Optical coherence tomography angiography measurements in neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody disease: A systematic review and meta-analysis.

PURPOSE: Neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) are immune-mediated disorders that can often manifest with optic neuritis (ON) among other symptoms. Optical coherence tomography angiography (OCTA) is an emerging diagnostic method that can quantify retinal capillary blood flow and vessel density (VD), which have been shown to be affected in NMOSD and MOGAD. Hence, we aimed to systematically review the studies addressing retinal microvasculature using OCTA in these diseases. DESIGN: Systematic review and meta-analysis. METHODS: PubMed, EMBASE, and Web of Sciences were systematically searched to identify articles addressing OCTA measurements in patients with NMOSD or MOGAD. Following the data extraction, a meta-analysis was performed on the study population and OCTA types amongst at least two homogenous studies. RESULTS: Twenty-two studies on NMOSD, MOGAD, or both were included. Parafoveal superficial retinal capillary plexus (SRCP) VD and radial peripapillary capillary (RPC) VD were diminished in NMOSD ON+ and NMOSD ON- groups compared to healthy controls (HCs). In addition, both the SRCP VD and RPC VD were significantly reduced in NMOSD ON+ compared to NMOSD ON-. However, meta-analysis for deep retinal capillary plexus (DRCP) did not show a significant difference between NMOSD patients and HCs, or among ON+ and ON- patients. Furthermore, there was no significant difference in foveal avascular zone (FAZ) area size between NMOSD patients and HCs. Regarding MOGAD, the meta-analysis showed decreased parafoveal SRCP VD and RPC VD in MOGAD ON+ patients compared to HCs. Comparing NMOSD ON+ and MOGAD ON+, a meta-analysis was conducted for RPC VD, which showed no significant difference between the two groups. CONCLUSIONS: This systematic review and meta-analysis confirmed reduced VD in the macular and peripapillary areas in NMOSD and MOGAD eyes, particularly in the parafoveal SRCP and RPC, which is further impacted by prior ON.

Sea-fan retinal neovascularization associated with rickettsial retinitis: a case report.

BACKGROUND: Rickettsial disease has been commonly associated with retinitis, retinal vasculitis, and optic nerve involvement, but the development of retinal neovascularization has been very rarely reported. We herein describe a case of rickettsial retinitis complicated with the development of sea-fan retinal neovascularization documented with multimodal imaging, including fundus photography, SS-OCT, fluorescein angiography, and SS-OCT angiography. CASE PRESENTATION: A 26-year-old female with a history of fever one week earlier presented with sudden decreased vision in the left eye. Best-corrected visual acuity (BCVA) was 20/2000 and the patient was diagnosed with rickettsial retinitis along the superotemporal retinal vascular arcade associated with serous retinal detachment and retinal hard exudates. The indirect immunofluorescence test was positive for Rickettsia conorii, and the patient was treated with oral doxycycline (200 mg/day) and oral prednisone (0.75 mg/kg/day, with gradual tapering). Four weeks after presentation, the retinal infiltrate and associated serous retinal detachment had resolved, but retinal hard exudates had increased. A large sea-fan preretinal fibrovascular neovascularization became apparent along the superotemporal retinal vascular arcade, but there was no associated retinal ischemia on fluorescein angiography. The patient received an adjunctive single intravitreal injection of 1.25 bevacizumab. Sequential follow-up examinations showed shrinking of sea-fan retinal neovascularization, a complete resolution of retinal hard exudates, and the development of a self-limited vitreous hemorrhage. On last follow-up, 30 months after intravitreal bevacizumab injection, BCVA was 20/25. CONCLUSION: Patients with rickettsial retinitis may develop a sea-fan retinal neovascularization, with subsequent vitreous hemorrhage, putatively through inflammatory mechanisms. Multimodal imaging including OCT, fluorescein angiography, and OCT-angiography, is highly useful for accurate diagnosis and reliable monitoring of the evolution of retinitis, retinal neovascularization, and other retinal changes. The use of a combination therapy with oral doxycycline and corticosteroids and intravitreal anti-VEGF can improve outcomes.

Optical coherence tomography angiography findings of systemic lupus erythematosus patients and the effect of neuropsychiatric involvement on it.

