RTVue XR Avanti Research Articles

Correlation between optical coherence tomography angiography measured vessel density and retinal nerve fiber layer thickness in moderate primary open angle glaucoma cases and normal controls

: Aim of this study was to establish a correlation between findings obtained from Optical Coherence Tomography Angiography (OCT-A) and Retinal Nerve Fiber Layer (RNFL) thickness measurements in a series of moderate Primary Open Angle Glaucoma (POAG) cases and normal controls. In this observational cross-sectional study a total of 100 eyes were included, comprising 50 eyes with glaucoma and 50 control eyes without glaucoma. All participants underwent comprehensive anterior and posterior segment evaluations, intraocular pressure (IOP) measurement using Goldmann applanation tonometer, gonioscopy, visual field testing, and OCT imaging, which included OCT-A. The OCT-A imaging was performed using the RTvue XR Avanti by Optovue. Two types of analysis were conducted: a comparative analysis between the normal and glaucomatous groups using an unpaired t-test to assess differences in RNFL thickness and vessel density values, and a correlation analysis within each group to examine the strength of correlation between RNFL loss and reduction in vascular density. The results showed a significant reduction in vessel density index in all quadrants of glaucomatous eyes compared to normal eyes. Moreover, this reduced vessel density was found to be significantly correlated with the reduction in RNFL thickness in glaucoma patients. Specifically, the uperior and inferior quadrants exhibited the strongest correlation with each other. The severity of vascular compromise demonstrated a significant correlation with the extent of retinal nerve fiber loss in patients with glaucoma. OCT-A can serve as a valuable adjunct in the diagnosis of glaucoma and monitoring its progression.

Smartphone Augmented En-Face Guided Epiretinal Membrane Peeling: A 3D Ngenuity Tool For Customized Treatment.

We aimed to introduce a novel visualization technique of en-face scans during epiretinal membrane (ERM) peeling, by using the in-built picture-in-picture (PIP) modality of the Alcon Ngenuity 3D System, connected to a smartphone. Prospective mono-centric interventional analysis on 20 patients undergoing vitrectomy and peeling for idiopathic ERMs. RTVue XR Avanti device was used perform a 6 × 6 mm optical coherence tomography angiography (OCTA). En-face image from a custom slab from 9 μm upon the internal limiting membrane (ILM) to 30 μm below the ILM was taken and 180° flipped. The smartphone was connected to the Alcon 3D Ngenuity display using an HDMI-to-USB cable and the picture-in-picture modality of the display was chosen in the software menu. ERM peeling was performed without dye stain starting from black linear structures on the en-face, indicating area of weaker adhesion to the ERM and could be used as cleavage point for membrane removal using vitreal forceps. We reported successful peeling initiation and flap lift at the first forceps' grasp in all cases (100%). After ERM peeling, dual blue staining highlighted ILM remnants in 15 cases (75%) and peeling was completed. Total surgical time, including cable connections and projection to the display, was 41.6±9.2 minutes. Intraoperative total peeling time was 11.1±2.6 minutes. Central macular thickness significantly reduced 1 month after surgery (p=0.01). In summary, this is a cheap and easily reproducible surgical technique to optimize ERM management, offering an intraoperative guide for peeling initiation and minimizing un-necessary surgical maneuvers.

Quantitative Volumetric Analysis of Retinal Ischemia with an Oxygen Diffusion Model and OCT Angiography

