Peripapillary Vessel Research Articles

Peripapillary vessels density is closely related to cerebral white matter hyperintensities: An OCTA study.

Chronic cerebral hypoperfusion triggers the development of white matter hyperintensities (WMHs), common in cerebral small vessel disease (CSVD). However, conventional imaging techniques cannot visualize cerebral small vessels. The retina, a direct extension of the central nervous system, has an unclear correlation with WMHs. This study employs Optical coherence tomographic angiography (OCTA) to investigate vascular changes in the retina and explore its correlation with WMHs, aiming to provide a new method for assessing perfusion in early ischemic brain WMHs. Forty-nine patients with WMHs were stratified into mild and moderate/severe WMHs groups based on MRI findings, utilizing the Fazekas and Scheltens scales. OCTA assessed fundus vessel microcirculation. Logistic regression analyzed the correlation between ocular fundus microcirculation and WMH severity and location. Additionally, ROC curves evaluated the diagnostic efficacy of each fundus vascular microcirculation index in determining WMH severity. After adjusting for multiple confounders, finding consistently indicated that the moderate/ severe WMHs group exhibited lower vessel density (VD) in the superior quadrant of the inner peripapillary region compared to the mild group [OR = 0.487, CI (0.255,0.929), p < 0.05]. ROC curves revealed that when combined with age, diabetes, and superior quadrant VD of the inner peripapillary region, specificity could be increased to 94.1%. Peripapillary vessel density correlates closely with the severity of cerebral WMHs. Early morphological changes due to chronic hypoperfusion may initiate from the inner layer of the optic disc, and OCTA could offer a novel method for evaluating blood perfusion in ischemic WMHs.

Evaluation of macular and optic nerve head changes by optical coherence tomography angiography in glaucomatous eyes

Background Optical coherence tomography angiography (OCTA) is introduced as a safe, noninvasive, and dye-free technology that provides an assessment of both large vessels and microvasculature of the retina and some parts of the choriocapillaris. Measuring vessel densities using OCTA at both the macula and optic nerve head (ONH) in glaucomatous eyes and comparing them with those of normal eyes will give us an idea about the effect of glaucoma on vessel densities and the role of OCTA in controlling and monitoring glaucoma progression, which remains despite the various medical and surgical treatment options, the second most common reason of blindness worldwide. Aims The current study aimed to assess vessel densities in glaucomatous patients at both the macula and ONH and compare them with vessel densities of normal participants and to assess if OCTA can be useful in the diagnosis and monitoring of the disease. Settings and design Case–control study. Patients and methods The study enrolled 60 patients who were divided into two groups. Group 1 included 30 patients with any type of glaucoma and group 2 included 30 normal participants. OCTA was performed on all of them to assess the macular and ONH vessel densities. Results Glaucomatous patients showed decreased vessel density at the macula and the ONH. The vessel densities at the foveal and all quadrants of parafoveal regions of the macula were decreased when compared with vessel densities of normal participants. Vessel densities at all quadrants of the peripapillary region also decreased when compared with those of normal participants with a strong positive correlation between average peripapillary vessel density and average peripapillary retinal nerve fiber layer thickness. Conclusions Both macular vessel density and ONH vessel density are affected in glaucoma and that may play a role in the diagnosis and follow-up of the disease.

Optical Coherence Tomography Angiography Analysis of Peripapillary Choroidal Microvascular Density in normal-tension Glaucoma and Primary open-angle Glaucoma.

