Retinal Area Research Articles

Human versus Artificial Intelligence: Validation of a Deep Learning Model for Retinal Layer and Fluid Segmentation in Optical Coherence Tomography Images from Patients with Age-Related Macular Degeneration.

Artificial intelligence (AI) models have received considerable attention in recent years for their ability to identify optical coherence tomography (OCT) biomarkers with clinical diagnostic potential and predict disease progression. This study aims to externally validate a deep learning (DL) algorithm by comparing its segmentation of retinal layers and fluid with a gold-standard method for manually adjusting the automatic segmentation of the Heidelberg Spectralis HRA + OCT software Version 6.16.8.0. A total of sixty OCT images of healthy subjects and patients with intermediate and exudative age-related macular degeneration (AMD) were included. A quantitative analysis of the retinal thickness and fluid area was performed, and the discrepancy between these methods was investigated. The results showed a moderate-to-strong correlation between the metrics extracted by both software types, in all the groups, and an overall near-perfect area overlap was observed, except for in the inner segment ellipsoid (ISE) layer. The DL system detected a significant difference in the outer retinal thickness across disease stages and accurately identified fluid in exudative cases. In more diseased eyes, there was significantly more disagreement between these methods. This DL system appears to be a reliable method for accessing important OCT biomarkers in AMD. However, further accuracy testing should be conducted to confirm its validity in real-world settings to ultimately aid ophthalmologists in OCT imaging management and guide timely treatment approaches.

EVALUATION OF CHORIORETINAL VASCULARIZATION WITH OCT AND ANGIO-OCT IN PRIMARY ALDOSTERONISM

Objective: Primary aldosteronism (PA), the most common cause of secondary hypertension, is associated with excess cardiovascular damage and, when unilateral, is amenable to surgical cure. Our objective was to determine whether the chorioretinal microvasculature is also affected. Design and method: Ocular CT-scan (OCT) and angio-OCT images of the superficial and deep retinal plexi were obtained in PA patients at diagnosis, in wash-out from RAAS-confounding drugs (WO), and again during mineralocorticoid receptor antagonist (MRA) therapy and 4-6 months after surgical cure (PS). The images were analysed for choroidal thickness and, upon automated ImageJ processing, for indexes of total vascular area density (VAD) and length fraction (VLF), a surrogate for the number of open vessels. Results: We enrolled 11 patients with PA (51±10 yrs; 27%F); of these, 10 who had unilateral PA underwent curative surgery (p<0.05 for BP, sK+ and ARR). We found that MRA therapy had no effect on any of the investigated parameters. At variance, curative surgery determined a reduction of VAD in both superficial and deep plexi (-6.4% retinal area, p=0.017 and -3.5%, p=0.023, respectively) and of VLF in the superficial plexus (-2.2%, p=0.033). Moreover, choroidal thickness (on average: -21μm, p=0.003 at 2-way ANOVA) decreased after adrenalectomy. Conclusions: OCT and angio-OCT images, which can accurately track changes in choroid- retinal vascularization, highlighted a decrease of retinal microvascular area and choroidal thickness in patients with unilateral PA, who were cured from PA.

