Corneal Dystrophy

Corneal distrophies are a group of rare and genetic diseases affecting the cornea. It runs in a families and may be present asymptomatic. They affect both the eyes and other parts of the families are not involved. Main cause of corneal dystrophies is foreign material build up in the cornea and that results in clouding of cornea and visual impairment.

The cornea is made up of five distinct layers:
The Epithelium - the outermost, protective layer of the cornea.
The Bowman's membrane - this second layer is extremely tough and difficult to penetrate further protecting the eye
The Stroma - the thickest layer of the cornea, consisting of water, collagen fibers and other connective tissue components that give the cornea its strength, elasticity and clarity.
Descemet's Layer - a thin, strong inner layer that also acts as a protective layer.
The Endothelium - the innermost layer consisting of specialized cells that pump excess water out of the cornea
Types of corneal dystrophies:
There are 20 different types of corneal distrophies but are groped in 3 main categories:

Anterior or superficial corneal dystrophies. These affect the outermost layers of the cornea: the epithelium and Bowman’s membrane.
Stromal corneal dystrophies affect the stroma, which is the middle and thickest layer of the cornea.
Posterior corneal dystrophies affect the innermost parts of the cornea: the endothelium and the Descemet membrane. The most common posterior corneal dystrophy is Fuchs’ dystrophy.
Symptoms of Corneal distrophies:
Symptoms like watery eyes, dry eyes, corneal erosions, Blurry vision, halos around light, light sensitivity and difficulty in seeing at night often overlaps with diseases like glaucoma and cataract. Two differentiating symptoms are pain and a feeling of something in the eye occurs in the corneal distrophies. As the condition worsens vision becomes poor and irregularities in the cornea may lead to fluctuating vision.

Who is at risk for corneal dystropies?
People having family history of the disease are at more risk than others. Corneal dystrophies can appear at any age. Men and women are equally affected by most corneal dystrophies, except for Fuchs’ dystrophy. Fuchs’ affects women more frequently than men.

What are my treatment choices?
Treatment for corneal dystrophies may vary from eye drops to corneal transplant and depends on:

The type of dystrophy
The severity of symptoms
In few cases, people with corneal dystrophy may have repeated corneal erosion. This condition may be treated with antibiotics, lubricating eye drops, ointments, or special soft contact lenses that protect the cornea. If erosion continues, other treatment options may include the use of laser therapy or a technique for scraping the cornea.

In severe cases, a corneal transplant (called keratoplasty) may be necessary. The damaged or unhealthy corneal tissue is removed and clear donor cornea tissue is put in its place. For endothelial dystrophies, such as Fuchs’ dystrophy, a partial cornea transplant (or endothelial keratoplasty) is used.