PurposeRetinal ischemia is a major feature of diabetic retinopathy (DR). Traditional nonperfused areas measured by optical coherence tomography angiography (OCTA) measure blood supply but not ischemia. We propose a novel 3-dimensional (3D) quantitative method to derive ischemia measurements from OCTA data. DesignCross-sectional study. ParticipantsWe acquired 223 macular OCTA volumes from 33 healthy eyes, 33 diabetic eyes without retinopathy, 7 eyes with non-referable DR, 17 eyes with referable but non-vision-threatening DR, and 133 eyes with vision-threatening DR. MethodsEach eye was scanned using a spectral-domain OCTA system (Avanti RTVue-XR, Visionix/Optovue, Inc) with 1.6 mm scan depth in a 3 × 3-mm region (640 × 304 × 304 voxels) centered on the fovea. For each scanned OCTA volume, a custom algorithm removed flow projection artifacts. We then enhanced, binarized, and skeletonized the vasculature in each OCTA volume and generated a 3D oxygen tension map using a zero-order kinetics oxygen diffusion model. Each volume was scaled to the average retina thickness in healthy controls after foveal registration and flattening of the Bruch membrane. Finally, we extracted 3D ischemia maps by comparison with a reference map established from scans of healthy eyes using the same processing. To assess the ability of the ischemia maps to grade DR severity, we constructed receiver-operating characteristic (ROC) curves for diagnosing diabetes, referable DR, and vision-threatening DR. Main outcome measuresSpearman correlation coefficient and area under ROC curve (AUC) were used to quantify the ability of the ischemia maps to DR. ResultsThe ischemia maps showed that the ischemic tissues were at or near pathologically non-perfused areas, but not the normally non-vascular tissue, such as the foveal avascular zone. We found multiple novel metrics, including inferred 3D-oxygen tension, ischemia index, and ischemic volume ratio, were strongly correlated with DR severity. The AUCs of ischemia index measured were 0.95 for diabetes, 0.89 for DR, 0.88 for referable DR, and 0.85 for vision threatening DR. ConclusionsA quantitative method to infer 3D oxygen tension and ischemia using OCTA in diabetic eyes can identify ischemic tissue that are more specific to pathologic changes in DR.

Blepharoptosis and corneal epithelial thickness alterations, is there any relation?

BackgroundTo compare the epithelial thickness map of ptotic eyes of blepharoptosis patients with contralateral non- ptotic eyes.MethodsUnilateral blepharoptosis patients were enrolled consecutively. Patients were underwent full ophthalmologic examination and their demographic data such as age and gender and specific ptosis findings e.g. the cause and duration, MRD-1, and levator palpebralis superioris function were registered. Anterior segment imaging for epithelial thickness measurements was done using the Avanti RTVue-XR platform. The corneal epithelial thickness maps of ptotic and non-ptotic eyes were compared.Results44 patients with unilateral blepharoptosis were included in the study. 27 (61.4%) of them were female and 17 (38.6%) cases were male. The mean of the patients’ ages was 24.40 ± 15.16 years. Ptotic eyes had significantly thinner superior (p = 0.000), superior-temporal (p = 0.000) and superior-nasal (p = 0.005) sectors of the cornea and slightly thicker corneal epithelium (CE) in the inferior-nasal sector. The correlation of difference of superior-inferior CE was evaluated with different parameters including patient’s age (p = 0.457), type of blepharoptosis (p = 0.786), duration of blepharoptosis (p = 0.477) and MRD1 (p = 0.248), but no correlation was found.ConclusionsThis study revealed that lid position in blepharoptosis may have effects on the corneal epithelial thickness map. Because of the lower position of upper eyelid, a thinning effect on superior corneal sectors may happen.

Optic nerve head alterations after COVID-19: an optical coherence tomography angiography-based longitudinal study.

To evaluate longitudinal changes in peripapillary vessel density (VD) following coronavirus disease 2019 (COVID-19) using optical coherence tomography angiography. As part of a prospective longitudinal observational study, we studied healthy individuals with a history of mild COVID-19 confirmed via real-time polymerase chain reaction. After recovery, we used the Optovue RTVue XR Avanti machine to perform optic nerve head (ONH) imaging. We also assessed the VD of all vessels and of small vessels in the disc and the radial peripapillary capillary (RPC) network at 1 and 3 months post-recovery. We included 17 patients (34 eyes; mean age: 36.9 ± 10.2 years, range: 24-62 years) who had recovered from COVID-19. No changes were observed in the ONH parameters. However, there was a noticeable trend of increased small vessel VD values in the RPC. These increases were significant for the peripapillary whole, superior hemifield, inferior-temporal, temporal-superior, and superior-temporal small vessels. Moreover, the evaluation of all vessel VD values in the RPC revealed a significant decrease in the inside disc and a significant increase in a grid-based inferior region. COVID-19 may affect VD of the RPC in the ONH, and should be considered in ONH evaluations.

