Radial Peripapillary Capillary Research Articles

Significant retinal microvascular impairments in multiple sclerosis assessed through optical coherence tomography angiography.

Multiple sclerosis (MS) is associated with different ocular disorders. This study aimed to investigate the retinal microvascular changes detected by optical coherence tomography angiography (OCTA) in eyes with MS with or without a history of optic neuritis (ON). A comprehensive literature search was conducted in the Web of Science, Embase, PubMed, and Cochrane Library databases on September 26, 2021 for articles focused on OCTA manifestations in the eyes of MS patients compared with healthy controls. RevMan Manager (v.5.4) and Stata (v.14.1) were used to analyze the main differences and publication risks. Weighted mean differences and 95% confidence intervals were calculated for continuous estimates. This study also included subgroup analysis between three groups: eyes with multiple sclerosis and with optic neuritis (MSON); eyes with multiple sclerosis and without optic neuritis (MSNON); and healthy controls. Thirteen studies with a total of 1803 eyes were identified, including 957 eyes with MS and 846 eyes of healthy controls. The vessel density of the MS eyes decreased significantly in most areas of the radial peripapillary capillary. A marked reduction in the macular superficial capillary plexus of MS eyes regardless of ON history was also confirmed. The results suggest that MS patients demonstrated significant retinal microvasculature impairment regardless of ON history, compared to healthy controls. Retinal vessel density attenuation detected by OCTA may serve as a reliable early marker of MS.

Optical coherence tomography angiography findings in transfusion-dependent beta-thalassemia patients with and without splenectomy

BackgroundOcular involvement is common in transfusion-dependent beta-thalassemia (TDβ-T) patients. We aimed to investigate the effect of splenectomy on optical coherence tomography angiography (OCTA) findings in TDβ-T patients. MethodsThe study is a prospective cross-sectional study. A total of 45 eyes of 23 patients with splenectomy (34.04±8.83 years), 18 eyes of 9 patients without splenectomy (27.44±5.43 years), and 54 eyes of 27 controls (33.22±6.44 years) were included. Vessel density in superficial capillary plexus, deep capillary plexus and radial peripapillary capillary, foveal avascular zone, choriocapillaris flow area, choroidal and retinal thickness detected by OCTA were evaluated. p < 0.05 was considered significant. ResultsVessel density of superficial capillary plexus and deep capillary plexus were similar in patients with and without splenectomy, and controls. Choriocapillaris flow area was significantly decreased in patients with splenectomy than that in those without splenectomy and controls (2.02±0.12 vs. 2.17±0.1 and 2.14±0.12; p < 0.001). Choroidal thickness was significantly lower in patients without splenectomy than in patients with splenectomy and controls (260.05±61.02 vs. 305.11±42.13 and 298.89±29.14, p = 0.008). Parafoveal and perifoveal thickness of the full retina and outer retina were significantly lower in patients without splenectomy than in patients with splenectomy and controls (301.06±10.0, 279.78±10.28 vs. 311.04±14.89, 290.87±13.67 and 316.63±13.57, 289.56±9.31, p < 0.001 and p = 0.002; 174.72±7.81, 167.17±6.21 vs. 182.87±8.81, 173.60±7.09 and 185.11±9.26, 173.96±6.79, p = 0.001 and p < 0.001, respectively). ConclusionsOCTA findings can provide information about the microvascular effects of splenectomy on the retina of patients with TDβ-T.

Impact of peripapillary staphylomas on the vascular and structural characteristics in myopic eyes: a propensity score matching analysis

