New Vitamin Treatment Avoids Corneal Transplants
By Robert L. Epstein, MD
Keratoconus is a condition that can cause severe visual loss. The condition, which occurs in about one out of every 2000 people, progresses slowly, can start in childhood or begin as late as age 65. The clear front wall of the eye, called the cornea, is the most important part of the eye concerned with focusing images of light. In keratoconus, the cornea becomes structurally weak and misshapen and that causes poor focusing of images and blurry vision.
People do not know right away that they have keratoconus. Most people just need changes in glasses. Typically that change is an increase in the astigmatism or cylinder correction in the eyeglass prescription. Increases in astigmatism are uncommon in healthy eyes. That type of change of eyeglass prescription is different the more common change to higher spherical correction without astigmatism. Early keratoconus can be detected with special diagnostic instruments in the office of the ophthalmologist (eye-MD).
Vision is often well corrected with glasses. For many people the use of soft contact lenses or rigid contact lenses provides excellent vision, better than glasses do. For some people, the condition worsens and contact lenses become ineffective. For people having too much trouble wearing the contact lenses, there are tiny invisible braces that can be placed within the cornea in a painless 15 minute office-based operation. For people not helped be all these methods corneal transplantation is performed, and that surgery is highly effective in restoring vision. But after corneal transplantation, it takes several months for the vision to be fully restored.
Now a newer treatment has been shown to eliminate the need for corneal transplantation in most cases where it was formerly done for keratoconus. In the treatment, called corneal collagen crosslinking, the patient goes into the operating room, however no corneal transplantation occurs. Instead, there is a treatment of the eye with vitamin B2 (riboflavin) eye drops for half an hour. During that time a low intensity ultraviolet light is shined onto the eye. The UV light intensity is equivalent to being outside on a cloudy summer day. The yellow riboflavin drops, which temporarily soak into the cornea, cause a strengthening and hardening of the structure of the cornea by a process called crosslinking. The yellow liquid also blocks the entry of ultraviolet light into the inside of the eye. The vitamin B2 treatment causes stabilization of corneal shape and can cause reversal of the keratoconus condition in many cases.
The treatment was developed by Dr. Theo Seiler of Zurich, Switzerland, has been in existence for five years and is being performed at centers all of the world. The treatment has been available in the United States for three years and its use is increasing lately with the U.S. FDA nationwide clinical study of a particular brand of ultraviolet lighting system for the collagen crosslinking treatment. The use of the riboflavin treatment is likely to increase greatly over the coming years.
New View of Cornea is Real Eye Opener
By Robert L. Epstein, MD
How clear we see depends on all the structures of our eyes being healthy. Critical to vision is the clarity of the front window, or cornea, of the eye. Now a rapid, no-touch test done in some eye doctors offices provides a very high power look for the doctor and the patient at the critical inside cell lining of the cornea. The view of these cells is positively "eye opening".
The internal corneal cell lining is critical for keeping the cornea clear, but the lining cells slowly die off each year of life without being replaced. With fewer cells in the lining, the cornea becomes thicker and less clear, and in severe cases developing a steamy front surface.
The second most optically important part of the eye is the internal crystalline lens of the eye. With age, the crystalline lens can become cloudy and produces glare, loss of sensation of color, and generally poorer vision. Clouding of the lens is called a cataract and doctors may employ sound wave energy in a brief outpatient procedure to remove the clouded lens and then implant a clear artificial lens to restore vision. Although the cataract removal process is typically quite successful, there is always some irreversible damage to the inside cell lining of the cornea, and that is a worry.
Whether a person should have cataract removal, or not, depends greatly on the degree of visual disability from the cataract. The worse the disability from cataract, the more compelling is the reason for cataract removal.
But another factor is that the denser the cataract is, the more sound wave energy is needed for cataract removal and the more irreversible damage happens to the cell lining of the cornea. Thus, for people whose corneal cell lining is relatively weaker, it may be better to not wait until the lens has become too dense because surgical results may not be as good later due to extra damage to the corneal cell lining. Corneal cell linings are weaker from inherited disorders, from increased age, from past bouts of inflammation inside the eye, prior eye surgery or eye injuries, and importantly from years of contact lens use.
Therefore, if you have been told that you have a cataract, then ask about what is the degree of visual loss from your cataract and also ask what is the cell count on the inner lining of the cornea. Even if you do not have a cataract and you believe you may have a reduced cell count, ask to have the test and record the cell count among your permanent records.