ECTATIC CONDITIONS OF CORNEA

SATISH REDDY A.N

1. Keratoconus

2. Keratoglobus

3. Keratotorus (Pellucid marginal degeneration)

CORNEAL ECTASIAS

KERATOCONUS

• Is a non-inflammatory bilateral(85%) ectatic condition of cornea (axial part)

• PUBERTY (early 20s)

• SLOWLY PROGRESSIVE

ETIOPATHOGENESIS

• Etiology of keratoconus remains unclear

• Theories – developmental condition, degenerative condition, hereditary dystrophy, endocrine anomaly

• Essential pathological changes – thinning and ectasia ( defective synthesis of Mucopolysaccharide and Collagen tissue)

CLINICAL FEATURES

SYMPTOMS

•Distorted and blurred vision

•Myopia (nearsightedness)

•Astigmatism

•Double vision

•Headaches due to eye strain

•Glare

•Light sensitivity

Signs of keratoconus

Placido disc examination Prominent corneal nervesVogt striae

Acute hydrops Munson sign Fleischer ring & scarring

Bulging of lower lids on downgaze

• Oil droplet reflex-

• Scissor reflex

Morphological classification of keratoconus

Nipple cone Oval cone Globus cone

Small and steep curvature Larger and ellipsoidal Largest

Ocular association

• Ectopia lentis

• Congenital cataract

• Aniridia

• Retinitis pigmentosa

• Vernal keratocongectivitis (VKC)

Systemic associations of keratoconus

Crouzon syndromeMarfan syndrome Osteogenesis imperfecta

Atopic dermatitis Down syndrome Ehlers-Danlos syndrome

Treatment• Spectacle correction

• Contact lenses – (rigid gas permeable)

• Intacts – intracorneal ring segmets

• Cornecollagen cross linkingal – may slow the progression of disease

• Keratoplasty – (required in later stages )

DALK-deep anterior lamellar keratoplasty

PK-penetrating keratoplasty

Keratoglobus

• Bilateral protrusion and thinning of entire cornea • Associations - Leber congenital amaurosis and blue sclera

• Onset usually at birth (hereditary and congenital disorder)

Pellucid marginal degeneration

• Bilateral crescent-shaped inferior corneal thinning

• Onset between 20 and 40 years