PurposeTo apply propensity score matching to evaluate the impact of peripapillary staphylomas (PPS) on vascular and structural characteristics in the myopic eyes.MethodsThis was a prospective, cross-sectional study. Forty-one control eyes and 41 eyes with PPS were analyzed. The eyes were selected using propensity score matching analysis based on the age and axial length. All subjects underwent ophthalmologic examinations for assessing vessel and structure parameters using swept-source optical coherence tomography (SS-OCT), OCT angiography, color fundus photography, and ocular biometry.ResultsAs compared with control eyes, the eyes with PPS had shallower anterior chamber depth (3.61 ± 0.24 mm vs 3.77 ± 0.24 mm, P = 0.004), higher intraocular pressure (IOP) (16.59 ± 2.88 mmHg vs 14.53 ± 2.45 mmHg, P = 0.002), and higher myopic spherical equivalent (− 11.52 ± 3.22D vs − 9.88 ± 2.20D, P = 0.009). while corneal curvature and lens thickness between the two groups were not statistically different. Compared with control eyes, increased macular deep vessel density, reduced macular choriocapillaris and radial peripapillary capillary, and thinning retinal layer, ganglion cell complex, choroidal layer as well as the superior and inferior peripapillary retinal nerve fiber layer were observed in eyes with PPS, apart from larger disc area, parapapillary atrophy area, and degree of disc rotation. Logistic regression analysis revealed that the IOP (P = 0.046), disc rotation (P = 0.003), and average peripapillary choroidal thickness (P = 0.009) were associated with the presence of PPS.ConclusionClose association of PPS with exacerbation of myopia and anatomical alterations was observed which not only affected the eye posterior segment but also the anterior segments. We further identified significant reductions in the radial peripapillary capillary and macular choroidal perfusion with the increase in macular deep retinal flow blood of myopic eyes with PPS. Higher IOP, thinner peripapillary choroidal thickness, and rotated optic disc were risk factors for the presence of PPS.

A Deep Learning System Using Optical Coherence Tomography Angiography to Detect Glaucoma and Anterior Ischemic Optic Neuropathy.

Glaucoma and non-arteritic anterior ischemic optic neuropathy (NAION) are optic neuropathies that can both lead to irreversible blindness. Several studies have compared optical coherence tomography angiography (OCTA) findings in glaucoma and NAION in the presence of similar functional and structural damages with contradictory results. The goal of this study was to use a deep learning system to differentiate OCTA in glaucoma and NAION. Sixty eyes with glaucoma (including primary open angle glaucoma, angle-closure glaucoma, normal tension glaucoma, pigmentary glaucoma, pseudoexfoliative glaucoma and juvenile glaucoma), thirty eyes with atrophic NAION and forty control eyes (NC) were included. All patients underwent OCTA imaging and automatic segmentation was used to analyze the macular superficial capillary plexus (SCP) and the radial peripapillary capillary (RPC) plexus. We used the classic convolutional neural network (CNN) architecture of ResNet50. Attribution maps were obtained using the "Integrated Gradients" method. The best performances were obtained with the SCP + RPC model achieving a mean area under the receiver operating characteristics curve (ROC AUC) of 0.94 (95% CI 0.92-0.96) for glaucoma, 0.90 (95% CI 0.86-0.94) for NAION and 0.96 (95% CI 0.96-0.97) for NC. This study shows that deep learning architecture can classify NAION, glaucoma and normal OCTA images with a good diagnostic performance and may outperform the specialist assessment.

Changes of Peripapillary Capillary Density in Patients with Vogt–Koyanagi–Harada Disease Evaluated by Optical Coherence Tomography Angiography

To analyze the longitudinal changes in peripapillary capillary density in patients with acute VKH with or without optic disc swelling by optical coherence tomography angiography (OCTA). Retrospective case series. 44 patients (88 eyes) were enrolled and were divided into two groups according to presence/absence of optic disc swelling before treatment. Peripapillary capillary images were obtained by OCTA before and after 6 months of corticosteroid treatment and used to determine the radial peripapillary capillary (RPC), retinal plexus, and choriocapillaris vessel perfusion densities. Optic disc swelling was present in 12 patients (24 eyes) and absent in 32 patients (64 eyes). The sex distribution, age, intraocular pressure, and best-corrected visual acuity before and after treatment were not significantly different between the two groups (all P > 0.05). Compared to those in nonoptic disc swelling group, the percentages of decreased vessel perfusion densities after treatment in the supranasal (RPC, 100.00% vs. 75.00%), infranasal (RPC, 100.00% vs. 56.25%), infratemporal (RPC, 66.67% vs. 37.50%), and infranasal quadrants (retinal plexus, 83.33% vs. 56.25%) were significantly more in optic disc swelling group. The choriocapillaris vessel perfusion density increased after treatment in both groups. Decreases in vessel perfusion densities of the RPC and retinal plexus after treatment in VKH patients with optic disc swelling were more common than in those without optic disc swelling. The choriocapillaris vessel perfusion density increased after treatment, regardless of the presence/absence of optic disc swelling.

