Reis-Bücklers Corneal Dystrophy

Reis-Bücklers corneal dystrophy (RBCD), also known as granular corneal dystrophy type III, is a rare form of superficial corneal dystrophy characterized by bilateral symmetrical reticular opacities in the superficial central cornea, with progressive visual impairment.

Epidemiology

Prevalence of this form of corneal dystrophy is not known.

Clinical description

Lesions develop at about 4 to 5 years of age. The opacities assume an irregular ring-shaped pattern of discrete spots and lines that focally elevate the corneal epithelium. RBCD 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 development of an irregular corneal surface. Compared to other variants of granular corneal dystrophy, RBCD involves earlier onset of symptoms and a higher frequency of recurrent erosions.

Etiology

Reis-Bücklers corneal dystrophy is caused by a specific mutation in the TGFBI gene (5q31).

Diagnostic methods

The superficial corneal stroma contains deposits of mutated transforming growth factor beta-induced protein that are indistinguishable from those of other forms of granular corneal dystrophies.

Differential diagnosis

RBCD is clinically similar to Thiel-Behnke corneal dystrophy (TBCD, see this term), but generally has a more severe course. Tissue examination or molecular genetic analysis can be used to differentiate RBCD and TBCD.

Genetic counseling

An autosomal dominant pattern of inheritance has been reported.

Management and treatment

In advanced cases of RBCD, a superficial keratectomy, phototherapeutic keratectomy (PTK) or lamellar keratoplasty (LKP) may improve vision, but a penetrating keratoplasty (PK) is rarely necessary because the pathologic changes only involve the superficial cornea.