Changes In Vessel Density Research Articles

Observation of microstructure and vessel density changes in the superficial retinal layer in buried optic disc drusen patients

Objective: To investigate the changes of the microstructure and vascular density in the superficial retinal layer of buried optic disc drusen (ODD) patients. Methods: Retrospective case-control study. A total of 36 ODD eyes (20 patients) and 26 normal control eyes were recruited in Beijing Union Medical College Hospital from January 2018 to July 2020. Measurement of best corrected visual acuity (BCVA), intraocular pressure, slit lamp, fundus examination and visual field examination were performed. The images and data of spectral domain-optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA) were analyzed and summarized. The differences of nasal retinal nerve fiber layer (RNFL), ganglion cell complex (GCC) thickness and macular superficial vascular density (VD) between ODD patients and normal controls were compared by independent sample t-test or Mann Whitney U test (the right eye was selected in bilateral ODD patients). Results: The 20 ODD patients and 26 normal controls were all female. There was no significant difference in age between the two groups (P>0.05). The BCVA and visual field examination was normal in all ODD patients. The SD-OCT examination showed an oval low signal shadow under the nasal outer nuclear layer of the optic disc, or local accumulation like a medium signal shadow with a clear boundary, and a high signal capsule in ODD patients. The RNFL in the upper nasal side of the ODD group was significantly different from the normal control group [(102.6±19.1) μm vs. (119.0±13.8) μm; t=-2.81; P<0.01]. Compared with normal control group [101.0 (100.0, 102.0) μm], the average GCC thickness in the ODD group [97.0 (89.3, 99.8) μm] was significantly different (U=48.50; P<0.01). The OCTA en-face scan showed that the vascular network in the macular area of the affected eyes was sparser than that of the control eyes. There was significant difference in superficial macular VD beteeen the ODD group (48.5%±2.8%) and the control group (51.0%±2.3%) (t=-2.63; P<0.05). Conclusions: There is thinning in the RNFL upper nasal side and GCC layer of the macular region in buried ODD patients, and the superficial VD of the macular region in buried ODD patients is lower than that in the normal controls.

Quantitative Evaluation of Macular Vessel Density Measurement by Optical Coherence Tomography Angiography in Patients with Inactive Ocular Sarcoidosis

ABSTRACT Purpose To evaluate the macular vessel density (VD) in inactive ocular sarcoidosis (OS) and investigatethe relationship between VD and both disease duration and visual acuity (VA). Methods This cross-sectional study was performed at a tertiary hospital. The macular VDs of patients with OSwere obtained using optical coherence tomography angiography and compared withhealthy subjects. Results Deep whole image macular VD (WI-MVD), parafoveal, and perifoveal VDs were lower in OS group (p =.01, p = .01, p = .02, respectively). Negative correlation between diseaseduration and both superficial and deep WI-MVD, parafoveal, and perifoveal VDswas obtained (for all p < .05). There was a positive correlation between VAand superficial VD (p < .001, r = 0.848 for WI-MVD). Conclusion OS affects deep VD significantly. Changes in superficial VD affect VA more. Disease duration is an important factor affecting macular VD.

Association of Initial Optical Coherence Tomography Angiography Vessel Density Loss With Faster Visual Field Loss in Glaucoma

