الفهرس 
Acknowledgemen
Classification according to disease evolutionOnly 14 pages are availabe for public view
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Abstract
- Keratoconus is a bilateral , asymmetric , corneal disorder that result in progressive thinng , steepening , irregular astigmatism & potential scarring .
- In very early cases of keratoconus , spectacles may provide adequate visual correction , but because spectacles don’t conform to the unusual shape of the cornea and the resultant induced astigmatism , contact lenses provide better correction and are the mainstay of therapy of keratoconus and represent the treatment of choice in 90% of patients .
- Although keratoconus is a bilateral condition , one eye tends to lead while the other eye lags behind in its progression , so anisometropia or anisokonia lead to spectacle magnification intolerance .
- Contact lenses are an effective therapeutic option for a majority of patients with keratoconus .
- A variety of contact lenses have been used including scleral and corneal lenses , rigid , soft and hybrid lenses and piggyback designs .
- Fitting of contact lenses for visual rehabilitation of keratoconus patients is very challenging , efforts at improvement in contact lens design have decreased the number of patients who would require penetrating keratoplasty .
- Good visual outcome have been reported in keratoconus with contact lenses in the base line finding in CLEK study , the visual outcome with patients fitted with rigid gas permeable contact lens was 6/12 or better in 77.9% eyes .
In another study by Dade et al , visual acuity was 6/9 or better in 65.03% of the patients .