Dr. Christina

Progressive disorder in which the cornea assumes a conical shape secondary to corneal thinning and protrusion

Onset is around puberty- progresses untill 3rd or 4th decades of life

Both eyes affected usually Role of hereditary transmission is not

clear.

PRESENTATION

Presents usually during puberty. Impairment of vision due to

progressive myopia and irregular astigmatism.

Asymmetrical nature. Approximately 50% of normal fellow

eyes will progress to keratoconus within16 years.

DIAGNOSIS

Central or paracentral stromal thinning, apical protrusion and irregular astigmatism

SIGNS: Direct ophthalmoscopy shows ‘oil

droplet sign’. Retinoscopy shows irregular’ scissor’

reflex’ Slit lamp microscopy showsfine,

vertical, deep stromal striae called vogts striae .

Epithelial iron deposits may surround the base of cone –’fleischer ring’.

Marked irregular myopic astigmatism with steep keratometry reading.

Bulging of the lower lid in down gaze- ‘munson sign’.

Corneal topography – sensitive method of detecting early keratoconus.

ACUTE HYDOPS

Caused by rupture of descemets membrane that allows influx of aqueous into the conea.

Causes sudden drop in visual acuity with discomfort and watering.

Usually the break heals within 6-10 weeks and edema clears but scarring results

Treatment is keratoplasty after edema resolves.

ASSOCIATIONS

SYSTEMIC DISORDERS LIKE Down, Turner, Ehler-Danlos and Marfan syndromes, atopy, oesteogenesis imperfecta, MVP, mental retardation.

OCULAR DISORDERS like vernal kerato conjunctivitis, blue sclera, aniridia, ectopia lentis, RP

TREATMENT

Spectacles in early stages. Rigid contact lenses for higher

degrees of irregular astigmatism..Piggy back lenses.

Keratoplasty : both lamellar and penetrating keratoplasty especially in cases of severe corneal scarring.

THANK YOU