Rapid vessel density loss during an initial follow-up period may be associated with the rates of visual field loss over time. To evaluate the association between the rate of vessel density loss during initial follow-up and the rate of visual field loss during an extended follow-up period in patients suspected of having glaucoma and patients with primary open-angle glaucoma. This retrospective cohort study assessed 124 eyes (86 with primary open-angle glaucoma and 38 suspected of having glaucoma) of 82 patients who were followed up at a tertiary glaucoma center for a mean of 4.0 years (95% CI, 3.9-4.1 years) from January 1, 2015, to February 29, 2020. Data analysis for the current study was undertaken in March 2021. The rate of vessel density loss was derived from macular whole-image vessel density values from 3 optical coherence tomography angiography scans early during the study. The rate of visual field loss was calculated from visual field mean deviation during the entire follow-up period after the first optical coherence tomography angiography visit. Linear mixed-effects models were used to estimate rates of change. A total of 124 eyes from 82 patients (mean [SD] age, 69.2 [10.9] years; 41 female [50.0%] and 41 male [50.0%]; and 20 African American [24.4%], 10 Asian [12.2%], 50 White [61.0%], and 2 other race or ethnicity [2.4%]) were assessed. The annual rate of vessel density change was -0.80% (95% CI, -0.88% to -0.72%) during a mean initial follow-up of 2.1 years (95% CI, 1.9-2.3 years). Eyes with annual rates of vessel density loss of -0.75% or greater (n = 62) were categorized as fast progressors, and eyes with annual rates of less than -0.75% (n = 62) were categorized as slow progressors. The annual rate of visual field loss was -0.15 dB (95% CI, -0.29 to -0.01 dB) for the slow optical coherence tomography angiography progressors and -0.43 dB (95% CI, -0.58 to -0.29 dB) for the fast optical coherence tomography angiography progressors (difference, -0.28 dB; 95% CI, -0.48 to -0.08 dB; P = .006). The fast optical coherence tomography angiography progressor group was associated with the faster overall rate of visual field loss in a multivariable model after adjusting to include concurrent visual field mean deviation rate (-0.17 dB; 95% CI, -0.33 to -0.01 dB; P = .04). The findings of this cohort study suggest that faster vessel density loss during an initial follow-up period was associated with faster concurrent and subsequent rates of visual field loss during an extended period.

OCT-Angiography Changes in Patients with Diabetic Macular Edema Treated with Intravitreal Dexamethasone Implant.

PurposeTo evaluate, using optical coherence tomography angiography (OCTA), the impact of intravitreal dexamethasone (DEX) implant on quantitative vascular measurements in patients with diabetic macular edema (DME).MethodsProspective, randomized, and open-label study. Primary endpoints were mean changes in vessel density (VD) and vascular perfusion (VP) in superficial capillary plexus (SCP) and VP in deep capillary plexus (DCP) and peripapillary capillary plexus (PCP).ResultsThirty-four eyes from 19 patients were included. Mean age was 67.4±7.3 years and 24 (76.5%) were men. VD in SCP in the 6 mm × 6 mm perifoveal ring was significantly decreased from 15.2±2.7 mm/mm2 at baseline to 13.5±3.1 at month-2, p, 0.0029. VP in SCP in the 6 mm × 6 mm perifoveal ring decreased significantly from baseline to month-2 (mean change −3.8%; 95% confidence-interval: −7.7% to −1.7%, p, 0.0028). Compared to baseline, the VP in DCP was significantly reduced at month 2 in the perifoveal ring of the 6 mm × 6 mm scan (p, 0.0063), and in the parafoveal ring of the 6 mm × 6 mm scan (p, 0.0048). Foveal avascular zone (FAZ) area did not change throughout the study. Central macular thickness significantly decreased from baseline in 210.3 µm (149.9–270.8 µm) and 201.8 µm (140.4–263.3 µm), p < 0.0001 each at month-2 and month-3, respectively.ConclusionsBesides functional and anatomical improvements, DEX implant significantly reduced VD and VP in DME patients.

MULTISCALE CORRELATION OF MICROVASCULAR CHANGES ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY WITH RETINAL SENSITIVITY IN DIABETIC RETINOPATHY.

To assess global, zonal, and local correlations between vessel density changes measured by optical coherence tomography angiography and retinal sensitivity measured by microperimetry across diabetic retinopathy severity. Diabetic patients and nondiabetic controls underwent optical coherence tomography angiography imaging and microperimetry testing. Pearson's correlation was used to assess associations between average sensitivity and skeletonized vessel density (SVD) or foveal avascular zone area centrally. Linear mixed effects modeling was used to assess relationships between local SVD measurements and their spatially corresponding retinal sensitivity measurements. Thirty-nine eyes from 39 participants were imaged. In all slabs, there was a statistically significant positive correlation between retinal sensitivities and SVDs on both global and zonal scales. No statistically significant correlation was found between central retinal sensitivities and the foveal avascular zone areas. Assessment of 1,136 spatially paired retinal sensitivity and SVD measurements revealed a statistically significant local relationship; this seemed to be driven by eyes with proliferative diabetic retinopathy that had reduced retinal sensitivities. This study supports positive correlations between SVD and retinal sensitivity at global and zonal spatial scales in diabetic eyes. However, our analysis did not find evidence of statistically significant correlations between retinal sensitivity and SVD on a local scale until advanced diabetic retinopathy.

