UNASSIGNED: To investigate the longitudinal alterations of retinal microvasculature in patients with primary coronavirus disease 2019 (COVID-19) infection.
UNASSIGNED: A cohort of participants, who had never been infected with COVID-19, was recruited between December 2022 and May 2023 at Peking Union Medical College Hospital in Beijing, China. Participants underwent comprehensive ophthalmologic examinations and fundus imaging, which included color fundus photography, autofluorescence photography, swept-source optical coherence tomography (SS-OCT) and SS-OCT angiography (SS-OCTA). If participants were infected with COVID-19 during the study, follow-ups with consistent imaging modality were conducted within one week and two months after recovery from the infection.
UNASSIGNED: 31 patients (61 eyes), with a mean age of 31.0 ± 7.2 years old, were eligible for this study. All participants contracted mild COVID-19 infection within one month of baseline data collection. The average period was 10.9 ± 2.0 days post-infection for the first follow-up and 61.0 ± 3.5 days for the second follow-up. No clinical retinal microvasculopathy features were observed during the follow-ups. However, SS-OCTA analysis showed a significant increase in macular vessel density (MVD) from 60.76 ± 2.88% at baseline to 61.59 ± 3.72%(p=0.015) at the first follow-up, which subsequently returned to the baseline level of 60.23 ± 3.33% (p=0.162) at the two-month follow-up. The foveal avascular zone (FAZ) remained stable during the follow-ups with areas of 0.339 ± 0.097mm2, 0.342 ± 0.093mm2, and 0.344 ± 0.098mm2 at the baseline, first follow-up (p=0.09) and second follow-up (p=0.052), respectively. Central macular thickness, cube volume and ganglion cell-inner plexiform layer showed a transient decrease at the first follow-up(p<0.001, p=0.039, p=0.002, respectively), and increased to baseline level at the two-month follow-up(p=0.401, p=0.368, p=0.438, respectively).
UNASSIGNED: Mild COVID-19 infection may temporarily and reversibly impact retinal microvasculature, characterized by a transient increase in retinal blood flow during the early recovery phase, which returns to the pre-infection level two months post-infection.

UNASSIGNED: With the improvement of the level of science and technology, diagnosis and treatment technology of ophthalmology has continuously improved, especially with the rise of optical coherence tomography. Alternative methods have enabled clinicians to obtain more information and make greater breakthroughs in the occurrence and development of many ophthalmic diseases.
UNASSIGNED: To investigate changes in retinal structure in the macular area of senile diabetic cataract patients undergoing cataract phacoemulsification.
UNASSIGNED: This was a prospective cohort study. A total of 68 cataract patients (78 eyes) who voluntarily received phacoemulsification combined with intraocular lens implantation in the Department of Ophthalmology of our hospital from December 2018 to December 2021 were selected. They were divided into A (diabetic) and B (non-diabetic) according to whether they were complicated with diabetes. There were 24 cases (28 eyes) in A and 44 cases (50 eyes) in B. Cataract patients were collected before and after surgery. Day, 1 week, and 1 month, data on the average thickness of the fovea retina and thickness of the retinal nerve fiber layer around the optic disc (average thickness, nasal thickness, topic side thickness, upper thickness, and lower thickness) were statistically analyzed analyze.
UNASSIGNED: The average retinal thickness of the macular fovea in Group A was found to be greater than that of Group B, however, there was no statistically significant difference between the two groups. At week one and week thirty, Group A\'s layer of retinal nerve fibers surrounding the optic disc thickened; there was no discernible difference between the two groups. One week and one month following surgery, however, showed a one-week difference in upper thickness compared to preoperative days. There was no discernible change between the preoperative and 1-day times.
UNASSIGNED: Both diabetic cataract patients and simple age-related cataract patients will have different degrees of increased foveal retinal thickness after surgery. However, the foveal retinal thickness of patients with diabetes increases more.

