Amyloidosis corneal

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.

Orpha Number: 98957

Definition

Gelatinous drop-like corneal dystrophy (GDCD) is a form of superficial corneal dystrophy characterized by multiple prominent milky-white gelatinous nodules beneath the corneal epithelium, and marked visual impairment.

Epidemiology

Worldwide prevalence of this form of corneal dystrophy is not known. Cases have been reported in patients from India, Tunisia, Vietnam, Turkey, the USA and other countries, but most cases seem to be in Japan where prevalence is estimated to be 1/300,000.

Clinical description

Lesions generally develop in the first or second decade of life. The clinical features include severe photophobia, tearing, a corneal foreign body sensation and severe progressive loss of vision.

Etiology

Gelatinous drop-like corneal dystrophy is mostly caused by mutations in the TACSTD2 gene (1p32) encoding tumor-associated calcium signal transducer 2. More than 20 mutations have been reported but some patients have been found not to have a mutation in this gene, which suggests genetic heterogeneity.

Diagnostic methods

Fusiform deposits similar to those in lattice corneal dystrophy (LCD, see this term) in the deeper stroma may be found by light microscopy.

Genetic counseling

An autosomal recessive pattern of inheritance has been reported.

Management and treatment

An unsatisfactory response has been observed to both lamellar keratoplasty (LKP) and penetrating keratoplasty (PK), as well as to a superficial keratectomy, since amyloid recurs in the graft within about 5 years.

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