Comparison of retinal layer thickness and microvasculature changes in patients with diabetic retinopathy treated with intravitreous bevacizumab vs panretinal photocoagulation

To compare changes in retinal layers and microvasculature in diabetic retinopathy (DR) patients after bevacizumab therapy and panretinal photocoagulation (PRP). This prospective study divided patients into two groups: patients treated with bevacizumab and those treated with PRP. Patients visited our retinal clinic at 1, 3, and 6 months after treatment. Retinal layer thickness and vessel density (VD) using optical coherence tomography angiography were analyzed. 37 eyes in the bevacizumab group and 36 eyes in the PRP group were enrolled. In the bevacizumab group, the parafoveal RNFL, GCL, and IPL thicknesses significantly decreased (P < 0.001, P = 0.013, and P = 0.017, respectively), whereas the thicknesses in the PRP group showed an increasing tendency over time (P = 0.087, P = 0.005, and P = 0.003, respectively). The VD of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in the bevacizumab group did not show significant changes, whereas the VD in the PRP group significantly increased over time (both P < 0.001). Additionally, RNFL (P = 0.001) and GCL thicknesses (P = 0.035) were significant factors affecting changes in BCVA, whereas the VDs of SCP and DCP did not. Patients who received bevacizumab therapy did not show a significant change in macular VD, whereas the VD of patients after PRP significantly increased after treatment. The increased macular VD in patients after PRP would be associated with the increased inner retinal layer thickness after treatment, which was significantly related to the impairment in visual acuity.

Microvasculature Recovery Detected Using Optical Coherence Tomography Angiography and the Rate of Visual Field Progression After Glaucoma Surgery.

PurposeWe evaluated microvascular changes using optical coherence tomography angiography (OCT-A) in glaucoma patients who underwent glaucoma surgery.MethodsThe macula and optic nerve head were imaged using an OCT-A device at one day before surgery and at one week, one month, three months, and six months after surgery. Measurements of vessel density (VD) were made in the intradisc region and macula, and the area of the foveal avascular zone (FAZ) was measured in both superficial and deep vascular layers. A mean deviation (MD) slope value of < −1.0 decibel/y was considered to be indicative of VF progression.ResultsA significant increase in VD was observed postoperatively in the deep vascular layer of the intradisc area (P < 0.001), and a significant decrease in the FAZ area was evident in the deep vascular layer (P = 0.018). An increase in the intradisc deep VD (17.48% ± 5.63%) was statistically significant in glaucoma eyes without progression, compared with those with progression (−1.27% ± 2.19%). Worse preoperative MD of the VF (P = 0.006), lower preoperative intradisc VD (P < 0.001), and fewer changes in the intradisc deep VD after surgery (P < 0.001) were significantly associated with MD slope.ConclusionsWe found deep VD changes in the laminar region of the optic nerve head and the macular area at up to postoperative one month after glaucoma surgery. An increase in the deep VD in the laminar region was beneficial to VF progression in glaucoma patients after surgery.

