Cornea guttata refers to little areas of collagen that collect abnormally at the back of the eye due to a growth abnormality of the cells at that location. These lumps can interfere with light transmission. If enough cells are affected, the cornea may become swollen, causing vision problems. Fuch's dystrophy, surgery to remove cataracts, and injury to the eye are some potential causes of cornea guttata.
An eye is basically a sphere, and the front part of the sphere is transparent to allow light into the eye. This translucent part of the eye is the cornea, and it covers the colored part of the eye, which is the iris, and the black part of the eye, which is the pupil. At the edges of the cornea, the translucency changes into the white sclera, which protect the rest of the eyeball.
Various layers make up a normal cornea. The outer edge contains the epithelial cells, which in turn covers the Bowman's layer, which is made of collagen. Inside the thin Bowman's layer is a thick layer called the stroma, which holds both collagen fibers and some cells. Under this is the Descemet's layer, which is also a collagen layer. The lowest layer of the cornea is the endothelium, which is made up of endothelial cells, which move excess fluid out of the stroma layer and help keep the cornea transparent.
It is the endothelial layer of the cornea that is affected by cornea guttata. The endothelial cells do not grow properly, and where cells die off, the gaps develop into bumps of collagen. These collagen bumps can occur when people are in their twenties or older, but it is only decades later that the bumps grow big enough to impact upon vision. Opthalmologists can spot cornea guttata as dark spots using a special microscopci method called the slit lamp technique.
When cornea guttata develop to the point where the remaining endothelial cells cannot perform their job properly, vision problems occur. The normal absorption and removal of fluid inside the stroma layer is disrupted, and the stroma becomes filled with fluid. This blocks a normal level of light from getting through the cornea and into the eye.
Patients experience a misty appearance to their sight, which can then get worse over time. Treatment for mild cases includes salt drops into the eye, but surgery is necessary for cases that severely impact on vision. Cornea guttata are caused primarily by mechanical damage to the eye such as by longterm contact lens use, surgery or injury, but they can also be related to aging. Fuch's endothelial dystrophy is another disease that has guttata as a symptom, and this condition is also associated with aging.