Changes of Optic Disc and Macular Vessel Perfusion Density in Primary Angle Closure Glaucoma: A Quantitative Study Using Optical Coherence Tomography Angiograph

Introduction: This study aims to investigate the changes of retinal vascular system in primary angle closure glaucoma (PACG) and acute primary angle closure (APAC) by optical coherence tomography (OCT) angiograph (OCTA) and to evaluate the diagnostic ability of changes of vessel density (VD) in different sectors and layers of optic disc and macular area in APAC and PACG. Methods: In this cross-sectional, observational study, 21 APAC patients (22 eyes) and 21 PACG patients (27 eyes) along with 17 healthy people were enrolled from August 2018 to March 2019. Optic disc region and macular region were imaged using swept-source OCTA system. VD of the macular region was quantified by Image J (1.52a, USA) and Matlab 2018a. The circumpapillary retinal nerve fiber layer (cpRNFL) thickness and ganglion cell complex thickness were obtained by spectral-domain OCT. Results: Compared with the healthy group, the cpRNFL thickness in superior sector was thicker in the APAC group, and this area had the most diffuse microvascular dropout as well. The difference in the macular superficial capillary plexus (SCP) VD between APAC and the control group was not statistically significant. The area under the ROC curves (AUC) of the total optic disc VD in the radial peripapillary capillary (RPC) layer was higher than the AUC of the papillary VD in the optic nerve head (ONH) layer. Compared to the control group, the total optic disc VD, peripapillary VD, and each quadrant of peripapillary VD were decreased in PACG (p < 0.01). In PACG macular region, SCP VD, and deep capillary plexus (DCP) VD, parafovea VD (except temporal sectors) decreased (p < 0.01). The PACG eyes had a greater decrease percentage of VD in total ONH than total macula. The diagnostic value of the VD in the ONH layer and the RPC layer was similar. The diagnostic value of the SCP VD in the macula was greater than the DCP VD in the macula. The AUC was no significant difference between cpRNFL thickness and the total optic disc VD AUC. Conclusion: Elevated intraocular pressure preferentially affects vascular perfusion in the optic disc region more than the macular region in APAC and PACG. In the APAC eyes, there was a perfusion defect in the optic disc region and an increase in RNFL thickness. In this study, the OCTA vascular parameters have similar performance to the OCT structural parameters for glaucoma diagnosis in PACG.

Evaluation of parafoveal and peripapillary vascular densities using optical coherence tomography angiography in children with thalassemia major.

Thalassemia major (TM) is an inherited anaemia caused by faulty haemoglobin synthesis. Reducing serum iron levels using iron chelating agents is an important step in the treatment of TM, and the effects on the eye of both the disease and these agents can be determined by regular eye examination. We evaluated macular and optic nerve vascular densities in children with TM and compared the results with healthy controls using optical coherence tomography angiography (OCTA). This is a prospective study. A total of 30 children with TM and 30 healthy controls were included in the study. The area of the foveal avascular zone (FAZ) and the vascular densities (VD) of the optic nerve head (ONH), radial peripapillary capillary (RPC) and deep and superficial retinal vascular networks were measured using OCTA. A statistically significant decrease in VD was observed in the whole image and the parafovea, superior hemi, superior and inferior parts of the superficial capillary plexus and in the whole image and the superior regions of the deep capillary plexus in the TM patient group compared with the control group (p < 0.05). A significant decrease in VD was also observed in the whole image and the inside disc, peripapillary, nasal, inferonasal and temporal regions of the ONH and in the whole image and the inside disc, peripapillary and inferonasal regions of the RPC network in patients with TM (p < 0.05). A significant positive correlation was observed between both serum ferritin levels and deferasirox dosage, on one hand, and both the superficial (p = 0.023 and p = 0.002, respectively) and deep FAZs (p = 0.015 and p = 0.045, respectively), on the other hand. A negative correlation was also found between the deferasirox dosage and the VDs of the superficial (p = 0.010) and deep (p = 0.001) foveal plexuses. Retinal VD and FAZ are affected in patients with TM. OCTA, which can noninvasively measure retinal VD in patients with TM, may be a useful tool for the early detection of retinal microvascular changes that may occur during the course of the disease.

