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Keratitis And Corneal Ulcers

 

I. Keratitis

 

 

Causes of keratitis:-

1. Infections by bacteria, viruses, fungi, ....

2. Non infective keratitis as:

- Trauma (mechanical, UV rays or chemical).

- Allergic.

- Degenerative as neurotrophic and atheromatous ulcers.

It is classified into groups according to:

1. Site of the pathology (superficial, interstitial or deep).

2. Nature of the pathology (Suppurative or non suppurative).

3. Etiology (infectious, allergic, traumatic, degenerative,...).

These groups are:

A. Superficial keratitis:-

1. Ulcerative (corneal ulcers).

2. Non ulcerative K. as Pannus (superficial corneal inflammation and vascularization).

B. Interstitial  keratitis:

1. Suppurative (Interstitial abscess).

2. Non suppurative I.K.:

a. Diffuse I.K. of congenital syphilis (affects all the cornea).

b. Localized I.K. (disciform keratitis): see dendritic corneal ulcer.

C. Deep keratitis:

1. Suppurative: posterior corneal abscess.

2. Non suppurative: Keratitis profunda.

CORNEAL ULCERS (ULCERATIVE K.)

The types of corneal ulcers are:

1. Non infective ulcers:

a. Traumatic ulcers (mechanical, chemical or physical trauma).

b. Degenerative ulcers as:

          - ulcer with lagophthalmos.

          - keratomalacia.

          - neurotrophic ulcer.

          - atheromatous ulcer.

c. Hypersensitivity reactions as catarrhal ulcers and phlyctenular ulcers.

d. Autoimmune diseases as Mooren's ulcer and rheumatoid arthritis.

2. Infective ulcers:

a. Bacterial ulcers.

b. Hypopyon corneal ulcer.

c. Dendritic corneal ulcer.

d. Fungal corneal ulcers.

e. Acanthameba corneal ulcer.

 

NB. Vital stains of the cornea:

1. Fluorescein stain: It stains the corneal stroma green and conjunctival ulcers yellow.

2. Rose bengal stain: It stains the viral infected cells.

3. Double stain: Fluorescein + metheline blue. It is not used now.