OCTDL: Optical Coherence Tomography Dataset for Image-Based Deep Learning Methods

Optical coherence tomography (OCT) is a non-invasive imaging technique with extensive clinical applications in ophthalmology. OCT enables the visualization of the retinal layers, playing a vital role in the early detection and monitoring of retinal diseases. OCT uses the principle of light wave interference to create detailed images of the retinal microstructures, making it a valuable tool for diagnosing ocular conditions. This work presents an open-access OCT dataset (OCTDL) comprising over 2000 OCT images labeled according to disease group and retinal pathology. The dataset consists of OCT records of patients with Age-related Macular Degeneration (AMD), Diabetic Macular Edema (DME), Epiretinal Membrane (ERM), Retinal Artery Occlusion (RAO), Retinal Vein Occlusion (RVO), and Vitreomacular Interface Disease (VID). The images were acquired with an Optovue Avanti RTVue XR using raster scanning protocols with dynamic scan length and image resolution. Each retinal b-scan was acquired by centering on the fovea and interpreted and cataloged by an experienced retinal specialist. In this work, we applied Deep Learning classification techniques to this new open-access dataset.

The long-term influence of perinatal factors on macular morphology and vessel density in preterm children

BackgroundIncreased survival rate of extremely preterm children is associated with a higher risk of retinopathy of prematurity (ROP) and long-term sequelae, which implicate retinal changes. PurposeTo assess an influence of perinatal characteristics on morphology and retinal vascularity of the macula in preterm children. MethodsA cohort of 123 preterm children at the age of 10.5 years (IQR: 8.12-12.77) was prospectively assessed. Optical coherence tomography angiography (OCTA) was performed using RTVueXR Avanti. Foveal thickness, parafoveal thickness, size of foveal avascular zone (FAZ), superficial and deep vessel density, central choroidal thickness (CCT) were analyzed. The associations between OCTA results and perinatal factors, including the presence of ROP and therapy requirements were assessed in preterm children. ResultsSignificantly smaller FAZ, higher foveal thickness and vessel density were noted in children with ROP, Respiratory Distress Syndrome, Bronchopulmonary Dysplasia, required erythropoietin, transfusion or steroids. Foveal thickness was increased in children with ROP (p < 0.001) and following laser treatment (p < 0.05). Thinner CCT was noted in children with a history of sepsis (p < 0.05) and ROP required treatment (p < 0.05). Pregnancy bleeding was associated with higher superficial foveal vessel density (p < 0.05) and smaller FAZ (p < 0.05). ConclusionNeonatal factors have a huge impact on retinal development, but the role of prenatal factors should not be neglected in preterm children.

Оценка микрокровотока макулы и субфовеолярной толщины хориоидеи у пациентов с различными стадиями хронической ишемической ретинопатии при помощи оптической когерентной томографии-ангиографии

Purpose. Assessment of macular microvasculature and subfoveal choroidal thickness (SFCT) in patients with various stages of chronic ischemic retinopathy (CIR) using optical coherence tomography angiography (OCT-A). Material and methods. The study included 54 patients (54 eyes) with manifestations of CIR in one eye. To assess the microcirculation of the macula, OCT-A was performed (RtVue xR Avanti, Optovue, Inc., USA). The parameters of microblood flow were studied: the area of the foveal avascular zone (FAZ, mm²), superficial choroid plexus (SCCP, %), superficial deep choroid plexus (SDCP, %), SFCT (µm). Results. Mild severity of CIR was characterized by a decrease in SCCP by 10.3 % and SDCP by 10.1 %, with a moderate degree by 19.7 % and 14.6 %, with a severe degree by 31.9 % and 31.5 %. The FAZ area increased: with a mild degree by 23.1 %, with a moderate degree by 38.1 %, with a severe degree by 58.2 %. SFCT in mild cases of CIR was reduced by 9.9 %, in moderate cases by 22 %, and in severe cases by 28.5 %. Conclusion. The OCT-A method is promising in the study of microblood flow and SFCT in patients with varying degrees of CIR. Keywords: chronic ischemic retinopathy, ocular ischemic syndrome, stenosis of the internal carotid artery, optical coherence tomography-angiography

Effect of treatment with carteolol and latanoprost in newly diagnosed primary open-angle glaucoma on peripapillary vessel density.

