The cornea is the eye’s outermost layer. It is the clear, dome-shaped surface that covers the front of the eye. It can be described as being like a window into the interior of the eye. The main function of the cornea is to allow light to pass into the eye, so that it can reach the lens and then the retina. For this reason the cornea must be transparent. A second chief function is to help focus light, like a camera lens.
Health of the cornea depends on a number of factors, including the health of the conjunctiva and of the eyelids. The conjunctiva is the tissue which covers the front part of the eyeball (but not the cornea) and lines the back of the eyelids. Both the conjunctiva and the eyelids contain glands which make tear fluid. Tear fluid is an essential part of the systems which maintain the health of the cornea.
Diseases of the cornea can cause distorted vision or even loss of vision. Keeping the cornea healthy is a vital part in protecting your vision and the health of your eyes.
If a cornea has become diseased or has become irregular, the vision will be impaired. To repair vision, the cornea will need to be replaced with either a new cornea in a corneal transplant called Penetrating Keratoplasty (PKP) or partially replaced by a procedure known as Descemet’s Stripping Endothelial Keratoplasty or DSEK.
Some disease like forms of Fuch’s Dystrophy and select cases of corneal swelling after eye surgery, are due to dysfunction of the cornea’s cells. This layer of cells, called the endothelium, can be replaced surgically with DSEK. With DSEK, the bottom layer of the cornea is removed and replaced with a small disc of cells from a donor. The replacement of the malfunctioning endothelial cells allows the cornea to once again become clear. DSEK is performed through small incisions and has a relatively fast recovery period. Usually, the cornea can be greatly cleared by 4 to 6 weeks after the procedure.
Like PKP, DSEK is a corneal transplant procedure, so a lifetime of eye drops and eye examinations are needed afterward.
DSEK is specifically suited for patients who have posterior corneal diseases with endothelial dysfunction. Patients with corneal conditions such as Fuch’s dystrophy, bullous keratopathy or failed prior corneal transplants are surgical candidates who may benefit from the DSEK cornea surgery.
Some eye problems are minor and fleeting. But some lead to a permanent loss of vision. Common eye problems include:
Your best defense is to have regular checkups, because eye diseases do not always have symptoms. Early detection and treatment could prevent vision loss. See an eye care professional right away if you have a sudden change in vision or everything looks dim or if you see flashes of light. Other symptoms that need quick attention are pain, double vision, fluid coming from the eye and inflammation.