Vascular and vegetative factors of glaucoma attack

Purpose. To study the involvement of vascular and vegetative factors in the pathogenesis of glaucoma attack. Material and methods. 12 patients (24 eyes) aged 49 to 82 — 5 men and 7 women, including 3 patients with acute glaucoma and 9 patients with subacute glaucoma were subjected to an ophthalmological examination that included visometry, tonometry, automated static perimetry, OCT and OCT angiography. They were also tested for heart rate variability (HRV) using a Polar heart rate monitor, and for plasminogen content and products of fibrin/fibrinogen degradation in the tear. For comparison, the contralateral eyes of these patients were examined. Results. In the eyes with an acute glaucoma attack, the vascular network was noticeably weakened, especially in the area of the deep peripapillary vascular plexus at the lamina cribrosa level, and focal capillary loss was observed. The peripapillary density of the deep vascular plexus in the eyes with an acute attack was 33.0 ± 5.6 % (М ± m), which was significantly (p < 0.01) lower as compared to 50.0 ± 4.7 % in the unaffected eyes. This indicator correlated with the thickness of the ganglion cell complex (GCC) (p < 0.01). In unaffected eyes, no correlations were found between these glaucoma-related parameters. A significant amount of fibrin/fibrinogen degradation products was found in the tear of glaucoma patients, which may point to a violation of blood circulation in the optic nerve vessels. It has been established that glaucoma attack occurs with increased activity of sympathetic regulation of blood flow. Conclusion. When monitoring this contingent of patients, it is essential to determine the sympathetic-parasympathetic status of the patient. Taking into account the vascular component of the condition, it is expedient to introduce the necessary additions into its treatment plans

Time-related OCT-A changes in preclinical retinopathy and their association with systemic factors

Background. Optical coherence tomography angiography (OCT-A) is a promising tool for the detection of microvascular impairment at the preclinical stage of diabetic retinopathy (DR). Evaluation of dynamic OCT-A changes and their association with systemic factors can help to reveal early biomarkers of DR progression.Aim: to evaluate time-related OCT-A changes and their association with systemic factors in type 1 diabetes mellitus (DM1) patients with no apparent DRMaterials and methods. 38 DM1 patients with no apparent DR and 39 healthy volunteers were included in the study. All participants underwent 7-fi eld fundus photography, OCT and OCT-A. We analyzed OCT-A parameters (foveal avascular zone (FAZ) area (mm2), acircularity index (AI), vessel density (VD), skeletonized density (SD)) as well as the results of blood and urea tests.Results. After one year of observation, AI was significantly higher (р = 0.005) and VD0–300 was signifi cantly lower in superfi cial vascular plexus (SVP, p < 0.0001) and deep capillary plexus (DCP, р = 0.032) in DM1 patients. We have also registered a positive correlation between AI and triglycerides (TG) level (r = 0.627, p = 0.007) as well as a negative correlation between ketones and VD (SVP VD0–300: r = –0.695, p = 0.030; intermediate capillary plexus (ICP, VD0–300: r = –0.551, p = 0.041; DCP, VD0–300: r = –0.704, p = 0.003; SVP, VD300–600: r = –0.853, p = 0.001).Conclusions. After one year of observation, we have registered an increase in AI level and a decline in VD in SVP and DCP which can be the earliest signs of DR progression. A signifi cant correlation between these parameters and systemic factors indicates their role as potential DR biomarkers.

Pathogenetic Justification of a New View on the Treatment of Angle-Closure Glaucoma

Purpose. To study the effectiveness of vascular, anti-inflammatory and fibrinolytic therapy, to conduct a comparative assessment with treatment without vascular therapy in patients with angle-closure (ACG) and mixed glaucoma.Methods. A total of 55 patients with angle-closure and mixed glaucoma, mainly with hypermetropic refraction of varying degrees, were examined: 7 people with acute glaucoma attack, 6 people with subacute glaucoma attack (group 1, with anti-inflammatory treatment), 7 people with acute glaucoma attack and 6 people with subacute glaucoma attack (group 2, with vascular treatment), 14 people with chronic angle-closure glaucoma (group 3) and 15 people with mixed glaucoma (group 4). All patients underwent an ophthalmological examination, which included visometry, refractometry, tonometry, computer perimetry, OCT and OCT angiography, and an ELISA analysis to determine cytokines.Results. The administration of the drug Pentoxifylline as a cytokine blocker and antiplatelet agent in ACG contributed, in our opinion, to an improvement in visual acuity, perimetry (MD), an increase in the density of capillaries of the deep vascular plexus at the level of lamina cribrosa in the peripapillary zone (%), i.e. improved blood circulation in the vessels of the optic nerve disc and also contributed to the blockade of cytokines, mainly in the 2-nd group of patients. In our opinion, a personalized approach to the treatment of ACG is to maintain the improvement of blood circulation in the peripapillary zone by prescribing a course of treatment with Pentoxifylline for 6 months after surgery. After phacoemulsification, there was a significant increase in the density of capillaries of the deep peripapillary vascular plexus at the level of lamina cribrosa (p ≤ 0.05) (51.0 ± 3.5 %), and after further treatment with Pentoxifylline, the capillary density continued to increase in 2–4 groups in the next 6 months of follow-up. The thickness of RNFL (Retinal nerve fiber layer, structural parameter) decreased due to a decrease in edema in 1–2 groups, slightly increased in 3–4 groups, in our opinion, due to improved blood circulation. Increased reperfusion in the capillaries of the deep plexus during normalization of IOP in glaucoma patients and further treatment with pentoxifylline indicates the effectiveness of the proposed treatment in addition to surgical treatment. The results obtained emphasize the advantages of the proposed therapy for the treatment of patients with angle-closure and mixed glaucoma.Conclusion. To date, there are no clear recommendations of vascular therapy for the treatment of patients with ACG and mixed glaucoma, which creates the need for its addition to treatment regimens, taking into account the vascular component of ACG and mixed glaucoma.

