IN THE NAME OF ALLAH WHO IS MOST MERCIFUL AND GRACIOUS

CORNEAL DEGENERATIONS

CORNEAL DEGENERATION VERSES CORNEAL DYSTROPHY

DIFFERENCES OF CORNEAL DEGENERATION FROM DYSTROPHY

laterality: May be unilateral or bilateral while dystrophy is bilateral
symmetry: Degenration is asymmetrical while dystrophy is symmetrical
Age in degeneration is usauly late while dystrophy present in young or adult age
Family history is positive in dystrophy while negative in degeneration
Site is central in dystrophy while peripheral in degeneration
vascularization is present in degeneration while negative in dystrophy

Spheroidal degeneration

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Risk factors

1. Men

2. Outdoor work

3. Ultraviolet light

Histology. Irregular proteinaceous deposits in the anterior stroma that replace the Bowman layer.

Clincal features

1. Amber-coloured granules in the superficial stroma of the peripheral interpalpebral cornea.

2. Increasing opacification, coalescence and central spread.

3. Advanced lesions commonly protrude above the corneal surface

4. the surrounding stroma is often hazy

Treatment.

1. Protection against ultraviolet damage with sun-glasses

2. superficial keratectomy

3. lamellar keratoplasty in a minority.

Band keratopathy

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age-related deposition of calcium salts in the Bowman layer, epithelial basement membrane and anterior stroma.

Etiology:

1. Chronic anterior uveitis

2. glaucoma,

3. phthisis bulbi,

4. silicone oil in the anterior chamber,

5. chronic corneal oedema

6. severe chronic keratitis.

7. Age-related affecting otherwise healthy individuals.

8. Metabolic (metastatic calcification)

clinical features

Peripheral interpalpebral calcification with clear cornea separating the sharp peripheral margins of the band from

the limbus

Gradual central spread to form a band-like chalky plaque containing transparent small holes
Advanced lesions may become nodular and elevated with considerable discomfort due to epithelial breakdown

treatment

Chelation

Method

performed using a microscope.

1. The corneal epithelium overlying the opacity and a solid layer of calcification are first scraped off with forceps and a scalpel blade (e.g. No. 15).

2. The cornea is then rubbed with a cotton-tipped applicator dipped in a solution of ethylenediaminetetraacetic acid (EDTA) 1.5–3.0% until all calcium has been removed.

3. Adequate time (15–20 minutes) must be allowed for chelation to occur

4. more than one session may be necessary.

5. Re-epithelialization can take many days

excimer laser keratectolmy

lamellar keratoplasty

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