Evaluation of peripapillary area and retinal nerve fiber layer thickness using OCT angiography in diabetic retinopathy

Background: It has been believed that diabetic retinopathy (DR) is a microvascular disorder. Recent research has linked DR to both neuronal and microvascular processes. The purpose of this research was to use optical coherence tomography angiography (OCTA) to compare the thickness of the peripapillary area and the retinal nerve fiber layer (pRNFL) in DR different stages.Methods: This cross-sectional controlled research was carried out on 40 subjects Cases were subdivided into four equal groups: diabetes mellitus (DM) group (having no DR) non-proliferative DR (NPDR) group, proliferative DR (PDR) group, controls: healthy persons (Healthy eyes with no evidence of diseases affecting macula or optic nerve. Duration of diabetics was not less than 5 years with controlled HbA1c level (5-6%).Results: Significant difference was observed regarding disease duration, Vessel density (VD) between the NPDR, PDR and controls, Thickness of the PRNFL (overall or segmental) between the Diabetes mellitus (DM) groups (DM-NPDR-PDR) and controls. A significant decrease in VD and Thickness of the PRNFL was observed in the optic disc and pRNFL among the DM groups compared to controls. Insignificant difference was observed regarding age, sex, side. A significant negative correlation was observed between disease severity and VD in the pRNFL.Conclusions: As DR worsened, the number of radial peripapillary capillaries in the peripapillary area of the retina dropped. Cases with DM, NPDR, and PDR had thinner PRNFL in the peripapillary area compared to those in the controls.

Swept‐source optical coherence tomography angiography in toxoplasmic retinochoroiditis

AbstractPurpose: To describe optical coherence tomography angiography (OCTA) findings in eyes with active and scarred toxoplasmic retinochoroiditis.Methods: OCTA scans in active (25 eyes) and scarred (17 eyes) retinochoroiditis were retrospectively reviewed at Fattouma Bourguiba University Hospital, Monastir, Tunisia.Results: In active lesions, OCTA findings included a non‐detectable flow signal area in retinal vascular plexuses and choriocapillaris in all 25 eyes (100%), an abnormal intraretinal vascular process in two eyes (8%), and an associated area of retinal flow deficit secondary to branch retinal artery occlusion in one eye (4%). In scarred lesions, OCTA findings included a flow deficit area in retinal vascular plexuses and choriocapillaris in all 17 eyes (100%), a visibility of larger deeper choroidal vessels at the level of choriocapillaris in nine eyes (53%), and a well‐defined intraretinal vascular network in one eye (5.9%). Peripapillary scars were associated on OCTA with wedge‐shaped loss of radial peripapillary capillaries with corresponding localized retinal nerve fibre layer defect and visual field loss.Conclusions: OCTA allows to non‐invasively detect retinal and choroidal vascular changes in active and scarred toxoplasmic retinochoroiditis.

A two-year longitudinal study of retinal vascular impairment in patients with amnestic mild cognitive impairment.

To evaluate the relation between retinal vascular impairment and cognitive decline in patients with amnestic mild cognitive impairment (aMCI) over time. Spectral domain-optical coherence tomography (SD-OCT) and OCT angiography study was performed in aMCI patients over 2 years follow-up and compared to baseline. Thirty-eight eyes from 19 aMCI patients were evaluated. Structural and vascular OCT measures were reduced at follow-up except for vessel density (VD) of the choriocapillaris, unchanged, and foveal avascular zone, which was increased; no changes in any parameter were found in 18 age-matched healthy controls. Overall, these findings were confirmed when patients were evaluated separately according to progression to dementia. Only non-converters to dementia showed significant VD reduction in the deep capillary plexuses (coeff. β = -4.20; p < 0.001), may be for an initial massive VD depletion becoming less evident with progression of the disease. MMSE reduction was associated with a higher ganglion cell complex reduction (coeff. β = 0.10; p = 0.04) and a higher VD reduction in the radial peripapillary capillary (RPC) plexus (coeff. β = 0.14; p = 0.02) in the whole patient group, while it was associated with a higher VD reduction only in RPC plexus in converters (coeff. β = 0.21; p < 0.001). Our data shows vascular impairment progression in the inner retina of aMCI patients and support the hypothesis that vascular changes may contribute to the onset and progression of Alzheimer's disease. Other follow-up studies, with a larger number of patients, are needed to better define VD as a potential biomarker.

Quantitative Assessment Parameters of Peripapillary Regions with Branch Retinal Vein Occlusion by Using Optical Coherence Tomography Angiography.