Features of the extrapancreatic action of glibenclamide in cerebral ischemia in the highlands

The features of remodeling of the components of the vascular plexus and the microcirculatory bed of the brain in cerebral ischemia in the highlands are studied, the features of the action of glibenclamide on these structures are presented. It is shown that the sulfonylurea receptor 1 (SUR 1) in the highlands becomes more sensitive to glibenclamide than in the low mountains. Key words: brain, ischemia, glibenclamide, highlands.

Artificial Intelligence and OCT Angiography in Full Thickness Macular Hole. New Developments for Personalized Medicine

Purpose: To evaluate the 1-year visual acuity predictive performance of an artificial intelligence (AI) based model applied to optical coherence tomography angiography (OCT-A) vascular layers scans from eyes with a full-thickness macular hole (FTMH). Methods: In this observational cross-sectional, single-center study, 35 eyes of 35 patients with FTMH were analyzed by OCT-A before and 1-year after surgery. Superficial vascular plexus (SVP) and deep vascular plexus (DVP) images were collected for the analysis. AI approach based on convolutional neural networks (CNN) was used to generate a continuous predictive variable based on both SVP and DPV. Different pre-trained CNN networks were used for feature extraction and compared for predictive accuracy. Results: Among the different tested models, the inception V3 network, applied on the combination of deep and superficial OCT-A images, showed the most significant differences between the two obtained image clusters defined in C1 and C2 (best-corrected visual acuity [BCVA] C1 = 49.10 [±18.60 SD] and BCVA C2 = 66.67 [±16.00 SD, p = 0.005]). Conclusions: The AI-based analysis of preoperative OCT-A images of eyes affected by FTMH may be a useful support system in setting up visual acuity recovery prediction. The combination of preoperative SVP and DVP images showed a significant morphological predictive performance for visual acuity recovery.

Assessment of the microvasculature in poppers maculopathy

Purpose To investigate a possible microvascular component of poppers maculopathy (PMP) using optical coherence tomography angiography (OCTA). Methods Twelve patients suffering from poppers maculopathy were included. Health records, optical coherence tomography (OCT), and OCTA data was gathered and compared to a healthy control group (HC). PMP lesion type was determined by manifestation in OCT. OCTA-based evaluation of retinal vascular plexus and choriocapillaris (CC) was executed. Vessel density (VD) and vessel length density (VLD) in superficial and deep capillary plexus (SCP, DCP), as well as flow deficits (FD), within the foveal avascular zone (FAZ) in CC were assessed. Results Median age of PMP patients was 40 (min 24; max 64) years, all male. Eleven patients presented with ellipsoid zone-type lesions; one patient showed a vitelliform-type lesion. No qualitative microvascular changes between PMP patients and HC were identified. Quantitative values for VD and VLD of SCP and DCP did not differ in between the two groups. The analysis of FDs in CC showed no deviation from PMP patients to HC. Conclusions No vascular anomalies in qualitative and quantitative analysis in OCTA were detected in PMP patients. The constitution of the CC within FAZ of PMP patients does not differ from HC when assessed as FD.