WHY HAPPENS A PROGRESSIVE DECREASE OF BLOOD PRESSURE AFTER RENAL DENERVATION

Objective: Long-term follow-up data from the SYMPLICITY 3 trial (Bhatt et al, Lancet, 2022) and the Global Symplicty Register data (Mahfoud et al, JACC, 2020) show a further decrease in BP over time up to 3 years post procedure. Yet these observations lack a mechanistic explanation. A decrease in vascular resistance could possibly explain the observed phenomenon. Scanning Laser Doppler Flowmetry (SLDF) allows the non-invasive assessment of vascular resistance and capillary density by using the retinal vasculature as a mirror of the systemic circulation. Design and method: Retinal parameters were assessed using SLDF together with office and 24-hour ambulatory BP before and 6 as well as 12 months after renal denervation in 63 patients with treatment resistant hypertension (TRH) (NCT01687725). SLDF allows the assessment of retinal capillary flow (RCF), pulsed retinal capillary flow (systolic retinal capillary flow – diastolic retinal capillary flow) (pRCF), retinal vascular resistance, capillary area (CapA) and intercapillary distance (ICD). Results: Mean age of the study cohort was 60±11 years, mean BMI 30.6±4.9 kg/m2. Patients took 5.8 antihypertensive medications on average. There was a significant reduction of systolic and diastolic 24-hour ambulatory as well office BP 6 as well as 12 months after RDN (table 1). There was no significant reduction in the number of antihypertensive medications taken between baseline and 12 months after RDN (5.8vs.5.7 antihypertensive pills, p=0.159). Retinal vascular resistance was reduced 6 months after RDN (table 1), pRCF was reduced 6 as well as 12 months after RDN and capillary density improved 12 months after RDN. Conclusions: In high-risk patients with TRH endovascular RDN improved vascular resistance and reversed capillary rarefaction in the retinal circulation, a prognostic marker of further end-organ damage. The reduction of pRCF indicates a decrease of shear stress on the vascular wall by the pulsed blood flow. Increment of capillary density was observed not already 6 months, but only 12 months after RDN. We conclude that, improvement of capillary rarefaction happens slowly after RDN and requires long-term effective BP control and, that reduction in vascular resistance might explain the prolonged BP reduction after RDN.

Chronic Serous Chorioretinopathy: A Case Study

Introduction Chronic central serous chorioretinopathy (CSCR) is characterized by persistent subretinal fluid that disrupts the outer layers of the retina and may lead to complications such as: outer retinal atrophy, increased risk of choroidal neovascularization (CNVM) and the potential for permanent vision loss. This report describes the clinical features of chronic CSCR. Case Presentation A 73-year-old male with a history of systemic steroid and inhaler use presented for a routine eye exam without visual complaints. Examination findings included normal visual acuity in both eyes and multiple areas of retinal hyper and hypopigmentation along the arcades with no macular involvement in the right eye; the left eye was unremarkable. Fundus photography and optical coherence tomography showed localized areas of outer retinal disruption and thinning near the optic nerve head and along the corresponding retinal areas of irregular pigmentation in the right eye; the left eye was unremarkable. Discussion In chronic CSCR, structural changes in the retina can lead to retinal dysfunction and permanent vision loss. Treatment options for chronic CSCR include photodynamic therapy, intravitreal anti-vascular endothelial growth factor therapy, or systemic steroid receptor blockers. Visual prognosis varies depending on the severity of the disease, age of onset, risk of CNVM and the degree of outer retinal degeneration. Conclusion Patients with chronic CSCR are at risk for permanent vision loss. The structural changes in the outer retina also increase the risk for CNVM. Hence, it is important that patients with chronic CSR receive regular eye examinations and are educated on the role of regular Amsler grid testing.

Influence of Aberration-Free, Narrowband Light on the Choroidal Thickness and Eye Length.

To determine whether light chromaticity without defocus induced by longitudinal chromatic aberration (LCA) is sufficient to regulate eye growth. An interferometric setup based on a spatial light modulator was used to illuminate the dominant eyes of 23 participants for 30minutes with three aberration-free stimulation conditions: (1) short wavelength (450nm), (2) long wavelength (638nm), and (3) broadband light (450-700nm), covering a retinal area of 12°. The non-dominant eye was occluded and remained as the control eye. Axial length and choroidal thickness were measured before and after the illumination period. Axial length increased significantly from baseline for short-wavelength (P < 0.01, 7.4 ± 2.2 µm) and long-wavelength (P = 0.01, 4.8 ± 1.7 µm) light. The broadband condition also showed an increase in axial length with no significance (P = 0.08, 5.1 ± 3.5 µm). The choroidal thickness significantly decreased in the case of long-wavelength light (P < 0.01, -5.7 ± 2.2 µm), but there was no significant change after short-wavelength and broadband illumination. The axial length and choroidal thickness did not differ significantly between the test and control eyes or between the illumination conditions (all P > 0.05). Also, the illuminated versus non-illuminated choroidal zone did not show a significant difference (all P > 0.05). All stimulation conditions with short- and long-wavelength light and broadband light led to axial elongation and choroidal thinning. Therefore, light chromaticity without defocus induced by LCA is suggested to be insufficient to regulate eye growth. This study helps in understanding if light chromaticity alone is a sufficient regulator of eye growth.