OBJECTIVE: To analyze the progression of structural and functional retinal impairment in type 1 diabetes mellitus (T1DM) patients with no clinical signs of diabetic retinopathy (DR) during a 3-year follow-up.
METHODS: This was an observational longitudinal study. Post-pediatric T1DM patients without clinical signs of DR, and sex- and age-matched healthy subjects were recruited at San Raffaele Hospital (Milan, Italy). Each patient underwent a comprehensive ophthalmological evaluation, including optical coherence tomography (OCT), OCT-angiography (OCT-A), retinal static and dynamic vessel analysis (DVA), and microperimetry.
RESULTS: 21 eyes of 21 T1DM patients (10 females; 24 ± 2 years old), and 21 age and sex-matched healthy subjects were enrolled. At baseline, T1DM eyes revealed a significantly decreased vessel length density using OCT-A (p < 0.001 and p = 0.046 in 3 × 3 and 6 × 6 mm images) and a significantly increased vessel density index (p = 0.013 and p = 0.087 in 3 × 3 and 6 × 6 mm images) of deep capillary plexus. DVA detected a significantly decreased vessel response to flicker light (p = 0.002). A significantly increased thickness of ganglion cellular layer 6-mm-diameter subfields in inferior and superior quadrants was found in diabetic patients (p < 0.001 in both subfields). At 3-years-follow-up no significant longitudinal changes were disclosed in all analyses.
CONCLUSIONS: Concomitant subclinical microvascular and neurodegenerative damages could be early signs of DR onset that precede functional alterations and clinical signs of DR development. These alterations demonstrated a stable trend over time.

Background and Objectives: Given the conflicting data available in the literature, this study aimed to investigate the impact of obstructive sleep apnea syndrome (OSAS) on the macular vascular density (VD) and perfusion density (PD). Materials and Methods: Based on the obstructive apnea-hypopnea index (OAHI), 61 prospectively recruited patients were assigned to either a control group (n = 12; OAHI < 5/h) or an OSAS group (n = 49; OAHI ≥ 5/h). The macular VD and PD of the superficial and deep capillary plexuses (SCP and DCP, respectively) were measured in the parafoveolar and perifoveolar areas using Zeiss PLEX Elite 9000 (6 × 6 mm). The values were compared between the control and OSAS groups. Results: Compared with the control group, the OSAS group demonstrated an increased VD of the DCP in the parafoveolar and perifoveolar areas and PD of the DCP in the perifoveolar area. No significant differences in either the macular VD or PD of the SCP were observed. There was no correlation between the OAHI and macular VD or PD. Conclusions: This study indicates that collateral vessel formation and possible retinal vasodilation occur in the DCP of patients with OSAS.

OBJECTIVE: To assess the repeatability, interocular correlation, and agreement of quantitative swept-source optical coherence tomography angiography (OCTA) optic nerve head (ONH) parameters in healthy subjects.
METHODS: Thirty-three healthy subjects were enrolled. The ONH of both eyes were imaged four times by a swept-source-OCTA using a 3 mm ×3 mm scanning protocol. Images of the radial peripapillary capillary were analyzed by a customized Matlab program, and the vessel density, fractal dimension, and vessel diameter index were measured. The repeatability of the four scans was determined by the intraclass correlation coefficient (ICC). The most well-centered optic disc from the four repeated scans was then selected for the interocular correlation and agreement analysis using the Pearson correlation coefficient, ICC and Bland-Altman plots.
RESULTS: All swept-source-OCTA ONH parameters exhibited certain repeatability, with ICC>0.760 and coefficient of variation (CoV)≤7.301%. The obvious interocular correlation was observed for papillary vessel density (ICC=0.857), vessel diameter index (ICC=0.857) and fractal dimension (ICC=0.906), while circumpapillary vessel density exhibited moderate interocular correlation (ICC=0.687). Bland-Altman plots revealed an agreement range of -5.26% to 6.21% for circumpapillary vessel density.
CONCLUSIONS: OCTA ONH parameters demonstrate good repeatability in healthy subjects. The interocular correlations of papillary vessel density, fractal dimension and vessel diameter index are high, but the correlation for circumpapillary vessel density is moderate.

