Corneal cross - linking methods and outcomes : A review

Keratoconus, which is a degenerative collagen disorder, affects approximately 1 in 2000 individuals in the general population.1,2 This corneal ectasia usually presents at late puberty and is shown to progress for approximately 10–20 years.3 Keratoconus results in changes within the ordered distribution of collagen fibrils in the cornea, leading to loss of stiffness in the stromal structure.1 The alterations occurring within the corneas of keratoconic patients lead to detrimental changes in vision as a result of increased myopia and irregular astigmatism.4 Keratoconus may be recognised by the para-central corneal thinning, the presence of Vogt’s striae as well as a possible Fleischer’s ring seen using a slit lamp biomicroscope, and patients with this condition may complain of ghosting and polyopia.3 The exact aetiology of keratoconus has not yet been determined; however, genetic, biochemical, environmental as well as physical factors have been suggested as causative factors in this condition.3 Because of the degenerative nature of this corneal ectasia, halting of the progression of keratoconus has become vitally important, with one of the prominent procedures, called corneal cross-linking, utilised to do so.