Today is World Sight Day (October 14), an international day of awareness that focuses on the global issue of eye health. At some point, nearly everyone will experience an eye health concern. We sat down with Dr. Christopher Chow, an expert on cornea and external diseases at Ophthalmic Specialists of Michigan, to discuss corneal transplants.
Let’s start with the basics, what is a cornea?
The cornea is the clear, dome-shaped window in the front of the eye that we see through. Our corneas serve several purposes. Along with the white of the eye, the cornea acts as a barrier against dirt, germs, and other harmful particles. The cornea filters out some amounts of the sun’s UV light. It also plays a vital role in our vision; as light enters the eye, it is refracted, or bent, by the outside shape of the cornea. This curvature helps determine how well your eye can focus on objects. In fact, our corneas do about 75% of our focusing. If the cornea becomes damaged through disease, infection, or injury, the resulting scars or discoloration can interfere with vision by blocking or distorting light as it enters the eye.
What is a corneal transplant?
Our corneas are like windows that we look through, and we need clear windows in order to see and undistorted windows to see in focus. When that window is no longer clear, or becomes distorted, a corneal transplant may be necessary. A corneal transplant is similar to other transplants, such as lung, heart, or kidney transplants. We use either a full, intact cornea or partial corneal tissue from a deceased organ donor to restore someone’s vision – to give them a new, clean window, hopefully with a good shape to allow clear focus. Unlike other transplants, we do not need a tissue match between donor and recipient except in very rare, high-risk cases.
Can you give some background on what conditions would lead to a corneal transplant?
There are three things that would cause someone to need corneal transplant surgery:
- Buildup of fluid and swelling in the cornea, typically in the form of corneal edema or Fuchs’ dystrophy, which are usually seen in patients aged 50 or older.
- Distortion of the cornea which can occur due to astigmatism, or keratoconus. This is when the eye is cone shaped and we typically see this in younger people from teenage years into their thirties.
- Injury or scars to the cornea as a result of accident or infection. Most infections occur from poor contact lens use, which can affect patients of any age. I strongly urge all contact lens wearers to follow their eye doctors’ instructions carefully. Corneal transplants for severe injury or infection is rare, but can occur.
What does a typical corneal transplant procedure include?
There are two main types of transplants: full and partial. Using our window analogy, a full transplant is like cutting through a wall and putting in a brand-new window with a brand-new view. A partial transplant is like having a window that has been covered in layers of wallpaper and we’re peeling off those layers to restore the view. Both partial and full transplants take about 40 to 60 minutes and are performed under local anesthesia, with IV medication to keep the patient comfortable and relaxed.
How does the technology used today differ from that of previous treatments and technologies?
Both partial and full transplants are relatively low-tech procedures in terms of equipment used during the actual surgery. Full corneal transplants have been around for about 40 years. Partial transplants utilize more technology prior to the procedure because an eye bank will prepare a thin layer of healthy cornea from an organ donor and then send it to us to transplant. We’ve performed partial corneal transplants for about 15 years. Both full and partial corneal transplants have reasonably high rates of success, about 90% in many cases.
How long is the recovery period following a transplant?
I won’t lie to you, it’s not a fast or an instant fix. You have to remember, we’re taking a major portion of the eye, removing it, and replacing it with a new piece. For partial transplants, it can take about three to six-weeks before patients are seeing clearer. For full transplants, it can take 6 months to a year or longer. Although that may seem daunting, the restoration of sight more than makes up for the recovery time.
Is there anything else you want patients to know about corneal transplants on World Sight Day?
The decision to have a corneal transplant is a big one and I find that many patients have a bit of a mental hurdle to get over before they are ready. But it’s a procedure we do regularly; in fact, there are almost 50,000 corneal transplants every year in the United States with about 90% success. This is a life-changing procedure that helps restore vision to thousands of patients every year. I am thrilled that I can offer this surgery to my patients who need it. If you’re concerned about your eyesight, I strongly encourage you to reach out to your eye care provider to discuss options. Today is World Sight Day, but it’s our mission for you to have healthy eyes year-round.