corneal ectasias
DESCRIPTION
ECTATIC,KERATOCONNUSTRANSCRIPT
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