Fuchs’ Endothelial Dystrophy – 福氏角膜內皮營養不良症

What is Fuchs’ Endothelial Dystrophy?

Fuchs’ endothelial dystrophy (FED) is a relatively common eye condition that affects the deepest layer of the cornea (endothelium). The endothelium is a densely-packed sheet of cells, which helps to maintain the transparency of the cornea by regulating the flow of fluid in and out of the cornea.

Normally, this unique layer of cells helps to maintain a healthy balance of fluids within the cornea and prevent it from swelling. The central endothelial cell density decreases throughout life at an average rate of about 0.6% per year, therefore the mean cell density was found to decrease from 3400 cells/mm at age 15 to 2300 cells/mm at age 85 years. But with FED, the endothelial cells gradually malfunction and they produce an abnormal substance, which appears as drop-like warts (guttae) that projects from the base layer (Descemet’s membrane) and create the condition known as cornea guttata.

Fuchs’ endothelial dystrophy usually affects both eyes, which can cause your vision to gradually worsen over years when fluid slowly builds up within your cornea. But most people with FED don’t develop symptoms until they reach their 50s or 60s.

What causes Fuchs’ Endothelial Dystrophy?

Fuchs’ endothelial dystrophy is an inherited eye disorder as people with a family history are at a higher risk of developing the disease, although the genetic nature of the disease is complicated. Family members can be affected to varying degrees or not at all.

This condition is slightly more common in women than in men. Also, smokers and diabetic patients may be more likely to have this disease.

What is the best treatment for Fuchs’ Endothelial Dystrophy?

Previously, a penetrating keratoplasty was the only effective treatment for advanced FED, which involves the replacement of the central full thickness of patient’s cornea with a donor corneal graft. Unfortunately, the recovery time is very long and the visual outcome is unpredictable.

In recent years, newer surgical techniques (endothelial keratoplasty) have been introduced which allow selective replacement of the bottom layers of the cornea through a small keyhole incision. Corneal surgeons may now be able to replace the inner 2 layers of the cornea (Descemet’s Stripping Automated Endothelial Keratoplasty or DSAEK). This procedure significantly reduces the postoperative recovery time and produces better visual outcomes. Moreover, it is now possible to replace only the endothelium with its thin supporting layer in the latest endothelial keratoplasty technique (Descemet’s Membrane Endothelial Keratoplasty or DMEK). This procedure can be done through an even smaller keyhole incision than DSAEK, and the recovery time is also quicker.