A case of uveitis associated with novel corona-virus inactivated vaccine engineered CHO cells: A case report

Rationale: The pathogenesis and course of recombinant Corona Virus Disease 2019 vaccine (CHO cell) associated uveitis is rarely seen in clinical practice, thus, it is difficult and time-consuming to diagnose. Patient concerns: An adult female patient suffered from binocular visual impairment after receiving the Corona Virus Disease 2019 vaccine. The patient was healthy and had no family history of retinal dystrophy previously. This case showed the following features in multimodal imaging including scattered speckled fluorescein leakage was seen around the optic disc, and the leakage was slightly enhanced in the later stage. The macular area showed about 4 papillary diameter size discoid retinal detachment area fluorescein pool staining. Optical coherence tomography showed retinal choroidal folds above the optic disc, a small amount of fluid under the neuroepithelial layer, and serous detachment of the neuroepithelial layer in the macular area. Diagnosis: Posterior uveitis of both eyes. Intervention: Orally Maizhiling, Ginkgo biloba leaves, and multivitamins. Outcome: After treatment, the symptoms of the patient were significantly improved, and optical coherence tomography reexamination showed exudation had been absorbed. Lessons: The injection of a novel coronavirus-inactivated vaccine (CHO cell) can lead to potential uveitis disorders, which is worthy of clinical attention, but the prognosis of patients is good.

Enhancement of the Inner Foveal Response of Young Adults with Extended-Depth-of-Focus Contact Lens for Myopia Management.

Myopia management contact lenses have been shown to successfully decrease the rate of eye elongation in children by changing the peripheral refractive profile of the retina. Despite the efforts of the scientific community, the retinal response mechanism to defocus is still unknown. The purpose of this study was to evaluate the local electrophysiological response of the retina with a myopia control contact lens (CL) compared to a single-vision CL of the same material. The retinal electrical activity and peripheral refraction of 16 eyes (16 subjects, 27.5 ± 5.7 years, 13 females and 3 males) with myopia between -0.75 D and -6.00 D (astigmatism < 1.00 D) were assessed with two CLs (Filcon 5B): a single-vision (SV) CL and an extended-depth-of-focus (EDOF) CL used for myopia management. The peripheral refraction was assessed with an open-field WAM-5500 auto-refractometer/keratometer in four meridians separated by 45° at 2.50 m distance. The global-flash multifocal electroretinogram (gf-mfERG) was recorded with the Reti-port/scan21 (Roland Consult) using a stimulus of 61 hexagons. The implicit time (in milliseconds) and response density (RD, in nV/deg2) of the direct (DC) and induced (IC) components were used for comparison between lenses in physiological pupil conditions. Although the EDOF decreased both the HCVA and the LCVA (one and two lines, respectively; p < 0.003), it still allowed a good VA. The EDOF lens induced a myopic shift in most retinal areas, with a higher and statistically significant effect on the nasal retina. No differences in the implicit times of the DC and IC components were observed between SV and EDOF. Compared with the SV, the EDOF lens showed a higher RD in the IC component in the foveal region (p = 0.032). In the remaining retinal areas, the EDOF evoked lower, non-statistically significant RD in both the DC and IC components. The EDOF myopia control CL enhanced the response of the inner layers of the fovea. This might suggest that, besides other mechanisms potentially involved, the central foveal retinal activity might be involved in the mechanism of myopia control with these lenses.

Investigation into safflower injection as a prophylactic treatment for retinal vein occlusion in a rabbit model

The study aimed to assess the effect and mechanism of safflower injection in preventing retinal vein thrombosis in rabbits. Twenty healthy adult pigmented rabbits were randomly assigned to either the experimental group, receiving safflower injection, or the control group, receiving normal saline. After two weeks of treatment, blood samples were collected to analyze platelet adhesion and aggregation rates. Photodynamic therapy was applied to induce occlusion in the target retinal vein. Fundus photography and fluorescein angiography were recorded using a dynamic microscopic monitoring system, and laser speckle imaging was employed to assess blood flow in the affected vein. The experimental group exhibited significantly lower rates of platelet adhesion and aggregation compared to the control group. Following the induction of retinal vein occlusion, the experimental group showed a lower complete occlusion rate of the target retinal vein. Although initial blood flow in the target vein was similar between groups, the blood flow at 1, 3, and 5 min post-occlusion was significantly higher in the experimental group. Safflower injection delayed retinal vein thrombosis formation, preserved blood flow in the affected retinal area, and reduced platelet adhesion and aggregation. These effects facilitated vascular reperfusion within a limited timeframe.

