Brian Foster, M.D.
The cornea is the clear tissue on the surface of the eye that covers the colored iris and pupil. Its role is to focus light and protect the inner-workings of the eye, much like the lens of a camera. If your cornea is injured or affected by disease, it may become swollen or scarred, and its smoothness and clarity may be lost. Scars, swelling or an irregular shape can cause the cornea to scatter or distort light, resulting in glare, blurry vision, or even pain.
There are many conditions that can affect the clarity of the entire cornea. For instance, trauma or injury to the cornea can cause scarring, as can infections (especially herpes keratitis). A hereditary condition called Fuchs' Dystrophy causes corneal failure and Keratoconus causes a steep curving of the cornea. Sometimes corneal failure can also occur after an eye surgery, such as cataract surgery.
Cornea Treatment Options
A corneal transplant is needed if vision cannot be corrected with eyeglasses or contact lenses, or if painful swelling cannot be relieved with medications or special contact lenses.
As a Fellowship-Trained Corneal Specialist, Dr. Foster has extensive experience in modern corneal transplantation techniques and has performed hundreds of these procedures. He has also spoken on modern transplant surgery at national meetings and published in several peer-reviewed journals.
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Traditional Corneal Transplant (Penetrating Keratoplasty)
With a traditional, full-thickness corneal transplant surgery, a circular portion is removed from the center of the diseased cornea. A matching circular area is removed from the center of a healthy, clear donor cornea, which is put into position and sutured into place.
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DSAEK (Descemet’s Stripping Automated Endothelial Keratoplasty)
DSAEK is a partial thickness corneal transplant procedure in which only the diseased inner cell layer of the cornea is replaced. The inner layer of the cornea is lined by cells (endothelium) that serve to pump fluid out of the cornea and keep it clear and thin. These cells can be damaged by prior surgery, inflammation, or by a condition known as Fuchs’ Dystrophy. As endothelial function declines the cornea swells and becomes cloudy, decreasing vision. If swelling becomes severe, blisters (bullae) can develop on the cornea and cause pain and infection. As these conditions progress, surgery is often required to help with pain or improve vision.
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How is DSAEK performed?
Dr. Foster measures your eye and the donor cornea tissue is cut to the appropriate size for your eye. A small incision is made in your cornea (much like cataract surgery) and the diseased endothelial cell layer is carefully removed. The donor tissue is then introduced into the eye and an air bubble is used to apply it to the back of the cornea. The air bubble remains for 1-2 days helping to keep the donor tissue in place. Surgery generally takes less than 30 minutes and you are able to return home. A protective eye shield is kept in place until Dr. Foster sees you the next day.
What are the advantages of DSAEK?
Compared to full thickness corneal transplants, there are many advantages to DSAEK. Since 95% of the corneal structure is unchanged, patients tend to have much less astigmatism and a much stronger cornea. Healing usually takes a few weeks and is much quicker than healing of a full thickness transplant.
What are the disadvantages of DSAEK?
Occasionally the donor tissue comes loose and requires repositioning and the placement of a second air bubble. Once the graft has been attached for a few days, there is no risk of dislocation at a later point. In some patients with severe corneal swelling, scarring is present that may limit best possible vision even though the swelling resolves.
What can I expect after surgery?
Initially the vision will be quite blurry but will clear over the first several weeks. The eye may be red, sore, light-sensitive, and watery for the first week or two after surgery. During the first 24 hours after surgery, Dr. Foster will ask you to keep your eye looking at the ceiling as much as possible to help graft adherence. It is also very important not to rub or touch the eye for the first few weeks.
Steroid eye drops are used to help the eye heal after surgery and prevent graft rejection for the long term. The risk of graft rejection is typically 5% or less but is high enough that long-term drops (usually once a day) are required. Dr. Foster will keep a close watch over your healing process and will cusomize an anti-rejection regimen appropriate for you.
For a consultation with Dr. Brian Foster, contact The Eye Associates, call 941-792-2020 or Toll-free 1-866-865-2020 to schedule an appointment.
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A typical characteristic of Fuchs’ Dystrophy are dewdrop-shaped outgrowths called guttata in the layer just underneath the endothelial cell layer (called Descemet's membrane). These growths can scatter light and significantly interfere with vision, much like a cataract.
