The diagnostic ability of peripapillary vessel density in primary open-angle glaucoma suspects.

OBJECTIVE: To assess the diagnostic ability of peripapillary vessel density (pVD) in primary open-angle glaucoma suspect (GS) patients. METHODS: Sixteen primary open-angle GS patients (22 eyes) and 20 normal controls (22 eyes) were included. In the GS group, OCTA measurements of pVD (superior, inferior, nasal, temporal, and global), OCT measurements of retinal nerve fiber layer (RNFL) thickness, disc area, rim area and ganglion cell complex (GCC) thickness were examined. In the control group, pVD measurements were performed. The vessel density between the two groups was compared. The correlation between OCTA and OCT parameters was evaluated. The receiver operating characteristic curve (ROC) was used to evaluate the diagnostic efficacy of OCTA measurements. RESULTS: The global (P<0.001), nasal (P=0.003), and inferior (P=0.002) quadrant pVD in GS group was considerably lower than the control group. The global pVD was positively correlated with the inferior RNFL thickness (r=0.492, P=0.023) and rim area (r=0.483, P=0.027). The inferior pVD was positively correlated with the inferior RNFL thickness (r=0.648, P=0.001), the nasal RNFL thickness (r=0.441, P=0.045), the rim area (r=0.439, P=0.046) and the GCC thickness (r=0.472, P=0.048). The global pVD had the best diagnostic value (AUC=0.825, sensitivity 86.36%, specificity 72.73%, cutoff value 45%), followed by the inferior (AUC=0.749) and nasal (AUC=0.748) quadrant pVD. CONCLUSION: In primary open-angle GS patients, the global and inferior quadrant pVD was lower than that of normal people, and it was positively correlated with the inferior RNFL thickness and rim area. The diagnostic value of pVD for discriminating GS from normal people was excellent with high sensitivity and specificity.

Study of the impact of the vascular systemic risk factors on peripapillary vascular density by optical coherence tomography angiography.

BACKGROUND: The focus of therapeutic tools in glaucoma has been mainly to control of intraocular pressure. Recently there has been a growing interest in investigating the relationship of vascular risk factors in the development of glaucoma. The aim of this study was to assess the association between systemic arterial hypertension, diabetes mellitus and hypercholesterolemia, and peripapillary vascularization measured by Optical Coherence Tomography Angiography (OCTA) in glaucoma and healthy subjects. METHODS: In this unicenter, observational, cross-sectional study, 212 subjects, 118 glaucoma patients and 94 controls were consecutively recruited. Of these, 86 participants were excluded due to poor OCTA image quality. Therefore, 146 subjects were included in the final analysis, 74 glaucoma patients and 72 controls. Using a linear regression model, with 95% confidence and 80% statistical power, the effect of vascular risk factors on OCTA parameters in the 146 subjects included in the final analysis was studied. RESULTS: No significant impact of vascular risk factors on OCTA measurements was found. Diabetic patients tended to show a lower peripapillary perfusion vascular density than subjects without diabetes (ß 0.016, 95%CI 0.003;0.030, p 0.016). Similarly, hypercholesterolemia patients appeared to show less peripapillary flow index than non-hypercholesterolaemic patients (ß 0.029, 95%CI 0.013;0.046, p 0.001). Glaucoma patients had 0.02% lower peripapillary perfusion vascular density (ß 0.020, 95% CI 0.011;0.029, p < 0.001), 0.04% lower peripapillary flow index (ß 0.036, 95%CI 0.022;0.051, p < 0.001) and 9.62% thinner retinal nerve fibre layer (ß 9.619, 95%CI 5.495;13.744, p < 0.001). CONCLUSIONS: In conclusion glaucoma has greater effect on peripapillary vascular density parameters than any of the vascular risk factors analyzed. KEY MESSAGES: What is known: • Vascular disfunction plays an important role in the development of glaucoma. • Optical coherence tomography angiography makes it possible to assess the retinal microvasculature and the role that its alterations could have in the development of glaucoma. WHAT IS NEW: • Decrease of the peripapillary microcirculation seems to be more related to the increase in intraocular pressure and the glaucoma itself than to the presence of cardiovascular risk factors. • The effect of having diabetes, systemic arterial hypertension or hypercholesterolaemia on vascular parameters or nerve fibre layer thickness was low. • There was also no relevant impact of the systemic medication used for these diseases on the peripapillary vascular parameters studied or on nerve fibre layer thickness.

