OPTOM FASLU MUHAMMEDNON ULCERATIVE KERATITIS

Non ulcerative keratitis

(a) non-ulcerative superficial keratitis and

(b) non-ulcerative deep keratitis.

NON-ULCERATIVE SUPERFICIAL KERATITIS

Diffuse superficial keratitis and Superficial punctate keratitis

DIFFUSE SUPERFICIAL KERATITIS

Diffuse inflammation of superficial layers of cornea occurs in two forms, acute and chronic

Etiology. Mostly of infective origin, may be associated with staphylococcal or gonococcal Infections.

SUPERFICIAL PUNCTATE KERATITIS (SPK)

SPK is characterized by occurrence of multiple, spotty lesions in the superficial layers of cornea.

Causes 1. Viral infections are the chief cause. :

herpes zoster, adenovirus , herpes simplex.

2. Chlamydial infections include trachoma

3. Trophic lesions e.g., exposure keratitis and neuroparalytic keratitis.

Morphological types (Fig. 5.14) 1. Punctate epithelial keratitis. 2. Punctate subepithelial keratitis. 3. Punctate combined epithelial and

subepithelial keratitis. 4. Filamentary keratitis

DEGENERATIONS

Corneal degenerations refers to the conditions in which the normal cells undergo some degenerative changes under the influence of age or some pathological condition

AGE-RELATED DEGENERATIONS

Arcus senilis It refers to an annular lipid

infiltration of corneal periphery. This is an age-related change

occurring bilaterally in 60 percent of patients between 40 and 60 years of age and in nearly all patients over the age of 80.

Sometimes, similar changes occur in young persons (arcus juveniles) which may or may not be associated with hyperlipidemia.

The arcus starts in the superior and inferior quadrants and then progresses circumferentially to form a ring which is about 1 mm wide.

Vogt's white limbal girdle It is also an age-related change seen

frequently in elderly people. It appears as bilateral chalky white

opacities in the interpalpebral area both nasally and temporally.

There may or may not be a clear area between opacity and the limbus. The opacity is at the level of Bowman's membrane.

PATHOLOGICAL DEGENERATIONS Fatty degeneration (Lipoid keratopathy) Fatty degeneration of cornea is characterized

by whitish or yellowish deposits. The fat deposits mostly consist of cholesterol and fatty acids.

1. Primary lipid keratopathy is a rare condition which occurs in a cornea free of vascularization.

2. Secondary lipid keratopathy occurs in vascularised corneas secondary to diseases such as corneal infections, interstitial keratitis, ocular trauma, glaucoma, and chronic iridocyclitis.

Calcific degeneration (Band Shape keratopathy) Band shape keratopathy (BSK) is

essentially a degenerative change associated with deposition of calcium salts in Bowman's membrane, most superficial part of stroma and in deeper layers of epithelium.

Etiology Ocular diseases. Band keratopathy is

seen in association with: chronic uveitis in

adults, children with Still's disease, phthisis bulbi, chronic glaucoma, chronic keratitis and ocular trauma.

Age related BSK is common and affects otherwise healthy cornea.

Metabolic conditions rarely associated with BSK include hypercalcaemia and chronic renal failure

Clinical features. It typically presents as a band

shaped opacity in the interpalpebral zone with a clear interval between the ends of the band and the limbus.

The condition begins at the periphery and gradually progresses towards the centre..

Salzmann's nodular degeneration Etiology. This condition occurs in eyes with

recurrent attacks of rosacea keratitis and trachoma.

The condition occurs more commonly in women and is usually unilateral.

Pathogenesis. In Salzmann's nodular degeneration,

raised hyaline plaques are deposited between epithelium and Bowman's membrane.

There is associated destruction of Bowman's membrane and the adjacent stroma.

Clinical features. Clinically, one to ten bluish white elevations

(nodules), arranged in a circular fashion, are seen within the cornea.

Patient may experience discomfort due to loss of epithelium from the surface of nodules. Visual loss occurs when nodules at the central zone.

Treatment is essentially by keratoplasty.

CORNEAL DYSTROPHIES

Corneal dystrophies are inherited disorders in which the cells have some inborn defects

There is no associated systemic disease.

Dystrophies occur bilaterally, manifesting occasionally at birth, but more usually during first or second decade and sometimes even later in life

ANTERIOR DYSTROPHIES STROMAL DYSTROPHIES POSTERIOR DYSTROPHIES

Epithelial basement membrane dystrophy Also known as Cogan's microcystic

dystrophy and map-dot finger print dystrophy

The typical lesions, involving corneal epithelium, are

bilateral dot-like microcystic, or linear finger-print like opacities.

Most cases are asymptomatic. However, about 10 percent patients

develop recurrent corneal erosions

Reis-Buckler dystrophy Also known as ring-shaped dystrophy primarily involving the Bowman's layer is a progressive corneal dystrophy

occurring in Childhood. It has got autosomal dominant

inheritance. Most patients get frequent attacks of

recurrent corneal erosions that usually result in diffuse anterior scarring.

Meesman's dystrophy

It is characterized by the presence of tiny epithelial cysts.

The disease occurs in early life and has autosomal dominant inheritance.

In most cases, condition is asymptomatic and does not require treatment.

Stromal dystrophy

Granular dystrophy Also known as 'Groenouw type I, is an

autosomal dominant dystrophy characterized by milky-granular hyaline deposits in anterior stroma.

The condition developing in first decade of life is slowly progressive and usually asymptomatic.

Occasionally visual acuity may be severely impaired, requiring keratoplasty.

Macular dystrophy (Groenouw type-II) It is an autosomal recessive dystrophy

characterized by appearance of dense grey opacity in the central cornea.

The condition results due to accumulation of mucopolysaccharides owing to a local enzyme deficiency.

It occurs in childhood (5 to 10 years) and leads to marked defective vision in early life, which usually requires penetrating keratoplasty

Lattice dystrophy

Also known as 'Biber-Haab-Dimmer dystrophy.

It is an autosomal dominant disease characterized by branching spider-like

amyloid deposits forming an irregular lattice work in the corneal stroma.

It appears at the age of 2 years, but the occurrence of recurrent erosions and progressive clouding of central cornea is apparent by the age of 20 years. Soon, visual acuity is impaired.

POSTERIOR DYSTROPHIES

Fuch’s dystrophy Fuch’s dystrophy is characterized by

excrescences thickening of the decrement's membrane with variable loss of endothelial cells.

Congenital hereditary endothelial dystrophy This is a rare dystrophy associated

with scanty or absent endothelial cells and thickened Descemet's membrane.

The basic endothelial deficiency results in diffuse milky or ground glass opacification and marked thickening of corneal stroma.

It may be inherited both dominantly and recessively.

KERATOCONUS

Keratoconus (conical cornea) (Fig. 5.18) is a noninflammatory bilateral (85%) ectatic condition of cornea in its axial part. It usually starts at puberty and progresses slowly.

Clinical features. Symptoms: Patient presents with a

defective vision due to progressive myopia and irregular astigmatism.