keratitis

1. INFLAMATION OF CORNEA
OPTOM FASLU MUHAMMED

2.  Inflammation of the cornea (keratitis) is
characterized by corneal oedema, cellular
infiltration and ciliary congestion.
 It is defined as a complex vascular response that
results in the accumulation of the cellular exudates

3.  KERATITIS
- central
 Superficial , deep
- non ulcerative , ulcerative
- Peripheral
 Superficial , deep
- non ulcerative , ulcerative

4. CORNEAL ULCER
 Localized necrosis of sup. Stroma with destruction
of overlying epithelium
 corneal ulcer may develop when:
 either the local ocular defence mechanism is
jeopardized, or
 there is some local ocular predisposing disease, or
host's immunity is compromised
 the causative organism is very virulent

5.  1. Corneal epithelial damage
 Corneal abrasion due to small foreign body,
 Epithelial drying as in xerosis and exposure
keratitis.
 Necrosis of epithelium
 Epithelial damage due to tropic changes as in
neuroparalytic keratitis.

6.  Causative organisms.
 Common bacteria associated with corneal
ulceration are:
 Staphylococcus aureus, Pseudomonas pyocyanea,
Streptococcus pneumoniae, E. coli, Proteus,
Klebsiella, N. gonorrhea, N. meningitidis and C.
diphtheria.

7. PATHOLOGY OF LOCALIZED CORNEAL ULCER
 1. Stage of progressive infiltration
 infiltration of polymorph nuclear and/or lymphocytes
into the epithelium from the peripheral circulation
supplemented by similar cells from the underlying
stroma if this tissue is also affected

8. 2. STAGE OF ACTIVE ULCERATION
 Active ulceration results from necrosis and
sloughing of the epithelium, Bowman's membrane
and the involved stroma.

9. 3. STAGE OF REGRESSION
 Regression is induced by the natural host defence
mechanisms
 A line of demarcation develops around the ulcer,
which consists of leucocytes that neutralize and
eventually phagocytes the offending organisms and
necrotic cellular debris

10. 4.STAGE OF CICATRIZATION
 In this stage healing continues by progressive
epithelization which forms a permanent covering.
 When ulcer involves Bowman's membrane and few
 superficial stromal lamellae, the resultant scar is called a
'nebula‘
 Macula – one third
 leucoma – more than one third of stroma