[Structural and functional changes in the retinal layers in patients with primary glaucoma and possible means of retinoprotection]

[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.

[Ocular iontophoresis]

Iontophoresis in medicine is a combined pharmacological and physical method of treatment that unites the therapeutic effect of an electric current with the pharmacological effect of medicinal substances administered at the same time via an electric current. The article describes the physical basis of the therapeutic effect of direct electric current on biological tissues, and highlights the physical and chemical mechanisms of target administration of pharmaceutical substances into the human body through intact skin or mucous membrane by means of direct electric current. In addition, it presents the results of international as well as Russian domestic scientific studies on the clinical effectiveness of iontophoresis in ophthalmology.

[Effect of retinal protective therapy on optical coherence tomography angiography (pilot study)]

PURPOSE

To assess the influence of the frequency of retinal protective therapy courses on the indicators of regional hemodynamics of the eye.

MATERIAL AND METHODS

The study included 17 patients (34 eyes) with a diagnosis of primary open-angle glaucoma (POAG), advanced stage. The patients were divided into 2 groups: the first group received a course of retinal protective therapy with Retinalamin every 3 months, the second group received a course of retinal protective therapy with Retinalamin every 6 months. All patients underwent standard ophthalmological examination including standard automatic perimetry according to the 24-2 program, optical coherence tomography angiography (OCT-A) of the macular area and optic disc.

RESULTS

The comparison of hemodynamic parameters of all vascular plexuses of the retina at the beginning and at the end of the study, as well as intergroup comparison did not reveal any statistically significant differences (p>0.05). However, when studying the density and fractal dimension of the vascular bed, multidirectional trends were observed. Specifically, in the peripapillary region, there was a decrease in the length from 19.8 (1/mm) to 19.0 (1/mm) (p=0.37) and the density from 36.6% to 35.7% (p=0.63) of the vascular bed of the peripapillary capillary plexus of the retina in patients of the first group. In the superficial vascular plexus, the trend in the density of the vascular bed in both groups slightly changed (in group 1 - 38.1% and 38.3%, p=0.97; group 2 - 37.8% and 38.7%, p=0.46). The fractal dimension of the vascular bed in the first group tended to increase during treatment from 18.8 (1/mm) to 19.1 (1/mm) (p=0.5), while in the second group, on the contrary, it had tendency to decrease from 18.6 (1/mm) to 17.9 (1/mm) (p=0.63). In the deep vascular plexus, the density of the vascular bed trended to decrease in both groups, but in group 2 (42.5% and 42.4%, p=1.0) it was more pronounced than in the first group (42.5% and 42.6%, p=0.82). However, the fractal dimension of the vascular bed increased in group 1 (21.0 (1/mm) and 21.3 (1/mm), p=0.43) and showed a slight tendency to decrease in group 2 (21.5 (1/mm) and 21.0 (1/mm), p=0.86).

CONCLUSION

The general trend of changes in hemodynamic parameters demonstrates a potential positive effect, especially in the data related to the deep vascular plexus.

[The effect of preservative-free treatment of primary open-angle glaucoma on the state of ocular surface in combination therapy (intermediate results)]

The goal of antihypertensive therapy is to reduce intraocular pressure (IOP). Sometimes it can only be achieved by using two or more drugs, which can lead to undesirable side effects on the ocular surface. The use of drugs that do not contain preservatives leads to fewer undesirable side effects, while also reducing the need for instillations of artificial tears, making it economically beneficial for patients.

PURPOSE

To assess the state of ocular surface in patients with POAG when switching to preservative-free carbonic anhydrase inhibitor (ICA) containing 0.18% sodium hyaluronate in combination with prostaglandin analogues and beta-adrenergic blocking agents.

MATERIAL AND METHODS

The study was conducted in 2019; according to selection criteria, it included 46 patients (80 eyes) with POAG and a control group of healthy persons. At the start of the study and one month later, after a change of treatment to uninterrupted ICA containing 0.18% sodium hyaluronate, the patients had state of their ocular surface examined: Norn's test (tear break-up time; TBUT), Schirmer's test, vital staining with lissamine green and an Ocular Surface Disease Index (OSDI) survey.

RESULTS

Replacing the ICA with benzalkonium chloride in the combination therapy of glaucoma with a preservative-free ICA containing 0.18% sodium hyaluronate - Dorzolan Solo (Solopharm, Russia) - expectedly did not lead to additional decrease of IOP, but resulted in a decrease in the width of the confidence interval according to both Maklakov's and Icare tonometers, which may be associated with increased treatment adherence. At the same time, the state of ocular surface in the observation group was statistically significantly improved according to Norn's test - from 3.57±1.3; 3.0 (3.0; 5.0) to 4.9±2.5; 5.0 (3.0; 6.0) (V=16.5; p=0.0039).

CONCLUSION

According to Schirmer's test and vital staining with lissamine green, no statistically significant changes have occurred. OSDI survey did not reveal changes in the study patients during 4 weeks of the follow-up, while the control group exhibited improvement.