To investigate the baseline parameters of peripapillary regions in both eyes of patients with unilateral branch retinal vein occlusion (BRVO) using optical coherence tomography angiography (OCTA) and their association with best-corrected visual acuity (BCVA). Forty-eight unilateral BRVO patients were enrolled. The 4.5 × 4.5 mm disc angiogram was acquired in the BRVO eyes and fellow eyes using the OCTA. Radial peripapillary capillary (RPC), whole vessel density, and retinal nerve fiber layer (RNFL) thickness in different regions and optic nerve head (ONH) analysis were automatically calculated. The partition includes the whole image, peripapillary, superior hemifield, inferior hemifield, eight equally divided sectors, and nine evenly divided square areas. All vessel density and capillary vessel density in the whole and peripapillary regions of BRVO eyes were significantly lower than those in fellow eyes. The RNFL peripapillary thickness in BRVO eyes was significantly higher than those in fellow eyes. In eyes with supertemporal vein occlusion, all vessel density both in the superior hemifield and in the G12 region was significantly reduced compared with that in the fellow eyes. The capillary vessel density was significantly lower in the superior hemifield, superior temporal (ST), superior nasal (SN), and temporal superior (TS) areas than in the fellow eyes. The RNFL thickness in the NI, IN, TI, and TS sectors was significantly higher than in fellow eyes (all P < 0.05). OCTA provided quantitative information on peripapillary vascular density and RNFL thickness changes in BRVO. Branch retinal vein occlusion not only affects the blood vessel density in the macular area but also decreases the radial peripapillary capillaries. The capillary density is mainly affected in the affected hemifield but not in the unaffected hemifield.

Correlation between radial peripapillary vascular density and reduced central corneal thickness in glaucoma suspect patients

BackgroundOptical coherence tomography (OCT) angiography (OCTA) provides a quantitative assessment of the microcirculation of the retina and choroid. It may precede the retinal nerve layer (RNFL) and optic disc head defects. Retinal nerve fiber layer defects and reduced central corneal thickness (CCT) are important parameters in the assessment of a glaucoma suspect patients. The aim of this study is to investigate any possible relationship between the reduced central corneal thickness and the radial peripapillary capillary (RPC) density defect in glaucoma suspect.MethodsIn this cross sectional study, 92 eyes were incorporated. Peripapillary OCT angiography (4.5 mm) and Anterior segment OCT for corneal pachymetry were done. C/D Ratio, thickness of nerve fiber layer, the blood flow indices and central corneal thickness also were evaluated.ResultsIn eyes of glaucoma suspect patients; a significant positive correlation between CCT and total RPC density was detected (r = 0.38, P < 0.001). A strong positive correlation was also found between total RPC and peripapillary RNFL thickness (r = 0.55, P < 0.001).ConclusionReduced central corneal thickness and peripapillary capillary density are two screening parameters for glaucoma suspect patients. The radial peripapillary capillary density is a valid diagnostic tool for glaucoma.

Macular and peripapillary optical coherence tomography angiography metrics in thyroid-associated ophthalmopathy with chorioretinal folds

PurposeTo evaluate macular and radial peripapillary capillary (RPC) microvascular densities and the thickness of the retinal nerve fiber layer (RNFL) in thyroid-associated ophthalmopathy (TAO) with chorioretinal folds (CRFs) and the associations of these characteristics with visual function. MethodA cross-sectional study was performed at the Ophthalmology Department of the Sun Yat-sen Memorial Hospital from March 2018 to August 2021. All patients underwent ocular examination, ophthalmic function tests and optical coherence tomography angiography (OCTA). The microvascular densities in the macula and optic papilla in the TAO with CRFs or without CRFs. Correlation analyses were used to examine the association of microvascular density and visual function. ResultsTen TAO patients with CRFs (CRF group, 20 eyes) and 10 TAO patients without CRFs (NCRF group, 20 eyes) were recruited for the study. Visual function measurements, including best-corrected visual acuity (BCVA), were found to be worse in the CRF group (all p < 0.05). The macular whole-image vessel density in the superficial layer (SLR-mwiVD) was significantly decreased in the CRF group (p < 0.05). The RPC whole-image vessel density (RPC-wiVD) was significantly decreased in the CRF group (p < 0.05), particularly in the temporal subfields. The P100 amplitude of visual evoked potentials (VEPs) was positively associated with SLR-mwiVD and RPC-wiVD. The thickness of RNFL in the CRF group was obviously thicker than that in the NCRF group (p < 0.05). ConclusionsOur study showed decreased microvascular density of the macula and RPC and thicker RNFL in TAO patients with CRFs. CRFs with decreased microvascular density should be regard as an indicator of visually threatening conditions.