OCTA-based research on changes of retinal microcirculation in digestive tract malignancy.

PURPOSE: This cross-sectional study measured retinal vessel density (VD) in patients with digestive tract malignancy by optical coherence tomography angiography (OCTA), and compared them with healthy controls to explore the retinal microcirculation changes in patients with digestive tract malignancy. METHODS: 106 eligible participants were divided into three groups: gastric cancer (GC) group (36 individuals), colorectal cancer (CRC) group (34 individuals), and healthy control group (36 individuals). Angio 6*6 512*512 R4 and ONH Angio 6*6 512*512 R4 modes were performed to collect retinal vessel density data centered on fovea and papillary, respectively. The retina was automatically segmented into different layers (superficial vascular plexus (SVP), the inner retinal layer, radial peripapillary capillary plexus (RPCP), deep vascular plexus (DVP)) and areas to analyze. RESULTS: At the optic nerve head (ONH) region, the VD of the inner retinal layer increased in both GC and CRC groups in all quadrants and areas. In the papillary area, VD in the inner retinal layer, SVP, and RPCP increased in the GC and CRC groups. In the parapapillary area, VD in the inner retinal layer increased in the GC and the CRC groups. Significant increase in the global VD were found in the GC group of the RPCP and SVP. Regarding the macular region, no statistical differences were observed in each layer. CONCLUSIONS: The study suggested that retinal vessel density changed in patients with digestive tract malignancy, especially in the inner retinal layer of the ONH region, revealing the potential relevance of the relation between gastrointestinal cancer and retinal microcirculation.

Optical Coherence Tomography-measured blood vessel characteristics of Port-Wine Birthmarks by depth: A cross-sectional study.

BACKGROUND: Port-Wine Birthmarks (PWB) are congenital capillary malformations requiring multiple treatments. Optical coherence tomography (OCT), a non-invasive imaging technique, characterizes vessels in cutaneous vascular lesions including PWBs. OBJECTIVE: To assess variability in blood vessel characteristics within and between individual PWBs. METHODS: OCT was used to measure blood vessel density (%) and modal vessel diameter (micrometres) at increments of 0.05 mm from skin surface to a depth of 0.50 mm at several adjacent spots of single PWBs in this cross-sectional study. Average ratios of vessel density and diameter in affected to control skin were obtained for each PWB by averaging data for all spots within a lesion. Statistical analysis was performed with linear mixed effects model using SPSS (IBM, Corp.). RESULTS: There was great variability in vessel density and diameter within and between PWBs. Depths where average ratios of vessel density were consistently greater in affected to control skin were shallow, between 0.15 - 0.2 mm deep from the skin surface. LIMITATIONS: Small sample size and device inability to measure diameters smaller than 20 micrometres. CONCLUSION: There is variability in vessel density and diameter within and between PWBs. Individualized treatment planning guided by OCT mapping should be studied further.

The impact of intraocular pressure on optical coherence tomography angiography: A review of current evidence.

A scoping review of 45 peer-reviewed manuscripts involving intraocular pressure (IOP) change and concurrent optical coherence tomography angiography (OCTA) assessments was performed to aggregate knowledge, summarize major findings, and identify gaps in literature and methodology relating to the effect of IOP change on OCTA. Articles were identified through PubMed/Medline, Google Scholar, Cochrane, Web of Science, and article reference lists. A total of 838 results were identified, and 45 articles met the inclusion and exclusion criteria for detailed analysis. OCTA metrics including vessel density (VD), perfusion density, and flow density of the superficial capillary plexus and the radial peripapillary capillaries were analyzed in relation to relative temporal IOP changes. Overall, IOP changes were found to affect superficial vascular plexus (VD) measurements on OCTA, especially when IOP elevated above the physiologic normal range (10-21 mmHg). No significant association was found between diurnal IOP variation and OCTA metrics. Cataract surgery improved the whole-image signal strength and VD regardless of changes in IOP. Beta-blockers were associated with paradoxically reduced vessel density in normal tension glaucoma patients in two studies. Although glaucoma surgical intervention studies were inconsistent and limited by scan quality and low sample sizes, patients requiring glaucoma surgery exhibited attenuated postoperative superficial VD recovery despite significant IOP reductions with surgical intervention. In addition to ensuring near-perfect signal strength with minimal media opacities and controlling for high myopia, central corneal thickness, and the presence of retinopathy, clinicians should consider the statistically significant impact of IOP on OCTA metrics when interpreting results.

