Corneal stromal dystrophy is, in fact, a term used to describe a number of related conditions, which cause opacification of the cornea. It is a sub division of a broader group of corneal dystrophies. The etiology is genetic, although inheritance patterns vary.
Corneal stromal dystrophy (CSD) includes a number of disorders such as macular, granular, reticular, lattice, fleck, and congenital stroma dystrophies . It is a genetic disease, and its incidence varies between different regions  . The inheritance pattern of CSD is mostly autosomal dominant, although other patterns such as recessive or X-linked have been described. Mutations in any one of several genes, such as transforming growth factor beta-induced (TGFBI), carbohydrate sulfotransferase 6 (CHST6), or keratin 3 (KRT3), lead to particular forms of CSD  . The extent of the phenotypic expression of a mutation varies between individuals. Corneal dystrophies, in general, involve disease of the cornea, while CSD specifically affects the stroma.
CSD is characterized by corneal opacities that are often bilateral and symmetrical. These lesions are caused by the deposition of non-transparent matter, which is not preceded by a history of inflammation or trauma to the eye. The deposited material may be present as ill-defined or irregular sheet, line, ring, dot or flake shaped areas. The surrounding cornea may be clear or opacified as well.
The features of CSD are variable with regard to the degree of visual impairment, presence or absence of systemic symptoms, and the severity of symptoms. CSD is usually slowly progressive. It may manifest congenitally (for example in congenital stroma corneal dystrophy), or as late as the fourth decade of life (for example in lattice corneal dystrophy type II), although its onset is commonly during childhood (examples are macular, fleck and granular corneal dystrophy) . Visual impairment is manifested as mild to severely decreased visual acuity, due to the altered corneal composition as well as reduced focusing power, although some patients such as those with fleck corneal dystrophy (FCD) suffer no loss of acuity throughout the course of the disease.
Diagnosis is usually clinical, and combines the patient's history, such as age of onset and family history of corneal stromal dystrophy, with the observation of abnormal deposits on the cornea by a slit lamp examination. This is reinforced by molecular and biochemical analysis conducted on excised corneal tissue   . These tests include:
Genetic counseling with a focus on expected disease progression and management options may be provided to patients and their families. Although prenatal diagnosis via amniocentesis or biopsy is theoretically possible, it is not carried out as the condition is not lethal.