Lattice Corneal Dystrophy Type I

Type I lattice corneal dystrophy (LCDI) is a frequent form of stromal corneal dystrophy (see this term) characterized by a network of delicate interdigitating branching filamentous opacities within the cornea with progressive visual impairment and no systemic manifestations.

Epidemiology

Prevalence of this form of corneal dystrophy is unknown. It is one of the more common forms in Western countries but has been reported worldwide.

Clinical description

Lesions mostly develop bilaterally towards the end of the 1st decade of life, but may develop in middle age, or rarely in infancy. LCDI is slowly progressive and usually results in substantial discomfort and visual impairment before the 6th decade. Corneal sensation is often diminished.

Etiology

Most cases of LCDI are caused by mutations in the multifunctional TGFBI gene (5q31).

Diagnostic methods

The interwoven linear opaque filaments have some resemblance to nerves, but may not be observed in all affected members of families with the condition. Recurrent corneal erosions may precede the corneal opacities and even appear in individuals lacking recognizable stromal disease. Amyloid deposits are found throughout the corneal stroma. Linear and other shaped opaque areas accumulate particularly within the central corneal stroma, while the peripheral cornea remains relatively transparent.

Genetic counseling

An autosomal dominant pattern of inheritance has been reported.

Management and treatment

A corneal graft may be necessary by 20 years of age, but is usually not indicated until after the 4th decade. The outcome of penetrating keratoplasty (PK) is excellent, but amyloid may deposit in the grafted donor tissue after 2 to 14 years.