Choroidal and retinal vascular changes in HLA-B27-associated anterior uveitis.

PURPOSE: To quantitatively analyze choroidal and retinal vascular changes in HLA-B27-associated anterior uveitis. STUDY DESIGN: A retrospective study. METHODS: Medical records of 51 eyes with unilateral HLA-B27-associated anterior uveitis, their fellow eyes and 47 sex and age-matched healthy eyes were retrospectively reviewed. Their choroidal and retinal vasculature were analyzed using swept-source (SS) optical coherence tomography (OCT) and OCT angiography (OCTA) scans. RESULTS: Deep capillary plexus (DCP) vessel density (VD) (p < 0.001), choroidal vascularity index (CVI) (p = 0.012), and choriocapillary flow deficit (CCFD) (p < 0.001) of uveitic and fellow eye group were significantly higher than those of control group. On the contrary, superficial capillary plexus (SCP) VD (p < 0.001) of uveitic and fellow eye group were significantly lower than of control group. The vascular parameters of uveitis and fellow eye group showed no significant difference between uveitic and resolution period. CONCLUSION: Certain choroidal and retinal vascular parameters were significantly changed in both HLA-B27-associated anterior uveitis without posterior segment involvement and the quiet fellow eyes, suggesting their possible effects as a systemic inflammatory disorder.

OCT angiographic evaluation of changes in macula and optic nerve head vessel density after a water drinking test in glaucomatous and healthy eyes.

PURPOSE: To evaluate the effects of a water drinking test (WDT) on the intraocular pressure (IOP) and vascular density of the optic nerve head and macula in healthy individuals and those with primary open glaucoma using optical coherence tomography angiography. METHODS: In this prospective comparative study, 30 healthy patients and 44 POAG subjects were divided into two groups. The study's outcome measures were the IOP and vessel density of the optic nerve and macular area. After ingesting 1000 ml of water in 5 min, the effect of the WDT on the IOP and the vascular density of the macular area and optic nerve head were measured at baseline and then 20, 40, and 60 min later at intervals of 20 min. RESULTS: The initial IOP in the healthy and glaucomatous eye groups was comparable (15.94 ± 2.6 and 16.87 ± 4.21 mmHg, respectively, P = 0.506). The IOP of both groups peaked at 40' measurements. POAG eyes had significantly higher IOP elevation (4.34 ± 0.30 vs. 2.24 ± 0.30 mmHg, P < 0.001). The glaucomatous eyes had lower radial peripapillary capillary (RPC) and whole macular superficial capillary plexus (SCP) densities at baseline (48.55 ± 5.99 vs. 51.33 ± 3.75) and (48.92 ± 3.41 vs. 45.29 ± 5.29), respectively (P < 0.001). After the WDT, the change in vessel density between groups in the RPC, whole superficial, and deep capillary plexuses was insignificant (SCP and DCP of 0.66 and 0.70, respectively, P = 0.16). CONCLUSION: The WDT caused a significant IOP jump in both glaucomatous and healthy eyes, but generally, the alterations in the glaucomatous eyes were more pronounced. The changes in vascular density in the macula and optic nerve head were similar between the groups.

Quantitative optical coherence tomography angiography assessments in the fellow eyes of those with central serous chorioretinopathy.

