Collagen crosslinking is a minimally invasive procedure used to prevent the progression of corneal ectasia, a condition where the cornea thins and bulges outward. This procedure is commonly used to treat conditions like keratoconus and post-LASIK ectasia.
How Collagen Crosslinking Works
Collagen crosslinking refers to the ability of collagen fibrils to form strong chemical bonds with adjacent fibrils. In the cornea, this crosslinking occurs naturally with aging due to an oxidative deamination reaction. However, in some cases, this natural crosslinking process can be accelerated through artificial means.
The most common collagen crosslinking technique involves the use of riboflavin (vitamin B2) and ultraviolet (UV) light. During the procedure:
- The corneal epithelium (outermost layer) is removed to allow better penetration of the riboflavin.
- Riboflavin drops are applied to the cornea, and the eye is exposed to UV light for around 30 minutes.
- The UV light triggers a photochemical reaction that increases the number of crosslinks between the collagen fibrils, strengthening the cornea.
Benefits of Collagen Crosslinking
The primary benefit of collagen crosslinking is to halt the progression of corneal ectasia. By strengthening the cornea, this procedure can:
- Stabilize the corneal shape and prevent further thinning or bulging
- Improve visual acuity in some cases by flattening the corneal curvature
- Reduce the need for more invasive treatments, such as corneal transplants, in the long run
Candidacy and Considerations
Collagen crosslinking is typically recommended for individuals with progressive corneal ectasia, such as keratoconus or post-LASIK ectasia. However, there are some contraindications, including:
- Corneal thickness less than 400 microns
- Prior herpetic eye infection
- Concurrent eye infection
- Severe corneal scarring or opacification
- History of poor epithelial wound healing
- Severe dry eye or other ocular surface diseases
- Autoimmune disorders