The inner lining of the cornea is a layer of tissue called the endothelium. It consists of a layer of cells that resemble a “tile floor” under the microscope. This lining is important because it serves as a water “pump”, pumping water out of the cornea back into the eye, which is necessary to maintain the cornea’s clarity. The number of cells per unit area, or density, determines how well the cornea can perform this important function.
Using an instrument called a specular microscope, an “endothelial cell count” can be performed to look at the density, size, and shape of the cells. The density of the cells can be affected in certain diseases, such as Fuchs Corneal Endothelial Dystrophy and can be monitored. The density may also affect the decision making of related eye surgeries such as cataract surgery, where the cornea could be further damaged and de-stabilized, requiring a corneal transplant. A variation in size of cells called “pleomorphism”, can be seen in other diseases, and polymegathism, (a variation in the size of endothelial cells), can be seen in contact lens wearers and may represent a sign of disturbed metabolism. If contact lens wear is reduced or discontinued, a return to proper cell shape can be observed.
In summary, your doctor may use your cell count to document a disease process, aid in planning the treatment of a corneal disease, document the delivery of medical treatment and the response to that treatment, and for patient education.
Our Guest Blogger: Dr. Joel Confino, M.D.: Cornea Specialist at The Eye Care & Surgery Center of Westfield, Warren and Iselin New Jersey