Optic disc cupping after circumpapillary Pd-103 slotted plaque radiation therapy

ObjectifExaminer les effets vasculaires et morphologiques sur le disque optique après une radiothérapie par plaque fendue dans le traitement d'un mélanome choroïdien touchant le disque optique. NatureÉtude transversale rétrospective. ParticipantsTrente-neuf patients atteints d'un mélanome choroïdien touchant le nerf optique. MéthodesChaque mélanome a été traité au moyen d'une plaque radioactive fendue (palladium-103) incluant et/ou entourant la gaine du nerf optique entre 2005 et 2019. Les images du nerf optique avant et après la radiothérapie ont permis de documenter et d’évaluer les changements au chapitre de la pâleur du nerf optique et du rapport cupule/disque (C/D). On a mesuré le rapport C/D à la tomographie par cohérence optique (OCT) de même que la pression intraoculaire (PIO) avant le traitement et pendant le suivi, et 22 patients ont également fait l'objet d'une angiographie-tomographie par cohérence optique (OCT-A) dont la qualité des images permettait l’évaluation de la densité et de la longueur des vaisseaux sanguins. On a noté une corrélation entre les différences quant aux mesures du rapport C/D et les modifications de la densité et de la longueur des vaisseaux sanguins visibles à l'OCT-A. RésultatsSuivant une radiothérapie par plaque fendue, on n'a pas observé de hausse significative de la PIO ni d'augmentation de la pâleur du nerf optique. Les images OCT et les photographies couleur ont mis au jour une augmentation significative (p < 0,001 pour les 2 techniques) du rapport C/D à la fin du suivi, comparativement à ce qui avait été mesuré avant le traitement. On notait une corrélation significative entre la hausse du rapport C/D selon l'OCT et les variations de la longueur des vaisseaux sanguins mesurées à l'OCT-A (p = 0,027). De même, on a établi une corrélation significative entre une augmentation du rapport C/D dans les photographies du fond d’œil et les variations de la densité (p = 0,043) et de la longueur (p = 0,019) des vaisseaux sanguins mesurées à l'OCT-A. ConclusionLes photographies du fond d’œil et les images OCT ont mis en lumière une augmentation du phénomène d'excavation du disque optique au décours d'une radiothérapie par plaque fendue. L'excavation était associée à une occlusion et à une atténuation vasculaires progressives synchrones de la zone péripapillaire, visibles à l'OCT-A. On en conclut que l'ischémie péripapillaire et papillaire due à la radiothérapie par plaque fendue s'accompagne d'une hausse du rapport C/D et d'une aggravation de l'excavation du disque optique.

Change of Retinal Vessel Density After Lowering Intraocular Pressure in Ocular Hypertension.

Purpose: To investigate the relationship between retinal microvasculature changes and intraocular pressure (IOP) for ocular hypertension (OHT) patients and further assess the factors associated with retinal microcirculation changes.Methods: This was a single-center prospective study designed for OHT patients, which consisted of two visits. After collecting baseline data of those who met the eligibility criteria, these patients were treated with latanoprost 0.005% ophthalmic solution for 4 weeks. Peripapillary vessel density (VD) of radial peripapillary capillaries (RPC) layer, macular VD in both superficial and deep layers, and foveal avascular zone (FAZ) area were measured by optical coherence tomography angiography (OCTA) before and after the treatment. We compared the changes in IOP and VD among the two visits by paired-sample t-test. Bonferroni correction was applied. Factors associated with VD changes were analyzed by linear regression analysis.Results: Thirty-four eyes of thirty-four patients were included. The mean IOP decreased by 6.5 ± 2.2 mmHg (p < 0.001). The peripapillary RPC VD increased significantly from 51.8 ± 2.5 to 53.0 ± 3.1% (Adjusted-p = 0.012). We found no significant difference in detailed sectors of the peripapillary region after correction. In the macular area, both the superficial and deep layers in foveal (superficial: 0.2 ± 1.9%, p = 0.523; deep: 0.0 ± 2.3%, p = 0.969) and parafoveal (superficial: 0.3 ± 3.0%, p = 0.565; deep: 0.5 ± 3.1%, p = 0.423) VD remained unchanged. The decrease of the mean FAZ area was insignificant (p = 0.295). The percentage of IOP reduction (β = 0.330, p = 0.031) and the baseline RNFL thickness (β = 0.450, p = 0.004) significantly correlated with the percentage of peripapillary RPC VD improvement in the multivariate linear regression analysis.Conclusion: The peripapillary VD in OHT patients increased after the reduction of IOP. The mild change of IOP did not alter the microcirculation in the macula. In addition, the percentage of IOP change and the baseline RNFL thickness were independent factors for the peripapillary RPC VD improvement.