Measurement of retinal and optic nerve head blood flow in glaucomatous individuals compared to normal individuals: an optical coherence tomography angiography study

Study aim Identifing quantitative differences in retinal and optic nerve head blood flow detected by optical coherence tomography (OCT) angiography in moderately to severely affected glaucoma eyes of primary open angle type versus normal individuals. Patients and methods Comparative noninterventional observational prospective research has been performed on 28 eyes (16 individuals). Participants went through examination and imaging protocols. Data were collected during the period from January 2020 to May 2020. The study population was split into two cohorts: the first cohort included 14 eyes of nine individuals who suffered from glaucoma of open-angle type (moderately to severely affected), and the second cohort included 14 eyes of seven normal sex-matching and age-matching individuals. Results We documented a reduction in the vessel density of both the optic nerve head area (P&lt;0.001) and superficial retinal areas in glaucomatous eyes (P&lt;0.001), and this reduction shows statistical significance. Conclusion Quantitative OCT angiography analysis proved affection of both peripapillary and macular vessel density in glaucoma of open-angle type, signifying the OCT angiography role in understanding the disease’s underlying etiology.

Customizing spatial remapping of letters to aid reading in the presence of a simulated central field loss.

Reading is a primary concern of patients with central field loss (CFL) because it is typically performed with foveal vision. Spatial remapping offers one potential avenue to aid in reading; it entails shifting occluded letters to retinal areas where vision is functional. Here, we introduce a method of creating and testing different remapping strategies-ways to remap text-customized for CFL of different shapes. By simulating CFL in typically-sighted individuals, we tested the customization hypothesis-that the benefits of different remapping strategies will depend on the properties of the CFL. That is, remapping strategies will aid reading differentially in the presence of differently shaped CFL. In Experiment 1, letter recognition in the presence of differently shaped CFL was assessed in and around central vision. Using these letter recognition "maps" different spatial remappings were created and tested in Experiment 2 using a word recognition task. Results showed that the horizontal gap remapping, which did not remap any letters vertically, resulted in the best word recognition. Results were also consistent with the customization hypothesis; the benefits of different remappings on word recognition depended on the different CFL shapes. Although the horizontal gap remapping resulted in very good word recognition, tailoring remapping strategies to the shape of patients' CFL may aid reading with the wide range of sizes and shapes encountered by patients with CFL.

Internal limiting membrane separation and posterior vitreous hyperreflective dots: novel OCT findings in Purtscher-like retinopathy

BackgroundPurtscher or Purtscher-like retinopathy is diagnosed by retinal hemorrhages and areas of retinal whitening on fundus examination, as well as a reduction in visual acuity due to microvascular occlusion of the precapillary retinal arterioles. We describe novel optical coherence tomography (OCT) findings of internal limiting membrane (ILM) separation and posterior hyperreflective dots in a case of Purtscher-like retinopathy in this report.MethodsA 33-year-old man with acute pancreatitis and alcohol-induced liver disease presented to the retina department complaining of four days of painless vision loss in both eyes. Both eyes’ anterior segment examination and intraocular pressure were normal. Dilated fundus examination of both eyes revealed confluent areas of retinal whitening, hemorrhages, and cotton-wool spots over the posterior pole, indicating Purtscher-like retinopathy. OCT scans through the macula revealed dense inner retinal reflectivity, thickening, and loss of retinal layer stratification, as well as outer retinal layer shadowing and islands of ILM separation, posterior vitreous hyperreflective dots, and minimal subfoveal fluid, all of which corresponded to areas of retinal whitening on fundus photographs. The patient was given a brief course of systemic steroids.ResultsOn the tenth day after the presentation, visual acuity in the right eye had improved to 6/18 and finger counting at 1 m in the left eye. The retinal findings had faded. The retina had reverted to its normal thickness on the OCT scans, with minimal hyperreflectivity remaining. The ILM separation and posterior vitreous hyperreflective dots were no longer present.ConclusionFollowing Purtscher or Purtscher-like retinopathy, we believe inflammation could play a major role in the development of these two novel OCT findings. This case offers an additional perspective on the underlying mechanisms responsible for the retinal manifestations observed in Purtscher or Purtscher-like retinopathy.

