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MattiSeppänen

Keratoconus (Conical Degeneration of the Cornea)

Essentials

  • Keratoconus (conical degeneration or conical bulging of the cornea) is a disease in which the cornea becomes thinner and more fragile.
  • The pressure in the eye makes the thinned cornea bulge conically outward.
  • Keratoconus often begins at the age of 12-20 years and typically progresses for 10-15 years.
  • In most cases, progression will stop before any significant impairment of visual acuity.
  • Keratoconus may also result from laser-assisted refractive surgery (usually LASIK surgery). In that case, it is called corneal ectasia.
  • The patients should be treated and monitored by an ophthalmologist.

Incidence

  • 1 in 1 500-2 000 people

Symptoms and findings

  • Reduced visual acuity
    • Increased astigmatism and myopia
  • Simultaneous perception of several images of a single object
  • Impaired contrast sensitivity (difficulty distinguishing between various shades of black and white)
  • Thinning cornea
  • Visible protrusion of the corneal surface

Workup

  • Visual acuity
  • Inspection of the eye: is there conical bulging of the cornea visible on lateral inspection (often best detectable if the patient looks down)?
  • Examinations by an ophthalmologist include corneal tomography and biomicroscopy.

Treatment

  • Corneal cross-linking
  • Corneal Intacs® rings
  • Hard contact lenses