Retinal Neurovascular Impairment in Non-diabetic and Non-dialytic Chronic Kidney Disease Patients

Background: Widespread neural and microvascular injuries are common in chronic kidney disease (CKD), increasing risks of neurovascular complications and mortality. Early detection of such changes helps assess the risks of neurovascular complications for CKD patients. As an extension of central nervous system, the retina provides a characteristic window to observe neurovascular alterations in CKD. This study aimed to determine the presence of retinal neurovascular impairment in different stages of CKD.Methods: One hundred fifteen non-diabetic and non-dialytic CKD patients of all stages and a control group of 35 healthy subjects were included. Retinal neural and microvascular parameters were obtained by optical coherence tomography angiography (OCTA) examination.Results: CKD 1–2 group (versus control group) had greater odds of having decreased retinal ganglion cell-inner plexiform layer thickness (GC-IPLt) (odds ratio [OR]: 0.92; 95% confidence interval [CI]: 0.86–0.98), increased ganglion cell complex-focal loss volume (GCC-FLV) (OR: 3.51; 95% CI: 1.27–9.67), and GCC-global loss volume (GCC-GLV) (OR: 2.48; 95% CI: 1.27–4.82). The presence of advanced stages of CKD (CKD 3–5 group versus CKD 1–2 group) had greater odds of having decreased retinal vessel density in superficial vascular plexus (SVP)-WholeImage (OR: 0.77, 95% CI: 0.63–0.92), SVP-ParaFovea (OR: 0.83, 95% CI: 0.71–0.97), SVP-ParaFovea (OR: 0.76, 95% CI: 0.63–0.91), deep vascular plexus (DVP)-WholeImage (OR: 0.89, 95% CI: 0.81–0.98), DVP-ParaFovea (OR: 0.88, 95% CI: 0.78–0.99), and DVP-PeriFovea (OR: 0.90, 95% CI: 0.83–0.98). Besides, stepwise multivariate linear regression among CKD patients showed that β2-microglobulin was negatively associated with GC-IPLt (β: –0.294; 95% CI: –0.469 ∼ –0.118), and parathyroid hormone was positively associated with increased GCC-FLV (β: 0.004; 95% CI: 0.002∼0.006) and GCC-GLV (β: 0.007; 95% CI: 0.004∼0.01). Urine protein to creatinine ratio was positively associated with increased GCC-FLV (β: 0.003; 95% CI: 0.001∼0.004) and GCC-GLV (β: 0.003; 95% CI: 0.001∼0.006).Conclusion: Retinal neuronal impairment is present in early stages of CKD (stages 1–2), and it is associated with accumulation of uremic toxins and higher UACR, while retinal microvascular hypoperfusion, which is associated with worse eGFR, was only observed in relatively advanced stages of CKD (stages 3–5). The results highlight the importance of monitoring retinal neurovascular impairment in different stages of CKD.

Optimal Hair Transplant Recipient Site Slit Design: Minimizing Vascular Damage

An often overlooked aspect of hair transplantation is the art of recipient site design and slit creation. There is also a lack of consensus on which technique provides the optimum coverage while minimizing vascular damage. This paper aims to provide logical arguments to determine the optimal instrument and method of slit creation, in order to ensure maximum density, optimal survival, minimal pop-out, and minimal damage to scalp vascularity.The use of semiconical blades reduces the damage to the dermis and vascular plexus as compared with rectangular blades and needles, as the depth of penetration required is lower. The use of acute angle reduces the depth of penetration for the same length of slit and decreases damage to deep plexus. Coronal slits produce less vascular damage than that of sagittal slits with the same size blades.We believe that these recommendations provide the optimum volume slits while causing minimal vascular damage.

OCT-Angiography Findings in Patients with Amblyopia: Comparison between Healthy Controls, Treatment-Responsive, and Treatment-Unresponsive Amblyopic Patients

There is no consensus on whether amblyopia affects the retinal vascular plexus and morphology. Previous studies focused on the differences between amblyopic patients and normal controls without evaluating amblyopic eyes after patching. To evaluate differences in the superficial vascular density of amblyopic eyes, normal eyes, and amblyopic eyes reaching normal BCVA after patch therapy, OCTA was used. All patients underwent a comprehensive ophthalmological examination, including visual acuity, refraction, ocular motility tests, and anterior and posterior segment examination. OCTA was performed by an expert physician using the Zeiss Cirrus 5000-HD-OCT Angioplex (Carl Zeiss, Meditec, Inc., Dublin, OH, USA). OCTA scans were performed using a 3 × 3 mm2 and 6 × 6 mm2 fovea-centered image setting. The mean outer macular vessel density in the previously amblyopic group was 19.15 ± 0.51%. This was statistically significantly higher than in both the amblyopic group (18.70 ± 1.14%) and the normal controls (18.18 ± 1.40%) (p = 0.014). The previously amblyopic group also significantly differed from both normal controls and amblyopic eyes with regards to the inner (p = 0.011), outer (p = 0.006), and full (p = 0.003) macular perfusion. Finally, linear regression analysis revealed that BCVA was linearly correlated to outer perfusion in amblyopic (p = 0.003) and ex amblyopic eyes (p < 0.001). Considering the cross-sectional nature of our study, from our results, we can only hypothesize a possible correlation between light stimulation and retinal vasculature development. However, further longitudinal studies are needed to support this hypothesis.