AIM: To investigate the radial peripapillary capillary plexus vessel density (RPCP-VD) and peripapillary retinal nerve fiber layer thickness (pRNFLT) of systemic lupus erythematosus (SLE) and neuropsychiatric SLE patients (NPSLE) using disc optical coherence tomography angiography (OCTA) and investigate the association between these parameters and SLE disease activity index (SLEDAI-2K). METHODS: A total of 64 'right eyes (36 SLE patients, 28 healthy controls (HCs)) were included in this cross-sectional case-control study. Ten (27.7%) patients had neuropsychiatric involvement. RPCP-VD and pRNFLT of patients were evaluated in all peripapillary sectors. RPCP-VD and pRNFLT of NPSLE, non-NPSLE, and HCs were compared. The correlation between SLEDAI-2K and OCTA findings was evaluated. RESULTS: SLE patients' RPCP-VDs were significantly lower compared with the HCs except for two sectors (p < .005). There was not a significant difference in pRNFLT of SLE patients and HCs. There was not a correlation between SLEDAI-2K and RPCP-VD in any subsectors but there was a significantly negative correlation between pRNFLT in tempo-inferior and inferior-temporal sectors. When compared with non-NPSLE-patients, NPSLE patients had significantly lower inferior-hemi (p = .001), inferior-nasal VDs (p = .003), and peripapillary (p = .012), superior-hemi (p = .038), inferior-hemi (p = .026), inferior-nasal (p = .002) and inferior-temporal (p = .012) pRNFLTs. A negative correlation was found between NPSLE and pRNFLT. CONCLUSION: SLE patients may have early subclinical vascular involvement leading to decreased RPCP-VD. A negative correlation between the SLEDAI-2K and pRNFLT in the temporal subsectors of all SLE patients may show an association between the disease activity and temporal pRNFL thinning. The presence of neuropsychiatric involvement may also be associated with decreased RPCP-VD and pRNFLT.

Retinal nerve fiber layer thickness and radial peripapillary capillaries density in myopic adults with optical coherence tomography angiography.

PURPOSE: To evaluate retinal nerve fiber layer thickness (RNFLT) and radial peripapillary capillaries (RPC) density in adults with different degrees of myopia using optical coherence tomography angiography (OCTA) and explore their relationship with ocular factors, such as axial length (AL) and disc area. METHODS: A total of 188 subjects were included in this cross-sectional study. The eyes were divided into four groups according to AL. OCTA was used for the assessment of RNFLT, RPC density, and other optic disc measurements, such as disc area. One-way analysis of variance was performed to compare differences between four groups, and P value < 0.01 was considered significant. RESULTS: The RNFLT was significantly thinner in high myopia (HM) group at inferior nasal (IN) quadrant (P = 0.004) than low myopia (LM) group, but thicker at temporal inferior (TI) quadrant (P = 0.006). The RPC density of nasal superior (NS) quadrant, nasal inferior (NI) quadrant, and inferior nasal (IN) quadrant significantly decreased as AL increasing. By simple linear regression analysis, the inside disc RPC (iRPC) density tended to be correlated significantly with AL (0.3997%/mm, P < 0.0001). Peripapillary RPC (pRPC) density was in significant correlation with AL (-0.2791%/mm, P = 0.0045), and peripapillary RNFLT (pRNFLT) was in significant correlation with disc area (0.2774%/mm2, P = 0.0001). CONCLUSION: RNFLT and RPC density were closely associated with AL and disc area. They might be new indexes in assessing and detecting myopia development via OCTA.

Acute macular neuroretinopathy following COVID-19 infection: Three case reports.

BACKGROUND: During the Coronavirus disease 2019 (COVID-19) pandemic, a notable increase in acute macular neuroretinopathy (AMN) cases was observed. This study aimed to investigate the potential association between AMN and COVID-19 by examining 3 cases in China. CASE SUMMARY: The first case involved a 30-year-old man who presented with progressive vision loss following a COVID-19 infection. Optical coherence tomography (OCT) and near-infrared imaging identified hallmark AMN lesions, hyperreflective disruptions within the outer plexiform layer, and hyporeflective anomalies in the ellipsoid zone, leading to an AMN diagnosis. Despite partial visual recovery, OCT angiography (OCTA) revealed persistent microvascular changes, specifically a decreased vascular density in the deep capillary plexus. The second case was a 24-year-old woman who experienced blurred vision and exhibited bilateral cotton-wool spots on fundus examination post-COVID-19. Imaging confirmed the presence of AMN along with paracentral acute middle maculopathy (PAMM). Follow-up OCTA found a progressive reduction in vascular density, indicating ongoing microvascular compromise. The third case was a 28-year-old woman who reported sensations of occlusion in her right eye following a COVID-19 infection. Imaging confirmed both AMN and PAMM, revealing similar decreases of microvascular density on OCTA despite a significant improvement in visual acuity. We noted that all 3 patients had received the COVID-19 vaccine prior to the appearance of symptoms. CONCLUSION: The findings highlight the diagnostic utility of advanced ocular imaging in detecting AMN in COVID-19 patients and the importance of comprehensive eye examinations.