Investigation of retinal microvasculature and choriocapillaris in adolescent myopic patients with astigmatism undergoing orthokeratology

BackgroundTo observe alterations of fundus microcirculation and retinal thickness in adolescent myopic patients with astigmatism after toric and spherical orthokeratology using optical coherence tomography angiography (OCTA), to explore the effects of orthokeratology on the retinal thickness and choroidal blood flow.MethodsA total of 48 patients were enrolled and divided into two group (toric orthokeratology (T) group and spherical orthokeratology (S) group) according to the type of lens design. OCTA was used to measure the superficial and deep retinal vessel densities at the macular region, radial peripapillary capillary (RPC) density, foveal avascular zone (FAZ) area, and choriocapillaris (ChC) perfusion area before and after orthokeratology for 3 months. The data were statistically analyzed by SPSS 19.0 software.ResultsCompared with before orthokeratology, the superficial vessel density in the fovea and parafovea in the T group significantly increased, and the deep vessel density in the whole area and fovea were significantly elevated after 3 months (P < 0.05). The superficial vessel density was significantly higher only in the parafovea in the S group after 3 months than that before orthokeratology (P < 0.05), deep vessel density in the whole area and parafovea after 3 months was significantly higher than that before orthokeratology (P < 0.05). RPC density in the two groups increased after 3 months of orthokeratology in the whole area and inside the disc area (P < 0.05).Three months after toric orthokeratology, FAZ area in the T group was significantly reduced by 0.05 (− 0.41 to + 0.08) mm2, while ChC perfusion area was enlarged by 0.06 ± 0.12 mm2. FAZ area in the S group significantly decreased by 0.01 (− 0.19 to + 0.01) mm2, whereas ChC perfusion area increased by 0.06 (− 0.07 to + 0.50) mm2. Retinal thickness in the two groups increased after 3 months of orthokeratology in the whole area and parafoveal area (P < 0.05).ConclusionOrthokeratology improved retinal blood flow in macular area and RPC while controlling myopia. The changes in FAZ and ChC perfusion areas did not significantly differ between toric and spherical orthokeratology.

Optic nerve head optical coherence tomography angiography findings in patients with thyroid eye disease: a case–control study

BackgroundTo evaluate changes in the vessel density (VD) of the optic nerve head (ONH) microvasculature in thyroid eye disease (TED) using optical coherence tomography angiography (OCTA). This study aimed to applicate the OCTA as a noninvasive modality in screening TED patients to assess sub-clinical changes.MethodsIn a cross-sectional study, the control group patients were healthy individuals with no ocular abnormalities and were euthyroid. All patients with TED had clinical features of the disease. We divided them into two groups using the clinical activity score (CAS). Patients with CAS scores 0–2 were categorized as group A, and scores three or more as group B. All vessels (AV) and small vessels (SV) VD inside disc and radial peripapillary capillary network were measured using the ONH-OCTA.ResultsWe evaluated 29 patients with TED and 28 healthy controls. The mean whole image AV VD (mean ± SD: 56.33 ± 2.56, p-value = 0.17) and the mean whole image SV VD (mean ± SD: 49.94 ± 2.56, p-value = 0.16) in the TED group had no statically significant difference compared with the control group (AV mean ± SD: 57.20 ± 20.22, SV mean ± SD: 50.84 ± 2.23). We found a non-significant decrease in AV and SV radial peripapillary capillary VD in the TED group. There was a significant decrease in the mean whole image AV VD (mean ± SD: 54.83 ± 3.07, p-value = 0.005) and the mean whole image SV VD (mean ± SD: 48.60 ± 3.18, p-value = 0.013) in CAS group B compared to group A (AV mean ± SD: 57.45 ± 1.33, SV mean ± SD: 50.95 ± 1.37).ConclusionOur study showed non-significant ONH vascular alterations in patients with TED, including reduced VD of ONH in the radial peripapillary capillary. Patients with higher CAS scores had a more noticeable decrease in ONH microvasculature.

Elevated pulse pressure correlated with reduced retinal peripapillary capillary in thyroid-associated ophthalmology with visual field defect.