Analysis of swept-source optical coherence tomography angiography measurement alterations in adult patients recovered from COVID-19

ABSTRACT Clinical Relevance Vessel density (VD) measurements obtained using swept-source optical coherence tomography angiography (SS-OCTA) of the retinal layers and choriocapillaris have the capacity to demonstrated retinal changes in COVID-19 patients. Background To investigate VD changes in the retinal layers and choroid using SS-OCTA in patients recovered from COVID-19. Methods This cross-sectionally designed study was conducted in a single eye centre. The diagnosis of COVID-19 disease was confirmed by a polymerase chain reaction test. Patients who had fully recovered from COVID-19 served as the COVID-19 group, and the control group comprised age- and gender-matched healthy subjects. VD measurements in the superficial and outer retina layers and the choriocapillaris were performed using SS-OCTA. Results VD measurements in the central fovea and all quadrants of superficial and deep retinal layers, and the choriocapillaris, showed a significant decrease in the COVID-19 group (P < 0.05 for all) compared to the control group. Significant reductions in VD measurements were more prominent in the choriocapillaris when compared to the retinal layers. Mean ferritin and C-reactive protein (CRP) concentrations showed negative correlations with VD measurements in certain quadrants of the deep retinal layer and choriocapillaris. Conclusion VD reductions occur the superficial and deep retinal layers and choriocapillaris in patients with pre-existing COVID-19. These results suggested the use of SS-OCTA as a microvascular biomarker and an auxiliary technique for the diagnosis and follow-up of COVID-19.

OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY EVALUATION OF PERIPAPILLARY MICROVASCULAR CHANGES AFTER RHEGMATOGENOUS RETINAL DETACHMENT REPAIR.

To evaluate the radial peripapillary capillary plexus (RPCP) vessel density (VD) and the retinal nerve fiber layer (RNFL) thickness in eyes successfully treated with pars plana vitrectomy for primary rhegmatogenous retinal detachment. In this cross-sectional multicenter clinical study, eyes with a minimum 12-month follow-up were reexamined. The RPCP VD and RNFL thickness in the rhegmatogenous retinal detachment subfields of the affected eye (study group) were compared with the corresponding areas of the healthy fellow eyes (control group). Fifty-three eyes were included in the study. A significantly lower RPCP VD and RNFL thickness were observed in those subfields affected by rhegmatogenous retinal detachment compared with those of the control group (P < 0.001). No statistically significant differences were observed between undetached subfields in the study group and their corresponding images in the control group. In the study group, a significant correlation was found between RPCP VD and RNFL thickness in subfields with detached retina (r = 0.393, P < 0.001) and undetached retina (r = 0.321, P < 0.001). Radial peripapillary capillary plexus VD changes were found in the subfields of detached retina successfully treated with pars plana vitrectomy and they correlated with RNFL thinning. These data suggest a coexistence of neuronal and microvascular damage in patients affected by rhegmatogenous retinal detachment.

Structural and Vascular Changes of the Choroid in Polypoidal Choroidal Vasculopathy after Intravitreal Anti-VEGF Therapy

Introduction: This study aimed to identify the changes in vessel density (VD) of the choriocapillaris (CC) and in subfoveal choroidal thickness (SFCT) and to evaluate their correlation with functional response after 3 monthly intravitreal injections of ranibizumab (loading phase [LP]) in patients affected by polypoidal choroidal vasculopathy (PCV). Methods: A total of 30 eyes of 30 PCV patients and 30 eyes of 30 healthy subjects as the control group were enrolled in this prospective study. The best-corrected visual acuity (BCVA) was measured at baseline and after 1 month from the third intravitreal injection in each patient. The VD of CC was evaluated in the macular area by means of optical coherence tomography angiography (OCTA). Central macular thickness (CMT) and SFCT were analyzed by enhanced depth imaging (EDI)-OCT. Results: The VD of CC showed statistically lower values in PCV patients at baseline with respect to after LP and normal eyes (p < 0.001). CMT and SFCT revealed a statistically significant reduction after LP (p < 0.001). Multiple regression analysis revealed a significant negative correlation between the reduced SFCT and CMT at baseline and the improvement of BCVA after LP (p < 0.05). Conclusion: The close relationship between the thinner SFCT and better visual outcome after LP reveals the role of the EDI-OCT assessment of the choroid as a predictive biomarker of functional response to anti-VEGF therapy. This tool could provide a quantitative evaluation of structural features of the choroid avoiding mistakes of evaluation at OCTA.