BACKGROUND: To analyze the vessel density (VD) of the retina and choriocapillaris (CC) layer and the structure of the foveal avascular zone (FAZ) in the fellow eyes of central serous chorioretinopathy (CSC) patients by using optical coherence tomography angiography (OCTA). METHODS: This was a case-control study. Unilateral CSC patients and age-matched healthy subjects were recruited from the Affiliated Eye Hospital of Wenzhou Medical University between July 2016 and July 2021. All eyes were divided into three groups: acute CSC (aCSC), chronic CSC (cCSC), and healthy controls. Both aCSC and cCSC were again divided into two subgroups: the affected eyes and the fellow eyes. In this study, all parameters of VD and FAZ were measured by self-software of OCTA. RESULTS: A total of 231 eyes of 137 subjects were included, with 47 aCSC patients, 47 cCSC patients, and 43 healthy controls. In the fellow eyes of CSC, the retinal VD was significantly lower (all P < 0.05), and the FAZ was significantly larger (all P < 0.05) in the cCSC group than in healthy controls, while no difference was detected in the CC layer. There was no significant difference between the aCSC group and healthy controls in all OCTA parameters. In the affected eyes of CSC, the superficial retinal vessel density (SRVD) was significantly higher (all P < 0.05) in healthy controls than in the aCSC and cCSC groups, while the deep retinal vessel density (DRVD) was significantly lower (all P < 0.05) and the FAZ was larger (all P < 0.05) in the cCSC group than in the aCSC group and healthy controls. A liner regression equation was established: Y (BCVA, best corrected visual acuity) = 3.692-0.036✱X1 (DRVD-Fovea)-0.031✱X2 (FD-300, vessel density around the 300 µm width of the FAZ), R2 = 0.427. CONCLUSION: Based on OCTA measurements, this study revealed that the retinal microvascular network was impaired even in the fellow eyes of those with cCSC, which should arouse attention to the observation of unilateral CSC.

Chorio-retinal vessel density in women affected by functional hypothalamic amenorrhea: a monocentric observational cross-sectional study to evaluate the impact of hypoestrogenism on chorio-retinal vascularization.

PURPOSE: Functional hypothalamic amenorrhea (FHA) is characterized by an estrogen deficiency which in turn can cause vascular dysfunction. The aim of this study is to evaluate any changes in the chorio-retinal circulation in patients affected by FHA. 24 patients with FHA and 24 age-matched controls underwent a gynecological evaluation and an OCT angiography (OCTA) to study chorio-retinal vascularization. RESULTS: OCTA in FHA patients showed an increase in vessel density in the choriocapillaris (CC) layer (both in the fovea area, at 5% p value = 0.037 and in the whole area, at 5% p value = 0.028) and an increase in vascular density in the deep fovea (DVP) (at 10% p value = 0.096) in the whole district compared to controls. Simple linear regressions show a significant negative association between CC vessel density and insulin (p = 0.0002) and glucose values (p = 0.0335) for the fovea district and a negative association between DVP vessel density and endometrial thickness (at 10%, p value: 0.095) in the whole district. CONCLUSION: Our study shows that CC vessel density is increased in women affected by FHA. This could represent a compensation effort to supply the vascular dysfunction caused by estrogen deficiency. We also found an increasing trend in vascular density in DVP associated with the decrease of endometrial thickness, an indirect sign of estrogenization. Considering that these changes occur in absence of visual defects, they could be used as a biomarker to estimate hypoestrogenism-induced microcirculation changes before clinical appearance.

[Terminology of quantitative optical coherence tomography angiography metrics]. / Osobennosti terminologii kolichestvennykh pokazatelei opticheskoi kogerentnoi tomografii-angiografii.

This review is devoted to the English- and Russian-language terminology of quantitative metrics that are used in the evaluation of images obtained by optical coherence tomography angiography (OCT-A). The paper presents an analysis of the use of terms characterizing intraretinal blood flow (vascular density, perfusion density, skeletonized density, etc.), area and shape of the foveal avascular zone, and choriocapillaris blood flow. The factors causing the heterogeneity of OCT-A terminology are described, including the lack of a unified international nomenclature for OCT-A, features of their Russian translation, inconsistency of the parameters in optical coherence tomography systems of different manufacturers. The article also considers ways to standardize the terminology.

