Sunday, March 8, 2020

Corneal Transplantation Essays

Corneal Transplantation Essays Corneal Transplantation Paper Corneal Transplantation Paper Corneal Transplantation Abstract This paper seeks to provide a brief overview of Corneal Transplantation inclusive of presentation, causation, treatment, recovery, complications, advances, etc.   In doing this, we will   define the cornea, its function, some diseases and disorders affecting the cornea, what corneal transplantation is used for, and type of problems that can develop from a corneal transplant.   Then we will discuss the follow-up and risks/complications of this type of surgery. Finally we will discuss when to call a professional after corneal transplantation; in conclusion we will look at the advances. There will be at least three types of sources used during the course of this discussion. Most of these sources will be essays and articles written by medical specialists and researchers. Introduction Corneal transplantation also referred to as corneal grafting or penetrating keratoplasty is a surgical procedure where a damaged or diseased cornea is replaced by donated corneal tissue which has been removed from a recently deceased individual having no known diseases which might affect the viability of the donated tissue. The cornea is the eyes outermost layer. It is the clear, dome-shaped surface that covers the front of the eye. The surgical procedure is performed by ophthalmologists, these are medical doctors who specialize in eyes, and are often done on an outpatient basis, meaning that the patient goes home following surgery. The need for Corneal Transplantation/Causation Corneal transplants are used to treat persistent corneal infections, diseases that cloud the cornea (corneal dystrophies), traumatic corneal injuries and corneal scars that cannot be corrected by other therapies. Some examples include: Bullous keratopathy, this is a progressive swelling and blistering of the cornea; Keratoconus, an eye disorder in which the middle of the cornea thins and eventually bulges outward; severe corneal ulcers caused by bacterial, fungal, parasitic or viral eye infections; severe traumatic injuries that pierce or cut the cornea; chemical burns of the eye; Corneal scars; Fuchs’s endothelial dystrophy, a progressive eye disease that causes swelling, cloudiness and blistering of the cornea; failure or rejection of a previous corneal transplant. Preparation for the Procedure It should be noted that in the event that the patient has any uncontrolled eye problems that might threaten the success of the surgery, the doctor will first treat them before surgery. There will also be a need for a basic medical evaluation to confirm that the patient is healthy enough to have the transplant procedure. The patient will be given instructions about when to stop eating and drinking before surgery. An antibiotic eye drops to be used before the surgery may be prescribed by the doctor. Also as part of the preparation for surgery, the doctor will need to know about any medications the patient is taking, including over-the-counter medications and natural or herbal remedies. The patient might have to discontinue or decrease certain drugs before surgery. This is because some medicines can increase the risk of bleeding or other surgical complications.   The local eye bank is expected to process and evaluate the donor cornea; this is done to confirm that the donor cornea is free of dangerous viral infections, such as human immunodeficiency virus and hepatitis. The donor cornea also must be transparent and structurally sound. The Corneal Transplantation Procedure The surgeon will make every attempt to confirm retinal and optic nerve function prior to surgery, so as to avoid cases in which visual improvement is unlikely. The majority of adult patients may be operated on under local anesthesia. General anesthesia will likely be required for children, anxious, or uncooperative patients. After the anesthetic is given, the surgeon usually sews a ring to the ocular surface to support the eye. The donor cornea is prepared using a punch or corneal trephine to create the corneal â€Å"button.† The corneal button will become the transplanted cornea. The diseased, or scarred, cornea is then removed using a corneal trephine, creating a â€Å"bed† for the transplant cornea. Finally, the donor cornea is gently sewn into place with ultra-fine sutures which is approximately one-third the thickness of human hair, or less. Corneal transplantation may be combined with other procedures, particularly cataract extraction with intraocular lens implantation. Follow-Up/Recovery After the transplant surgery, the patient must be careful not to touch or press the eye. However, any discomfort can be relieved with over-the-counter pain pills. Usually, the first follow-up visit will be scheduled for the day after surgery, during which the doctor will remove the eye patch and check the new cornea. Special steroid eye drops to help prevent the body from rejecting the transplanted tissue will be prescribed by the doctor. At the end of this visit, the doctor will either leave the eye patch off or ask that the patient wear it a little while longer. The eye patch will remain in place for one to four days after surgery.   The surgeon will likely begin to remove some sutures from the cornea within a few weeks to a few months after surgery. However, all of the sutures need not be removed. In general, sutures are removed to help alleviate astigmatism once the cornea begins to show signs of being securely healed into place. Risks/Complications The most common complication of corneal transplantation is rejection of the new cornea. This is called graft rejection where the bodys immune system identifies the donor cornea as a foreign tissue and begins to attack it. In most cases, it can be treated successfully with medication. Although most corneal transplants are successful, the risks of the transplant procedure include bleeding, infection, broken sutures and anesthetic side effects from anesthesia. In addition, since transplantation opens the front of the eye, there is some danger that eye fluid may start to leak out of the eye after surgery. There is also a risk that fluid pressure inside the eye will become abnormally high or low, or that the retina may detach that is, separate from the back of the eye. All of these problems are rare. Overall, more than 90% of corneal transplants are successful. Most people find that their vision improves significantly following a corneal transplant, although many people have a degree of a stigmatism, an uneven contour of the cornea that can cause some vision problems such as blurriness. After a transplant, vision improves gradually over a period of months. When to call a Professional It is advisable to that a doctor should be called immediately if the patient develops any of the following symptoms after a corneal transplant: pain or increased discomfort in the eye that received the transplant, increased redness of the eye, unusual sensitivity to light, decreased vision and flashing lights or floaters (semitransparent floating shapes) in your field of vision. Conclusion It is note worthy that the chances of success of this operation have risen dramatically because of technological advances, such as less irritating sutures, or threads, which are often finer than a human hair; and the surgical microscope. Corneal transplantation has restored sight to many, who a generation ago would have been blinded permanently by corneal injury, infection, or inherited corneal disease or degeneration. References Albert, Daniel M., Frederick A. Jakobiec (2000). Principles and Practice of Ophthalmology, 2nd Edition. Braunweld, Eugene, Anthony Fauci, Dennis Kasper, Stephen Hauser, Dan Longo, J. Jameson, Harrisons(Feb., 2001). Principles of Internal Medicine. Aetna Intelihealth site: intelihealth.com/IH/ihtIH/WSIHW000/24479/32200.html