Characterization of the visually impaired patients with diabetes mellitus in Japan.

To conduct a multicenter survey of visually impaired patients with diabetes mellitus (DM) and to identify the physical and ocular characteristics that lead to blindness in Japan. Visually impaired patients with diabetes mellitus in Japan were divided into blind and low-vision groups according to the World Health Organization classification. Data on parameters related to diabetes mellitus and ocular complications in the right and left eyes were collected from 19 highly advanced medical facilities and compared between the two groups. Among 408 visually impaired persons (blind group: 257, low-vision group: 151), 72.1% were under 70 years of age. The rates of neovascular glaucoma (NVG) (right eye, P = 0.041; left eye, P = 0.0031) or proliferative diabetic retinopathy (PDR) (right eye: P = 0.014, left eye: P = 0.0047) and the rate of proliferative membrane beyond half of the retinal area (right eye: P = 0.0263, left eye: P = 0.037) were significantly higher in the blind group. The direct cause of visual impairment was retinal atrophy, common in both groups. Neovascular glaucoma and diabetic macular edema were equally prevalent in the blind and low-vision groups, respectively. In Japan, blind patients with diabetes mellitus are characterized by severe conditions such as neovascular glaucoma and progressive proliferative diabetic retinopathy upon their initial visit to an advanced care facility. These results highlight the importance of monitoring retinopathy through regular ophthalmological examinations, internal medicine, and appropriate therapeutic intervention.

Experimental rationale for the use of thioctic acid and indomethacin in the therapy of the early stage of retinal neurodegeneration

Purpose: to assess the possibility of using thioctic acid and indomethacin tin eyedrops for the therapy of early stages of retinal neurodegeneration.Material and methods. The study was performed on 20 Chinchilla rabbits, including 16 rabbits in whom the neurodegenerative process in the retina was produced by intravitreal installation of 6-hydroxydopamine (6-OHDA), 0.25 mg per eye, and 4 rabbits (8 eyes) served as control. Thioctic acid 0.5% and Indocollir 0.1% were instilled separately and in combination 5 times daily for 7 days after the injection of 6-OHDA. Pupillary light reaction was estimated and eye fundus condition analyzed. Alpha2-macroglobuline ( 2-MG) and SOD activity, dopamine and protein concentrations were measured in retinal homogenates.Results. Instillations of thioctic acid reduced the retinal damage area almost by half as compared to the untreated group (p d 0.005). Indomethacin was less effective, but the combination of the two drugs brought about a maximal reduction of the damage area (p d 0.05 against the untreated group). Both preparations normalized the disturbed pupillary light reaction. The injection of 6-OHDA caused a decrease of dopamine concentration in the retina (0.050 ± 0.009 pg/mg as against 0.095 ± 0.031 pg/mg in healthy controls, р d 0,05). After instillations of indomethacin and thioctic acid, the concentration tended to increase, and it increased significantly after treatment with their combination (0.141 ± 0.037 pg/mg, p d 0.01 as against untreated animals). The activity of 2-MG in retina decreased after a 6-OHDA injection (2.93 ± 0.42 pg/mg as against 5.5 ± 1.2 pg/mg in healthy controls, р &lt; 0 005) just as they increased the decreased SOD (13.30 ± 5.68 U/mg in healthy controls, 5.41 ± 1.50 U/mg in untreated animals, р &lt; 0.05). Both preparations applied separately or in combination caused a significant increase of 2-MG activity (thioctic acid — 4.19 ± 0.91 pg/mg, indomethacin — 6.95 ± 1.09 pg/mg, combination — 7.25 ± 0.63 pg/mg, р &lt; 0.05 as against the untreated animals) and SOD activity (thioctic acid — 8.25 ± 1.27 U/mg, indomethacin — 29.84 ± 6.63 U/mg, combination — 23.99 ± 3.78 U/mg, р &lt; 0.01 as against the untreated animals).Conclusion. The combination of indomethacin and thioctic acid in eyedrops is the most effective for the prevention of eye damage caused by 6-OHDA, which makes this method promising for the treatment of eye diseases accompanied by neurodegeneration.