Vessel Density in the Macular and Peripapillary Areas in Preperimetric Glaucoma to Various Stages of Primary Open-Angle Glaucoma in Taiwan.

Peripapillary and macular vessel density (VD) are reduced in myopic non-glaucomatous eyes, the dynamic range of VD may be decreased by myopia, and whether VD measurement has the potential in differentiating stages of glaucoma severity in patients with myopic glaucoma remains questionable. This observational, cross-sectional study aimed to clarify the changes in peripapillary and macular VDs in preperimetric glaucoma (PPG) and primary open-angle glaucoma in the early, moderate, and late stages. A total of 1228 eyes from 661 participants (540 normal, 67 PPG, and 521 glaucomatous) were included. Participants underwent free blood tests at the internal medicine clinic to retrieve systemic data. Patients with glaucoma were grouped by disease severity, defined by glaucomatous visual field mean defect, including early-(224 eyes), moderate-(103 eyes), and late-stage glaucoma (194 eyes), and further divided into advanced (158 eyes) and terminal glaucoma (36 eyes). Macular VD, peripapillary VD, circumpapillary retinal nerve fiber layer (cpRNFL) thickness, and ganglion cell complex (GCC) thickness were evaluated and divided into superior and inferior parts. One-way analysis of variance was performed, followed by Tukey’s post-hoc test. The peripapillary VD was significantly different between the healthy and PPG groups and the early-, moderate-, and late-stage glaucoma subgroups (all p < 0.001). Peripapillary VD measurements are helpful in differentiating the various stages of glaucoma even in patients with myopic glaucoma.

Microvascular Structure Changes After Intravitreal Ranibizumab Injection in Retinal Vein Occlusion Patients With and Without Macular Ischemia

Purpose: To investigate the changes in the macular microvascular structure after anti-vascular endothelial growth factor (anti-VEGF) treatment in retinal vein occlusion (RVO) patients with and without macular ischemia.Methods: A total of 39 patients were divided into the macular ischemia group (n = 22) and the nonischemia group (n = 17) at baseline. All the patients received an intravitreal injection of ranibizumab with a 3+ pro re nata (PRN) regimen. The foveal avascular zone (FAZ) areas, macular vessel density (VD), and macular ischemic index (ISI) were evaluated at baseline and 3 and 6 months after treatment.Results: After treatment, some patients in the macular ischemia group achieved obvious reperfusion in macular nonperfusion areas. The VD and macular ISI improved in RVO patients, but the changes in VD and macular ISI were different in the two groups. The improvement of best corrected visual acuity (BCVA) was positively correlated with the improvement of macular perfusion status. Macular perfusion remained stable in most patients in RVO and only one patient had macular ischemia aggravation.Conclusion: The macular microvascular structures were stable in most RVO patients after anti-VEGF treatment. At the same time, some patients with macular ischemia presented reperfusion in macular nonperfusion areas, and still a few patients presented aggravated macular ischemia. Macular ISI is a good way to evaluate macular perfusion status in RVO compared to VD.

Macular and peripapillary microvasculature after dexamethasone injection in diabetic macular edema.

To evaluate the microvascular changes in the macular and peripapillary area after intravitreal dexamethasone implant in diabetic macular edema (DME). We included 31 eyes of 31 patients treated with a single dose dexamethasone implant for DME. All subjects underwent swept-source optical coherence tomography (OCT) and OCT angiography imaging before (T0), and one month (T1), two months (T2), and four months (T4) after dexamethasone injection. The foveal avascular zone (FAZ) area of superficial and deep capillary plexus (SCP and DCP) was calculated by delineating the FAZ border using the measurement tool of the device. The vessel density (VD) of SCP and DCP and choriocapillaris (CC) in the macular and peripapillary area were automatically calculated. There was an insignificant reduction in FAZ area measurements of SCP after dexamethasone injection in DME patients (p = 0.846). The FAZ area of DCP were significantly smaller compared to T0 measurements at T1, T2, and T4 (p = 0.013, p = 0.031, and p = 0.029, respectively). The mean average parafoveal VD measurements were significantly decreased after dexamethasone injection in SCP and DCP (p = 0.004, p = 0.005). The peripapillary VD in retinal capillary plexuses and choriocapillaris showed no significant difference after dexamethasone injection. Intravitreal dexamethasone leads to a significant FAZ area decrease in DCP with a reduction in parafoveal VD measurements. In addition, no significant VD changes were observed in the peripapillary area after dexamethasone. These findings indicate that dexamethasone may improve macular ischemia with no significant effects on peripapillary microvasculature in DME patients.

