[Etiopathogenesis of primary open-angle glaucoma]

[Assessment of environmental and genetic risk factors for the development of primary open-angle glaucoma]

Primary open-angle glaucoma (POAG) is a multifactorial disease with both environmental and genetic factors involved in its pathogenesis.

PURPOSE

The study evaluates the role of a number of environmental and genetic risk factors in the risk of POAG development and builds a prognostic model.

MATERIAL AND METHODS

The study group included 197 patients aged 44 to 90 years (98 - patients with POAG, 99 - the control group), who were treated in the Republican Clinical Ophthalmological Hospital of the Ministry of Health of the Republic of Tatarstan named after Prof. E.V. Adamyuk.

RESULTS

Age, family history of the disease, presence of type 2 diabetes mellitus, arterial hypertension were revealed to be associated with an increased risk of POAG development. The polymorphisms of matrix metalloproteinase MMP9 and vitamin D receptor (VDR) genes were shown to influence the development of POAG. The prognostic model considering these factors had high sensitivity and specificity (72.0% and 82.6% respectively).

CONCLUSION

The prognostic model based on environmental and genetic factors is important for assessing the risk of POAG and early detection of the disease.

[The effect of systemic antihypertensive drugs on the risk of primary open-angle glaucoma]

Primary open-angle glaucoma (POAG) is a common disease. Elevated blood pressure has been reported as a significant risk factor for the development and progression of POAG.

PURPOSE

The goal of the present study was to test the effect of systemic antihypertensive drugs on the risk of POAG using cis-Mendelian randomization (cis-MR) approach.

MATERIAL AND METHODS

The study involved summary statistics from genome-wide association studies (GWAS) for POAG (15229 cases and 177 473 controls) and from GWAS for systolic blood pressure meta-analysis (757 601 individuals). Drug targets for beta-blockers and for calcium channel blockers and genes coding these targets were identified via DrugBank. Genetic variants within the regions of these genes were selected for the Mendelian randomization analysis.

RESULTS

The effect of a 10-mm Hg decrease in systolic blood pressure caused by calcium channel blockers on the risk of POAG amounted to: odds ratio (OR) 0.90 (95% CI 0.63-1.30, p=0.59). For beta blockers the cis-MR estimated effect on the risk of POAG was OR=0.95 (95% CI 0.34-2.70, p=0.92).

CONCLUSION

The results of the present study do not confirm the hypothesis of causal effect of antihypertensive drugs intake on the risk of developing POAG.

[The effect of antioxidant therapy on some pathogenetic factors of primary open-angle glaucoma]

In patients with glaucoma, one of the main initiating mechanisms that triggers the chain of events is disruption of the universal mechanism for regulating vascular tone due to endothelial dysfunction (ED). The main manifestation of ED is an imbalance of vasoconstrictor and vasodilator endothelial mediators, which inconsistency triggers the mechanisms of adaptive distress leading to the progression of morphological destruction, dyslipidemia, acceleration of atherogenesis, development of hemodynamic and hydrodynamic disorders. The drug Mexidol has a wide range of pharmacological activity and affects the main pathogenetic links of primary open-angle glaucoma (POAG).

PURPOSE

The study analyzes the vascular remodulation, antioxidant and antihypoxic effects of the drug Mexidol in patients with PAOG.

MATERIAL AND METHODS

The study included 78 patients with POAG of the early (n=43) and advanced stage (n=35) with average age of 67.8±1.5 years. The main study group consisted of 47 patients who received Mexidol in addition to local hypotensive treatment; 31 patients comprised the control group. In the comparison groups, the degree of ED was determined by the results of reactive hyperemia test, patients' blood plasma was analyzed for levels of stable nitric oxide metabolite (nitrite NO2-) and endothelin-1 (ET-1). General assessment of oxidative stress was carried out by high-performance liquid chromatography. Functional activity of the retina was studied using an electroretinograph and static computer perimetry performed according to the standard technique.

RESULTS

The following changes are observed in patients of the main group using Mexidol: the index of oscillatory potentials significantly increases, peak latency decreases, perimeter indices show positive trends, vascular endothelial function improves according to reactive hyperemia test, concentration of vasoconstrictor mediator ET-1 in blood plasma decreases and of nitrite (NO2-) increases moderately, the coefficient of bioeffective vasotonic activity decreases, the level of glutathione peroxidase increases (p<0.05 compared to the baseline value), the level of malonyldialdehyde decreases, lipid metabolism improves (reduction in total cholesterol, low-density lipoprotein-cholesterol, triglycerides, decrease in the Atherogenic Index compared to the initial level).

CONCLUSIONS

The drug Mexidol proved to be an effective endothelial protector, a powerful antioxidant and antihypoxant, contributed to deceleration of atherogenesis in patients with POAG.

[Study of the functional significance of polymorphic loci of the LOXL1 gene associated with glaucoma according to genome-wide studies (in silico analysis)]

Glaucoma is one of the most common eye diseases leading to blindness, and whole-genome studies have shown that genetic factors are important in its formation.

Purpose - to perform an in silico analysis of the functional significance of polymorphic loci of the LOXL1 gene associated with glaucoma, using data from wholegenome studies.

MATERIAL AND METHODS

Using the catalog of genome-wide studies (GWAS) of the National Human Genome Research Institute (https://www.genome.gov/gwastudies/), three polymorphic loci of the LOXL1 gene (rs2165241, rs4886776, rs893818) associated with glaucoma (pseudoexfoliation glaucoma/syndrome) were chosen for the study. Using modern databases on functional genomics (SIFT, PolyPhen-2, HaploReg, GTExportal), the functional significance of these polymorphic loci was assessed (nonsynonymous substitutions, epigenetic effects, association with gene expression, associations with alternative splicing of gene transcripts).

RESULTS

The work establishes the important functional significance of the rs2165241, rs4886776 and rs893818 polymorphic loci of the LOXL1 gene. They demonstrate significant epigenetic effects (affect the affinity to five transcription factors, are located in the region of promoters and enhancers, in the region of hypersensitivity to DNase-1), are associated with the expression and alternative splicing of three genes (LOXL1, LOXL1-AS1, RP11-24D15.1) in cell cultures, organs and tissues pathogenetically significant for development of glaucoma, are strongly linked to the rs1048661 polymorphism, which causes the replacement of the Arg141Leu amino acid in the LOXL1 polypeptide.

CONCLUSION

Polymorphic loci of the LOXL1 gene (rs2165241, rs4886776, and rs893818) are of great functional importance (epigenetic, eQTL, and sQTL), which may be the biomedical basis of their associations with glaucoma.

[Classification, diagnosis and treatment of juvenile glaucoma]

Juvenile open-angle glaucoma is a disease with complex pathogenesis affecting young people of working age that can lead to disability. The article describes modern concepts of diagnosis, classification and approaches to the treatment of juvenile glaucoma with special attention paid to the differential diagnostic criteria of juvenile open-angle glaucoma and congenital glaucoma.