UNASSIGNED: The retina is a protrusion of the brain, so researchers have recently proposed retinal changes as a new marker for studying central nervous system diseases. To investigate optic nerve head neurovascular structure assessed by optical coherence tomography angiography (OCTA) in schizophrenia compared to healthy subjects.
UNASSIGNED: The study was conducted from 2019 to 2021 at the Ibn Sina Psychiatric Hospital in Mashhad, Iran. We enrolled 22 hospitalized known cases of schizophrenia, treated with risperidone as an antipsychotic drug, and 22 healthy subjects. The two groups were matched in age and gender. In the schizophrenic group, the positive and negative syndrome scale test was used to assess the illness severity. All subjects underwent complete ophthalmic evaluations and OCTA imaging.
UNASSIGNED: We found that the cup/disc area ratio, vertical cup/disc ratio, and horizontal cup/disc ratio are significantly higher in patients with schizophrenia than in healthy subjects (with p-values of 0.019, 0.015, and 0.022, respectively). No statistically significant difference in the peripapillary retinal nerve fiber layer and vascular parameters of the optic nerve head was observed between schizophrenia and healthy groups.
UNASSIGNED: We found evidence regarding the difference in the optic nerve head tomographic properties in schizophrenia compared to healthy subjects. However, ONH vascular parameters showed no significant difference. More studies are needed for a definite conclusion.

OBJECTIVE: To evaluate longitudinal changes in optical coherence tomography angiography (OCTA) metrics in children and adolescents with type 1 diabetes (T1D).
METHODS: This prospective observational cohort study included thirty-two eyes from thirty T1D children with no history of diabetic retinopathy (DR) who were followed up for 4 years. Participants underwent OCTA examinations at baseline and during follow-up. Quantitative OCTA metrics were measured using a customized MATLAB algorithm. Generalized mixed-effect models were used to determine their relationship with DR development. Systemic parameters and OCTA metrics were screened using least absolute shrinkage and selection operator to identify predictors for visual function.
RESULTS: Over the 4-year period, seven of the included eyes developed DR, and most OCTA metrics decreased with diabetes duration. Higher peripapillary and parafoveal nasal quadrant vessel area density (VAD) in the superficial capillary plexus (SCP) and vessel skeleton density (VSD) in both the SCP and the deep capillary plexus (DCP) were associated with a lower risk of DR in T1D. Parafoveal DCP VSD and VAD in the temporal and inferior quadrants were anticorrelated with changes in best corrected visual acuity.
CONCLUSIONS: OCTA metrics dynamically change over the duration of diabetes and can be used as biomarkers to improve the risk evaluation of DR development and visual function in T1D children and adolescents.

BACKGROUND: We aimed to employ Optical Coherence Tomography Angiography (OCTA) to comprehensively assess changes in the optic nerve head (ONH) and macular perfusion before and after the Corneal Collagen Cross-Linking (CCL) procedure in patients with keratoconus.
METHODS: A total of 22 keratoconus patient\'s candidate for CCL procedures were included based on specific criteria, with meticulous exclusion criteria in place to minimize potential confounders. Participants underwent OCTA assessments of the ONH and macula using the Spectralis OCT (Heidelberg) before CCL, as well as at 1- and 3-months post-CCL. MATLAB software was utilized for image analysis.
RESULTS: The mean age of the participants was 20.09 ± 6.11, including 59% male, and the mean intraocular pressure (IOP) before the surgery was 13.59 ± 2.85 mmHg. Peripapillary Retinal nerve fiber layer (ppRNFL) thickness and overall retinal thickness remained stable post-CCL. However, significant alterations were observed in macular vessel density, emphasizing regional variations in vascular response. For macular large vessel density (LVD), both superficial and deep vascular complex (SVC and DVC) demonstrated significant differences between before surgery and the 3 months post-surgery follow-up (p < 0.001 and p = 0.002, respectively). Optic nerve head markers demonstrated relative stability, except for changes in avascular complex density, which was 49.2 ± 2.2% before the surgery and decrease to 47.6 ± 1.7% three months after the operation (P-value = 0.005).
CONCLUSIONS: While CCL appears to maintain the integrity of certain ocular structures, alterations in macular perfusion post-CCL suggest potential effects on retinal blood supply. Long-term monitoring is crucial to understand the implications of these changes, particularly in the context of conditions such as diabetes.

