The cornea is composed of five layers.
Epithelium Layer – an exceedingly thin surface layer of cells in the cornea’s outermost region, comprising about 10 percent of the tissue’s thickness. Its primary function is to block the passage of foreign material and provide a smooth surface that absorbs oxygen and cell nutrients from tears and then distributes them to the rest of the cornea.
Bowman’s Layer – compromised of strong layered protein fibers called collagen, the Bowman’s layer is a tough layer of basement membrane that keeps the cornea from swelling forward.
Stroma – Compromising about 90% of the cornea’s thickness, the stroma consists of 79% water and 16% highly arranged collagen fibers and supporting keratocytes, and contains no blood vessels. The collagen gives the cornea its strength, elasticity, and form
Descemet’s Membrane – located below the stroma, Descemet’s membrane is a thin but strong, inner layer of basement membrane that is important for the health of endothelial cells. It also serves as a protective barrier against infection and injuries.
Endothelium – a crucial, extremely thin layer that works as a barrier and pump that keeps the cornea from getting too wet by pumping the excess fluid out of the stroma. In a healthy eye, a perfect balance must be maintained between the fluid moving into the cornea and being pumped out of the cornea. When endothelium cells are destroyed by disease or trauma, they are lost forever and may lead to corneal edema or blindness.
The purpose of the cornea is to help shield the eye from germs, dust, and other harmful matter and controls and focuses the entry of light into the eye.
When the epithelium does not stay attached correctly to the tissue below, including the Bowman’s layer, corneal erosion may develop. When this condition occurs repeatedly, it is referred to as recurrent corneal erosion. If you have a history of eye injury, corneal disease (corneal dystrophy), wear contact lenses that are not properly fitted or cared for, or have had an eye ulcer, you may be at risk for corneal erosion.
Symptoms of corneal erosion:
- Mild to severe pain, typically at the time of awakening or during sleep.
- Light sensitivity
- Blurred vision
- Foreign body sensation
- Water eyes (especially on waking)
Treatment may include use of artificial tears several times a day and a lubricating ointment at bedtime to prevent your eyelid from sticking to the epithelium. Also, if the defect is large, a patch may be recommended. In the case of recurring corneal erosion, your ophthalmologist may recommend surgery.
If you are experiencing any of the symptoms above, it is important to see an eye doctor right away to prevent further damage to your cornea which could result in vision loss. Set up an appointment with one of our board-certified ophthalmologist at Fort Lauderdale Eye Institute today!