Bibliometric analysis of ophthalmic OCT and OCT angiography research trends over the past 20 years.

PURPOSE: Optical coherence tomography (OCT) and OCT angiography (OCTA) are widely used in the diagnosis of ophthalmic diseases. This study aims to provide a comprehensive bibliometric analysis of ophthalmologic OCT and OCT angiography. METHODS: We retrieved publications on ophthalmic OCT and OCTA from 2003 to 2022 from the Web of Science Core Collection and used bibliometric tools to analyze and visualize the distribution, trend, and hotspots. RESULTS: In total, 20,817 articles written by 48,160 authors from 106 countries were selected. The number of publications has significantly increased. In the last two decades, the USA was the most productive country and received the highest citations. The most productive journal was Investigative Ophthalmology and Visual Science and received the highest number of citations. Moorfields Eye Hospital was the most productive institution. Bandello F published the most papers, while Spaide RF was the highest cited author. SPAIDE RF, 2011, AM J Ophthalmology was the most cited document. "OCT", "glaucoma" and "OCTA" were three hotspots in the last two decades. "Vessel density" and "deep learning" would be research hotspots in the future. CONCLUSION: The bibliometric analysis of ophthalmic OCT and OCTA research over the past two decades on keywords, authors, citations, hotspots and trends will provide global researchers with valuable information for future research and cooperation.

Evaluation of optical coherence tomography angiography and pattern and flash electroretinography in diabetes mellitus without retinopathy.

PURPOSE: To evaluate the findings and the correlation of optical coherence tomography angiography and pattern and flash electroretinography in diabetes mellitus without retinopathy. METHODS: Seventy-six eyes of 38 diabetic patients and age- and gender-matched control subjects were included in the study. The foveal avascular zone (FAZ), whole, foveal, parafoveal and perifoveal vascular densities of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillary plexus (CCP) layers were analyzed using optical coherence tomography angiography (OCTA). The amplitudes and implicit times of P50 and N95 waves of the pattern ERG (pERG) and the amplitudes and implicit times of the scotopic and photopic b-waves and oscillatory potentials (OP) of the flash ERG (fERG) tests were evaluated using the Metrovision brand monpack model device. RESULTS: The mean age of the patients was 59.7 ± 7.9 [range 43-79] years. Eighteen (47%) of the patients were female and 20 (53%) were male. The mean duration of diabetes was 7.45 ± 6.2 [range 1-20] years. No significant difference in FAZ area was found between study subjects and controls. Vascular density (VD) values of the superficial capillary plexus (SCP) layer were significantly lower (whole VD, 44.7 ± 3.3 vs. 46.6 ± 3.2%, p = 0.01, foveal VD 16.8 ± 6.4 vs. 24.9 ± 6.1%, p < 0.01, parafoveal VD 45.6 ± 4.5 vs. 47.1 ± 4.4%, p = 0.27 and perifoveal VD 45.5 ± 3.3 vs. 47.3 ± 3.1%, p = 0.01, respectively) in the diabetic group except the parafoveal area. VD measurements in deep and choriocapillary plexuses did not significantly differ between the groups (p > 0.05). ERG tests revealed significantly lower scotopic b-wave amplitudes (130.2 ± 39.3 µV vs.163.3 ± 47.8 µV, p < 0.01) and photopic b-wave amplitudes (83.2 ± 20.7 µV vs. 99.6 ± 29.4 µV, p < 0.01) in the diabetic patients. The implicit time of the photopic responses was significantly prolonged (28.9 ± 1.3 ms vs. 27.8 ± 2.1 ms, p = 0.01) in the patients. Oscillatory potentials in all components consisting of O1 to O4 and the sum of the OP potentials were lower in the diabetic group than the control subjects (p < 0.001). The P50 and N95 amplitudes and implicit times were comparable between the groups (p > 0.05). Correlation analysis showed a positive correlation between N95 amplitudes in pERG and the superficial vessel densities in OCTA (r = 0.26, p = 0.04). A negative correlation was found between photopic implicit times in fERG and the choriocapillary vessel densities (r=-0.27, p = 0.03). CONCLUSION: OCTA revealed decreased superficial vascular densities with the onset of the metabolic process of diabetes mellitus. As a result of these structural changes, lower scotopic and photopic amplitudes, decreased OP amplitudes, and prolonged implicit times in flash ERG were obtained.