Glaucoma patients had a reduction in the inner annulus peripapillary choroidal microvascular density (PCMD) that became worse as the glaucoma severity progressed, which might provide new evidence supporting the vascular theory. To compare PCMD among normal-tension glaucoma (NTG), primary open-angle glaucoma (POAG), and healthy controls using optical coherence tomography (OCT) angiography (OCTA). The study included 40 POAG, 25 NTG, and 33 healthy controls. All subjects underwent OCT and OCTA testing. Inner annulus and outer annulus PCMD, as well as peripapillary vessel density (VD), was calculated. One-way analysis of variance was used to compare the vascular parameters of the three groups. Pearson correlation analysis or Spearman correlation test was used to evaluate the correlation between PCMD and glaucomatous severity factors. The spatial positional relationship between PCMD and corresponding peripapillary retinal nerve fiber layer (RNFL) thickness and visual field (VF) mean deviation (MD) was also assessed. The average and four quadrants of the inner annulus PCMD and peripapillary VD in the two glaucomatous groups were significantly lower than in normal eyes (P<0.05). Strong correlations were found between inner annulus PCMD and VF MD, peripapillary VD, and RNFL in POAG patients. Similarly, the inner annulus PCMD in NTG patients was strongly correlated with peripapillary VD and RNFL (all r>0.5). Strong positional correlations were found between inner superior quadrantal PCMD and RNFL thickness in both POAG and NTG patients (r=0.566, r=0.731, respectively). Likewise, inner inferior quadrantal PCMD exhibited a strong correlation with RNFL thickness in POAG patients (r=0.608). Strong positional correlations were also found between inner superior PCMD and VF MD in both POAG and NTG patients (r=0.589, r=0.622, respectively). Inner inferior PCMD exhibited a moderate correlation with VF MD in both POAG and NTG patients (r=0.487, r=0.440, respectively). The study found that the inner annulus PCMD decreased to varying degrees in NTG and POAG patients. The inner annulus PCMD was closely related to the structural and visual function parameters of glaucoma in both NTG and POAG. Furthermore, inner PCMD demonstrated a spatial correlation with corresponding RNFL thickness and VF MD.

Neuroretinal and microvascular retinal features in dementia with Lewy body assessed by optical coherence tomography angiography.

To explore retinal changes in patients with Dementia with Lewy Bodies (DLB) using Spectral Domain-Optical Coherence Tomography (SD-OCT) and Optical Coherence Tomography Angiography (OCTA), aiming to identify potential biomarkers for diagnosis and monitoring. A cross-sectional study analyzed 15 DLB patients and 18 matched controls. Participants underwent physical, neurological, neuropsychological, and ophthalmological evaluations, including SD-OCT and OCTA. Logistic regression, adjusted for age, sex, and inter-eye correlation, was employed to identify retinal alterations in patients affected by DLB. OCTA revealed that DLB is associated with reduced superficial and deep vessel densities (SVD and DVD) in the macula (p < 0.01), as well as decreased peripapillary vessel density (ppVD, p < 0.01). SD-OCT parameters showed correlations with DLB, including reduced central macular thickness (CMT, p < 0.001) and thinning of the ganglion cell layer-inner plexiform layer (GCL-IPL, p < 0.01). Logistic regression (R²=0.26) identified reduced ppVD as a significant predictor of DLB (p = 0.030). Impairments in retinal capillaries, especially lower ppVD, might mirror cerebral hypoperfusion in DLB, potentially due to reduced Vascular Endothelial Growth Factor (VEGF) levels and increased α-synuclein. Further investigations are warranted to confirm the causal relationship between these observations, disease severity, and progression, as well as their potential role as biomarkers for DLB.

Effect of Buerger’s disease on ocular microvascular structure

ABSTRACT Clinical relevance Buerger’s disease, being a systemic inflammatory vasculopathy, may present with ocular findings. Background This study aims to understand the potential role of optical coherence tomography and angiography findings in evaluating the course of Buerger’s disease. Methods This was a prospective, cross-sectional study that included 25 patients with Buerger’s disease (Group 1) and 51 healthy control participants, of whom 27 were smokers (Group 2) and 24 were non-smokers (Group 3). Following a detailed ophthalmic examination, optical coherence tomography and angiography measurements were conducted on participants. The values of macular superficial and deep capillary plexus, peripapillary capillary plexus vessel density measurements were taken into account from optical coherence tomography angiography measurements. Furthermore, measurements were taken for the parameters of the foveal avascular zone, including its area, perimeter and acircularity index. Additionally, the choriocapillaris flow area was assessed between radii of 1 mm, 2 mm, and 3 mm. Results In patients with Buerger’s disease, the area and perimeter of the foveal avascular zone were higher than in both smoker and non-smoker healthy groups (p < 0.001 for all). The vessel densities in superficial capillary plexus were found to be lower in patients with Buerger’s disease compared to both smokers and non-smokers in all regions except the parafovea (p < 0.05 for all). The radial peripapillary capillary plexus vessel densities in the whole retina and peripapillary region were lower than those in the non-smoker group (p < 0.001 and p = 0.008). The choriocapillaris flow areas in all three radius were lower in the smoker group than in the non-smoker group (1 mm, p = 0.01; 2 mm, p = 0.005; 3 mm, p = 0.011) Conclusions Buerger’s disease extends beyond the extremities, affecting vascular density and tissue perfusion in the optic disc and macula, making it a systemic condition. This disease can have ocular involvement without causing serious ocular findings.

