Corneal Collagen Cross Linking
Keratoconus is a progressive disease of the cornea in which the corneal tissue is weak. This results in gradual thinning and bulging outward of the cornea. As the name Keratoconus implies Kerato - meaning cornea, Conus - meaning cone, the condition results in conical protrusion of the cornea.
The patients may present with complaints of blurry and distorted vision. This results due to the abnormal curvature of the cornea leading to irregular astigmatism. The chances of suffering from this problem is one in two thousand. Approximately half of the keratoconus patients need help beyond corrective glasses. The other modalities of treatment available now such as Rigid Gas Permeable lenses, Intact are often uncomfortable to the patient and restricts the life style.
In advanced Keratoconus the only option to restore vision is a corneal transplant. This new modality of treatment known as a collagen cross-linking with Riboflavin has proven to strengthen the weak corneal structure. During this 30 minute cross linking treatment custom made Riboflavin eye drops are applied to the cornea which is then activated by UV-A light. Under the influence of the UVA, chemical bonds form in the corneal collagen lamellae, which are the structural backbone of the corneal tissue, and this strengthens the cornea and stiffens the tissue. The increase in tissue rigidity appears to slow or stop the progression of the corneal thinning and shape changes that normally occur in keratoconus.
Keratoconus is a debilitating condition that affects vision in people starting their careers and is hence a serious problem. However, with recent advances in instrumentation, early diagnosis is possible, and with newer modalities of treatment available in the form of cross linking to patients who had no hope science has made yet another mark in helping people with a progressive blinding disorder.
An eye with keratoconus - showing the conical corneal protrusion centrally, and the pigment ring at the base of the corneal cone. (Fig.1)
Collagen Cross-Linking with Riboflavin (C3R) is a new procedure using riboflavin drops and ultraviolet light to halt the progressive corneal thinning and shape change that occur in keratoconus.(Fig.2)
Newer designs of contact lens allow good vision in those with moderate keratoconus.(Fig.3)
Deep anterior lamellar keratoplasty (DALK) replaces only the anterior corneal layers, and is safer and allows faster visual recovery.(Fig.4)