Viral Anterior Uveitis: Differences in Retinal Vessel Area Density between the Affected and Non-Affected Eye Using Optical Coherence Tomography Angiography

ABSTRACT Purpose To investigate differences in the retinal vessel area density (VAD) on optical coherence tomography angiography (OCTA) between eyes with unilateral herpetic viral anterior uveitis (VAU) (herpes-simplex virus (HSV) and varicella-zoster virus (VZV)) and the non-affected fellow eye. Methods In this monocentric, observational, prospective case series we analyzed the VAD of the macula, optic disc, and peripapillary region in affected and non-affected eyes of 22 patients with HSV-positive and 22 patients with VZV-positive VAU using OCTA. We analyzed also the visual field mean deviation (MD), the retinal nerve fiber layer (RNFL) thickness, Bruch’s Membrane Opening-Minimum Rim Width (BMO-MRW), and ganglion cell layer (GCL) thickness on OCT and correlated the results with the different VADs. Results The macular VAD in the superficial vascular plexus (SVC) was significant lower in the affected compared to the non-affected eye for both viruses (HSV: 33.0% ± 3.3% vs. 34.7% ± 2.6%, p = 0.011; adjusted p = 0.040; VZV: 33.1% ± 3.2% vs. 34.3% ± 2.8%, p = 0.012; adjusted p = 0.050). Additionally, the VAD of the peripapillary SVC differed between the affected and non-affected eye for VZV-positive VAU (47.1% ± 6.2% vs. 50.5% ± 6.3%, p = 0.048, adjusted p = 0.100). For both HSV-positive and VZV-positive VAU, there were correlations between macular or peripapillary SVC VAD and BMO-MRW, GCL thickness, RNFL thickness or MD of the affected eye. Conclusion We observed vascular dysfunction characterized by decreased macular and peripapillary VAD in the superficial plexus on OCTA in eyes with HSV- and VZV-positive VAU compared to non-affected fellow eyes. These changes might be an early sign of glaucomatous damage or may be a direct consequence of the herpes viruses themselves.

Accuracy of generative deep learning model for macular anatomy prediction from optical coherence tomography images in macular hole surgery

This study aims to propose a generative deep learning model (GDLM) based on a variational autoencoder that predicts macular optical coherence tomography (OCT) images following full-thickness macular hole (FTMH) surgery and evaluate its clinical accuracy. Preoperative and 6-month postoperative swept-source OCT data were collected from 150 patients with successfully closed FTMH using 6 × 6 mm2 macular volume scan datasets. Randomly selected and augmented 120,000 training and 5000 validation pairs of OCT images were used to train the GDLM. We assessed the accuracy and F1 score of concordance for neurosensory retinal areas, performed Bland–Altman analysis of foveolar height (FH) and mean foveal thickness (MFT), and predicted postoperative external limiting membrane (ELM) and ellipsoid zone (EZ) restoration accuracy between artificial intelligence (AI)-OCT and ground truth (GT)-OCT images. Accuracy and F1 scores were 94.7% and 0.891, respectively. Average FH (228.2 vs. 233.4 μm, P = 0.587) and MFT (271.4 vs. 273.3 μm, P = 0.819) were similar between AI- and GT-OCT images, within 30.0% differences of 95% limits of agreement. ELM and EZ recovery prediction accuracy was 88.0% and 92.0%, respectively. The proposed GDLM accurately predicted macular OCT images following FTMH surgery, aiding patient and surgeon understanding of postoperative macular features.