A novel nomogram to predict glucocorticoid response in thyroid-associated ophthalmopathy: findings from a pilot study.

PURPOSE: Aimed to create a nomogram using clinical and eye-specific metrics to predict the efficacy of intravenous glucocorticoid (IVGC) therapy in patients with active and moderate-to-severe Thyroid-Associated Ophthalmopathy (TAO). METHODS: This study was conducted on 84 eyes from 42 moderate-to-severe TAO patients who received systemic IVGC therapy, and 42 eyes from 21 controls. Data were collected retrospectively from June 2020 to December 2021. The least absolute shrinkage and selection operator (LASSO) method was used to identify predictive factors for "unresponsiveness" to IVGC therapy. These factors were then analyzed using logistic regression to create a nomogram. The model's discriminative ability was robustly assessed using a Bootstrap resampling method with 1000 iterations for receiver operating characteristic (ROC) curve analysis. RESULTS: The LASSO analysis identified six factors with non-zero coefficients as significant, including Schirmer I test values, Meibomian gland (MG) diameter, MG length, disease duration, whole capillary vessel density (VD) in the radial peripapillary capillary (RPC), and whole macular VD for the superficial retinal capillary plexus (SRCP). The subsequent logistic regression model highlighted MG length, whole macular VD for SRCP, and disease duration as independent predictors of IVGC therapy response. The constructed nomogram demonstrated an area under the curve (AUC) of 0.82 (95% CI: 0.73-0.91), affirming the model's consistent and reliable ability to distinguish between responsive and non-responsive TAO patients. CONCLUSION: Our nomogram, combining MG length (<4.875 mm), SRCP VD (<50.25%), and disease duration (>5.5 months), reliably predicts lower IVGC therapy effectiveness in active, moderate-to-severe TAO patients.

Optical coherence tomography angiography features in Waldenström macroglobulinemia patients without Hyperviscosity syndrome: A pilot prospective study.

PURPOSE: To evaluate the retinal vessel density (VD) with optical coherence tomography angiography (OCTA) in asymptomatic patients affected by Waldenström macroglobulinemia (WM) without hyperviscosity syndrome (HVS) and to highlight the presence of microvascular damage in theese clinically asymptomatic WD patients. DESIGN: Prospective study. METHODS: A total of 43 eyes from 43 WM patients (24 females, 19 males, mean age 55.1 ± 13.6 years) were enrolled from January 2023 to December 2023 in the Eye Clinic of the University of Naples Federico II. Along with WM patients, 40 healthy subjects (HS) (20 females, 20 males, mean age 52.3 ± 15.6 years) with a normal ophthalmic examination and no history of intraocular surgery or retinal pathologic features were included as control group All patients and controls underwent OCTA RESULTS: The two groups were not significantly different for age and sex Visual acuity examination showed no statistically significant difference in BCVA between controls and patients Compared to HS, WD patients showed lower VD values in the SCP in the whole image (47.95 ± 5.17% vs. 52.99 ± 2.52 %; p < 0.001), as well as in the parafovea (53.01 ± 6.69% vs. 55.30 ± 2.61 %; p = 0.002), and fovea (21.38 ± 9.01% vs. 30.31 ± 5.84 %; p < 0.0001). On the other hand, in the DCP VD values were significantly higher in patients compared to controls in the whole image (55.82 ± 8.07% vs. 50.83 ± 5.46 %; p = 0.005), as well as in the parafovea (56.76 ± 6.26% vs. 52.59 ± 5.46 %; p = 0.0001), and fovea (38.75 ± 8.59% vs. 33.43 ± 8.68 %; p < 0.0001). CONCLUSION: The finding that OCTA confirmed the presence of widespread microvascular damage in WD patients clinically silent. Thus, OCTA is a safe rapid imaging technique that could represent a valid biomarker of systemic vascular dysfunction.

New findings on retinal microvascular changes in patients with primary COVID-19 infection: a longitudinal study.

Purpose: To investigate the longitudinal alterations of retinal microvasculature in patients with primary coronavirus disease 2019 (COVID-19) infection. Methods: 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. Results: 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). Conclusion: 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.