In a previous follow-up of glaucoma patients taking carteolol or latanoprost, we found a greater progression of visual field changes with the prostaglandin than the betablocker. In the present study we compared the impact of carteolol and latanoprost on peripapillary vessel density in newly diagnosed primary open-angle glaucoma (POAG) patients. The study consisted of two groups of POAG patients. There were 46 patient eyes treated with carteolol (Carteol LP 2%) in the first group and 52 eyes treated with latanoprost (Xalatan 0.005%) in the second. Intraocular pressure (IOP), vessel density (VD) and visual field were assessed in all patients. VD was measured peripapillary by optical coherence tomography angiography (OCTA) with the Avanti RTVue XR in eight segments: Inferior Temporal - IT (1); Temporal Inferior -TI (2); Temporal Superior - TS (3); Superior Temporal - ST (4); Superior Nasal - SN (5); Nasal Superior - NS (6); Nasal Inferior - NI (7) and Inferior Nasal - IN (8). The measurements were compared before and after three months of treatment. The visual field was examined with a fast threshold glaucoma program using a Medmont M 700 instrument from Medmont International Pty Ltd. and only when a diagnosis of POAG was done. The overall defect (OD) was assessed. Before treatment, there was no difference between groups in either OD or VD. After treatment, there was a decrease in IOP in both groups. In the carteolol-treated group, the mean decrease was 5.8 mmHg and in the latanoprost-treated eyes, the mean decrease was 7 mmHg. The difference was not statistically significant (P=0.133). After treatment with carteolol, there was a statistically significant increase in VD in segments 4, 5 and 6. After latanoprost treatment, VD was statistically significantly improved only in segment 5. A greater increase in VD values was found in eyes treated with carteolol than in eyes treated with latanoprost. Carteolol had a better effect on vessel density than latanoprost.

Морфологические особенности макулы у детей

With the development of modern technologies, diagnosing genetic diseases is not very difficult. The main difficulty is the assumption of the presence of a mutation when there are no ophthalmoscopic signs or functional disorders. Fundamental research into the morphology of the posterior pole of the eyeball in children has serious applied significance. Detection of the disease in the early stages allows young patients to receive high-quality and timely treatment, maintaining a high quality of life. Purpose of the study: to identify the morphological features of the macula in children. A retrospective analysis of optical coherence tomography materials was carried out on 24 children aged 4 to 12 years (average age 9.1 ± 2.5 years). All children had high visual functions; there were no hereditary eye diseases in their parents or family. The study was carried out on an Optovue RTVue XR Avanti Sistem device using standard Retina Map and 3D Retina programs. Conclusions: Intravital anatomy of the posterior pole of the eyeball can be qualitatively and quantitatively described using optical coherence tomography. With increasing age, the thickness of the retina in the central zone of the macula increases, and in the area of the retinal eminence decreases. The anatomical shape of the macula area does not change throughout childhood. Keywords: macula, human anatomy, age characteristics, individual approach

