, i.e. expulsive haemorrhage.
- 12. ENDOPHTHALMITIS-Endophthalmitis is an infection of the tissues or fluids inside the eyeball. Endophthalmitis is a purulent inflammation of the intraocular fluids (vitreous and aqueous) usually due to infection. Exogenous Endophthalmitis-This is the most common type of endophthalmitis. With this type, the source of the infection comes from outside the body. Bacteria or fungi gets inside the eye from surgery or through perforation during ulcer. Endogenous Endophthalmitis-This is the second main type of endophthalmitis. It starts as an infection in another part of the body and spreads to the eye. For example, this can happen with a urinary tract infection or blood infection.
- 13. THANK YOU By; ASWIN.AK SRI RAMACHANDRA MEDICAL COLLEGE AND RESEARCH INSTITUTE