The cornea is the clear front lens of the eye. It disseminates light throughout the interior of the eye allowing us to see clearly. Corneal disease is a serious and sometimes painful condition that can cause clouding, distortion, and eventually blindness. There are many types of corneal disease including keratoconus, Fuchs’ endothelial dystrophy, and bullous keratopathy.
Types of Corneal Diseases
Keratoconus is diagnosed when the cornea develops a cone-shaped deformity through the weakening and thinning of the central cornea membrane. Keratoconus most commonly affects both eyes, but may only affect one eye. Progression of this condition can vary from rapid, gradual, or intermittent.
Symptoms of keratoconus include increasingly blurry vision. Wearing contact lenses is often used as early treatment of keratoconus, but can become difficult as the disease progresses and distorts the shape of the cornea, preventing the lens from fitting properly. Please visit our crosslinking page to read more about an exciting clinical trial that Drs. Slade & Parkhurst are involved in to help stop the progression of keratoconus.
Fuchs’ Endothelial Dystrophy
Fuchs’ Endothelial Dystrophy is a hereditary abnormality that affects the endothelium, the inner cell layer of the cornea. The purpose of the endothelium is to pump fluids out of the cornea, keeping it thin and crystal clear. If fluids are not pumped out, the cornea swells and becomes cloudy resulting in decreased vision.
Bullous Keratopathy is a condition in which the cornea becomes permanently enlarged. This occurs because the endothelium, the inner layer of the cornea, is damaged and no longer extracting fluids from the tissue.
Symptoms of both Fuchs’ endothelial dystrophy and bullous keratopathy include possible glare around lights at night and eventually in bright sunlight. Vision may be foggy or blurry in the morning and then clear up later in the day. As the disease further progresses, vision will continue to be blurry throughout the day and eventually may not clear at all.
Corneal Disease Causes & Risk Factors
Corneal disease can be caused by any number of factors including:
- Age: The natural aging process can affect both the clarity and health of the cornea
- Infection: Bacterial, fungal, and viral infections are common causes of corneal damage.
- Systemic disease: Leber’s congenital amaurosis, Ehlers-Danlos syndrome, Down’s syndrome, and osteogenesis imperfecta commonly lead to corneal disease.
- Certain eye diseases: Retinitis pigmentosa, retinopathy of prematurity, and vernal keratoconjunctivitis also commonly lead to corneal disease.
- Eye trauma
- Contact lenses
- The cause of keratoconus in most patients is unknown
Corneal diseases should be treated immediately. There are early treatment methods, such as contact lenses, that can be used to prolong vision, as well as new light therapy crosslinking for keratoconus. In cases of Fuch’s dystrophy or other endothelial dystrophies, there are new techniques where only the back layer of the cornea is replaced, leaving the front portion intact. Dr. Walton (link) performs cutting-edge, micro-invasive DMEK (Descemet membrane endothelial keratoplasty) transplants as well as DSAEK (Descemet stripping automated endothelial keratoplasty). In some cases, a full-thickness corneal transplant is necessary. Fortunately, this treatment is now done with a laser to speed recovery. Dr. Slade was one of the first in the US to do corneal transplants with the laser. The laser treatment can restore vision when the cornea becomes clouded with a very high percentage of success.