WHAT IS ENDOTHELIAL CELL DYSTROPHY?
The innermost layer of the cornea is the endothelial cell layer. It is just a single layer of cells, which cannot be regenerated once damaged. The endothelium actively pumps fluid out of the cornea back into the inside of the eye. The cornea needs to be relatively dehydrated in order to be clear. In endothelial cell dystrophy the endothelium is damaged so that the active pumping function begins to fail allowing for fluid to enter the cornea that cannot be readily removed. The progressive over-hydration of the cornea leads to a cloudy appearance and visual impairment. In some cases too much fluid within the cornea can lead to bullae formation and corneal ulcers.
WHAT ARE THE SIGNS OF ENDOTHELIAL CELL DYSTROPHY?
A cloudy appearance of the cornea is typical for those cases. Usually both eyes are affected. The cloudiness becomes more pronounced over time. In cases with corneal ulcers, your dog will show signs of discomfort such as squinting, tearing, or rubbing at its eyes.
WHAT BREEDS ARE AFFECTED?
Endothelial dystrophy can be hereditary as in the Boston Terrier and in Chihuahuas. However, any breed may be affected. Most animals are middle aged to older. Trauma to the endothelial cell layer can cause dysfunction as well and may be seen in any age animal.
WHAT IS THE TREATMENT FOR ENDOTHELIAL CELL DYSTROPHY?
Unfortunately there is no therapy to repair the endothelium. Topical osmotic agents such as 5% NaCl solutions or ointments can help to remove some fluid from the cornea. If ulcers occur other medications will be necessary. Since ulcers with this disease are difficult to heal just with medications, a surgical procedure may be indicated to provide your pet with comfort.
WHAT IS THE PROGNOSIS?
Since endothelial cells can not be repaired, the treatment aims to keep your pet visual and comfortable. It is unlikely that the cornea will become completely clear with treatment. But long-term vision can be maintained in most patients.