Marginal corneal ulcer, also known as Mooren's ulcer, is a rare degenerative ulcer that starts at the corneal margin and spreads circumferentially and axially over the cornea. It is a rapidly progressive and painful ulcerative keratitis that can only be diagnosed in the absence of a systemic cause. It must be differentiated from other corneal abnormalities. Benign cases are unilateral, respond well to treatment, and affect elderly people, while malignant cases are bilateral, respond poorly to treatment, and affect younger people in a progressive manner. It is considered an autoimmune disorder associated with infections and various theories about antigen-antibody reactions and molecular mimicry stimulating an autoimmune response.
2. It is a rare, degenerative, superficial ulcer,
starting at the corneal margin and
spreading circumferentially and axially
over the whole of this tissue.
It is a rapidly progressive, painful,
ulcerative keratitis
It can be only be diagnosed in the
absence of systemic cause and must be
differentiated from other corneal
abnormlities such as,Terriens
degeneration.
3.
4. BENIGN /TYPICAL
Unilateral
Reponds well to treatment
Elderly people
MALIGNANT
Bilateral
Very poorly responds to
treatment
Younger people
progressive
5.
6. It is an auto immune disorder.
Associated with infections- helminthiasis,
hepatitisC, herpes simplex and zoster.
Various theories
The antigen antibody reaction to infectious
toxin deposited in the peripheral cornea
causes inflammation and ulceration.
7. Molecular mimicry may be involved,
stimulating an auto immune response.
Deposition of immune complex over
peripheral cornea
Other causes:
Physical trauma, foreign bodies, chemical
burns, surgeries such as cataract extraction
and keratoplasty.
8. Auto immune lysis of the epithelium with
release of collagenolytic enzymes.
Grey infiltrates , which break down, forming
small ulcers that spread and coalesce.
It destroys the epithelium and superficial
stromal lamellae, forming a whitish
overhanging edge, while the base quickly
becomes vascularised.
9. severe and persistent neuralgic pain.
Redness
Photophobia
Lacrimation
Decrease in visual acuity due to associated
iritis, central corneal involvement and
irregular astigmatism.
12. Topical steroids and antibiotics
Excision of a 4-7 mm strip of adjacent
conjunctiva may prove successful by
eliminating conjunctival sources of
collagenase , proteoglycanase and other
inflammatory mediators.
Perforation:
ulcer debridement
cyanoacrylate adhesive
soft contact lenses.
Lamellar keratoplasty with i.v methotrexate
– halt the process