Fuchs' dystrophy is a progressive disease and because of this, over time, changes to the corneal cells may interfere with vision. If guttata or corneal swelling are causing a significant decrease in vision, surgery may be necessary to restore it.
Fuchs' dystrophy is somewhat more common in women and usually affects people in their 50s or 60s, although occasionally it appears earlier in one's adulthood. It is usually inherited but can be present in individuals without a family history due to sporadic mutation. Those who inherited the condition from a parent have a 50 percent chance of passing it on to their children.
For an appointment with Dr. Foster, contact us or call 941-792-2020.
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Keratoconus is a condition in which the normally round, dome-like cornea (the clear front window of the eye) becomes thin and develops a cone-like bulge. Keratoconus literally means “cone-shaped cornea”. When the shape of the cornea is altered by the disease vision is distorted, making activities like driving, typing on a computer, watching television or reading difficult.
Keratoconus is a hereditary condition but only about 10% of patients have an affected family member. It is associated with excessive eye rubbing and prolonged contact lens wear. It is also associated with certain eye diseases, such as retinitis pigmentosa, retinopathy of prematurity and vernal keratoconjunctivitis and systemic diseases such as Leber's congenital amaurosis, Ehlers-Danlos syndrome, Down syndrome and osteogenesis imperfecta.
Keratoconus tends to progress slowly. As it gets worse the most common complaints are increased astigmatism or near-sightedness, blur or distortion of vision, frequent eyeglass prescription changes and inability to wear contact lenses. Usually, patients with keratoconus can see much better after a careful fitting with a rigid gas permeable (RGP) contact lens. Our Board Certified Optometrists at The Eye Associates are very skilled at fitting contact lenses on Keratoconus patients.
When good vision is no longer possible with other treatments, a corneal transplant may be recommended. With this procedure, Dr. Foster removes the diseased portion of the cornea and replaces it with healthy donor tissue. He performs a revolutionary partial thickness transplants for Keratoconus called Deep Anterior Lamellar Keratoplasty (DALK).
Click here to schedule an appointment with Dr. Brian Foster or call Toll-free 1-866-865-2020.
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Dr. Foster is one of only a few surgeons in the country skilled in Deep Anterior Lamellar Keratoplasty or DALK. Many keratoconus patients are candidates for this modern corneal transplant technique because the inner layer of corneal cells (endothelium) is healthy. During the procedure, Dr. Foster removes the top 95% of the cornea and replaces it with healthy donor tissue. Patients keep their own healthy endothelial cells and the eye maintains greater strength with a lower risk of rejection than full-thickness transplants.
Even with modern techniques, a transplanted cornea heals slowly. It can take up to a year for good vision after corneal transplantation. While a corneal transplant will relieve the symptoms of keratoconus, it may not provide you with flawless vision and often rigid contact lenses are required to see your best. However, of all conditions requiring corneal transplants, keratoconus has the best prognosis for clear vision.
For a consultation with Dr. Brian Foster, contact The Eye Associates or call 941-792-2020 to schedule an appointment.
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Lamellar Keratectomy (LK)
There are several common conditions that affect the most superficial layer of cells, the epithelium. These conditions include recurrent corneal erosion (RCE), band keratopathy, Salzmann’s nodular degeneration, and epithelial basement membrane dystrophy (EBMD). These conditions can interfere with vision and even cause significant pain and gritty sensation, due to a rough and irregular ocular surface.
If ocular lubricants fail to improve the pain or vision, a procedure known as Lamellar Keratectomy or LK can be beneficial. After the eye is anesthetized with drops or ointment, Dr. Foster selectively removes the diseased epithelium. A soft contact lens is placed that minimizes discomfort after the procedure. This remains in place until it is removed by Dr. Foster. In a few days, a stronger, healthier cell layer will replace that which was removed. Some scratchiness and irritation is normal for a few days after the procedure until the surface has healed.
Click here to schedule an appointment with Dr. Brian Foster or call 941-792-2020 or Toll-free 1-866-865-2020.
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by Brian Foster