Most patients remain asymptomatic and corneal edema is usually absent. Congenital hereditary endothelial corneal dystrophy is characterized by a diffuse ground-glass appearance of both corneas and markedly thickened (2–3 times thicker than normal) corneas from birth or infancy. Differential diagnosis
Main differential diagnosis include various causes of monoclonal gammopathy, lecithin-cholesterol-acyltransferase deficiency, Fabry disease, cystinosis, tyrosine transaminase deficiency, systemic lysosomal storage diseases, and several skin diseases (X-linked ichthyosis, keratosis follicularis spinolosa decalvans). Historically, an accumulation of small gray variable shaped punctate opacities of variable shape in the central deep corneal stroma immediately anterior to Descemet membrane were designated deep filiform dystrophy and cornea farinata because of their resemblance to commas, circles, lines, threads (filiform), flour (farina) or dots. These abnormalities are now known to accompany X-linked ichthyosis, steroid sulfatase deficiency, caused by steroid sulfatase gene mutations and are currently usually not included under the rubric of the corneal dystrophies.In the past, the designation vortex corneal dystrophy (corneal verticillata) was applied to a corneal disorder characterized by the presence of innumerable tiny brown spots arranged in curved whirlpool-like lines in the superficial cornea. An autosomal dominant mode of transmission was initially suspected, but later it was realized that these individuals were affected hemizygous males and asymptomatic female carriers of an X-linked systemic metabolic disease caused by a deficiency of α-galactosidase, known as Fabry disease. Classification
Corneal dystrophies were commonly subdivided depending on its specific location within the cornea into anterior, stromal, or posterior according to the layer of the cornea affected by the dystrophy.In 2015 the ICD3 classification was published.
Superficial corneal dystrophies do not need a penetrating keratoplasty as the deeper corneal tissue is unaffected, therefore a lamellar keratoplasty may be used instead.Phototherapeutic keratectomy (PTK) can be used to excise or ablate the abnormal corneal tissue. Patients with superficial corneal opacities are suitable candidates for this procedure. See also
Recurrent corneal erosion
Keratoconus
Keratoglobus
Corneal dystrophies in dogs
Dyskeratosis corneal and photophobia in XLPDR


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