Internal limiting membrane peeling for large macular holes induces only structural remodeling without functional impairment over 12 years.

PURPOSE: To evaluate the very long-term functional and structural outcomes of internal limiting membrane (ILM) peeling for full-thickness macular holes (FTMH). DESIGN: Observational case series nested within a multicenter, randomized, controlled clinical trial (RCT) (ClinicalTrials.gov: NCT00190190). SUBJECTS: Patients who underwent vitrectomy with or without ILM peeling for an idiopathic large FTMH in a tertiary ophthalmology center, with a minimum follow-up of 10 years after surgery. METHODS: Review of charts, spectral domain optical coherence tomography (SD-OCT) scans, OCT-angiography (OCT-A) scans, and microperimetry of patients originally enrolled in the RCT. MAIN OUTCOME MEASURES: Primary outcome was functional assessment in both groups (ILM peeling or not) including the retinal sensitivity (RS), distance and near best-corrected visual acuity (BCVA), number of eyes achieving ≥0.3 logMAR more than 10 years after surgery. Secondary outcomes were structural assessment in the entire 3x3mm and 6x6mm areas, and regionally in the different areas of the ETDRS grid: OCT and OCT-A biomarkers in both groups and fellow eyes. RESULTS: Thirteen eyes of 13 patients with a mean follow-up of 12 ±0.73 years were included. The mean RS and BCVA, or visual improvement did not differ between ILM peeling (n=8) and no peeling (n=5) (all p>0.05). The dissociated optic nerve-fiber layers on en-face OCT were only observed in eyes with ILM peeling, predominantly in temporal parafoveal (20%) and perifoveal (19%) rings. The mean total retinal thickness and inner retinal thickness in the parafoveal ring were significantly lower in peeled eyes (309 ±11 µm and 94 ±9 µm respectively) versus non-peeled eyes (330 ±21 µm and 108 ±11 µm respectively; p=0.037 and p=0.040), without significant difference in ganglion cell or retinal nerve fiber layers. Accordingly, the mean superficial capillary plexus density in the parafoveal ring was significantly lower in eyes with peeling versus without, (39.65 ±3.76 % versus 47.22 ±4.00; p=0.005). The mean foveal avascular zone area was smaller in eyes with peeling versus without (0.24 ±0.05 mm2 versus 0.42 ±0.13 respectively, p=0.005), CONCLUSION: Despite persistent structural changes especially in the parafoveal ring, ILM peeling for idiopathic large FTMH did not appear to impact long-term RS or BCVA over 12 years.

A Comparison of Optical Coherence Tomography Angiography Metrics and Artifacts on Scans of Different Sizes in Diabetic Macular Ischemia: The effect of different size scans on DMI evaluation.

PURPOSE: Changes in the foveal avascular zone (FAZ) metrics over time are key outcome measures for clinical trials in diabetic macular ischemia (DMI). However, artifacts and automatically delineated FAZ measurements may influence the results. We aimed to compare the artifact frequency and FAZ metrics on 3 × 3 versus 6 × 6 mm optical coherence tomography angiography (OCTA) macular scans in patients with DMI. DESIGN: Prospective, comparative image quality analysis with one-year follow-up. METHODS: Patients with diabetic retinopathy (DR) were recruited if they presented with OCTA evidence of DMI, defined as an automated FAZ (aFAZ) ≥0.5 mm2 or parafoveal capillary nonperfusion (CNP) ≥1 quadrant if the aFAZ <0.5 mm2. Only those who had both size scans were included in the analysis. The types of artifacts and FAZ delineation errors were graded before manual correction. After excluding scans with poor quality, the aFAZ, corrected FAZ (cFAZ), whole image superficial vessel density (wiSVD), and whole image deep vessel density (wiDVD) were compared on both size scans. RESULTS: Fifty-seven patients (81 eyes) with paired OCTA 3 × 3 and 6 × 6 mm scans at baseline were included in the image quality analysis. The 6 × 6 mm scan presented with more severe motion artifact (P = .02). Conversely, the 3 × 3 mm scans were more susceptible to mild decentration (P = .009). After removing all the poor-quality images, 55 eyes with both size scans entered the longitudinal analysis. The 3 × 3 mm FAZ was significantly larger than the 6 × 6 mm FAZ using either aFAZ or cFAZ (both P < .05). In contrast, the 6 × 6 mm wiSVD and wiDVD were remarkably higher than those on the 3 × 3 mm scans (both P < .001). There was a steady increase in cFAZ over one year on both size scans (both P < .01). However, the 3 × 3 mm aFAZ decreased numerically at 52 weeks (P = .02). After reviewing all the scans, poor identification of parafoveal CNP was the most common reason for erroneous aFAZ delineation. CONCLUSIONS: In DMI, the FAZ metrics are best evaluated on the 3 × 3 scan due to better resolution. However, manual correction of the FAZ margin is needed. The frequency of artifacts and aFAZ delineation errors suggest that further technical refinement is required.

