Posterior Corneal Steepening in Posterior Polymorphous Corneal Dystrophy.

PURPOSE: The aim was to evaluate the anterior and posterior corneal topographic characteristics of three patients with posterior polymorphous corneal dystrophy (PPCD) using a rotating Scheimpflug camera combined with a Placido disc system (Sirius, CSO, Italy). CASE REPORTS: Two children with unilateral PPCD and a 53-year-old woman with bilateral PPCD were diagnosed by the presence of vesicles and railroad track lesions at the level of the Descemet membrane with slitlamp biomicroscopy and in vivo confocal microscopy. Anisometropic and/or meridional amblyopia was detected in both children. In the 16-year-old child, there was unilateral anterior corneal steepening with high astigmatism (plano -7.00 x 170) in the eye with PPCD. The 5-year-old boy had unilateral axial myopia and against-the-rule corneal astigmatism (-12.00 -2.00 x 90). Corneal topography of the woman revealed with-the-rule astigmatism and thin corneas (464 µm OD and 445 µm OS) in both eyes. Posterior corneal steepening greater than 25 µm either in a vertical or in a horizontal pattern changing with the orientation of the railroad track band lesions was detected in all subjects. CONCLUSIONS: Besides anterior corneal changes, PPCD seems to cause posterior corneal elevation, which necessitates corneal tomographic evaluation. In unilateral or highly asymmetric cases, children with PPCD should be screened for amblyopia.

Investigation of TGFBI (transforming growth factor beta-induced) Gene Mutations in Families with Granular Corneal Dystrophy Type 1 in the Konya Region.

Objectives: Granular corneal dystrophies (GCD) are characterized by small, discrete, sharp-edged, grayish-white opacities in the corneal stroma. Among the genes responsible for the development of GCD, the most strongly related gene is transforming growth factor beta-induced (TGFBI), located in the 5q31.1 locus. Studies show that R124H in exon 4 and R555W in exon 12 are hot-spot mutations in the TGFBI gene that lead to GCD development. In this study, we aimed to investigate these two hot-spot mutations in exons 4 and 12 of the TGFBI gene and other possible mutations in the same regions, which code important functional regions of the protein, in Turkish families with GCD and to determine the relationship between the mutations and disease and related phenotypes. Materials and Methods: The study included 16 individuals diagnosed with GCD type 1 (GCD1), 11 of these patients' healthy relatives, and 28 unrelated healthy individuals. DNA was obtained from peripheral blood samples taken from each individual and polymerase chain reaction was used to amplify target gene regions. Genotyping studies were done by sequence analysis. Results: The R124S mutation in exon 4 of TGFBI was not detected in the patients or healthy individuals in our study. However, all individuals diagnosed as having GCD1 were found to be heterozygous carriers of the R555W mutation in exon 12 of TGFBI. This mutation was not detected in healthy family members or control individuals unrelated to these families. In addition, we detected the silent mutation F540F in exon 12 and c.32924 G>A substitution in an intronic region of the gene in a few patients and healthy individuals. Conclusion: Our study strongly supports the association of GCD1 with R555W mutation in exon 12 region of the TGFBI gene, as reported in the literature.