Retinal venous pressure in chronic smokers.

BACKGROUND: The overall aim of this study was to determine retinal venous pressure (RVP) in healthy chronic smokers and compare values to those of healthy non-smokers. METHODS: Both eyes of 25 healthy chronic smokers and 41 healthy non-smokers were included. Measurements of RVP were performed by means of contact lens ophthalmodynamometry. Ophthalmodynamometry is done by applying increasing force on the eye via a contact lens. If a spontaneous venous pulsation was present, it was noted. If not, the compressive force was increased until the first venous pulsation was detected, and the measurement value was fixed and read. RVP was calculated as the sum of pressure increase induced by the instrument and intraocular pressure. RESULTS: Smokers had a significantly higher frequency of spontaneous venous pulsations than non-smokers (p < 0.001). Mean values of RVP were slightly lower in smokers than in non-smokers: 15.3 and 15.5 (smokers) versus 15.9 and 16.2 (non-smokers) for the right and left eye, respectively; however, the difference in RVP between the two groups did not reach significance. There was no significant difference in blood pressure between the two groups, but heart rate was significantly higher in smokers (p = 0.043). CONCLUSIONS: RVP values may differ in healthy smokers than in non-smokers. Therefore, smoking habits should be considered when interpreting RVP results.

Exclusion of TACSTD2 in an Iranian GDLD pedigree.

PURPOSE: To perform a mutation screen of TACSTD2 in an Iranian Gelatinous Drop-like Corneal Dystrophy (GDLD) pedigree. METHODS: In addition to the coding region of TACSTD2, for the first time the promoter, the entire 5'-noncoding region, and the entire 3'-untranslated region of the gene were sequenced from an affected member of the pedigree. Phenotypic features of affected individuals were assessed. RESULTS: The proband carried six sequence variations in TACSTD2. One of the variations was homozygous and caused a synonymous codon change. The remaining five were heterozygous variations in the 3'-untranslated region. None of the variations were assessed to be associated with GDLD. Fibroblastic scars were evident in in corneal histology sections of two affected members of the pedigree. CONCLUSIONS: It is concluded that GDLD in the pedigree is probably not caused by mutations in TACSTD2, supporting evidence for the existence of at least one other locus for GDLD. Phenotypic features of the Iranian patients, including the existence of fibroblastic scars in the corneas, were similar to those of a previously reported GDLD patient without TACSTD2 mutations. This suggests the disease in these individuals may be due to mutations in the same gene.

Four mutations (three novel, one founder) in TACSTD2 among Iranian GDLD patients.

PURPOSE: To perform a mutation screening of TACSTD2 in 13 Iranian Gelatinous Drop-like Corneal Dystrophy (GDLD) pedigrees. To assess genotype-phenotype correlations. To determine intragenic SNP haplotypes associated with the mutations, so as to gain information on their origin. METHODS: The coding region of TACSTD2 was sequenced in the probands of 13 unrelated Iranian GDLD pedigrees. Variations were assessed in other available affected and unaffected family members and in unrelated normal control subjects by restriction fragment length polymorphism (RFLP). The variations were classified as being associated with disease if they segregated with the disease phenotype in the families, were not observed in 100 control individuals, disrupted protein expression, or affected conserved positions in the coded protein. Three intragenic single-nucleotide polymorphisms (SNPs) were used to define haplotypes associated with putative disease-causing mutations. RESULTS: The probands were each homozygous for one of four putative disease-causing variations observed in TACSTD2: C66X, F114C, L186P, and E227K. Three of these are novel. E227K was found in 10 of the Iranian patients. There were some phenotypic differences among different patients carrying this mutation-for example, with respect to age at onset. Genotyping of intragenic SNPs identified four haplotypes. C66X, F114C, and L186P were each associated with a haplotype common among control chromosomes, whereas all E227K alleles were associated with a haplotype not found among the control chromosomes. CONCLUSIONS: Although mutations in TACSTD2 among Iranian patients with GDLD were heterogeneous, E227K was found to be a common mutation. It is suggested that E227K may be a founder mutation in this population. Based on positions of known mutations in TACSTD2, significance of the thyroglobulin domain of the TACSTD2 protein in the pathogenesis of GDLD is suggested.