The cornea is the clear window over the surface of the eye that all light must pass through. It functions to prevent infection by creating a barrier to bacteria and viruses; it must stay clear to maximize vision; and it helps to focus the light that comes in. When there is a problem with the cornea, any one of these functions may break down and result in disease. Some of the conditions that can occur that result in problems with sight include Fuchs dystrophy, bullous keratopathy, keratoconus, and corneal scars. Sometimes, we are able to use drops, contact lenses or other treatments to care for these conditions. Other times, the only option to improve the vision is a cornea transplant. With a cornea transplant, we take a cornea from a deceased donor, and transfer that tissue to the diseased cornea. In the past, we often had to transfer the entire thickness of the cornea regardless of the problem. It is kind of like replacing the engine because of a bad spark plug. However, I am able to now usually replace just the damaged tissue by doing partial thickness cornea transplants. For example, Fuchs dystrophy has a bad internal pump that allows fluid to build up in the cornea. Currently, I will perform DMEK (Descemet membrane endothelial keratoplasty) or DSEK (Descemet stripping endothelial keratoplasty) to treat this condition by only removing the inner layer of cells. In DMEK, the same layer that is removed is replaced, and in DSEK a small extra amount of tissue is replaced. Both surgeries have faster visual rehabilitation, and better outcomes than the previous methods. DMEK only requires one stitch and DSEK is usually only 3 stitches. For patients with keratoconus or corneal scars, I now perform deep anterior lamellar keratoplasty (DALK). This involves removing the front layer of the cornea while still maintaining the endothelium (Fluid pump cells). The endothelium is the site most likely to experience a damaging rejection so by replacing the front layer, we can often reduce or stop steroid drops, and there is much less risk of rejecting the transplant. Sometimes we still have to do a penetrating keratoplasty which involves removing the cornea in a full thickness fashion, but using modern techniques, that surgery is still fairly low risk overall. There are other variants of cornea transplants, but these represent the main layers of the cornea. If you think you have a condition that may need a cornea transplant, do not hesitate to call our office at 512-686-1224 to schedule an appointment.