Retinal vessel density and choroidal flow changes in oligoarticular juvenile idiopathic arthritis with and without uveitis.

PURPOSE: This cross-sectional optical coherence tomography angiography (OCTA) study aimed to assess the macular and optic nerve head (ONH) vascular density, foveal avascular zone, and outer retina and choriocapillaris flow in oligoarticular juvenile idiopathic arthritis (oJIA). STUDY DESIGN: Prospective. METHODS: Twenty-two eyes of 22 oJIA patients with uveitis (oJIA-U), 20 eyes of 20 oJIA patients without uveitis (isolated oJIA), and 26 healthy volunteers of similar ages and sexes were investigated. The superficial capillary plexus (SCP) and deep capillary plexus (DCP), ONH, foveal avascular zone (FAZ) parameters, the flow area of the outer retina, and choriocapillaris were evaluated. RESULTS: Compared with the control group, both the oJIA-U group and isolated oJIA group showed significantly decreased vessel density of parafovea (p = 0.031 and p = 0.047, respectively) in DCP. Choriocapillaris flow area at 1 mm radius was significantly lower in the oJIA-U group compared to the control group (p = 0.001). Choriocapillaris flow area at 2- and 3-mm radius were significantly lower in the oJIA-U group compared to the control group (p < 0.001, for both) and isolated oJIA-U group compared to the control group (p = 0.008 and p = 0.001, respectively). The VD and thickness parameters of SCP and ONH, FAZ, and outer retina flow area were similar between the groups. CONCLUSIONS: oJIA patients with and without uveitis revealed a decreased vessel density in the deep parafoveal region and choriocapillaris flow. Our findings suggest that retinal choroidal microvascular changes could be evident in oJIA-U patients without posterior segment involvement as well as oJIA patients without uveitis.

Wide-field swept-source optical coherence tomography angiography (SS-OCTA) in the assessment of retinal vessel density and thickness in 4-to 16-year-old myopic children.

PURPOSE: To analyze the characteristics of macular retinal vessel density and thickness in children with myopia. METHODS: A cross-sectional study was conducted. A total of 228 children aged 4-16 years who visited the Ineye Hospital of Chengdu University of Traditional Chinese Medicine from September 2022 to November 2023 were included. Those with -0.5D < spherical equivalent (SE) < +2.0D were included in the non-myopia group (150 eyes), those with -3.0D < SE ≤ -0.5D were included in the low myopia group (246 eyes), and those with SE ≤ -3.0D were included in the moderate-to-high myopia group (60 eyes). All subjects underwent cycloplegic refraction, IOLmaster500, and Wide-field SS-OCTA (to exclude some peripheral retinal degeneration). Multiple linear regression analysis was used to analyze the correlation between macular ETDRS subfield of full retinal thickness (FRT), outer, inner retinal thickness (ORT, IRT), retinal vessel density (VD), deep and superficial retinal vessel density (DVD, SVD), and SE, axial length (AL). RESULTS: There were statistically significant differences (P < 0.05) in FRT in the central fovea (1 mm diameter)and perifovea (Diameter 3 to 6 mm) among the non-myopia group, low myopia group, and moderate-to-high myopia group. The three groups also showed statistically significant differences (P < 0.05) in VD in the central fovea and parafovea with a diameter of 1 to 3 mm (except the lower part). In multiple linear regression analysis adjusted for gender and age, SE and AL were found to be correlated with FRT in all ETDRS regions (except the central fovea) (P < 0.01), and SE and AL were correlated with IRT in the central fovea and perifovea, respectively (ß range -2.302 to 1.652; P < 0.05). SE and AL were also correlated with ORT in the parafovea and perifovea, respectively (ß range -4.371 to -2.344; P < 0.05). AL was negatively correlated with VD in the central fovea and parafovea (except the inferior region) (P < 0.05), as well as with DVD in all ETDRS regions (ß range -1.314 to -1.031; P < 0.05). AL was only negatively correlated with SVD in the parafoveal nasal region (ß = -0.633, P < 0.05). Additionally, the correlation between AL and DVD, ORT was higher than that with SVD, IRT. CONCLUSION: The more severe the myopia, the longer the AL, the thinner the FRT in the perifovea, and the lower the VD in both the fovea and parafovea in children. In addition, DVD and ORT were more significantly correlated with AL, suggesting that they may be more closely related to the growth of AL.