PurposeTo quantify the retinal vessel density in thyroid-associated ophthalmology (TAO) patients with visual field (VF) defect and examine its associations with mechanical and system vascular risk factors for underlying pathogenesis of VF defect in TAO.MethodsThe cohort was composed of 62 TAO eyes (39 with VF defect and 23 without VF defect). The pulse pressure (PP), intraocular pressure (IOP), ophthalmic rectus muscular index (MI), superficial retinal capillary plexus (SRCP), radial peripapillary capillary (RPC) density, and other related parameters were measured. The associations among these factors and VF mean deviation (MD) were analyzed.ResultsIn TAO patients with VF defect, reduced RPC density, higher PP, and larger horizontal and vertical MI were found (all P < 0.03) when compared to TAO patients without VF defect. The RPC density was correlated with VF MD value (r = 0.242, P = 0.029), while SRCP density was not (P = 0.419). In univariable general estimating equation (GEE) analysis with RPC density as the outcome, PP and its fluctuation showed a significant association (both P < 0.04). In the final RPC model with multivariable GEE analysis, only PP (β = -0.082, P = 0.029) showed significance while PP fluctuation (P = 0.080) did not.ConclusionsThe elevated PP was correlated with reduced retinal peripapillary perfusion in TAO resulting in VF defect. These data suggested that the system vascular factor may be important in the pathogenesis of reduced retinal perfusion resulting in visual impairment in TAO.

Changes in macrophage-like cells characterized by en face optical coherence tomography after retinal stroke.

PurposeThe retina could serve as a window of neuroinflammation, but the in vivo changes in macrophage-like cell (MLC), such as microglia, in acute ischemic retinal stroke remain unclear. Thus, the current study aimed to investigate the in vivo changes in MLC characterized by en face optical coherence tomography (OCT) after acute ischemic retinal stroke.MethodsTwenty patients with unilateral acute nonarteritic reperfused central retinal artery occlusion (CRAO) were participated in this study, and their contralateral eyes served as control group. A 3 μm en face OCT slab on the inner limiting membrane of the optic nerve head (ONH) region or macular region was used to visualize and binarize the MLCs. The MLCs were binarized and quantified using a semiautomated method. OCT angiography was used to evaluate the reperfusion status and obtain the structural data of the inner retina in the ONH and macula. The thickness of the ganglion cell complex in the macular region was measured. The optical intensity and optical intensity ratio of the inner retina were calculated to evaluate the ischemia severity.ResultsIn the ONH region, decreased vessel densities of radial peripapillary capillaries accompanied by increased thickness of the retinal nerve fiber layer were found in the CRAO eyes in comparison to the unaffected eyes (p=0.001, p=0.009, respectively). In the macular region, significantly lower vessel densities in both the superficial and deep capillary plexus and increased thickness of the ganglion cell complex were also found in the CRAO eyes (all p ≤ 0.001). The ONH and macular MLC quantities and densities in CRAO eyes were significantly higher than those in the unaffected eyes (both p<0.001). Larger and plumper MLCs were observed in the CRAO eyes compared with their unaffected eyes. ONH and macular MLC densities were positively associated with the disease duration in the acute phase and the optical intensity ratio of inner retina.ConclusionsThe increased density and morphological changes of MLCs may indicate the aggregation and activation of MLCs following acute reperfused CRAO. The aggregation of MLCs may be more pronounced in CRAO eyes with longer disease duration and more severe ischemia. MLCs characterized by en face OCT may serve as an in vivo visual tool to investigate neuroinflammation in the ischemic-reperfusion process of stroke.

Deep learning-based noise reduction improves optical coherence tomography angiography imaging of radial peripapillary capillaries in advanced glaucoma.

Purpose We applied deep learning-based noise reduction (NR) to optical coherence tomography-angiography (OCTA) images of the radial peripapillary capillaries (RPCs) in eyes with glaucoma and investigated the usefulness of this method as an objective analysis of glaucoma. Subjects and methods This cross-sectional study included 118 eyes of 94 open-angle glaucoma patients (male/female =38/56, age: 56.1 ± 10.3 years). We used OCTA (OCT-HS100, Canon) and built-in software (RX software, v. 4.5) to perform NR and calculate RPC vessel area density (VAD) and skeleton vessel length density (VLD). We also examined NR’s effect on reproducibility. Finally, we assessed the vascular structure (PRCs)/function relationship at different glaucoma stages with Spearman's correlation. Results Regardless of NR, RPC parameters had excellent coefficients of variation (1.7 to 4.1%) in glaucoma patients and controls, and mean deviation (MD) was significantly correlated with VAD (NR: r = 0.835, p < 0.001; non-NR: r = 0.871, p < 0.001) and VLD (NR: r = 0.829, p < 0.001; non-NR: r = 0.837, p < 0.001). For mild, moderate, and advanced glaucoma, the correlation coefficients between MD and VLD were 0.366 (p = 0.028) 0.081 (p = 0.689), and 0.427 (p = 0.017) with NR and 0.405 (p = 0.014), 0.184 (p = 0.360), and 0.339 (p = 0.062) without NR, respectively. Conclusions Denoised RPC images might have the potential for a closer structural/functional relationship, in which the floor effect of retinal nerve fiber layer thickness affects measurements. Deep learning-based NR promises to improve glaucoma assessment.

