VASCULARIZATION OF CORNEA

Normal cornea is avascular except for small capillary loops which are present in the periphery for about 1 mm. In pathological states, it can be invaded by
vessels as a defence mechanism against the disease or injury. However, vascularization interferes with corneal

CORNEAL OEDEMA

 Corneal oedema

The water content of normal cornea is 78 percent. It is kept constant by a balance of factors which draw water in the cornea (e.g., intraocular pressure and swelling pressure of the stromal matrix = 60 mm of Hg) and the factors which draw water out of

POSTERIOR CORNEAL DYSTROPHIES

Cornea Guttata of vogt
This condition is characterised by drop-like excrescences involving the entire posterior surface of Descemet's membrane. These are similar to Hassal- Henle bodies which represent the age change and are mainly found in the

STROMAL CORNEAL DYSTROPHIES

Granular dystrophy
Also known as 'Groenouw type I, is an autosomal
dominant dystrophy characterised by milky-granular
hyaline deposits in anterior stroma. Intervening
stroma is

Anterior corneal dystrophies

ANTERIOR DYSTROPHIES

Epithelial basement membrane dystrophy
Also known as Cogan's microcystic dystrophy and
map-dot finger print dystrophy, is the most common
of all corneal dystrophies seen in working age adults.
The typical lesions, involving corneal

CORNEAL PATHOLOGICAL DEGENERATIONS

Fatty degeneration (Lipoid keratopathy)
Fatty degeneration of cornea is characterised by whitish or yellowish deposits. The fat deposits mostly consist of cholesterol and fatty acids. Initially fat deposits are intracellular but some become extracellular with necrosis of stromal

Syphilitic (luetic) interstitial keratitis

INTERSTITIAL KERATITIS
Interstitial keratitis denotes an inflammation of the corneal stroma without primary involvement of the epithelium or endothelium.

Causes. Its common causes are:
Congenital syphilis
Tuberculosis
Cogan's syndrome
Acquired syphilis
Trypanosomiasis
Malaria
Leprosy
Sarcoidosis

Syphilitic (luetic) interstitial keratitis
Syphilitic interstitial keratitis is associated more frequently (90 percent) with congenital

MOOREN'S ULCER

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The Mooren's ulcer (chronic serpiginous or rodent ulcer) is a severe inflammatory peripheral ulcerative keratitis.

Etiology
Exact etiology is not known. Different views are :
1. It is an idiopathic degenerative conditon.
2. It may be due to an ischaemic necrosis resulting from vasculitis of limbal vessels.
3. It may be due to the effects

ROSACEA KERATITIS

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ROSACEA KERATITIS is defined as : Corneal ulceration is seen in about 10 percent cases of acne rosacea, which is primarily a disease of the sebaceous glands of the skin.

Clinical features
1. The condition typically occurs in elderly women in the form of facial eruptions presenting as butterfly configuration, predominantly involving
the malar and nasal

Treatment of corneal ulcer

 corneal ulcer treatment

[A] Clinical evaluation
Each case with corneal ulcer should be subjected to:
1. Thorough history taking to elicit mode of onset, duration of disease and severity of symptoms.

2. General physical examination, especially for built, nourishment, anaemia and any immunocompromising disease.

3. Ocular examination should include:
i. Diffuse light examination for gross lesions of the lids, conjunctiva and cornea including testing for sensations.
ii. Regurgitation test and syringing to rule out lacrimal sac infection.
iii. Biomicroscopic examination after staining of corneal ulcer with

corneal ulcer Complications

 Complications of corneal ulcer

1. Toxic iridocyclitis. It is usually associated with cases of purulent corneal ulcer due to absorption of toxins in the anterior chamber.

2. Secondary glaucoma. It occurs due to fibrinous exudates blocking the angle of anterior chamber (inflammatory glaucoma).

