Keratoconus treatment c3r to halt the progress of Keratoconus eye disorder has been a huge breakthrough. Cornea cross linking with riboflavin was originally proposed and published by Wollensak and Seiler. They proposed removing the epithelium and soaking the eye with riboflavin. In 2004 Dr Boxer wachler proposed a modification. He suggested to leave the epithelium on.
In the last 10 years nomenclature for this new keratoconus treatment has been modified to avoid confusion. C3R is an acronym for cornea collagen cross linking with Riboflavin which encompasses all current crosslinking.. The original cxl is now called epi on . The proposal by Dr. Boxer wachler is now termed as epi on or tranepithelial (TE) crosslinking. Finally, Dr Boxer Wachler has relabelled his exact method to be called Holocomb C3R.
Since we have discussed epi off cornea cross linking, This discussion will cover epi off or TE cornea cross linking. We will not indulge in Holocomb C3R.
In trans epi C3R the epithelium is retained. This layer is approximately 50 microns in normal individuals. In keratoconus eye disorder it is thinner. Removal of this layer improves uniform absorption of riboflavin into the deeper layers of the cornea. Removal of the epithelium can cause discomfort and even pain. Infections are more likely to occur. Cornea swelling is als0 noted more often.
So Epi onKeratoconus treatment c3r allows speedier healing with less discomfort. It is less likely to get infected. Patients can return to work faster. Even both eyes can be done on the same day.
So in working adults the quicker recovery allows them to return to their job faster.
It is also beneficial in thinner corneas. We know that he cornea has to be at least 400 microns before UV radiation is begun. This margin prevents damage to the inner most cells of the cornea called the endothelium. If the cornea is already thinner than 400 microns removing the epithelium will make it even more thin. TE C3R is therefore helpful.
It may also be used in people above 45 years where there is no progression but patient wants some cross linking done.
To make Keratoconus treatment c3r epi off or Transepithelial effective riboflavin must penetrate the corneal stroma. It can reach there if no epithelium is present like in epi off C3R. Or as Dr Boxer Wachler proposed the tight junctions of the epithelium cells can be weakened by using preoperative anesthetic eye- drops containing benzalkonium chloride.
All studies show that epi off allows more uniform penetration of the riboflavin. In rabbit studies cross linking has been more stronger and deeper with epi off. No clinical study has shown Keratoconus treatment c3r epi off or Transepithelial to be as effective. The reason may be that riboflavin and UV radiation penetration may be patchy.
For the time being FDA Avedro approved cornea crosslinking epi off remains the gold standard.