Features of the Optic Disc Anatomy in Elderly Men

Among the anomalies of the optic disc development, which change its anatomical characteristics, are the druses of the optic disc. Diagnostically, the druses of the optic disc are manifested by protrusion into the vitreous body, and changing in the area of the optic disc and its excavation. The aim of the study is to obtain new data on the optic disc anatomy in elderly men. Material and methods. The study was conducted in a group of men from 61 to 75 years old. The study included 53 eyes of patients treated with a disease of the visual organ unrelated to the pathology of the optic disc and macula. The study was carried out on the Optovue RTVue XR Avanti Sistem device using standard 3D Disc, GCC, ONH programs. Using optical coherence tomography the following morphometric parameters of the optic disc were evaluated: the volume of excavation, the thickness of the retinal nerve fiber layer, the area of the optic disc, the depth, the width and the area of the excavation of the optic disc in the horizontal plane. Conclusion. In the group of men from 61 to 75 years old, with increasing age, there is a decrease in the thickness of the retinal nerve fiber layer, the width of the excavation of the optic disc and the area of the optic disc. The shapes of optic disc excavation in elderly men are different, the triangular shape prevails – 47,8%, the remaining shapes occur with the same frequency.

Quantitative Analysis of Retinal Perfusion in Patients with Frontotemporal Dementia Using Optical Coherence Tomography Angiography.

Optical coherence tomography angiography (OCT-A) provides detailed visualization of the perfusion of the vascular network of the eye. While in other forms of dementia, such as Alzheimer's disease and mild cognitive impairment, reduced retinal perfusion was frequently reported, data of patients with frontotemporal dementia (FTD) are lacking. Retinal and optic nerve head perfusion was evaluated in patients with FTD with OCT-A. Quantitative OCT-A metrics were analyzed and correlated with clinical markers and vascular cerebral lesions in FTD patients. OCT-A was performed in 18 eyes of 18 patients with FTD and 18 eyes of 18 healthy participants using RTVue XR Avanti with AngioVue. In addition, patients underwent a detailed ophthalmological, neurological, and neuropsychological examination, cerebral magnetic resonance imaging (MRI), and lumbar puncture. The flow density in the optic nerve head (ONH) and in the superficial capillary plexus (SCP) of the macula of patients was significantly lower compared to that of healthy controls (p < 0.001). Similarly, the VD in the deep capillary plexus (DCP) of the macula of patients was significantly lower compared to that of healthy controls (p < 0.001). There was no significant correlation between the flow density data, white matter lesions in brain MRI, cognitive deficits, and cerebrospinal fluid markers of dementia. Patients with FTD showed a reduced flow density in the ONH, and in the superficial and deep retinal capillary plexus of the macula, when compared with that of healthy controls. Quantitative analyses of retinal perfusion using OCT-A may therefore help in the diagnosis and monitoring of FTD. Larger and longitudinal studies are necessary to evaluate if OCT-A is a suitable biomarker for patients with FTD.

Peripapillary retinal nerve fiber layer following vessel density correction at different IOP values.

The aim of this study was to define the thickness of the retinal nerve fiber layer (RNFL) in the peripapillary region of the retina after adjusting for the effect of vessel density (VD) in patients with pathological intraocular pressure (IOP). 69 patients (122 eyes) with IOP >21 mmHg (range 21-36 mmHg, mean 23.65±2.70 mmHg). 32 were men (average age 55±13 years) and 37 were women (average age 52±14 years). IOP was measured using the Ocular Response Analyser (ORA). VD and RNFL were measured peripapillary by OCT (Avanti RTVue XR) in eight segments: Inferior Temporal - IT (1); Temporal Inferior - TI (2); Temporal Superior -TS (3); Superior Temporal - ST (4); Superior Nasal - SN (5); Nasal Superior - NS (6); Nasal Inferior - NI (7) and Inferior Nasal - IN (8). The VD value was subtracted from the total RNFL value. A corrected value for the RNFLc nerve fiber layer thickness (RNFLc) was introduced to account for VD across the RNFL volume in each segment. Person's correlation coefficient (r) was used to assess the correlation between IOP and RNFLc. The strongest correlations in RNFLc were in segments 5 (r=-0.32, P=0.002) and 8 (r=-0.21, P=0.037). The greatest changes in RNFLc (RNFL minus VD) were in eyes with pathological IOP in segments 5 and 8, the location of the retinal ganglion cell magnocellular fibers. That is, when the thickness of the nerve fiber layer was reduced by correcting for vessel density, there was a significant correlation in segments 5 (r =-0.32, p<0.05) and 8 (r =-0.21, P<0.05) with intraocular pressure. The results suggest use of a corrected RNFL from VD value as more appropriate for detecting early changes in glaucoma.

