الفهرس 
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Abstract
Keratoconus is a degenerative, non-inflammatory progressive disorder of the cornea, characterized by central and para-central thinning, protrusion, steeping and subsequent corneal ectasia. This distortion of the corneal shape, results in irregular astigmatism with associated reduction and distortion of vision. Keratoconus is relatively common, afecting nearly one person in two thousand (0.05٪). It occurs in all ethnics worldwide with both sexes affected in equal rate. It is usually bilateral, but with an asymmetric presentation. Changes in corneal collagen structure and intercellular matrix, as well as apoptosis and necrosis of keratocytes, exclusively involving the central anterior stroma and the Bowman‟s membrane are documented in structurally weakened corneal tissue typical of keratoconus. The management of keratoconus starts with spectacles or contact lenses, 10-25٪ of patients with Keratoconus progress to a point where surgical intervention is required. Surgical options include: Intra-corneal ring segment, corneal cross linkage (CXL), lens implantation, PRK or corneal transplantation (PK or DALK). or combination of different modalities Introduction of intracorneal rings have provided us with tools for managing keratoconus Crosslinking stabilizes stromal collagen, increasing the biomechanical stability of the cornea. A combination of these modalities would provide the best results because these procedures complement each other. In our study we have found that ICRS implantation (Intacs) is a very effective method for the improvement of UCVA and BCVA and correct corneal surface
irregularities and topography (fattest, steepest and mean keratometry), and reduce refractive errors(sphere and cylinder). The addition of CXL to the procedure slows down the progression of the disease and gives greater improvements. Combined ICRS and CXL can be performed safely and effectively in single simultaneous session or in two sequential sessions and there is No statistically significant difference between the two methods.