Prevalence of transforming growth factor β-induced gene corneal dystrophies in Chinese refractive surgery candidates

Abstract

Purpose: To determine the prevalence of the transforming growth factor (TGF) β-induced gene corneal dystrophies in refractive surgery candidates in China.

Setting: Five hospitals in China.

Design: Prospective case series.

Method: Refractive surgical candidates from 5 preselected eye hospitals/centers in China were recruited after providing informed consent. All patients had slitlamp biomicroscopy and collection of a buccal swab as a source of DNA for screening of the TGF β-induced gene for the 5 most common mutations associated with Reis-Bückler corneal dystrophy, Thiel-Behnke corneal dystrophy, granular corneal dystrophy type 1, granular corneal dystrophy type 2, and lattice corneal dystrophy type 1.

Results: Of the 2068 refractive surgery candidates analyzed, 4 had corneal opacities in both eyes on slitlamp examination. Screening for the TGF β-induced gene found the heterozygous p.R124H mutation associated with granular corneal dystrophy type 2 in each of the 4 individuals with corneal opacities as well as in a fifth individual who did not have any corneal opacities, for a prevalence of 0.24%. Exacerbation of dystrophic corneal deposition developed after laser refractive surgery in 2 individuals who did not have preoperative TGF β-induced gene screening.

Conclusions: The prevalence of the TGF β-induced gene corneal dystrophies in Chinese refractive surgery candidates was estimated to be approximately 0.24%. Genetic testing is recommended to identify and exclude from candidacy all individuals with a TGF β-induced gene dystrophy before elective keratorefractive surgery to avoid causing accelerated postoperative dystrophic deposition.