Corneal dystrophies encompass a group of genetically heterogeneous disorders of the cornea which are bilateral and symmetrical. The different phenotypes are classically divided based on the main corneal layer affected.

Fuchs corneal dystrophy is the most common form of corneal dystrophy. It is characterised by the presence of guttata on slit lamp examination. Progressive endothelial cell loss leads to corneal oedema which can be addressed with corneal transplant.

Posterior polymorphous corneal dystrophy is characterised by Descemet layer bands and endothelial cells vesicles. Some cases may decompensate leading to secondary corneal oedema.

Congenital hereditary endothelial dystrophy is characterised by bilateral diffuse corneal opacification that is present from birth.

Epithelial-stromal TGFBI-associated corneal dystrophy are a range of ocular phenotypes caused by autosomal dominant variants in the TGFBI gene. The phenotypes include Reis-Bucklers corneal dystrophy, Thiel-Behnke corneal dystrophy, lattice corneal dystrophy and granular corneal dystrophy.

Meesmann corneal dystrophy is an epithelial dystrophy characterised by clear intra-epithelial cysts in the central interpalpebral zone. It can cause recurrent corneal erosions if the cysts has broken through the corneal surface.

Gelatinous drop-like corneal dystrophy is characterised by progressive amyloid accumulation between the corneal epithelium and stroma.

Epithelial recurrent erosion dystrophy is caused by mutations in the COL17A1 gene. It initially causes frequent recurrent corneal erosions, but the frequency of flare-ups reduce over time, with progressive development of sub-epithelial opacities.

Schnyder corneal dystrophy is characterised by progressive corneal opacification due to abnormal deposition of cholesterol and phospholipids in the cornea.

Macular corneal dystrophy is characterised by a diffuse stromal haze initially, followed by central, sharply defined flecks at the pre-Descemet storm, extending to the limbus over time.