Optical coherence tomography angiography suggests choriocapillaris perfusion deficit as etiology of acute macular neuroretinopathy

PurposeAcute macular neuroretinopathy (AMN) can cause sudden-onset and permanent scotoma in healthy young patients. Analysis of optical coherence tomography (OCT) and OCT angiography (OCTA) of AMN patients may provide insights into disease mechanism.MethodsWe conducted a retrospective study of consecutive SARS-Cov-2-related AMN patients that presented in our clinic between Jan 1st, 2022, and April 30th, 2023, within 30 days of symptom onset. Retinal vessel area density (VAD) of AMN lesions in OCTA was quantified and compared to an adjacent tissue control (ATC). This quantification was performed for the superficial vascular plexus (SVP), the intermediate capillary plexus (ICP), the deep capillary plexus (DCP), the choriocapillaris (CC), and choroid. Furthermore, en face OCT images were analyzed.ResultsNine AMN patients were identified, 6 of these (4 female, 2 male, average age 25 years) fulfilled the inclusion criteria and were included into this study. Average time from symptom onset to OCTA was 14.3 days. No VAD differences between AMN and adjacent tissue were found in either retinal layer (SVP, ICP, DCP). In contrast, VAD in CC was reduced by 27% against the ATC (p = 0.007) and choroidal VAD was reduced by 41% (p = 0.017). Further analysis of en face OCT could show that the pathognomonic infrared hyporeflectivity in AMN is caused by photoreceptor alterations rather than changes in the inner retinal layers.ConclusionsOur data suggests that a perfusion deficit in the choroidal layers is responsible for AMN rather than in the DCP, which is the predominant hypothesis in current literature.

Apoptotic Vesicles Modulate Endothelial Metabolism and Ameliorate Ischemic Retinopathy via PD1/PDL1 Axis.

Pathological angiogenesis with subsequent disturbed microvascular remodeling is a major cause of irreversible blindness in a number of ischemic retinal diseases. The current anti-vascular endothelial growth factor therapy can effectively inhibit angiogenesis, but it also brings significant side effects. The emergence of stem cell derived extracellular vesicles provides a new underlining strategy for ischemic retinopathy. Apoptotic vesicles (apoVs) are extracted from stem cells from human exfoliated deciduous teeth (SHED). SHED-apoVs are delivered into the eyeballs of oxygen-induced retinopathy (a most common model of angiogenic retinal dieseases) mice through intravitreal injection. The retinal neovascularization and nonperfusion area, vascular structure, and density changes are observed during the neovascularization phase (P17) and vascular remodeling phase (P21), and visual function is measured. The expression of extracellular acidification rate and lactic acid testing are used to detect endothelial cells (ECs) glycolytic activity. Furthermore, lentivirus and neutralizing antibody are used to block PD1-PDL1 axis, investigating the effects of SHED-apoVs on glycolysis and angiogenic activities. This work shows that SHED-apoVs are taken up by ECs and modulate the ECs glycolysis, leading to the decrease of abnormal neovessels and vascular remodeling. Furthermore, it is found that, at the molecular level, apoVs-carried PD1 interacts with PDL1 on hypoxic ECs to regulate the angiogenic activation. SHED-apoVs inhibit pathological angiogenesis and promote vascular remodeling in ischemic retinopathy partially by modulating ECs glycolysis through PD1/PDL1 axis. This study provides a new potential strategy for the clinical treatment of pathological retinal neovascularization.

Cilastatin as a Potential Anti-Inflammatory and Neuroprotective Treatment in the Management of Glaucoma.

Glaucoma is a neurodegenerative disease that causes blindness. In this study, we aimed to evaluate the protective role of cilastatin (CIL), generally used in the treatment of nephropathologies associated with inflammation, in an experimental mouse model based on unilateral (left) laser-induced ocular hypertension (OHT). Male Swiss mice were administered CIL daily (300 mg/kg, i.p.) two days before OHT surgery until sacrifice 3 or 7 days later. Intraocular Pressure (IOP), as well as retinal ganglion cell (RGC) survival, was registered, and the inflammatory responses of macroglial and microglial cells were studied via immunohistochemical techniques. Results from OHT eyes were compared to normotensive contralateral (CONTRA) and naïve control eyes considering nine retinal areas and all retinal layers. OHT successfully increased IOP values in OHT eyes but not in CONTRA eyes; CIL did not affect IOP values. Surgery induced a higher loss of RGCs in OHT eyes than in CONTRA eyes, while CIL attenuated this loss. Similarly, surgery increased macroglial and microglial activation in OHT eyes and to a lesser extent in CONTRA eyes; CIL prevented both macroglial and microglial activation in OHT and CONTRA eyes. Therefore, CIL arises as a potential effective strategy to reduce OHT-associated damage in the retina of experimental mice.

