The cornea is the outermost layer of the eye: the clear dome that covers the front of the eye and works to focus your vision. It is the part that is reshaped during laser eye surgery and the part that feels itchy or irritated when your eyes are too dry. But for people who have a more serious corneal injury or disease, new research can hopefully address the serious side effects and restore improved function to this incredibly important tissue.

What is the cornea, and what does it do?

Despite its clear appearance, the cornea is actually a highly organized tissue comprised of five layers that, unlike most other bodily tissues, has no blood vessels whatsoever – it is protected and nourished instead by the tears, and by the fluid that lies behind it. The cornea, in turn, protects the eye from damaging UV rays, particles of dirt, and invasive germs that could harm it. It also focuses light onto the retina, which is then translated into electrical impulses that ultimately lead to image perception. The cornea is basically the eye’s camera lens, putting things into proper focus so the retina can produce vision.

What can go wrong with the cornea?

Unfortunately, corneal tissue is delicate and susceptible to several common problems. The cornea has strong healing powers that allow it to quickly repair itself after sustaining minor injuries, but a deeper injury can cause scarring, which can result in:

• Blurred, impaired vision
• Eye pain
• Sensitivity to light
• Eye redness and inflammation
• Chronic headaches and fatigue
• Nausea and disorientation when focusing

Disease is also a major factor affecting the cornea. The most common corneal disease is keratoconus, a progressive thinning of the cornea that, rather than occurring with age, is most prevalent in teenagers and young adults. Keratoconus causes the cornea to curve and bulge abnormally, leading to blurred vision, nearsightedness, astigmatism, and increased light sensitivity. Optometrists use a slit lamp exam and to diagnose keratoconus. Distorted vision resulting from keratoconus can usually be corrected with glasses or contacts.

Other corneal diseases include various corneal dystrophies, tissue growths and shingles. Current treatments for ocular problems are conducted with lasers or conventional surgery, but research offers hope for a better tomorrow for those with corneal damage.

Corneal research by the U.S. National Eye Institute

Researchers at the NEI are currently conducting studies into wound healing of the cornea, which could lead to new treatments and improved outcomes for corneal transplants and grafts. Because the need for donor corneal tissue habitually outstrips supply, research is being done into more refined artificial corneas that are engineered in the lab and can actually be injected into the eye, as opposed to making a larger surgical incision. Research is also being done into a procedure that uses low doses of UV light to strengthen the collagen bonds of the cornea, promoting faster wound healing. To learn more about the specific types of research being conducted into corneal health, visit the National Eye Institute here.

One essential element of eye health is to maintain a regular schedule of visits to your eye care professional. If you do not already have a family optometrist in Toronto, Toronto Eye Care would be pleased to step into that role to assess the health of your corneas and ensure optimum eye care at all ages and stages.