Foveal avascular zone area measurement in diabetic patients: Superficial, deep or combined retinal vascular complex?

PURPOSE: To compare differences in the foveal avascular zone (FAZ) area, measured in the Superficial Vascular Complex (SVC), Deep Vascular Complex (DVC) and a combined analysis of both (SDVC), using two Spectral Domain OCT angiography (OCT-A) protocols, High Speed (HS) and High Resolution (HR). METHODS: A total of 26 eyes of diabetic patients, with and without macular oedema, were examined with two different fovea centered OCT-A volume scans. The two protocols were HS and HR volume scans, and the foveal avascular zone was manually measured in the SVC, DVC, and SDVC slabs by two masked investigators. Inter and intraoperator variability was analysed using Intraclass Correlation Coefficient (ICC) and differences were compared between the HR and HS acquisitions throughout the different vascular slabs. RESULTS: Intraoperator variability was low in all slabs (ICC > 0.9) and interoperator variability was lower for HR (ICC 0.835-0.911) compared to HS (ICC between 0.604 and 0.865). Comparing HS and HR measurements for the same slab, the correlation was only moderate in SVC and DVC (ICC was 0.640 and 0.568 respectively) but was good in the SDVC (ICC = 0.823). FAZ area measurement in SDVC also showed the smallest bias (mean difference 0.009 mm2) and the narrowest limits of agreement (-0.175 to 0.193 mm2). CONCLUSIONS: Even in cases of diabetic macular oedema, when measuring the FAZ area, the reproducibility was better between HS and HR protocols when using the SDVC slab, compared to the SVC or DVC slabs alone. Further studies should evaluate the use of the combined SDVC slab for the FAZ assessment, compared to the SVC and DVC slabs alone, in the detection and progression of different retinal diseases.

Harnessing deep learning for detection of diabetic retinopathy in geriatric group using optical coherence tomography angiography-OCTA: A promising approach.

The prevalence of diabetic retinopathy (DR) among the geriatric population poses significant challenges for early detection and management. Optical Coherence Tomography Angiography (OCTA) combined with Deep Learning presents a promising avenue for improving diagnostic accuracy in this vulnerable demographic. In this method, we propose an innovative approach utilizing OCTA images and Deep Learning algorithms to detect diabetic retinopathy in geriatric patients. We have collected 262 OCTA scans of 179 elderly individuals, both with and without diabetes, and trained a deep-learning model to classify retinopathy severity levels. Convolutional Neural Network (CNN) models: Inception V3, ResNet-50, ResNet50V2, VggNet-16, VggNet-19, DenseNet121, DenseNet201, EfficientNetV2B0, are trained to extract features and further classify them. Here we demonstrate:•The potential of OCTA and Deep Learning in enhancing geriatric eye care at the very initial stage.•The importance of technological advancements in addressing age-related ocular diseases and providing reliable assistance to clinicians for DR classification.•The efficacy of this approach in accurately identifying diabetic retinopathy stages, thereby facilitating timely interventions, and preventing vision loss in the elderly population.

Diameter-dependent classification of dermal vasculature using optical coherence tomography angiography.