ULTRA-WIDEFIELD IMAGING DETECTION RATE IN IDENTIFYING PERIPHERAL RETINAL TEARS IN SINGLE VERSUS MONTAGE OF PERIPHERAL STEERING.

To compare the detection rate of orthogonal, directed peripheral steering, and automontaged images with ultra-widefield imaging and the factors influencing the ability to identify retinal breaks. Retrospective cohort study. Three hundred and seventy-six treatment-naive eyes (349 patients) that underwent laser retinopexy for retinal breaks between 2015 and 2021 were included. Pretreatment ultra-widefield orthogonal, peripheral steering, and automontage were cross-referenced to scleral-depressed examination to determine whether images successfully visualized all retinal breaks. Total relative retinal area (RRA) visualized was divided by its optic disk area (pixels) to calculate relative retinal area. Potential associations were assessed by linear regression analysis. One hundred and sixty two eyes (154 patients) met inclusion criteria. Orthogonal, peripheral steering, and automontage images showed detection rates of 47.5%, 90.7%, and 80.0%, respectively. Relative retinal area increased from orthogonal versus montage by 34.7% ± 26.5% (mean ± SD), which increased the detection rate by 90.8% ( P = 0.006). In linear probability models, vertical meridian tears decreased probability of identification in orthogonal, peripheral steering, and automontage by -26.6%, -86.2%, and -68.7%, respectively ( P < 0.001), and horizontal meridian tears increased the probability by 62.2%, 92.9%, and 85.5%, respectively, ( P < 0.001). Tears posterior to the equator in orthogonal images increased the probability (91.4%, P < 0.001). Artifacts such as lids/lashes, reflection, and face guard decreased the probability in directed peripheral steering by -28.6%, -50.0%, and -66.7%, respectively, ( P = 0.020, P = 0.049, and P = 0.016). Using directed peripheral steering and automontage increases RRA and detection rate of identifying peripheral retinal breaks. Tears in horizontal meridians or posterior to the equator increase the probability of identification. Common ultra-widefield imaging artifacts can significantly limit the probability of identifying retinal tears.

The correlation of folic acid and homocysteine serum with vascular density and retinal non-perfusion area in diabetic retinopathy

Background : Diabetic Retinopathy (DR) is the most common microvascular complication of Diabetes Mellitus (DM). Homocysteine has been studied as a biomarker in DR, while folic acid exhibits anti-proliferative effects in DR.&#x0D; Objective : To analyze the correlation between folic acid and homocysteine serum with vascular density and retinal non-perfusion area in healthy individuals and patients with diabetic retinopathy.&#x0D; Methods : This is an observational study with a cross-sectional design, conducted in Dr. Kariadi Hospital and GAKI laboratory in Semarang in January 2023. This study included 60 samples: 15 healthy individuals, 15 patients with DM but no DR, 15 patients with Non-Proliferative Diabetic Retinopathy (NPDR), and 15 patients with Proliferative Diabetic Retinopathy (PDR). Patients were examined for serum folic acid and homocysteine using blood laboratory tests, vessel density and retinal non-perfusion areas using optical coherence tomography angiography (OCTA).&#x0D; Results : There was a negative correlation with weak strength between folic acid levels and retinal non-perfusion area of the retina in all samples (Folic acid levels vs retinal non-perfusion area, p = 0.009, Spearman correlation = -0.335). There was a positive correlation with weak strength between folic acid levels and vascular density in all samples (Folic acid levels vs vascular density, p = 0.009, Spearman correlation = 0.337). There was a positive correlation with moderate strength between homocysteine levels and retinal non-perfusion area in all samples (Homocysteine levels vs non–perfusion area of the retina, p = 0.001, Spearman correlation = 0.426). There was a positive correlation with moderate strength between homocysteine levels and vascular density in all samples (Homocysteine levels vs vascular density, p = 0.001, Spearman correlation = -0.414).&#x0D; Conclusion : There was a correlation between folic acid and homocysteine serum with vascular density and retinal non-perfusion areas.