3. Descemetocele. Some ulcers caused by virulent organisms extend rapidly up to Descemet's membrane, which gives a

Hypopyon corneal ulcer "cornea"

Etiopathogenesis of Hypopyon corneal ulcer " cornea"

Causative organisms. Many pyogenic organisms (staphylococci, streptococci, gonococci, Moraxella) may produce hypopyon, but by far the most dangerous are pseudomonas pyocyanea and pneumococcus. Thus, any corneal ulcer may be associated with hypopyon, however, it is customary to reserve the

corneal ulcer Pathogenesis and pathology

Pathology of corneal ulcer Once the damaged corneal epithelium is invaded by the offending agents the sequence of pathological changes which occur during development of corneal ulcer can be described under four stages, viz., infiltration, active ulceration, regression and cicatrization. The terminal course of corneal ulcer depends upon the virulence of infecting

Pathology of sloughing corneal ulcer and formation of anterior staphyloma

When the infecting agent is highly virulent and/or body resistance is very low, the whole cornea sloughs with the exception of a narrow rim at the margin and
total prolapse of iris occurs. The iris becomes inflamed and exudates block the pupil and cover the iris surface; thus a false cornea is formed. Ultimately these exudates organize and form a thin fibrous layer over which the conjunctival or corneal epithelium rapidly grows and thus a pseudocornea is

ULCERATIVE KERATITIS

Inflammation of the cornea (keratitis) is characterised by corneal oedema, cellular infiltration and ciliary congestion.

ULCERATIVE KERATITIS
Corneal ulcer may be defined as discontinuation in normal epithelial surface of cornea associated with necrosis of the surrounding corneal tissue.
Pathologically it is characterised by oedema and cellular infiltration. Common types of corneal ulcers are described below.INFECTIVE KERATITIS
BACTERIAL CORNEAL ULCER
Being the most anterior part of eyeball, the cornea is exposed to atmosphere and hence prone to get infected easily. At the same time cornea is protected
from the day-to-day minor infections by the

ACUTE FOLLICULAR CONJUNCTIVITIS

Acute follicular conjunctivitis is an acute catarrhal conjunctivitis"OR KNOWN AS ACUTE MUCOPURULENT CONJUNCTIVITIS" associated with marked follicular hyperplasia especially of the lower fornix and lower palpebral conjunctiva.

General clinical features
Symptoms are similar to acute catarrhal conjunctivitis and include: redness, watering, mild mucoid discharge, mild photophobia and feeling of

Trachoma Management

Management of trachoma should involve curative as
well as control measures.

A. Treatment of active trachoma
Antibiotics for treatment of active trachoma may be
given locally or systemically, but topical treatment is
preferred because:

• It is cheaper,
• There is no risk of systemic side-effects, and

Grading of trachoma

McCallan's classification
McCallan in 1908, divided the clinical course of the
trachoma into following four stages:

• Stage I (Incipient trachoma or stage of infiltration). It is characterized by hyperaemia of palpebral conjunctiva and immature follicles.
• Stage II (Established trachoma or stage of florid infiltration). It is characterized by appearance of mature

TRACHOMA Symptoms & Signs

Symptoms

• In the absence of secondary infection, symptoms are minimal and include mild foreign body sensation in the eyes, occasional lacrimation, slight stickiness of the lids and scanty mucoid discharge.
• In the presence of secondary infection, typical symptoms of acute mucopurulent conjunctivitis develop.

Signs
A. Conjunctival signs
1. Congestion of upper tarsal and forniceal conjunctiva.

2. Conjunctival follicles. Follicles (Fig. 1 and Fig.2) look like boiled

INFECTIVE & BACTERIALCONJUNCTIVITIS

Infective conjunctivitis, i.e., inflammation of the
conjunctiva caused by microorganisms is the
commonest variety. This is in spite of the fact that
the conjunctiva has been provided with natural
protective mechanisms in the form of :

•  Low temperature due to exposure to air,
•  Physical protection by lids,
•  Flushing action of tears,
•  Antibacterial activity of lysozymes and
•  Humoral protection by the tear immunoglobulins.

 BACTERIAL CONJUNCTIVITIS
There has occurred a relative decrease in the
incidence of bacterial conjunctivitis in general and
those caused by gonococcus and corynebacterium
diphtheriae in particular. However, in developing
countries it still continues to be the commonest type
of conjunctivitis. It can occur as sporadic cases and
as epidemics. Outbreaks of bacterial conjunctivitis
epidemics are quite frequent during monsoon season.

Etiology
A. Predisposing factors for bacterial conjunctivitis,
especially epidemic forms, are flies, poor hygienic
conditions, hot dry climate, poor sanitation and dirty
habits. These factors help the