is a group of disorders, characterised by a noninflammatory, inherited, bilateral opacity of the transparent front part of the eye
called the cornea
. It is commonly seen in humans
as well as dogs
. It is rare in cats.
Signs and symptoms
Corneal dystrophy may not significantly affect vision in the early stages. However, it does not require proper evaluation and treatment for restoration of optimal vision. It can, however, rarely cause corneal ulceration
, especially with epithelial dystrophy. It appears as grayish white lines, circles, or clouding of the cornea
. Corneal dystrophy can also have a crystalline appearance.
A corneal dystrophy can be caused by an accumulation of extraneous material in the cornea - it can be in the form of lipids
Corneal dystrophies are commonly subdivided depending on its specific location within the cornea. It can be basically divided into anterior
, or posterior
according to the layer of the cornea affected by the dystrophy.
Suboptimal vision caused by corneal dystrophy usually requires surgical intervention in the form of corneal transplantation
. Penetrating keratoplasty
is commonly performed for extensive corneal dystrophy. Corneal dystrophy in dogs usually does not cause any problems and treatment is not required.
Early stages may be asymptomatic and may not require any intervention. Initial treatment may include hypertonic eyedrops and/or ointment to reduce the corneal edema and may offer symptomatic improvement prior to surgical intervention.
With penetrating keratoplasty (corneal transplant), the long term results are good-excellent. Recent surgical improvements have been made which have increased the success rate for this procedure. However, recurrence of the disease in the donor graft is not ruled out.
Corneal dystrophy in dogs: Commonly affected breeds
Many breeds are affected by corneal dystrophy with many different appearances. These breeds most commonly have these criteria.
Corneal endothelial dystrophy
Corneal endothelial dystrophy is an age-related change that affects the inner layer of the corneal, the endothelium
. Leakage of fluid into the cornea causes edema
, causing a bluish appearance. This will eventually involve the whole cornea. Bullous keratopathy
in the cornea) may also form, leading to nonhealing and recurrent corneal ulceration. Hyperosmotic
agents are sometimes used topically for treatment, but success with these medications is inconsistent and can cause irritation. Bad cases may require a corneal transplant
, which is a grid of superficial burns to the cornea that causes anterior stromal fibers to contract and prevent fluid uptake by the stroma. The most commonly affected breeds are the Boston Terrier
, and Dachshund
. The age of onset in the Boston is five to nine years and eight to thirteen years in the Chihuahua and Dachshund. The disease is similar to Fuch's dystrophy