History - FAQs - Parts of the Eye - The Mechanics of Sight - Eye Disorders
A History of Corneal Donation and TransplantAttempts to transplant an animal cornea to a human recipient were first made in Germany in the 1800's, but failed due to tissue rejection. Finally, an Austrian doctor performed the first successful full-thickness corneal transplant in 1905 after obtaining tissue from an 11-year-old donor.
Corneal transplant was infrequently performed until the early 1940's - primarily because no donor program existed and tissue was very rarely available. Dr. R. Townley Paton, then president of the Manhattan Eye, Ear and Throat Hospital in New York City, was a prominent surgeon who was determined to obtain needed tissue for his patients. Each time a prisoner at Sing Sing was executed, Dr. Paton drove forty miles to secure the cornea. During this time, prisoner donation was the only source of donor eye tissue.
To improve on this cumbersome arrangement and to increase tissue availability, Dr. Paton and a group of associates formed the first eye bank in 1944. New laws governing the donation of eye tissue had to be enacted and the public desperately needed education.
During WWII, blindness increased due to war trauma and disease. As corneal transplant surgery became more successful, the need for transplant eye tissue multiplied. Eye banks began to spring up in other parts of the country to meet the need. Today, approximately 47,000 transplants are performed each year, and eye tissue used for other surgeries, research and teaching has increased tremendously.
"There is no lovelier way to thank God for your sight
than to give a helping hand to those in darkness."
Corneal Transplant: The Procedure
FAQs
What is an eye bank?
An eye bank is an agency staffed with trained medical professionals who recover, evaluate, process and distribute eye tissue for surgical, research and teaching purposes, using strict medical guidelines. Standards for eye banking in the United States are extremely high and rigidly enforced by the Eye Bank Association of America through an exhaustive certification program
What is a cornea?
The cornea is a clear surface on the front of the eye, much like the crystal on your watch. It is the main focusing element of the eye and light must pass through it in order to have sight. If it becomes cloudy or scarred from disease, injury, infection or other cause, vision is dramatically reduced or completely lost. In many cases, a corneal transplant is recommended by the ophthalmologist.What is a corneal transplant?
It is a surgical procedure in which a disc-shaped segment of the injured cornea is replaced with a similar segment of a healthy, donor cornea. Over 90% of all corneal transplants successfully restore the recipient's vision. Although 47,425 corneas were provided for transplant last year in North America, the demand for tissue is never satisfied. There are as many as 5,000 individuals on waiting lists around the country every day.What is the source of transplant tissue?
Transplant tissue comes from only one precious source - an eye donor. Thoughtful and caring people or their families may choose to donate eye tissue at the time of death. As of now, there is no synthetic material suitable for corneal tissue; therefore, it is only living corneal tissue from a recently deceased donor, which can be used for transplant.Who can be an eye donor?
Anyone can be an eye donor regardless of age or poor eyesight - everyone can lend a hand in the fight against blindness.
How is the recipient chosen?
After testing and evaluation by the Eye Bank, corneal tissue is offered to the eye surgeon who has the next patient on the waiting list. Distribution is based on "first come, first served," except in an emergency situation. The decision to accept a cornea for a specific patient rests with the surgeon.How safe is transplanted tissue?
Donated eye tissue and the donor's medical history are evaluated extensively by The Eye Bank, in accordance with strict medical standards. Extensive blood testing and careful training of laboratory personnel ensure the safety of all surgical tissue.Can the whole eye be transplanted?
No, only the cornea and segments of sclera can be transplanted. Scleral tissue comes from the outer white portion of the eye and is used for certain glaucoma procedures and reconstructive surgery. However, whole eyes are very important for research and teaching. Research on glaucoma, retinal disease, diabetes complications and other sight disorders help find new treatments and cures.How soon must the cornea be procured and when is it transplanted?
Corneas should be procured as soon as possible after death, preferably within a few hours. Ideally, transplantation is performed within a few days.Will eye donation affect the donor appearance or change funeral arrangements?
Not at all. Great care is taken to preserve the natural appearance of the donor. Funeral arrangements, with viewing if desired, may take place without delay.Are there any religious objections to donation?
All major religious faiths support this program for sight restoration, viewing it as an opportunity to restore health and give the gift of sight.Is there a fee charged for donation?
There is absolutely no charge to the family or estate of the donor for the donation process. All costs associated with the eye recovery are charged to the serving eye bank.Will the recipient and donor family be given each other's names?
The gift of sight is made and received anonymously. However, most Eye Banks encourage and convey anonymously written notes between recipients and donor families.Will the quality of medical care be affected if one is a known donor?
Absolutely not. Strict laws and legal guidelines must be followed before death can be certified. The physician certifying the patient's death can in no way be involved with the eye procurement or with the transplant.
How can I leave the legacy of sight?
First and foremost, tell your family that you want to be a donor. They will be asked to give consent before a donation can take place and it helps them to make a decision if they know what your wishes are. You may wish to visit the Louisiana Organ Procurement Agency to join the Donor Registry, which allows individuals to express their willingness to donate corneas, tissue and organs for transplantation.For a donor card or more information, contact us or call us at 225-766-8996.
Know Your Eyes
An Overview of one of man's most precious possessions
Parts of the EyeAlthough the eye is a small structure, it is extremely complex and contains an immense network of nerves, blood vessels, cells and specialized tissues.
