- Non-inflammatory, ectatic corneal disease.
- Clinical features:
- Symptoms:
- Painless or may become painful in acute corneal hydrops
- Decreased corneal sensation
- Decreased vision
- Distorted vision due to irregular astigmatism, corneal scarring
or corneal edema
- Photophobia
- Signs:
- Bilateral, progressive abnormal thinning of either the central
or paracentral inferior corneal stroma
- Onset usually during puberty
- Munson's sign: a V-shaped dent of the lower lid produced
by the conic cornea in downgaze
- Rizutti's sign: conical reflection on the nasal cornea if
light is shined from temporal side
- Fleischer's ring: a partial or complete iron deposition
ring in deep epithelium
- Vertical Vogt's striae may be evident in deep stroma of
the apex of the cone
- Descemet's membrane rupture may result in acute hydrops
with stromal or epithelial edema and subsequent subepithelial
central scarring
- Distortion of the corneal image on keratometry, retinoscopy,
keratoscopy, and computerized corneal topography
- May be associated with a variety of ocular and systemic diseases
such as habitual eye rubbing, atopic dermatitis, Down's syndrome,
Marfan's syndrome, osteogenesis imperfecta or Ehlers-Danlos syndrome.
- Management:
- Astigmatic spectacle or rigid contact lens correction.
- Superficial keratectomy or epikeratoplasty may be attempted.
- Penetrating keratoplasty for advanced cases.
- Recent development: intrastromal corneal ring implant.
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