Diagnosis can be established on clinical grounds and this may be enhanced with studies on surgically excised corneal tissue and in some cases with molecular genetic analyses. As clinical manifestations widely vary with the different entities,<unk> es should be suspected when corneal transparency is lost or corneal opacities occur spontaneously, particularly in both corneas, and especially in the presence of a positive family history or in the offspring of consanguineous parents. Superficial<unk> es – Meesmann dystrophy is characterized by distinct tiny bubble-like, punctate opacities that form in the central corneal epithelium and to a lesser extent in the peripheral cornea of both eyes during infancy that persists throughout life. Symmetrical reticular opacities form in the superficial central cornea of both eyes at about 4–5 years of age in Reis-Bücklers<unk> . Patient remains asymptomatic until epithelial erosions precipitate acute episodes of ocular hyperemia, pain, and photophobia. Visual acuity eventually becomes reduced during the second and third decades of life following a progressive superficial haze and an irregular corneal surface. In Thiel–Behnke dystrophy, sub-epithelial corneal opacities form a honeycomb-shaped pattern in the superficial cornea. Multiple prominent gelatinous mulberry-shaped nodules form beneath the corneal epithelium during the first decade of life in gelatinous drop-like<unk>  which cause photophobia, tearing, corneal foreign body sensation and severe progressive loss of vision. Lisch epithelial<unk>  is characterized by feather shaped opacities and microcysts in the corneal epithelium that are arranged in a band-shaped and sometimes whorled pattern. Painless blurred vision sometimes begins after sixty years of life. Corneal stromal dystrophies – Macular<unk>  is manifested by a progressive dense cloudiness of the entire corneal stroma that usually first appears during adolescence and eventually causing severe visual impairment. In granular<unk>  multiple small white discrete irregular spots that resemble bread crumbs or snowflakes become apparent beneath Bowman zone in the superficial central corneal stroma. They initially appear within the first decade of life. Visual acuity is more or less normal. Lattice dystrophy starts as fine branching linear opacities in Bowman's layer in the central area and spreads to the periphery. Recurrent corneal erosions may occur. The hallmark of Schnyder<unk>  is the accumulation of crystals within the corneal stroma which cause corneal clouding typically in a ring-shaped fashion. Posterior<unk> es – Fuchs<unk>  presents during the fifth or sixth decade of life. The characteristic clinical findings are excrescences on a thickened Descemet membrane (cornea guttae), generalized corneal edema and decreased visual acuity. In advanced cases, abnormalities are found in all the layers of the cornea. In posterior polymorphous<unk>  small vesicles appear at the level of Descemet membrane. Most patients remain asymptomatic and corneal edema is usually absent. Congenital hereditary endothelial<unk>  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<unk> es. In the past, the designation vortex<unk>  (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<unk> es 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. and has classified disease into four groups as follows: Epithelial and subepithelial dystrophies * Epithelial basement membrane dystrophy * Epithelial recurrent erosion dystrophies (Franceschetti<unk> , Dystrophia Smolandiensis, and Dystrophia Helsinglandica) * Subepithelial mucinous<unk>  * Meesmann<unk>  * Lisch epithelial<unk>  * Gelatinous drop-like<unk>  Bowman Layer dystrophies * Reis–Bücklers<unk>  * Thiel–Behnke<unk>  * Stromal dystrophies- * TGFB1<unk> es * Lattice<unk> , type 1 variants (III, IIIA, I/IIIA, IV) of lattice<unk>  * Granular<unk> , type 1 * Granular<unk> , type 2 Stromal dystrophies * Macular<unk>  * Schnyder crystalline<unk>  * Congenital stromal<unk>  * Fleck<unk>  * Posterior amorphous<unk>  * Central cloudy dystrophy of François * Pre-Descemet<unk>  Endothelial dystrophies * Fuchs' dystrophy * Posterior polymorphous<unk>  * Congenital hereditary endothelial dystrophy * X-linked endothelial<unk>  The following (now historic) classification was by Klintworth: Superficial dystrophies: * Epithelial basement membrane dystrophy * Meesmann juvenile epithelial<unk>  * Gelatinous drop-like<unk>  * Lisch epithelial<unk>  * Subepithelial mucinous<unk>  * Reis-Bucklers<unk>  * Thiel–Behnke dystrophy Stromal dystrophies: * Lattice<unk>  * Granular<unk>  * Macular<unk>  * Schnyder crystalline<unk>  * Congenital stromal<unk>  * Fleck<unk>  Posterior dystrophies: * Fuchs' dystrophy * Posterior polymorphous<unk>  * Congenital hereditary endothelial dystrophy
Corneal dystrophy
Macular corneal dystrophy
Congenital cataract
Granular corneal dystrophy
Band keratopathy
Ocular melanosis
Bullous keratopathy
Fundic gland polyposis