When an optometrist tells a patient they have keratoconus, the common response is, "What is that?" Unfortunately, it is not a clear-cut answer. Fully understanding the condition and what causes it can take time and effort.
The basics of keratoconus are that the cornea, the clear tissue overlying the colored part of a person's eye, becomes thinner than normal and begins to bulge in the shape of a cone. When looking at the roots of the term keratoconus, this is exactly what it is describing: “kerato” in Greek means cornea and “conos” means cone, describing a cornea shaped like a cone. In contrast, a normal cornea is more spherical, shaped similarly to a basketball that has been cut in half.
Diagnosing keratoconus begins with accurately determining the shape of the cornea, which is much easier with today's technology than it was in the past. The Pentacam® is a piece of equipment that simultaneously measures the shape and thickness of a patient's cornea. This is a helpful tool, due to the dual nature of keratoconus, which exhibits a conic shape occurring in an area of thin corneal tissue.
Now that the patient has a basic understanding of what it is, they often then ask, "What caused it to happen?" This is when the answer begins to get a little complicated. There are theories as to what contributes to keratoconus, but a definitive reason has not been determined as to the cause. Most people agree there is a genetic component to the condition.
Whenever a parent has keratoconus, children are monitored more closely for keratoconus symptoms. There has also been a correlation to people with atopic conditions that are related to allergic hypersensitivity. These conditions can include allergic dermatitis, allergic asthma and allergic conjunctivitis of the eyes. These situations do not guarantee everyone with an allergy is at a high risk for keratoconus; however, individuals who tend to be highly sensitive may be more at risk for keratoconus development. It is thought that constant eye rubbing can cause keratoconus, and in people with atopic conditions, eye rubbing can be habitual. It is not known whether the condition itself or the act of rubbing the eyes plays a larger role in keratoconus development.
The last thing patients ask is, "What can I do about it?" The answer to this question depends on the severity of the condition. In the early stages of keratoconus, vision can generally be corrected using contact lenses. The normal type of lens necessary is a rigid gas-permeable lens which most people know as a "hard" contact lens. As the condition progresses, keratoconus treatment may call for surgical intervention.
When exploring the surgical keratoconus treatment options, there is a type of corneal implant technology that alters the shape of the cornea that helps decrease the amount the cornea bulges. This type of implant has been shown to aid in vision correction and is also reversible if removal is necessary. Ultimately, if the condition progresses severely enough, a cornea transplant can be deemed necessary. Once performed, most people obtain functional vision while wearing a rigid gas permeable lens similar to the type worn in early keratoconus.
Fortunately, new technology is now available that may help decrease the number of people needing a cornea transplant. This is called corneal cross-linking or CXL. This process strengthens corneal tissue, preventing it from thinning or bulging more than it currently does. Corneal cross-linking allows a solution of riboflavin (Vitamin B2) to saturate the cornea followed by an ultraviolet light of specific power and duration. This combination ultimately strengthens the cornea. This does not cure keratoconus, but halts the progression so a cornea transplant is not required in most cases.
There are two types of corneal cross-linking:
Epi-OFF corneal cross-linking was approved by the FDA in the middle of 2015; However, it took over five years to gain governmental approval for Epi-OFF corneal cross-linking. Because of this, it is considered outdated compared to Epi-ON. Although Epi-ON corneal cross-linking is not yet readily available, at Providence Eye & Laser Specialists we are working diligently to provide this option to our patients as soon as medically possible.
Many people diagnosed with keratoconus have a grim outlook for their vision. Fortunately, today's advancements help provide people with not only functional, but good vision. As always, our goal is to provide patients with the information needed to make an informed decision. Our mission is to deliver the best outcome possible.
To learn more about keratoconus and the keratoconus treatment options, contact Providence Eye & Laser Specialists today!