Exploring the utility of retinal optical coherence tomography as a biomarker for idiopathic intracranial hypertension: a systematic review.

This study aimed to examine the existing literature that investigated the effectiveness of optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A) as a biomarker for idiopathic intracranial hypertension (IIH). Our search was conducted on January 17th, 2024, and included the databases, Medline, Scopus, Embase, Cochrane, Latin American and Caribbean Health Sciences Literature (LILACS), International Standard Randomized Controlled Trial Number (ISRCTN) registry, and the International Clinical Trials Registry Platform (ICTRP). Our final review included 84 articles. In 74 studies, OCT was utilized as the primary ocular imaging method, while OCT-A was employed in two studies including eight studies that utilized both modalities. Overall, the results indicated that IIH patients exhibited significant increases in retinal nerve fiber layer (RNFL) thickness, total retinal and macular thickness, optic nerve head volume, and height, optic disc diameter and area, rim area, and thickness compared to controls. A significant correlation was observed between cerebrospinal fluid (CSF) pressure and OCT parameters including RNFL thickness, total retinal thickness, macular thickness, optic nerve head volume, and optic nerve head height. Interventions aimed at lowering CSF pressure were associated with a substantial improvement in these parameters. Nevertheless, studies comparing peripapillary vessel density using OCT-A between IIH patients and controls yielded conflicting results. Our systematic review supports OCT as a powerful tool to accurately monitor retinal axonal and optic nerve head changes in patients with IIH. Future research is required to determine the utility of OCT-A in IIH.

Optical coherence tomography angiography reveals macular microvascular changes in myopic adolescents following orthokeratology lens wear.

BACKGROUND: This study aimed to investigate the 6-month effects of wearing orthokeratology (OK) lenses on the retina vessel density (VD), vessel diameter index (VDI), and foveal avascular zone (FAZ) of myopia children using optical coherence tomography angiography, and to further investigate the underlying mechanisms of Orthokeratology in myopia control. METHODS: Sixty-two eyes form 62 subjects were included in the study. Baseline and 6-month measurements of axial length (AL), anterior chamber depth (ACD), FAZ area, FAZ perimeter, FAZ circularity, vessel density (VD) and VDI from both the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were obtained. RESULTS: The mean age of the participants was 11.02 years (range: 8 years to 15 years), with 41.9% males and 58.1% females. Six months after orthokeratology, ACD decreased significantly, and AL remain unchanged. SCP-VD and DCP-VD significantly increased after treatment without obvious change of VDI, and FAZ parameters remained unchanged. During follow-up period, SCP-VD increased in all subgroups especially in mild myopia group, and DCP-VD increased significantly in all subgroups except for the group 8-10 years. CONCLUSION: After the 6-month treatment of orthokeratology in myopia children, the macular microvasculature changed significantly. We observed a significant increase of vessel densities in both SCP and DCP without obvious effect on vascular morphology. The changes of DCP-VD tended to be more sensitive in the elder subgroup, and the efficacy of orthokeratology might be greater in mild myopia group. OCT-A may provide additional information on myopia progression and the mechanisms of controlling myopia with OK lens treatment.

Peripapillary microvasculature and retinal nerve fiber layer damage according to the severity of diabetic retinopathy.

