Cornea Surgery Q & A
How is pterygium surgery performed?
Pterygium, also called surfer’s eye, is a growth affecting the conjunctiva, the clear tissue covering your eyeball and lining your eyelid. Common among people who spend a great deal of time outdoors, it’s not a serious condition, but it has such annoying symptoms as redness, irritation, and burning. If the pterygium growth spreads into your cornea, you may notice blurriness and other changes in vision.
The causes of pterygium include:
- Extended exposure to ultraviolet light
- Airborne irritants such as dirt and dust
- The drying effects of the wind
Pterygium may advance to the point that you need surgery to reverse its effects. In typical pterygium surgery, Dr. Jones removes the abnormal tissue, then patches your eye using healthy conjunctiva or placenta tissue. You can expect pterygium surgery to take less than an hour, and recovery time is usually several days.
What is corneal collagen crosslinking?
Keratoconus is a degenerative condition of the cornea that typically affects those between the ages of 10 and 40. Over time, the disorder can cause thinning and reshaping of your cornea.
Until recently, if you had keratoconus, your doctor would prescribe gas-permeable contact lenses. As the disease progressed and your cornea shape changed, you wouldn’t be able to wear the lenses anymore because of the discomfort. Corneal transplant would be your next step.
Now, you have a new treatment option — corneal collagen crosslinking — which stops the advance of keratoconus in its earlier stages. Also called CXL, crosslinking refers, in this case, to the bond between two chemical chains. CXL uses ultraviolet light and riboflavin — vitamin B2 — together to strengthen the bonds within the stroma of the cornea.
Dr. Jones applies a solution of riboflavin to your eye and then activates it with ultraviolet light. The riboflavin promotes the bonding of the collagen strands in the corneal stroma, strengthening the cornea.
Cross-linking is a minimally invasive outpatient procedure that combines the use of UVA light and riboflavin eye drops to add stiffness to corneas which have been weakened by disease or refractive surgery. Cross-linking, which has been performed in Europe since 2003, is considered the standard of care around the world for keratoconus and corneal ectasia following refractive surgery
- Creates new corneal collagen cross-links
- Results in a shortening and thickening of the collagen fibrils
- Leads to the stiffening of the cornea
Riboflavin (vitamin B2) is important for body growth, red blood cell production and assists in releasing energy from carbohydrates. Its food sources include dairy products, eggs, green leafy vegetables, lean meats, legumes, and nuts. Breads and cereals are often fortified with riboflavin.
Under the conditions used for corneal collagen cross-linking, riboflavin 5’-phosphate, vitamin B2, functions as a photoenhancer which enables the cross-linking reaction to occur.
Ultra-Violet A (UVA)
UVA is one of the three types of invisible light rays given off by the sun (together with ultra-violet B and ultra-violet C) and is the weakest of the three.
A UV light source is applied to irradiate the cornea after it has been soaked in the photoenhancing riboflavin solution. This cross-linking process stiffens the cornea by increasing the number of molecular bonds, or cross-links, in the collagen.
Is Cross-Linking Right for Me?
Patients over the age of 14 who have been diagnosed with progressive keratoconus or corneal ectasia following refractive surgery should ask their doctor about corneal cross-linking.
Our practice is proud to offer patients in our practice the first and only therapeutic products for corneal cross-linking which have been FDA approved to treat progressive keratoconus. This approval offers an effective treatment for patients who, until recently, had no therapeutic options to limit the progression of this sight-threatening disease.
For information on the FDA approved corneal cross-linking procedure for the treatment of keratoconus and corneal ectasia following refractive surgery, visit www.Avedro.com.
First used in Germany in 1998, CXL received Food and Drug Administration approval in 2016.