Retinal and Choroidal Vascularization Parameters in Patients with Type 2 Diabetes Without Diabetic Retinopathy.

The purpose of this study was to evaluate retinal and choroidal vascularization parameters in patients with type 2 diabetes mellitus (DM), without diabetic retinopathy (DR), and to compare them to healthy controls. Seventy-four eyes from 74 patients (40 eyes in the DM group and 34 eyes in the control group) were included in the study. Optical coherence tomography angiography RTVue XR Avanti was used to obtain 3×3mm scans of the macula. The choroidal vascularity index (CVI), superficial and deep capillary plexus vascular densities (SCP and DCP, respectively), and choroidal thickness (CT) were measured. In the diabetic group, SCP was lower in the superior and nasal segments (48.68 vs 50.62, p=0.02; 45.50 vs 48.82, p=0.02, respectively). The DCP did not differ between the groups. CVI was significantly lower in the study group in all measured segments, including central and parafoveal (31.73 vs 48.86 and 50.32 vs 59.58, p<0.001, respectively). CT was larger in the study group only at the center of the macula (281.89µm vs 268.37µm p<0.001) and in the inferior segment (337.47µm vs 329.40µm, p<0.001). In the multivariate regression, clinical and vascularization parameters affecting CVI and CT were analyzed after adjusting for age and sex. Decreased central CVI was associated with the presence of DM, lower central SCP, and bigger foveal avascular zone area (b=-0.68, b=0.47, b=-0.21). Parafoveal CVI was also negatively affected by DM (b= -0.46) and positively by parafoveal SCP (b= 0.44). Increased central CT was found to be positively associated with higher central SCP (b=0.48) and male sex (b=0.20). The results of our study confirmed a reduction of SCP and CVI in diabetic patients without DR. DM and SCP are age and sex independent parameters affecting CVI. Central CT is affected by SCP and sex, rather than the presence of diabetes.

Radiation Maculopathy in Patients with Malignant Melanoma of the Corpus Ciliare and Choroidea Following One-Day Session of Stereotactic Radiosurgery.

The aim of the thesis is to present the case of apatient in whom bilateral calcification of the hydrophilic intraocular lens (IOL) Lentis M+ LS-313 MF30 (Oculentis) has developed. Due to the negative effect on visual functions, explantation and replacement of the artificial lens was necessary in both eyes. Case Report: An overview of the available literature summarized the diagnostics, current examination methods and possibilities of the surgical solution of calcification of the bifocal hydrophilic lens Lentis M+ LS-313 MF30 (Oculentis). The specific solution is described in acase report of apatient in whom calcification of both lenses developed 6 years after implantation of the IOL. In 2015, the patient underwent uncomplicated cataract surgery of both eyes with the implantation of an artificial intraocular lens into the capsule. In September 2021, an 82-year-old man was examined at our outpatient clinic for deterioration of visual acuity and changes in the material of the artificial IOL which were perceptible during aclinical examination, on the recommendation of alocal ophthalmologist. Blurred vision predominated. Adiagnosis of intraocular lens opacification was confirmed and documented using aScheimpflug camera (OCULUS Pentacam HR) and anterior OCT (Avanti RTVue XR Optovue,). The patient was indicated for explantation and replacement of the opacified intraocular lens in the left and subsequently in the right eye- The same type of IOL was used for reimplantation with good functional results. Conclusion: Since 2010, multifocal lens implantation has been on an upward trend worldwide. This type of MF IOL has also been used in thousands of implantations. Anumber of other explantations can be expected in the coming years. The optimal solution is the correct replacement of the calcified IOL with the same construction made of safer hydrophobic material.

Distal Nasal Part of the Visual Field and RNFL in Primary Open-Angle Glaucoma.

