Cross-Sectional Study of the Prevalence of TGFBI Corneal Dystrophies

It is well established in the peer-reviewed literature that elective keratorefractive surgery is contraindicated in individuals with granular corneal dystrophy type 2 (GCD2).1,2,3,4 Although all reported cases of exacerbation of dystrophic stromal deposits have been in individuals with GCD2, it may be assumed that a similar accelerated deposition would occur in individuals with any of the TGFBI dystrophies, and thus elective keratorefractive surgery should be avoided in any individual with a TGFBI dystrophy. The commercially available Avellino Refractive Surgery Safety Test (Avellino Universal Test) offers an accurate, rapid and affordable way to screen for five corneal dystrophies associated with mutations in the TGFBI gene prior to keratorefractive surgery. These dystrophies are granular dystrophy type 1 (GCD1), GCD2, lattice corneal dystrophy type 1 (LCD1), Reis-Buckler corneal dystrophy, and Thiel- Behnke corneal dystrophy.

This is a multicenter, cross-sectional, observational study of the prevalence of TGFBI corneal dystrophies in a North American population. Patients presenting to the clinical site for an ocular examination with a refractive complaint (non-medical complaint) or for refractive surgery consultation will be asked to participate in this study. Prior to the collection of any study data, Informed Consent will be obtained.

A a serial number / bar code controlled case report form (CRF) single nucleotide variants implicated in the pathogenesis of the TGFBI corneal dystrophies. The CRF will be used to collect demographic information from the patient. Slit lamp examination of the corneas will be performed, and the presence or absence of corneal opacities, whether characteristic or not of a TGFBI dystrophy, will be documented on the CRF form.

Once all data has been collected, descriptive statistics will be computed to identify the prevalence of each of the TGFBI corneal dystrophies as defined by the genotype. Demographic data will be compared between unaffected individuals and those identified to have a coding region mutation associated with one of the five aforementioned TGFBI corneal dystrophies.