Glaucoma Detection in Myopic Eyes: Structural and Vascular Assessment by Optic Coherence Tomography Methods.

Retinal nerve fiber layer (RNFL) thickness is helpful in the diagnosis of glaucoma in myopic eyes but neuroretinal rim (NRR) thickness is the most valuable measure. However, changes in optical coherence tomography angiography (OCT-A) parameters are insufficient for the diagnosis of mild to moderate glaucoma in myopia. To detect how a multimodal evaluation, which includes RNFL, NRR thickness, and optic nerve head (ONH) OCT-A, affects glaucoma diagnosis in myopic patients. Parameters of healthy myopic and myopic glaucoma eyes with an axial length of ≥24 mm were compared. The ONH structural features and peripapillary RNFL thickness were determined with Cirrus 5000 HD-OCT (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA). The Cirrus 5000 HD-OCT with AngioPlex was utilized to perform OCT-A imaging. The sensitivity and specificity levels were calculated by the best cut-off values with area under curve (AUC). One hundred healthy myopic and 54 myopic glaucoma eyes were evaluated. In all areas, myopic glaucoma patients exhibited lower RNFL and NRR thickness than healthy myopic individuals ( P <0.05), with the exception of nasal quadrant RNFL thickness ( P =0.152). The mean entire and 4 quadrants of global radial peripapillary capillary (RPC)-perfusion and global RPC flux index (FI) were significantly lower in the group of myopic glaucoma patients except for the nasal quadrant mean RPC perfusion ( P =0.224). The average RNFL and NRR thickness had a significant difference in AUC for the diagnosis of glaucoma in myopic individuals ( P =0.001, for each). The average NRR showed excellent diagnostic performance, whereas the average RNFL showed good diagnostic performance. Average RPC perfusion and average RPC FI showed poor diagnostic ability. The average NRR AUC was more significant than average RPC perfusion and average RPC FI AUC ( P <0.001). Although RNFL thickness was helpful to diagnose glaucoma in patients with myopia, the diagnostic power of NRR thickness performed best. OCT-A parameters showed poor diagnostic accuracy for glaucoma and the observed perfusion decrease in myopic glaucoma eyes was not sufficiently discriminative compared with NRR and RNFL thickness measurements.

Optical Coherence Tomography Angiography in Schizophrenia.

The aim of this study is to investigate the retinovascular structure of schizophrenia patients using optical coherence tomography angiography (OCTA). 47 eyes of schizophrenia patients were compared with 50 eyes of demographically matched healthy controls in terms of OCTA measurements. Schizophrenia patients were evaluated in two groups as short-term (≤ 5years) and long-term (> 5years) according to the time elapsed after the diagnosis of schizophrenia. Schizophrenia patients showed overall thinning of retinal nerve fiber layer and macula, and lower vessel density (VD) compared to controls. The results were significant for thickness measurements of general macula and for VD in specific areas (P < 0.05); however, they were not significant for the RNFL measurements except the mean circumpapillary RNFL, which was noted to approach significance (P = 0.055). Long-term patients showed significantly lower VD in the whole and perifoveal region of superficial capillary plexus, the whole, perifoveal and foveal region of deep capillary plexus, and the whole area and the disc of radial peripapillary capillaries compared to short-term patients (P = 0.014, P = 0.009, P = 0.011, P = 0.010, P = 0.011, P = 0.035, P = 0.030). These findings suggest that schizophrenia may be a neurodegenerative disease with progressive microvascular involvement over the years, and that OCTA has the potential to be a useful tool in detecting retinovascular changes in patients with schizophrenia.