The association of cerebrospinal fluid pressure with optic nerve head and macular vessel density.

The present study aims to investigate the effect of temporary cerebrospinal fluid pressure (CSFP) reduction on optic nerve head (ONH) and macular vessel density (VD) using optical coherence tomography angiography. Forty-four eyes of 44 adults with diagnostic lumbar puncture and CSFP reduction were recruited. Thirty-two eyes of 32 healthy volunteers were controls. ONH and macular VD images were evaluated differences between baseline and after CSFP reduction. The results showed that the mean CSFP decreased from (11.6±2.1) mmHg to (8.2±3.4) mmHg (P<0.001). VD in the macular regions decreased significantly after CSFP reduction in the study group (all P<0.05). The control group showed no significant changes in macular VD (all P>0.05). In the study group, decreased VD in the macular parainferior region was associated with CSFP reduction (R2=0.192, P=0.003), the reduction of macular VD in parafoveal (R2=0.098, P=0.018), parainferior (R2=0.104, P=0.021), parasuperior (R2=0.059, P=0.058), paranasal (R2=0.057, P=0.042), paratemporal (R2=0.079, P=0.026) was associated with mean ocular perfusion pressure decrease following CSFP reduction. ONH vessel density did not differ after CSFP reduction (all P>0.05). In conclusion, macular vessel density decreased in association with CSFP reduction. Retinal vessel density in the macular region is more sensitive than that in peripapillary region after CSFP reduction.

Topographic Variation of Retinal Vascular Density in Normal Eyes Using Optical Coherence Tomography Angiography.

PurposeTo establish a continuous topography of retinal vessel density in normal eyes using optical coherence tomography angiography (OCTA).MethodsA retrospective chart review was performed, and 8-mm × 8-mm OCTA images from 22 normal eyes were analyzed. Vessel density was plotted as a continuous function of distance from the foveal center (radial vessel density) and directional meridians (directional vessel density) for the superficial capillary plexus and deep capillary plexus.ResultsContinuous radial and directional vessel density plots for the superficial and deep capillary plexus were generated. Radial vessel density analysis revealed transition points at 657 microns (95% confidence interval [CI], 619–696) and 950 microns (95% CI, 903–997) from the foveal center for the superficial plexus and deep plexus, respectively. Directional vessel density analysis demonstrated significant vessel density variations in these vascular layers and provided greater detail compared to traditional quadrant analysis.ConclusionsThere are significant topographic variations of retinal vessel density in normal eyes. Continuous vessel density analysis offers greater sensitivity in detecting topographic vessel density changes compared to traditional methods of analysis.Translational RelevanceThis study establishes a normative continuous vessel density topography that may help elucidate the role of the vascular bed in different chorioretinal diseases.

Comparison of the Effect of Pan-Retinal Photocoagulation and Intravitreal Conbercept Treatment on the Change of Retinal Vessel Density Monitored by Optical Coherence Tomography Angiography in Patients with Proliferative Diabetic Retinopathy.