PURPOSE: To identify damage to the inner retinal layer and microvasculature in the peripapillary area according to the severity of diabetic retinopathy (DR). METHODS: Patients were divided into four groups: control (group 1), type 2 diabetes (T2DM) without DR (group 2), mild to moderate nonproliferative DR (NPDR) (group 3), and severe NPDR (group 4). The peripapillary retinal nerve fiber layer (pRNFL) thickness and peripapillary vessel density (VD) were compared. Linear regression analysis was performed to identify factors associated with the DR severity. RESULTS: The average pRNFL thicknesses were 96.2 ± 7.1, 94.1 ± 9.6, 92.0 ± 9.9, and 90.3 ± 12.4 µm in groups 1, 2, 3, and 4, respectively (P = 0.003) (post hoc analyses: group 1 vs. group 2, P = 0.529; group 2 vs. group 3, P = 0.627; group 2 vs. group 4, P = 0.172; group 3 vs. group 4, P = 0.823). The VDs of the outer ring were 18.9 ± 0.6, 18.4 ± 0.8, 17.9 ± 1.1, and 17.3 ± 1.6 mm-1 in groups 1, 2, 3 and 4, respectively (P < 0.001) (all pairwise comparisons, P < 0.050). In multivariate analysis, the VD of the outer ring (B = - 0.35, P < 0.001) was significantly associated with the DR severity. CONCLUSIONS: The peripapillary microvasculature reflects retinal damage following DR progression better than the structure of the pRNFL.

Investigating the Impact of Bariatric Surgery on Macular and Peripapillary Vessel Density in Obese Individuals without Metabolic Disease.

INTRODUCTION: It is well established that microvascular structures are affected in obese people with metabolic disease. We aimed to evaluate the effect on microvascular structures by examining macular and peripapillary vessel density with optical coherence tomography angiography after bariatric surgery in obese individuals without metabolic disease. METHODS: This prospective study included 96 eyes of 48 obese patients. Body mass index (BMI), macular vessel density in the superficial, intermediate, and deep capillary plexus, and peripapillary vessel density were measured before and 6 months after bariatric surgery. RESULTS: BMI decreased significantly to 43.75 ± 4.4 kg/m2 postoperatively compared to 55.31 ± 5.1 kg/m2 preoperatively (p < 0.05). A significant increase was observed in macular vessel density in the deep capillary plexus postoperatively (p < 0.01). However, no significant postoperative increase occurred in macular vascular density in the superficial and intermediate capillary plexus (p > 0.05). Moreover, there was no change in peripapillary vascular density (p > 0.05). Postoperative thickening of the foveal, parafoveal, and perifoveal retinal layers was significant (p < 0.001). No significant correlation was detected between BMI change and macular and peripapillary vessel density changes (p > 0.05). CONCLUSION: An increase in macular vascular density, particularly in the deep capillary plexus, and retinal layer thickness has been observed following bariatric surgery performed on obese individuals without metabolic disease. This increase may indicate that microvascular structures are affected even in the absence of metabolic disease and that microperfusion improves with surgery.

Can optic disc vessel density help in cases of residual disc elevation after shunt surgery in cases of idiopathic intracranial hypertension?

AIM: To detect if we can use the reduction in the optic disc vessel density as an indicator to the reduction in intracranial tension in patients with residual optic disc elevation after shunt surgery as fundus examination in those cases is not conclusive. PATIENTS AND METHOD: 21 patients with papilledema due to idiopathic intracranial hypertension underwent shunt surgery. Full neurological and ophthalmological assessments were done. The optic disc vessel density was measured before and 3 months after surgery. Patients were then divided according to the resolution of papilledema into 2 groups: 1) Residual disc elevation group. 2) Completely resolved disc edema group. CSF pressure was measured via lumber puncture preoperative for all patients and 3 months post-operative only for patients with residual disc edema. A comparison between both groups was done. RESULTS: There was a highly statistically significant difference between the two groups as regard the papilledema grade (the residual disc elevation group had a higher grade of papilledema) with P-value=0.000. As regard the difference in the preoperative optic disc vessel density between the two groups, there were statistically significant differences (optic disc vessel density was more in the residual disc elevation group). As regard the postoperative optic disc vessel density, there were non-significant differences between the two groups in whole image, inside disc and peripapillary vessel density (either in macro or microvasculature). CONCLUSION: The optic disc vessel density decreased with normal postoperative CSF opening pressure in cases with residual disc elevation postoperatively. Thus, in cases of residual optic disc swelling after shunt surgery, we can detect the reduction of intracranial pressure by the reduction in the optic disc vessel density which is a safe non-invasive technique. That may help in cases of residual disc elevation.