Association of WDR36 polymorphisms with primary open angle glaucoma: A systematic review and meta-analysis.

BACKGROUND: The association of the WDR36 gene with glaucoma has been controversial in the literature. We therefore conducted a systematic review and meta-analysis to assess the association of all reported common polymorphisms in WDR36 with primary open angle glaucoma (POAG) and its subtypes: high tension glaucoma (HTG) and normal tension glaucoma (NTG). METHODS: Publications in PUBMED and EMBASE databases up to March 9, 2016 were searched for case-control association studies of WDR36 with POAG, HTG, and/or NTG. Reported studies giving adequate genotype and/or allele information were included. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) of individual polymorphisms were estimated using the allelic model. RESULTS: Our literature search yielded 122 records, among which 5 studies were eligible for meta-analysis, involving a total of 1352 POAG patients and 894 controls. Five WDR36 polymorphisms were meta-analyzed, rs11241095, rs10038177, rs17553936, rs13186912, and rs13153937. However, none of them was significantly associated with POAG, HTG, or NTG. The most-investigated polymorphisms, rs11241095 and rs10038177, had a pooled-OR of 1.09 (95% CI: 0.94-1.28, P = .25, I = 0) and 0.99 (95% CI: 0.71-1.39, P = .97, I = 77%), respectively, for POAG. CONCLUSION: The existing data in the literature do not support a significant role of WDR36 in the genetic susceptibility of POAG or its subtypes. Further replication studies in specific populations are warranted.

Decreased Circulating Levels of Dickkopf-1 in Patients with Exudative Age-related Macular Degeneration.

Aberrant activation of the Wnt/ß-catenin signaling pathway plays a pathogenic role in retinal inflammation and neovascularization. Here, we investigated whether circulating levels of Dickkopf-1 (DKK-1), a specific inhibitor of this pathway, are altered in patients with exudative age-related macular degeneration (AMD). Plasma was obtained from 128 patients with exudative AMD, 46 patients with atrophic AMD and 111 healthy controls. DKK-1 levels in plasma were measured using ELISA, and data analyzed with one-way ANOVA, logistic regression analysis and receiver-operating characteristic analysis (ROC). We found that DKK-1 levels were decreased in exudative AMD patients, compared with healthy controls (P < 0.001) and atrophic AMD patients (P < 0.001). The decrease was more prominent in patients with classic choroidal neovascularization (CNV) than those with occult CNV (P < 0.001). The odds ratio (OR) of exudative AMD was 11.71 (95% CI; 5.24-6.13) for lowest versus upper quartile of DKK-1 levels. For discriminating exudative AMD patients, the optimum diagnostic cutoff of DKK-1 was 583.1 pg/mL with the area under curve (AUC) 0.76 (95% CI, 0.70-0.82; P < 0.001), sensitivity 78.1% and specificity 63.1%. These findings suggested that decreased circulating DKK-1 levels are associated with the development and severity of exudative AMD, and have potential to become a biomarker for exudative AMD.