Background: Dermal blood vessels beneath the epidermis play critical roles in epidermal homeostasis and are functionally divided into several types, such as capillaries. Optical coherence tomography angiography (OCTA) is a powerful tool for the non-invasive assessment of dermal vasculature. However, the classification of vessel types has been limited. To address this issue, we proposed an algorithm for diameter-dependent classification that preserves three-dimensional (3D) information using OCTA. Methods: OCTA data were acquired by a prototype swept-source-type optical coherence tomography (OCT) system, which was processed through several imaging filters: an optical microangiography (OMAG) imaging filter, a vesselness imaging filter, and a diameter map filter. All vessels were visually classified into three types based on their diameters, as micro-vessels, intermediate vessels, and thick vessels. Aging-related alterations and their association with the epidermis were investigated for each vessel type. The measurements were conducted on the cheeks of 124 female subjects aged 20-79 years. Results: The 3D vascular structure was visualized by applying our proposed post-processing filters. Based on visual assessment, the thresholds for the diameters of the micro, intermediate and thick vessels were set at 80 and 160 µm. It was found that micro-vessels were predominantly located in the upper layer of the dermis and thick vessels in the deeper layer. Analysis of vessel metrics revealed that the volume density of the micro-vessels decreased significantly with age (r=-0.36, P<0.001) and was positively correlated with epidermal thickness (r=0.50, P<0.001). In contrast, the volume density of thick vessels significantly increased with age (r=0.2, P<0.05) and was not significantly correlated with epidermal thickness (r=0.13, P≥0.05). Conclusions: In this study, we proposed a 3D quantification method using OCTA for dermal blood vessels and various vessel metrics, such as vessel volume density. This proposed classification will be beneficial for determining the function of the dermal vasculature and its diagnostic applications.

Inter-eye asymmetry of microvascular density in patients on hydroxychloroquine therapy by optical coherence tomography angiography.

AIMS: To explore the inter-eye retinal microvascular density asymmetry of patients on hydroxychloroquine (HCQ) therapy through optical coherence tomography angiography (OCTA). METHODS: 40 subjects were enrolled in this cross-sectional study, including 20 systemic lupus erythematasus patients currently treated with HCQ (40 eyes) and 20 age- and sex-matched normal controls (NCs, 40 eyes). OCTA images were obtained to measure macular and peripapillary mircrovasculatures and microstructures, including vessel density, retinal nerver fiber layer thickness, and peripapillary ganglion cell-inner plexiform layer thickness. The absolute values of the difference between right and left eyes were taken as a measure of inter-eye asymmetry. RESULTS: Macular whole image vessel density (wiVD-M) and perifoveal vessel density (pfVD) of superficial capillary plexus (SCP) were notably reduced in both the right and left eyes of the HCQ treatment group compared with NCs. Specifically, SLE patients treated with HCQ have higher inter-eye asymmetry of wiVD-M of SCP (2.28 ±â€¯1.03 vs 1.27 ±â€¯0.79, p < 0.01) and pfVD of SCP (2.55 ±â€¯1.26 vs 1.78 ±â€¯1.06, p = 0.04) compared with NCs. There were no significant differences in inter-eye asymmetry of structure parameters. Inter-eye asymmetry of wiVD-M of SCP (AUC = 0.80, p < 0.01) and pfVD of SCP (AUC = 0.71, p = 0.02) exhibited greater discrimination power. CONCLUSION: SLE Patients treated with HCQ exhibited a notably higher inter-eye vessel density asymmetry compared to that of NCs. Thus, inter-eye vessel density asymmetry could be used to screen for HCQ retinal toxicity.

Comparison of macular thickness in diabetic patients acquired from optical coherence tomography mode and optical coherence tomography angiography mode in Cirrus HD-OCT 5000.

PURPOSE: To compare macular thickness obtained using two different modes of image acquisitions with Cirrus HD-OCT 5000. METHODS: Patients with diabetes were recruited and macular thickness were obtained using optical coherence tomography (OCT) mode and optical coherence tomography angiography (OCTA) mode. The OCT mode involved a Macular Cube (512×128 pixels) centred on the fovea covering a 6 × 6 mm2 macular region. The OCTA acquisition involved scanning of a 6 × 6 mm² scan (350×350 pixels) centred on the fovea. Data was exported and compared according to the Early Treatment Diabetic Retinopathy Study (ETDRS) subfields. Fixation deviation was defined as the deviation of the foveal point from the grid center in the OCT scan and OCTA scan. RESULTS: Eighty-six diabetic patients were recruited had similar macular thickness in all ETDRS subfield except the superior outer sector. The 95 % limits of agreement between the two modes were within 9.7µm to -9.0µm. It took longer to complete each OCTA mode (median of 7.4 s) than the OCT mode (median time of 5.8 s) (Wilcoxon test, p < 0.001), but OCTA generated a smaller fixation deviation (median 68.8µm) than the OCT mode (median 103.0µm) (Wilcoxon test, p = 0.014). CONCLUSIONS: Improved fixation in OCTA compared with OCT was evident, likely because of the faster scanning speed and higher sampling density of OCTA. Macular thickness was found similar. There appears no requirement to obtain macular thickness measurements using a separate OCT mode. This approach can reduce patient chair time, improve patient comfort, and streamline the clinical workflow.

