cornea class 6

CORNEA

CORNEAL DYSTROPHIES &DEGENERATIONS

Corneal dystrophies Corneal dystrophies are progressive

hereditary corneal disorder. It is bilaterally symmetrical Non vascularized Shows no signs of inflammation and are

without associated systemic disease.

CORNEAL DEGENERATION

These are non hereditary Usually unilateral condition May be associated with systemic disease

KERATOCONUS Defn- noninflammatory bilateral{85%}

ectatic condition of cornea in its axial part due to defective synthesis of mucopolysaccharide & collagen tissue

Starts at puberty and progresses slowly

KERATOCONUS

Thinning Bulges

KERATOCONUS

KERATOCONUS Present with “defective vision” does not

improve despite full correction with glasses

Irregular astigmatism

KERATOCONUS Placido disc Keratometry depicts misalignment of

miresSlit lamp Thinning of central cornea Fleischer’s ring at the base of cone Folds in descements vogts striae

KERATOCONUS Munsons sign

Retinoscopy yawning/ scissoring reflex

Distant direct ophthalmoscopy- oil droplet reflex

Complication Acute hydrops:- sudden development of

corneal oedema, defective vision, pain, photophobia, lacrimation

Rupture of descemet’s membrane

ACUTE HYDROPS

Association

OcularVernal Catarrh Ectopia lentis Cong cataract AniridiaRetinitis pigmentosa

Systemic Marfan’s syndrome Atopy Down’s syndrome

KeratoconusInvestigationsKeratometryCorneal topographyTreatment Contact lens Penetrating keratoplasty

Intracorneal rings Collagen cross linking

KERATOGLOBUS

KERATOGLOBUS Hereditary, bilateral & congenital

disorder Thinning & hemispherical protrusion

of cornea

Corneal dystrophies CLASSIFICATION A] Anterior dystrophies 1.Epithelial basement membrane dystrophy 2.Reis Buckler dystrophy 3.Meesman`s dystrophy

Recurrent corneal erosion syndrome B] Stromal dystrophies 1.Granular dystrophies 2.Lattice dystrophy 3.Macular dystrophy 4.Crystalline dystrophy

Corneal dystrophies

C] Posterior dystrophies 1.Cornea guttata 2.Fuchs` endothelial dystrophy 3.Posterior polymorphous dystrophy 4.Congenital hereditary endothelial dystrophy

Corneal dystrophiesANTERIOR DYSTROPHIES

Corneal dystrophiesRecurrent corneal erosion syndrome

TREATMENT: patching with plain ointment for 1 to 2 days Hypertonic saline drops or ointment decreases attack of

erosion by reducing epithelial oedemaLubricant eyedrops

Corneal dystrophiesSTROMAL DYSTROPHIES

Corneal dystrophies2.Fuchs endothelial dystrophy -slowly progressive bilateral

condition affecting females more than males

-usually 5th and 7th decade of life

-primary open angle glaucoma is its common association

CORNEAL DEGENERATION

These are non hereditary & usually unilateral condition

Classification:-A] Age related degeneration:- Arcus senilis, Vogt’s white limbal girdle, Hassal-Henle

bodies, Mosaic degenerationB] Pathological degeneration:- Fatty degeneration, Amyloidosis, Calcific

degeneration, Salzmann’s degeneration, Furrow degeneration, Spheroid degeneration, Pellucid marginal degeneration, Terrien’s marginal degeneration

ARCUS SENILIS Annular lipid

infiltration of corneal periphery in

Age related, occurs bilaterally in elderly

Arcus juvenilis :- similar changes in young, may or may not be associated with hyperlipidaemia

Vogt’swhite limbal girdle

Band Keratopathy Deposition of calcium

salt in Bowman’s membrane, sup. Part of stroma,& deep layer of epithelium

Band Keratopathy Etiology: Association with hypercalcaemia, chronic uveitis,

phthisis bulbi, chronic glaucoma, chronic keratitisCf.:- Band shaped opacity begins at periphery centre Later stage –transparent clefts due to

cracks or tears in calcium plaques

Band Keratopathy Treatment:- A] Chemical removal of calcium salts - EDTAB] Phototherapeutic keratectomyC] Keratoplasty