Background: This study compares the changes in retinal vessel density (VD) after pan-retinal photocoagulation (PRP) and intravitreal conbercept (IVC) treatment in proliferative diabetic retinopathy (PDR) eyes by optical coherence tomography angiography (OCTA). Methods: A total of 55 treatment-naïve PDR eyes were included in this retrospective study. Of these, 29 eyes were divided into a PRP group, and 26 eyes were divided into an IVC group based on the treatment they received. OCTA was performed to measure macular and papillary VD at each follow-up in both groups. Results: The macular VD for superficial capillary plexus (SCP), deep capillary plexus (DCP), choriocapillaris (CC) and papillary VD for radial peripapillary capillary (RPC) between the two groups demonstrated no significant difference at baseline and month 12 (p > 0.05). The paired t-test results showed that the macular VD for SCP, DCP, CC and papillary VD for the RPC at month 12 did not differ to the baseline in each group (p > 0.05). Conclusions: During the 12-month follow-up, there was no significant change of macular and papillary VD between the PRP and IVC treatment in PDR eyes. Additionally, compared to the baseline, there were no significant changes of macular and papillary VD after either the PRP or IVC treatment. Considering the decrease in VD as DR progress, both treatment modalities can potentially prevent macular and papillary VD loss in PDR.

Acute and subacute macular and peripapillary angiographic changes in choroidal and retinal blood flow post-intravitreal injections

Whether post injectional acute intraocular pressure (IOP) increase is associated with decreased peripapillary and macular perfusion is still under debate. Here, we investigated early changes in the choroidal and retinal blood flow using OCTA imaging in a cohort of patients undergoing anti-VEGF intravitreal injections (IVI) for macular edema following retinal vein occlusion and diabetic retinopathy. In this prospective single-center, observational study, the pre- and post-IVI changes in retinal perfusion were examined via assessment of vessel length density (VLD) and vessel density (VD) in deep and superficial capillary segmentations (DCP and SCP), foveal avascular zone (FAZ) in SCP, as well as flow signal deficits in the choriocapillaris segmentation. Mean IOP significantly changed over the study course (p = 0.000; ANOVA). Measurements at 5 min post-IVI (33.48 ± 10.84 mmHg) differed significantly from baseline (17.26 ± 2.41 mmHg, p = 0.000), while measurements from one day, one week, and one-month post-IVI did not (p = 0.907, p = 1.000 and p = 1.000 respectively). In comparison to baseline, no changes in OCTA parameters, including FAZ, VD, VLD, and FV, were detected 5 min post-IVI. No significant alterations in OCTA parameters were observed during study course. Increased IOP spikes were detected post-IVI; however, no potential permanent ischemic retinal damage was suspected.

Optic Nerve Head Vessel Density Changes from Graves' Disease without TED to TED Dysthyroid Optic Neuropathy: Does Optic Nerve Head Ischemia Play a Role?

To compare the retinal peripapillary capillary (RPC) vessel density (VD) between 5 groups of patients on the spectrum of thyroid eye disease (TED). This is a prospective comparative study looking at 5 groups of patients who were consecutively included from January 2018 to March 2021. They were composed of: Healthy volunteers (39 eyes and 20 subjects), patients with Graves' disease without TED (26 eyes and 13 patients), mild TED (28 eyes and 14 patients), moderate-severe TED (30 eyes and 17 patients), and TED with dysthyroid optic neuropathy (DON) (21 eyes and 12 patients). Ocular and periocular examination, visual field indices, RPC-VD (with optical coherence tomography angiography), and retinal nerve fiber layer, and macular ganglion cell complex thickness were recorded. An initial insignificant (0.5 < p < 0.9) rise in the peripapillary-VD (pp-VD) and whole image-VD (wi-VD) from the healthy subject to the Graves' disease without TED was followed by a significant (p = 0.001) fall in RPC-VD in different severity grades of the TED. Paired comparison between the 5 groups showed that the statistically significant fall from the Graves' disease group occurred in the moderate-severe and DON groups (0.001 ≤ p ≤ 0.04). No variable significantly affected the VD (0.08 ≤ p ≤ 0.9). A lower wi-VD and pp-VD were significantly (0.001 ≤ p ≤ 0.009) correlated with the impaired optic nerve functional and structural tests. The sensitivity and specificity of wi-VD (81% and 76%) and pp-VD (69% and 71%) for detecting the DON were statistically significant (p < 0.001). Despite an insignificant rise in the wi- and pp-VD from the healthy volunteers to the patients with Graves' disease without TED, VD showed a declining trend in the course of patients with TED, which was statistically significant in the moderate-severe TED and DON groups.