Fuchs Corneal Dystrophy

Fuchs Corneal Dystrophy

Fuchs Corneal DystrophyFuchs Corneal Dystrophy is a degenerative eye disorder which is slowly progressive bilateral condition affecting females more than males, occurring mainly between fifth and seventh decade of life affecting cornea (the transparent front surface).

Cause

Normally in a person the endothelial layer of cornea prevents from accumulation of fluid but in a person suffering from fuchs corneal dystrophy, the endothelial cells start to die and as a result accumulation of fluid occurs which result in oedema, blurring of vision, pain.

Inheritance: It is an autosomal dominant. It means that one gets affected from parent and there are 50% chances of inheriting the gene and 50% chances of having normal gene. Genetic Locus is 13p.

Clinical features

Fuchs Corneal Dystrophy is classified in 4 stages. These stages are:

Fuchs Corneal Dystrophy showing Guttata1. Stage of Corneal Guttata (guttata means mushroom shaped bodies in corneal endothelium):

It is an asymptomatic stage characterized by presence of Hassall-Henle type of excrescences in central part of cornea. With increase of guttae in peripheral part it gives rise to ‘beaten-metal’ appearance.

[*] Hassall-Henle bodies are drop like excrescences in anterior chamber around the corneal periphery arising from Descemet’s membrane.

2. Oedematous Stage: It is characterized by stromal oedema and epithelial dystrophy. There is blurring of vision in this stage.

3. Stage of Bullous Keratopathy: In this stage there is epithelial oedema with formation of bullae which on rupture cause pain, discomfort, irritation and reduced visual acuity.

4. Stage of Scarring: In this stage bullae are replaced by scar tissue which result in opaqueness of cornea. It can be complicated by occurrence of secondary infection or glaucoma.

Diagnosis

The diagnosis of Fuchs Corneal Dystrophy is made by the examination of the cornea using Slit-lamp. This may detect a partial absence of endothelium, corneal edema, bullous changes in the epithelium layer. In addition, pachymetry used to detect the thickness and swelling of the cornea.

Specular Microscopy is used to confirm the diagnosis. It reveals decreased endothelial count, increased average cell diameter with increased variation in cell size.

Treatment

There are no Medication available to cure the Fuchs Corneal Dystrophy. But symptomatic treatment is done using hypertonic saline instillation to draw excess fluid from the cornea, which improves the vision temporarily.

The treatment of choice for Fuchs Corneal Dystrophy is the Penetrating Keratoplasty. But there are high risk of complications  associated with surgery, it is usually assigned when visual acuity of less than 0.1-0.3.

Reference

1. A.K Khurana, MD “Ophthalmology” (New Age International Publisher, Inc 2012).

2. Fuchs Corneal Dystrophy showing Guttata image used on this page is copyright to American Academy of Ophthalmology (www.geteyesmart.org).