BACKGROUND: The aim of the study was to detect the changes in retinal and choroidal vasculature via optical coherence tomography angiography (OCTA) by comparing the quantitative OCTA parameters in patients with and without myotonic dystrophies (DM).
METHODS: The cross-sectional study. Forty-one consecutive patients affected by DMs were enrolled. The inclusion criteria were molecular diagnosis of DM types 1 and 2. To avoid the age effect on microvascular changes and to justify a comparison between DM1 and DM2 patients, two control groups matched for sex and age were established.
RESULTS: The vascular density was found to be significantly decreased in the DM groups compared to the controls in the macular, parafoveal and perifoveal zone of superficial capillary plexus (p < 0.001 for the DM1 group, and p = 0.001, p = 0.005 and p = 0.026, respectively, for the DM2 group), as well as in the macular zone in the deep capillary plexus for DM1 (p = 0.002) and deep macular and perifoveal zone for DM2 (p = 0.007, p = 0.001, respectively). The foveal avascular zone showed no significant differences between DM1 and DM2 compared to their control groups (p = 0.320 and p = 0.945, respectively).
CONCLUSIONS: Our results show that DM is associated not only with the classic pigmentary changes but also with superficial and deep retinal microvasculature abnormalities, suggesting that these changes may be related to local hypoperfusion. Optical coherence tomography angiography is a useful tool for the diagnosis and characterization of retinal changes in DM and should be part of the standard evaluation of these patients.

OBJECTIVE: To determine the microvascular and structural changes in the peripapillary and macular areas observed in patients with active thyroid orbitopathy(TO) before and after steroid treatment and compare with inactive TO and the control group by optical coherence tomography angiography (OCTA).
METHODS: This cross-sectional study included 34 eyes of 17 active TO patients, 108 eyes of 54 inactive TO patients, and 60 eyes of 30 healthy controls. Central macular thickness (CMT), ganglion cell layer-inner plexiform layer (GCL-IPL) thickness, central choroidal thickness (CCT), retinal nerve fiber layer (RNFL) thickness, choroidal thickness in the peripapillary region, superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris vessel densities were determined by OCTA in before and after 12-week steroid treatment of active TO cases, inactive TO and control groups.
RESULTS: Between the three groups in macula OCTA, a statistically significant difference was observed in the inferior and nasal quadrants in SCP (all p = 0.01) and only in the temporal quadrant choriocapillaris (p = 0.005). In peripapillary OCTA, a statistically significant difference was found only in the central choriocapillaris (p = 0.03). In the comparison of the active group before and after treatment, there was a statistically significant decrease in CMT and CCT; a statistically significant increase was observed in GCL-IPL (all p < 0.01). There was a statistically significant decrease in SCP and DCP only in the central (all p < 0.01). There was a statistically significant increase was found in the lower quadrant macular SCP vessel density and mean macular DCP in post-treatment measurements (p = 0.01 and p = 0.03, respectively). Peripapillary SCP and DCP vessel density was increased after treatment (p < 0.01).
CONCLUSIONS: Active TO group had lower vessel density than inactive group and after treatment, vessel density was increased. Non-invasive quantitative analysis of retinal and optic disc perfusion using OCTA could be useful in early treatment before complications occur and monitoring patients with TO.