ASSOCIATION STUDY BETWEEN POLYMORPHISMS OF THE p53 AND LYMPHOTOXIN ALPHA (LTA) GENES AND THE RISK OF PROLIFERATIVE VITREORETINOPATHY/RETINAL DETACHMENT IN A MEXICAN POPULATION.

PURPOSE: To report the results of an association study between single-nucleotide polymorphisms of the p53 and LTA genes and the risk of proliferative vitreoretinopathy (PVR)/retinal detachment (RD) in a Mexican cohort. METHODS: A total of 380 unrelated subjects were studied, including 98 patients with primary rhegmatogenous RD without PVR, 82 patients with PVR after RD surgery, and 200 healthy, ethnically matched subjects. Genotyping of single-nucleotide polymorphisms rs1042522 (p53 gene) and rs2229094 (LTA gene) was performed by direct nucleotide sequencing. Allele frequencies, genotype frequencies, and Hardy-Weinberg equilibrium were assessed with HaploView software. RESULTS: No significant differences in the allelic distributions of the previously identified risk C allele for LTA rs2229094 were observed between RD subjects and controls (odds ratio [95% confidence interval] = 0.8 [0.5-1.2]; P = 0.3). Conversely, the C allele for rs1042522 in p53 was positively associated with an increased risk for RD (odds ratio [95% confidence interval] = 1.4 [1.01-1.9]; P = 0.04). No significant differences were observed when the subgroup of 82 RD + PVR subjects was compared with the subgroup of 98 patients with RD. CONCLUSION: The C allele for rs1042522 in p53 was genetically associated with a higher risk for RD but not for PVR in this cohort. This is the first association study attempting replication of PVR-associated risk alleles in a nonwhite population.

Orbital Emphysema as a Rare Complication of Retina Surgery.

Three patients with a history of previous pars-plana vitrectomy, 2 of them with perfluoropropane, and 1 with sulfur hexafluoride used, experienced eyelid swelling and pain after travelling to a higher altitude city. Gas was found in the orbit and periocular tissues, causing orbital compartment syndrome in 2 of the patients. The gas persisted on these patients despite surgical intervention, so hyperbaric oxygen therapy was advised. One patient refused, the other patient responded well to this therapy and the gas disappeared. The patient without an orbital compartment syndrome made a full recovery without needing medical or surgical intervention.

Genome-wide mRNA analysis reveals a TUBD1 isoform profile as a potential biomarker for diabetic retinopathy development.

Diabetic retinopathy (DR) affects approximately one third of all diabetic subjects and is the leading cause of blindness in young to middle-aged adults in the developed world. While early diagnosis is crucial for preventing DR-associated visual loss, the identification of accessible biomarkers that could lead to presymptomatic recognition of the disease is of great clinical importance. The aim of this work was to investigate the possible involvement of alternative splicing events in DR development by performing a genome-wide transcriptional profiling comparing blood-derived RNA from DR subjects and from diabetic-non DR controls. A total of 95 RNA samples, 67 from patients with bilateral DR and 28 from diabetic patients without DR after a period of at least 10 years with type 2 DM, were compared in a genome-wide transcriptome analysis using the GeneChip® Human Gene 2.0 ST Array which contains probe sets covering all exons of ∼33,500 coding transcripts of annotated genes. Microarray data analysis followed by RT-PCR and cDNA sequencing identified important differential splicing events in TUBD1 (Tubulin, Delta-1) isoforms between DR and DM samples. Specifically, the co-expression of particular TUBD1 isoforms was significantly associated with NPDR risk (p = 0.039 by Pearson's chi-squared test; OR (CI 95%): 8.1 (1.0-72.7)). Analysis of TUBD1 signal pathways and regulating networks using a MetaCore platform showed that HIF-1, a molecule playing an important role in the pathogenesis of DR, is a direct regulator of TUBD1 expression. In conjunction, our data suggest that TUBD1 mRNA isoform expression profile in peripheral blood could be an accessible biomarker for predicting the risk for diabetic retinopathy development.

Susceptibility to advanced age-related macular degeneration and alleles of complement factor H, complement factor B, complement component 2, complement component 3, and age-related maculopathy susceptibility 2 genes in a Mexican population.

PURPOSE: To investigate the association of age-related macular degeneration (AMD)-high risk alleles of the complement factor H (CFH), complement factor B (CFB), complement component 2 (C2), complement component 3 (C3), and age-related maculopathy susceptibility 2 (ARMS2) genes in a Mexican population for the first time. METHODS: Genotyping was performed for the Y402H variant of CFH, for the L9H, R32Q, and K565E variants of CFB, the E318D variant of C2, the A69S variant of ARMS2, and the R102G variant of C3 in 159 Mexican mestizo patients at advanced stages of AMD, i.e., CARMS (Clinical Age-Related Maculopathy Staging System) grade 4 or 5. The frequency of these variants was also investigated in a group of 152 control subjects without AMD. Genomic DNA was extracted from blood leukocytes, and genotyping was performed using PCR followed by direct sequencing. Allele-specific restriction enzyme digestion was used to detect the R102G polymorphism in C3. RESULTS: There were significant differences in the allelic distribution between the two groups for CFH Y402H (p=1×10(-5)), ARMS A69S (p=4×10(-7)), and CFB R32Q (p=0.01). The odds ratios (95% confidence interval) obtained for the risk alleles of these three variants were 3.8 (2.4-5.9), 3.04 (2.2-4.3), and 2.5 (1.1-5.7), respectively. Haplotype analysis including the two most significantly associated alleles (CFH Y402H and ARMS A69S) indicated that the C-T combination conferred an odds ratio (95% confidence interval) of 6.9 (3.2-14.8). The exposed attributable risk for this particular haplotype was 85.5%. CONCLUSIONS: This is the first case-control investigation of AMD-high risk alleles in a Latino population. Our results support that CFH, ARMS2, and CFB AMD-risk alleles are consistently associated with the disease, even in ethnic groups with a complex admixture of ancestral populations such as Mexican mestizos.