Eye Disorders: Fuch's Endothelial Corneal Dystrophy
treatment with an endothelial corneal transplant (DSEK) discussed below
The cornea is a clear window that covers the front of the eye. The cornea has three layers with different functions: the epithelium, which coats the surface; the middle stroma, which focuses light; and the inner endothelium, which pumps water out of the cornea to keep it relatively dehydrated and clear. Fuch's dystrophy occurs when the endothelial cells are not keeping up, causing the cornea to swell with water and become cloudy. People with Fuch's have a low number of endothelial cells present. The cause is thought to be genetic, but there are other factors that may be involved, such as previous eye surgery for example. Fuch's tends to develop later in life. It is a common condition.
What are the symptoms of Fuch's dystrophy?
Blurry vision is the primary symptom. Initially, the blurry vision may be very mild, or only present first thing in the morning. The condition may remain quite stable for many years and not seem to progress. If the condition progresses, the blurry vision will persist throughout the day. The blurry vision is proportional to how swollen the cornea is. Contrast sensitivity, which is the ability to see in low light conditions, or read grey on grey print (like the newspaper) can become worse.
How is Fuch's dystrophy treated?
Fortunately most people with Fuch's will not require treatment. Dehydrating eyedrops, called Muro-128, may be offered. If vision loss progresses to the point that quality of life suffers, a corneal transplant may be considered.
What is a corneal transplant, and what is Descemet's Stripping Endothelial Keratoplasty DSEK?
A corneal transplant is a surgery meant to restore vision by implanting a healthier and clearer cornea. There are two choices of cornea transplants: a Full Thickness Corneal Transplant, or a DSEK corneal transplant. Full thickness corneal transplants will replace the entire thickness of the cornea including the endothelium. This is the traditional technique that has been in practice for many decades. DSEK corneal transplant is a recently developed technique designed to replace just the sick inner endothelial layer, leaving the remainder of your healthy cornea in place.
What are the advantages and disadvantages to the traditional full thickness transplant?
The advantage of the traditional full thickness corneal transplant surgery is the longevity of the practice and the high success rate. The rate of rejection after surgery is less than 10%. The disadvantages of the traditional full thickness corneal transplant are the length of the procedure (60 to 90 minutes); occasional difficulties in suturing the new cornea in place; and occasional problems with the sutures coming loose which may cause infections and/or astigmatism (an irregular corneal shape). Astigmatism often can be too severe for vision correction with glasses, in which case contact lenses or further surgery will be required for useful vision. It may take up to a year to see complete results after a full thickness corneal transplant. As a result of the full thickness corneal transplant wound being 360 degrees, it is always delicate and at risk to rupture or breaking open from mild or incidental trauma, even several years after the surgery.What are the advantages and disadvantages to DSEK endothelial transplant?
There are several advantages to DSEK corneal transplant as compared to the standard full thickness corneal transplant. The surgical skill and expertise required is comparable, but the surgical time is generally less. The surgical incisions are much smaller, heal more rapidly and consistently, and require far fewer sutures. There is less chance of astigmatism due to smaller wounds and fewer sutures. Visual recovery is often complete within three to four months. Only the thin inner endothelial layer of the cornea is replaced, leaving over 90% of the original cornea remaining, which therefore contributes to greater structural integrity and reduces the chance of rejection. The primary disadvantages of the DSEK corneal transplant compared with the full thickness corneal transplant are the final outcome if best corrected vision may not be as clear; and further surgery may be needed within the weeks following the first transplant surgery if the transplanted tissue does not stay in place. DSEK corneal transplant surgery can be repeated if this occurs. If several attempts in performing DSEK corneal transplant surgeries do not result in a stable graft, a traditional full thickness corneal transplant may need to be performed. For a day or so after DSEK, you will lay on your back with your face pointing up, which will help ensure the graft stays in place.
What are the general risks of a corneal transplant?
The general risks of DSEK Corneal Transplant surgery are similar to traditional Full Thickness Corneal Transplant surgery. These risks include: bleeding; infection; swelling of the retina causing temporary or permanent blurring of vision; retinal detachment; glaucoma or high pressure in the eye; chronic inflammation; double vision; glare; and/or a droopy eyelid. There may be other unexpected or unforeseen risks or complications that can occur that are not listed here or discussed by your doctor. These or other complications may possibly lead to poor vision, total loss of vision, or on rare occasion loss of the eye. Some complications will require the care of other doctors, long term use of eye drops, or repeat surgeries. The transplanted corneal tissue may lose endothelial cell function at any time following the transplant surgery causing corneal cloudiness and/or blurry vision to return. During the course of the operation, unforeseen conditions could be revealed which may require different or additional procedures to be performed. There may be other conditions in your eye, like macular degeneration, that contribute to your vision loss in addition to the cloudy cornea.
You will receive human corneal tissue from a donor which will have been precut for the surgery. Prior to being approved for transplant, the tissue will be screened for clarity, adequate endothelial cells, and tested for infectious diseases. Despite the screening process, on occasion the endothelial cells will not function well, and there is a rare risk of transmission of infectious diseases. As with all transplanted tissue, there is a risk of rejection at any time following the transplant surgery. You will use eye drops that reduce the risk of rejection. If the graft is rejected or otherwise fails, a repeat transplant may be necessary.
More information about Fuch's dystrophy can be found at the National Eye Institute's website under the corneal disease section.