Contact Lenses for Keratoconus
Keratoconus is something of a misnomer, along with many other medical conditions. The name suggests a conical shape, but there are many variants, few of which anything like resemble a cone. For some reason, the cornea becomes thinner than normal and distends, a process referred to as ectasia. As a result, the front surface of the cornea is more curved than normal, and often becomes irregular at the visual axis. So a more appropriate name for keratoconus is primary corneal ectasia, which describes the whole range of ‘keratoconus’ profiles. Some ophthalmology publications use this expression. In fact, it is more complex than thinning and distension, as many with keratoconus have experienced. – Continue reading….
Corneal Collagen Cross Linking (CXL)
Developed in Switzerland and Germany since 1998, corneal collagen crosslinking (C3R or UV-X) uses ultraviolet light with riboflavin dye to stiffen the cornea. This is the only treatment to treat the underlying cause of keratoconus. It works by linking the protein fibres in the cornea to each other and within themselves. This stops progression in all corneas so long as the cornea isn’t too thin or too steep to start with, and it cannot be used on significantly scarred corneas. Total UV exposure is similar to a day’s mountain walking. – Continue Reading…
Intacs and Ferrara Rings
Perspex ring implants placed in the cornea to flatten and make more regular the shape of a keratoconic cornea. There are two main types: Intacs which sit further out and cause less glare and Ferrara rings. – Continue reading…
Piggy-backing
Piggy-backing is the term used to describe wearing two lenses at once in the same eye. – Continue reading….
When to go for a Transplant
Corneal transplants have been refined to an exceptionally high level of expertise over the years, and KC is one of the most commonly encountered indications. For other conditions, the surgeon is usually dealing with a seriously unhealthy cornea which may be opaque and vascularised. In such cases, there is much to gain and nothing to lose from the standpoint of achieving a visual improvement, but there is a high risk of rejection and transplant failure from other complications. – Continue reading…