Macular vascular density alteration patterns in paediatric optic neuritis patients with serum MOG antibody positivity detected by optic coherence tomography angiography.

PURPOSE: The retinal microvascular network plays a crucial role in inflammatory injury in paediatric optic neuritis (PON) with serum MOG antibody positivity (MOG + PON). This study compared retinal microvascular densities and structural alterations in MOG + PON eyes with paediatric isolated optic neuritis (PION) eyes and followed up with the final best-corrected visual acuity (BCVA) after 6 months. METHODS: A total of 29 children (52 eyes) with PON, including 15 MOG + PON cases (28 eyes), 6 PION cases (10 eyes), 2 neuromyelitis optica spectrum disorders associated PON(NMOSD-PON) cases (4 eyes), 6 MOG-associated disease (MOGAD) patients without ON-affected eyes (MOG + NPON) cases (10 eyes) and age- and gender-matched healthy controls (HCs) underwent superficial/deep retinal angiography density (SAD/DAD) by optical coherence tomography angiography (OCTA). Their BCVAs were followed up until 6 months after PON onsets. RESULTS: MOG + PON cases had better final BCVAs than PION and NMOSD-ON. MOG + PON (35.7 ± 10.3 %) and PION (40.1 ± 10.3 %) eyes experienced severe SAD reductions in contrast to MOGAD+NPON (48.7 ± 5.2 %) and HCs eyes (55.6 ± 8.2 %). However, DAD in MOG + PON eyes (48.5 ± 9.2 %) and MOG + NPON eyes (53.1 ± 3.3 %) increased compared to HC eyes (45.7 ± 9.6 %; p = 0.028 and 0.009, respectively). SAD reduction occurred in acute PON and was detected as early as 2 weeks after PON onset. CONCLUSIONS: MOG + PON eyes had better final BCVAs than PION eyes, which displayed superficial retinal microvascular perfusion reductions and deep microvascular perfusion increases. SAD could be a sensitive surrogate for PON attacks in children with MOGAD.

Comparative of OCT and OCTA parameters in patients with early chronic angle-closure glaucoma and early pituitary adenoma.

Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) have the potential application in evaluating pathological structural change of the optic nerve. We aimed to evaluate the value of the OCT and OCTA parameters of the optic disk and macular in differentiating early chronic primary angle-closure glaucoma (CPACG) and early pituitary adenoma (PA) in case of mild visual field defects (the mean defect (MD) > 6 dB). The results showed that regarding OCTA parameters, CPACG patients had lower retinal blood flow density of most layers of the optic disk and macular than PA patients. Regarding OCT parameters, CPACG patients had thinner circumpapillary retinal nerve fiber layer (CP-RNFL) in all quadrants and average CP-RNFL, ganglion cell layer (GCL) and macular ganglion cell complex (GCC) in each quadrant of macular inner and outer rings, and inner plexus layer (IPL) of macular inner ring, superior-outer ring and temporal-outer ring than PA patients. The Z test indicated that OCTA parameters and OCT parameters had similar value in the diagnosis of disease. In conclusion, in the case of similar visual field damage, early CPACG patients have smaller blood flow density and thinner optic disk and macular than early PA. OCTA has similar performance to OCT in diagnosing CPACG and PA.

The Effect of Cryotherapy on Buccal Blood Vessels Evaluated by Optical Coherence Tomography Angiography: A Pilot Study.

While cryotherapy is one of the traditional ways to reduce postoperative complications in maxillofacial surgery, the cooling degree is not regulated in most cases and the achieved effect is not properly controlled. Therefore, to develop optimal cooling modes, we propose to study the buccal vascular response to cooling, which has not been previously shown. To evaluate the effect of cooling, we analyzed vessel networks using optical coherence tomography angiography (OCT-A). The cheek vessels were OCT-A monitored using cooling by an ice bag/cooling mask. We found the advantages of using a cooling mask over an ice bag consist of a statistically significant decrease in the perfused vessel density (PVD) of the papillary layer at the oral mucosa. The absence of the reticular layer vessel reaction to any type of cooling was noted. We argue for the necessity to develop optimal modes of cryotherapy, which will contribute to blood perfusion reduction and reduction of PVD recovery.

