Collagen Crosslinking (CCL) using Riboflavin and Ultraviolet light exposure or C3R ? A new hope for Keratoconus patients.

Keratoconus refers to a disease of the cornea wherein the cornea progressively becomes thin and weak, resulting in outward protrusion of this structure of the eye. This irregular shape of the cornea results in astigmatism, wherein the rays of light entering the eye cannot be brought to a point focus. Although in the initial stage of the disease, glasses with cylindrical power can help improve eyesight, but as the disease progresses, rigid gas permeable contact lenses (RGP) are required to achieve clear vision. 21% of keratoconus patients ultimately require surgical replacement of the thinned cornea with donor tissue to restore corneal anatomy and improve eyesight. Intacs are plastic ring segments which can be inserted into the mid peripheral cornea, resulting in flattening of the central cornea. Although this treatment modality may help reduce the severity of keratoconus, it does not modify the disease progression in any manner.

Fortunately a new modality of treatment has evolved over 7 years of research, which strengthens the corneal structure and thereby prevents progression of keratoconus. This treatment is called Collgen Crosslinking (CCL) using photosensitizer riboflavin and Ultraviolet light (365nm) exposure to induce crosslinking of the collagen fibres of the cornea. This method works by increasing collagen crosslinking, which are the natural "anchors" within the cornea. These anchors are responsible for preventing the cornea from bulging out and becoming steep and irregular, consequence of advanced keratoconus.

The treatment consists of application of riboflavin eyedrops to the exposed corneal surface for a duration of 30 minutes. This is followed by exposure of the corneal surface to Ultraviolet light (365nm) for a duration of 30 minutes. During the treatment, riboflavin eye drops are applied to the cornea, which is then activated by ultraviolet light. This amazingly simple process has been shown in laboratory and clinical studies to increase the amount of collagen cross-linking in the cornea and strengthen the cornea. Over 300 procedures have been performed over the past 6 years at different centers all over the world. Arrest of keratoconus progression has been noted in all cases. In 15 -20% eyes even regression of keratoconus by 1 -2 diopters has been noted. No sight threatening complications have been reported so far.

This treatment modality has been started at Apollo Hospitals, Hyderabad, India, by Dr Rajesh Fogla, Senior Consultant, Corneal Surgeon.