The cornea is the clear tissue on the front of the eye and is responsible for two-thirds of the focusing power of the eye. (The lens, where cataracts develop, does the other third of the focusing). Because the cornea does most of the focusing of light, changes in its shape or clarity can significantly impact the degree to which the light is clearly focused.
The cornea and surrounding ocular surface can be the site of numerous diseases, ranging from dry eye to those that require transplantation. Corneal diseases generally fall into three categories, those that:
- Change the shape of the cornea
- Create scars/opacities
- Cause pain
It is quite common to have all three combined.
The most common corneal infections are herpes simplex and those caused by contact lenses.
The most common non-traumatic/non-infectious shape problem is called keratoconus. This is a familial, progressive thinning and warping of the cornea, which initially requires rigid contact lenses and ultimately, in many cases, a corneal transplant.
The most common non-infectious/non-traumatic opacity is called Fuchs’ dystrophy. This is also an inherited disease that causes progressive thickening and haziness. Salt drops can be of some benefit, but the condition can also lead to corneal transplantation.
Common diseases that can be purely characterized by pain/discomfort are:
- Dry eye
- Corneal abrasions (scratching the superficial surface layer)
- Recurrent erosions. With erosions, the surface comes partially off due to previous trauma or a genetic dystrophy of the cornea.
Dr. Steiner performs penetrating keratoplasty, which is a traditional, full thickness, corneal transplant. This is often done for keratoconus or scarring. He also performs two newer partial thickness transplant techniques; These are Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK)and Descemet’s Membrane Endothelial Keratoplasty (DMEK). DSAEK and DMEK are are used when only the back or posterior layer of the cornea is involved. Fuch’s Dystrophy is the most common condition that benefits from these surgerys. But other diseases that affect the posterior layer (Descemets and Endothelium) and those causing corneal edema can benefit from DSAEK or DMEK, as well.