To understand how the eye operates, it is first necessary to know the names and functions of some of its parts.Cornea (kor'ne-ah)
The clear, transparent front portion of the fibrous coat of the eye; functions as an important refractive medium.Sclera (skle'rah)
The tough white protective coat of the eye. The portion of the sclera that surrounds the cornea is covered by the conjunctiva.Conjunctiva (kon-junk'ti-va)
A mucous membrane extending from the eyelid margin to the corneal limbus, forming the posterior layer of the eyelids and the anterior layer of the eyeball.
Iris (i'ris)
A colored, circular membrane suspended behind the cornea and immediately in front of the lens. It regulates amount of light entering the eye by adjusting size and pupil.Pupil (pu'pil)
The opening at the center of the iris of the eye; it contracts when exposed to strong light or when the focus is on a near object and it dilates when in the dark or when the focus is on a distant object.Aqueous (a'kwe-us)
Watery liquid that flows between the lens and the cornea and nourishes them.Lens (lenz)
The transparent tissue behind the iris that bends light rays and focuses them on the retina.Schlemm's Canal (Schlemz ke'nal)
A passageway for the aqueous fluid to leave the eye.Vitreous body (vit're-us)
Transparent, colorless mass of soft, gelatinous material that fills the center of the eye behind the lens.Retina (ret'i-nah)
Light-sensitive tissue at the back of the eye that transmits visual impulses via the optic nerve to the brain.Macula (mak'u-lah)
Pigmented central area, or "yellow spot," of the retina devoid of blood vessels. It is the most sensitive area of the retina and is responsible for fine or reading vision.Choroid (ko'roid)
Blood vessel-rich tissue behind the retina that is responsible for its nourishment.Optic nerve (op'tick nurv)
The nerve at the back of the eye that carries visual impulses from the retina to the brain. The area at which the optic nerve connects with the retina is known as the optic disc.
The Mechanics of Sight
The mechanics of sight are complex and research has provided a great deal of information about the visual system. Such information is valuable, not only for understanding how the eyes function in health, but also for studying certain disease processes.
Accommodation
Ability of the eye to adjust its focus for near and distant visions.Cones
Specialized visual (photoreceptor) cells in the retina, responsible for sharpness of vision and color vision (see Rods).Dark Adaptation
Biochemical and neurological process by which the eye becomes more sensitive to light in the dark.Distance Vision
Ability to perceive objects distinctly at a distance usually measured at 20 feet.Near Vision
Ability to perceive distinctly objects at a normal reading distance, about 14 inches from the eyes.Peripheral Vision
Ability to perceive the presence, motion or color of objects outside the direct line of vision.Refraction
Bending of light rays when passing from one transparent medium into another of different density. In vision, refraction by the cornea and lens brings images to sharp focus on the retina.Rhodopsin
Light sensitive pigment of the rods; bleaches in the light and regenerates in the dark. It plays a key role in the transformation of light energy into visual perception.
Rods
Straight, thin cells in the retina containing light-sensitive pigments. They are responsible for night vision (see Cones).Visual Activity
Part of the cerebral cortex of the brain primarily responsible for interpreting signals from the eye.Diseases of the eye can cause visual disability ranging from minor impairments to total blindness. Some forms of visual disability can be prevented through prompt attention, and others may be cured. But, unfortunately, there are other eye conditions that can not be prevented or treated. Research is aimed at improved prevention, diagnosis and treatment of visual disorders. Through research, a great deal of knowledge has already been gained about the eye and the diseases that threaten its normal function.
Cataract (kat'ah-rakt)
One of the leading causes of blindness in the country, cataract is a clouding of the lens which obstructs the passage of light to the retina. Almost all cataracts can be successfully removed by surgery with resulting restoration of useful vision. There are four main types of cataract: senile, which is the most common form and is associated with aging; congenital, which occurs at birth; secondary, which follows another eye disease; and traumatic, which follows an injury.Corneal Disease (kor'ne-al)
Diseases of the cornea may scar this transparent tissue causing disability. Causes of corneal disease include injury, infection and allergic reactions. Corneal diseases can frequently be successfully treated by drugs or surgery. In some cases, corneal transplants can restore vision to people who have suffered severe corneal scarring.
Diabetic retinopathy (ret'I-nop'ah-thee)
Disorder of the blood vessels in the retina stemming from diabetes. It is one of the leading causes of blindness in this country. The disease is sometimes treated with laser or other forms of light energy.Glaucoma (glaw-ko'mah)
Increased pressure in the eye causing damage to the optic nerve and impaired vision. Glaucoma is another leading cause of blindness. If detected early, the most common form of the disease usually can be controlled with drugs. In other cases, surgery may be necessary.Macular Degeneration (mak'u-lar)
Irreversible and progressive damage to the macula portion of the retina resulting in a gradual loss of fine or reading vision. It is a leading cause of blindness in this country and is usually associated with aging.Retinal Detachment (ret'n-el)
Separation of the inner sensory layer of the retina from the outer pigment epithelium, leading to loss of retinal function. Usually caused by a hole or break in the inner sensory layer that permits fluid from the vitreous to leak under the retina and lift off the innermost layer of the retina. If detected early and treated promptly with surgery, retinal detachment can often be repaired and vision restored.Information provided in part by the Eye Institute, an agency of the US Department of health, Education and Welfare.
