There are many hereditary disorders that impact the cornea, the clear windshield at the front of the eye. All of these cause some decrease in clarity of the cornea and consequently patients experience loss of clear, sharp vision. They are called dystrophies which refers to the progressive degeneration of tissue.
This type of corneal dystrophy has its onset in the first decade of life but vision remains clear until patients become older. Small, discrete, grayish-white opacities appear in the cornea and resemble granules, hence the name. These opacities may enlarge and increase in number and eventually become dense enough to interfere with vision. There is considerable variation in the number and size of the granules among people. No systemic disease is associated with the corneal opacities.
This is an autosomal dominant disease so that the disease pattern in families tends to be vertical as parents pass the condition to their children.
Cloudiness of the cornea may be apparent by simple inspection in adults. However, only an eye doctor can make the exact diagnosis as other corneal diseases can appear similar. A corneal transplant can restore clear vision but the opacities tend to recur. Various laser refractive surgeries have been reported to stimulate a worsening of the opacities in some patients.