The aim of this study was to compare changes in the conventionally undiagnosed distal nasal visual field with RNFL in patients with early primary open-angle glaucoma (POAG). 59 eyes of 32 patients (18 women, 14 men) with early stage POAG were included. All eyes were found to have a normal visual field (fast threshold program of 50 degrees nasally and 22 degrees temporally) with the Medmont M700. Visual acuity was 1.0 (with a possible correction ±3 D), and they had no other ocular pathology except glaucoma. The visual field was subsequently examined with the same instrument by moving the fixation point 40 degrees temporally (spatially adaptive program) and simultaneously turning the head 10 degrees nasally. A total of 89 examination points were included using flicker stimuli in a range of 0-120 degrees nasally. Nerve fiber layer (RNFL) and vessel density (VD) was measured using the in-built software of the Avanti RTVue XR instrument. Using Pearson's correlation coefficient, the results of visual field examination with RNFL without and after correction (by subtracting VD from total RNFL value) in the superior-nasal (SN-5) and inferior-nasal (IN-8) segments were compared. In all eyes, changes were found in the distal periphery of the nasal part of the visual field. No correlation was noted by comparison with RNFL. After adjusting RNFL for VD, we observed no correlation in the SN segment (5) (r=-0.03) and a very weak correlation in the IN segment (8) (r=-0.16). With a normal visual field tested by the rapid threshold glaucoma program, changes in the distal part of the nasal periphery of the visual field were found in the entire cohort and did not correlate with the RNFL and RNFL results after correction from VD.

Does SarsCoV-2 infection really cause damage to retinal microcirculation in mild cases of COVID-19?

Aim To evaluate changes of retinal microcirculation in mild cases of recovered COVID-19 patients at least three months after the infection by optical coherence tomography angiography (OCTA) non-invasive method. Methods In this prospective cross-sectional study, 50 right eyes of 50 recovered COVID-19 patients were compared with 50 right eyes of age and gender-matched healthy controls. After the complete ophthalmological examination, all participants underwent OCTA measurements (RTVue XR Avanti, Optovue, Fremont, CA, USA). Results The time between the initial onset of symptoms, and ophthalmologic examination was 479.20 ±197.10 (126-754) days. Findings of ophthalmic examination of all eyes of the recovered COVID-19 patients were within normal range. Significantly reduced superficial (p=0.046) and deep (p=0.044) macular vessel density (VD) in foveal region in the eyes of the recovered COVID-19 patients was found compared with healthy controls. Significantly enlarged foveal avascular zone (FAZ) area and perimeter in the eyes of the recovered COVID-19 patients (p<0.001) were found too. Conclusion Recovered COVID-19 patients have impaired retinal microcirculation, which can be a cause of the development of retinal vascular diseases.

State of the Retina and Optic Nerve in 21-Day Head-Down Tilt Bed Rest

Studies in conditions of head-down tilt bed rest are widely used experiments which imitate redistribution of body fluids similar to the redistribution of fluid media in microgravity. To study the mechanism of development of spaceflight-associated neuro-ocular syndrome (SANS) in head-down tilt bed rest studies scientists have evaluated, among other things, participants’ visual system parameters. The main symptom of SANS is an edema of an optic disc and a retina. To date, the results describing the influence of head-down tilt bed rest on the visual system are ambiguous, which determines the relevance of further research. The aim of the study is to analyze retinal morphometry in the optic disc area and macular area in participants before and after 21-day head-down tilt bed rest. The study was performed using an optical coherence tomography with angiography function (Optovue RTVue XR Avanti System) before and after 21-days of head-down tilt bed rest. In 4 participants (8 eyes) (men, mean age ± standard deviation: 29.3 ± 3.9 years) the macular zone and optic disc area were evaluated according to standard scanning modes. To analyze the values obtained, we used mean tendency scores, mean comparison criteria, and graphical analysis. The results of the retinal thickness in the optic disc zone were consistent with those of other researchers, indicating a possible increase in retinal thickness, but our results did not reach the level of statistical significance. A statistically significant thickening of the retina in the macular zone was shown for the first time, but the increase is significantly less in amplitude than the thickening of the nerve fiber layer in the optic disc zone. Analysis of vascular density under head-down tilt bed rest conditions was performed for the first time both for the optic disc zone and the macula zone, but additional studies are required to obtain steady conclusions. For the first time, an increase in retinal thickness in the macula zone in participants of head-down tilt bed rest experiments was shown; for the optic disc zone, data consistent with the results of other researchers were obtained. For the first time, angiographic data were obtained for the macula and optic disk areas, but the obtained differences in vascular density did not reach the level of statistical significance.

