The cornea is the clear front surface of the eye. It lies directly in front of the iris and pupil, and it allows light to enter the eye. It also serves to protect the eye from the environment and helps filter out some of the sun’s most damaging ultraviolet (UV) rays.
In order to function properly and provide the best vision, the cornea must remain healthy and clear. When the cornea is damaged either by injury, disease or due to hereditary conditions, it may become swollen or scarred. These scars may cause the cornea to scatter or distort light, resulting in reduced vision, sometimes to the point of blindness. If the cornea becomes cloudy or distorted, the only way to restore sight may be a corneal transplant.
Common Corneal Issues
Also known as a scratched cornea, an abrasion can be very painful and if untreated can lead to an infection. There are multiple treatments that can immediately eliminate the pain as well as decrease the risk of infection
There are many causes of dry eyes, but they all eventually affect the cornea. The cornea has a significant number of nerve endings so when it dries out people may feel irritation, burning, tearing and grittiness.
A chalazion is a blocked oil gland in the eyelids. It can cause eyelid swelling with pain and blurry vision. Often it can be treated with warm compresses, but a small percent need to be surgically drained.
A corneal ulcer is a serious condition in which the cornea tissue starts to melt. Most commonly caused by bacterial infections, an ulcer is an urgent condition that is sight threatening and causes redness, pain, sensitivity to light, and decreased vision.
A dystrophy is a genetic disease that causes weakening or degeneration of tissue. These come in many forms in the cornea. Most can be monitored but as they progress will often require a corneal transplant.
Epithelial Basement Membrane Disease
Often described as “wrinkles” in the cornea, epithelial basement membrane disease is a degeneration of the cornea that worsens with age. It causes many of the same symptoms of dry eye disease. It can also cause severe pain upon wakening. Removal of these “wrinkles” will eliminate the symptoms.
This is a thinning and deformation of the cornea that occurs during a patient’s teenage years. It can slowly progress over time leading to vision loss that cannot be corrected with glasses. Special contact lenses are used to correct the vision instead. In severe cases a corneal transplant is necessary to replace the deformed cornea.
Corneal Transplant Advances
There are two types of corneal transplantation: full thickness and partial thickness. With a full thickness transplant, the complete disease cornea is removed and new cornea is sutured in place. 20 years ago, this was the only method for corneal transplantation. With recent advancements though, these are only used with most severe corneal disease.
Nowadays most patients undergo a partial thickness corneal transplant. The benefit of this surgery is increased safety and quicker visual recovery. The most modern form of this surgery is called a Descemet’s Membrane Endothelial Keratoplasty (DMEK). This provides the best chance for good vision, but is difficult to perform so only a small percentage of corneal specialists can do this surgery. Luckily, Dr. Pierson has expertise in this surgery providing patients the highest level of care.