Investigation of optical coherence tomography angiography findings in patients with bipolar disorder.

OBJECTIVES: Bipolar Disorder (BD) is an important psychiatric disease that progresses with attacks, can be chronic and causes serious mental problems. In this study, we aimed to identify the retinal vascular pathologies in BD patients by optical coherence tomography angiography (OCTA) imaging. METHODS: Retinal vascular analysis from 35 BD patients and 30 healthy controls (HCs) were scanned using the OCTA machine. In addition, psychometric tests such as the Young Mania Rating Scale (YMRS) and Clinical Global Impression Scale (CGI-S) were applied to BD patients to assess the severity of the disease and determine the patient's level of functionality. RESULTS: As a result of OCTA scans, there were significant differences between the groups as following; Deep retinal vessel density (VD) in the total, parafoveal and perifoveal area, Macular thickness in the inner parafoveal area, VD of retinal capillary plexuses in the inside disk and the Choroidal thickness (p < 0.05). Furthermore, according to the results of Pearson correlation analysis between OCTA scans and YMRS and CGI-S scores, it was determined that there was no significant relationship in any measurement (p > 0.05). CONCLUSION: In our study, it was determined that there were general differences in deep retinal vascular density and inner macular thickness in BD patients. These findings demonstrate that the deep and inner zone of the retina is affected in BD patients.

The role of Perifoveal Arteriolar Tortuosity in Optical Coherence Tomography Angiography (OCTA) images as an early indicator of hypertensive retinopathy.

PURPOSE: To assess the value of increased perifoveal retinal vascular tortuosity in optical coherence tomography angiography (OCTA) images as a biomarker of early hypertensive retinopathy and compare its clinical sensitivity and accuracy with traditional morphological changes used for Scheie classification. METHODS: OCTA images of 81 eyes (40 eyes from 20 hypertensive subjects and 41 eyes from 21 control subjects) were obtained retrospectively. Hypertensive retinopathy changes in randomized eyes were graded according to the Scheie classification, and perifoveal vessels were traced in a masked fashion. Tortuosity values of the perifoveal vessels were then calculated along with interobserver agreement in determining the morphometric values. RESULTS: There were no differences in perifoveal venular tortuosity between the hypertensive and control groups (Mean = 1.13 ± 0.04 vs. 1.13 ± 0.03), but significant differences existed for arterioles (Mean = 1.14 ± 0.05 vs. 1.11 ± 0.04). Tortuosity measurements demonstrated a significant interobserver agreement (p < 0.001), while Scheie ratings had a poor interobserver agreement (p = 0.735). There was a significant difference in Scheie classification between the hypertensive and control groups (Mean = 1.06 ± 0.54 vs. 0.50 ± 0.43, p = 0.005). CONCLUSIONS: OCTA-based perifoveal retinal arteriolar tortuosity may be a potential reliable biomarker with certain advantages for detecting early hypertensive retinopathy than morphological changes used for the Scheie classification. This may have broad applications and establish important parameters in utilizing OCTA for screening protocols, considering the importance of early detection of systemic hypertension.

Optical coherence tomography angiography of the retina and choroid in systemic diseases.

Optical coherence tomography angiography (OCTA) has transformed ocular vascular imaging, revealing microvascular changes linked to various systemic diseases. This review explores its applications in diabetes, hypertension, cardiovascular diseases, and neurodegenerative diseases. While OCTA provides a valuable window into the body's microvasculature, interpreting the findings can be complex. Additionally, challenges exist due to the relative non-specificity of its findings where changes observed in OCTA might not be unique to a specific disease, variations between OCTA machines, the lack of a standardized normative database for comparison, and potential image artifacts. Despite these limitations, OCTA holds immense potential for the future. The review highlights promising advancements like quantitative analysis of OCTA images, integration of artificial intelligence for faster and more accurate interpretation, and multi-modal imaging combining OCTA with other techniques for a more comprehensive characterization of the ocular vasculature. Furthermore, OCTA's potential future role in personalized medicine, enabling tailored treatment plans based on individual OCTA findings, community screening programs for early disease detection, and longitudinal studies tracking disease progression over time is also discussed. In conclusion, OCTA presents a significant opportunity to improve our understanding and management of systemic diseases. Addressing current limitations and pursuing these exciting future directions can solidify OCTA as an indispensable tool for diagnosis, monitoring disease progression, and potentially guiding treatment decisions across various systemic health conditions.