Comparison between open-angle glaucoma and angle-closure glaucoma regarding the short-term optic disc vessel density changes after trabeculectomy

To compare the microvasculature of the optic disc in open-angle glaucoma (OAG) and angle-closure glaucoma (ACG) after trabeculectomy. This study included 34 patients divided into two groups based on the angle: (1) the OAG Group, which included 24 eyes from 24 patients, and (2) the ACG Group, which included ten eyes from 10 patients. All patients were subjected to comprehensive ophthalmic examinations. It included best-corrected visual acuity (BCVA), Goldmann applanation tonometry, gonioscopy, slit-lamp biomicroscopy, dilated fundus examination, and stereoscopic examination of the optic disc. The central corneal thickness was measured using a Nidek AL scan optical biometer. The visual field was evaluated by standard automated perimetry using Humphrey Field Analyzer (24–2 Swedish interactive threshold algorithm; Carl-Zeiss Meditec, Dublin, CA). Moreover, optical coherence tomography angiography (OCT-A) was performed utilizing the RTVue XR Avanti scanner (Optovue Inc., Fremont, CA, USA) preoperatively as well as 1 month after surgery. There was a statistically significant increase in optic disc vessel density (VD) in the whole image, radial peripapillary, inferior, superior, temporal, and nasal quadrant in OAG after surgery. Regarding the change in VD after surgery in ACG patients, there was a statistically significant increase in optic disc VD in the whole image, radial peripapillary, inferior, superior, temporal, and nasal quadrant in ACG after surgery.Regarding the percentage of VD change following trabeculectomy surgery, there were highly significant differences between the two groups for the whole image, radial peripapillary, inferior quadrant, and temporal quadrant VD. Statistically significant changes were also observed in the superior and nasal quadrants of VD. However, no significant change in VD was detected within the disc. In conclusion, the optic disc VD improved after the reduction of intraocular pressure (IOP) by surgery in both OAG and ACG. However, ACG demonstrated a significant improvement than the OAG.

Relationship between nonperfusion area from widefield optical coherence tomography angiography and macular vascular parameters in diabetic retinopathy

PurposeTo evaluate the relationship between the nonperfusion area (NPA) from widefield optical coherence tomography angiography (OCTA) and macular vascular parameters in diabetic retinopathy (DR).MethodsIn total, 51 eyes from 51 patients with proliferative DR (PDR) or moderate/severe non-PDR were included. Widefield OCTA using the Zeiss Plex Elite 9000 was performed. A semi-automatic algorithm calculated the percentages of the NPA within the total image. Macular OCTA (3 × 3 mm and 6 × 6 mm area) was scanned using the RTVue-XR Avanti. Vessel density (VD) was automatically separated into the superficial (SCP) and deep capillary plexus (DCP), and foveal avascular zone (FAZ) measurements were computed according to the parafoveal (1–3 mm) and perifoveal (3–6 mm) regions.ResultsA negative correlation was found between the average VD of the SCP and DCP obtained 3 × 3 mm and 6 × 6 mm area and the NPA. Multiple regression analysis revealed that the temporal–perifoveal region most negatively correlated with the NPA (r = − 0.55, p < 0.0001). No correlation was found between FAZ measurements and DR severity (area, p = 0.07; perimeter, p = 0.13).ConclusionDiabetic macular nonperfusion was significantly associated with the NPA from widefield OCTA. In particular, the temporal–perifoveal DCP disorder may be a sensitive indicator of wide NPA.