Changes in Ocular Blood Flow After Intravitreal Injection for Diabetic Macular Edema Between Aflibercept and Faricimab.

In this study, we aimed to evaluate and compare the effects of intravitreal aflibercept (IVA) and intravitreal faricimab (IVF) injections on the blood flow of retinal vessels in the peripapillary region and optic nerve head (ONH) in eyes with diabetic macular edema (DME) using laser speckle flowgraphy (LSFG). This study included 20 eyes of 18 patients treated with IVA and 15 eyes of 11 patients treated with IVF for DME. The mean blur rate (MBR) of the ONH and retinal artery and vein of the peripapillary region were measured using LSFG at baseline and 1 month after injection. Central retinal thickness (CRT) and best-corrected visual acuity (BCVA) were measured for all patients. CRT decreased significantly in both IVA-treated (p = 0.0003) and IVF-treated groups (p = 0.0004). Some of the MBR-related parameters of the ONH, such as MBR of all areas (MA), MBR of vascular areas (MV), and MBR of tissue areas (MT), decreased significantly 1 month after IVA and IVF compared to baseline values (MA of IVA, p < 0.0001; MT of IVA, p = 0.0220; MA of IVF, p = 0.0002; MT of IVF, p = 0.0461). MBR of the retinal artery (MBR-A) and vein (MBR-V) also decreased significantly 1 month after IVA and IVF compared with baseline values (MBR-A of IVA, p = 0.0002; MBR-V of IVA, p = 0.0010; MBR-A of IVF, p = 0.0368). No significant difference in ocular perfusion was observed between the IVA-treated and IVF-treated groups. Intravitreal injection led to a reduction in ocular blood flow in both retinal peripapillary vessels and the ONH in both IVA-treated and IVF-treated groups. No significant difference was observed in MBR reduction between the IVA-treated and IVF-treated groups. Our findings warrant further long-term investigations to reveal differences between aflibercept and faricimab.

Effect of Intraocular Pressure Lowering Treatment on Peripapillary and Macular Vessel Density on Normotensive Eyes with Optic Disc Drusen: A Randomized Controlled Trial

ABSTRACT To evaluate the effect of intraocular pressure (IOP) reduction on peripapillary and macular vessel density parameters from optical coherence tomography angiography (OCT-A) in normotensive eyes with optic disc drusen (ODD). Randomized controlled trial, with 6 months of follow-up, including normotensive eyes with ODD divided into two groups: control group (lubricating eye drop) and case group (latanoprost 50mcg/ml). We used OCT-A to evaluate peripapillary and macular vessel density parameters. Data were collected at baseline and at 1, 3, and 6 months following the use of eye drops. This study included a total of 32 eyes (16 cases and 16 controls) from 19 patients. After 6 months, the group using latanoprost IOP reduced IOP to 10.8 ± 0.64 versus 13.5 ± 0.54 mmHg in the control group (p < 0.001). We observed significant changes in OCT-A vessel density peripapillary parameters. The total radial peripapillary capillary (RPC) density (%) at month 6, in the eyes using latanoprost was 55.1 ± 1.05% and control was 57.9 ± 0.88%, p = 0.033. However, no changes were observed in macular vessel density parameters as well as retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness between groups after 6 months of using latanoprost. No sight-threatening events were observed during follow-up in either group. Until now there is no evidence that just lowering IOP can benefit normotensive patients with ODD. In fact, we observed a significant decrease in RPC vessel density after 6 months of IOP reduction using latanoprost, compared to the control group.

Clinical observation of the subthreshold micropulse laser combined with ranibizumab for treatment of diabetic macular edema

Objective: To evaluate the efficacy and safety of the subthreshold micropulse laser (SMPL) combined with ranibizumab in treating diabetic macular edema (DME). Methods: This was a prospective randomized controlled study. Patients diagnosed with DME in the Ophthalmology Department of Beijing Hospital were enrolled from January 2020 to December 2022. Patients were randomized in a ratio of 1∶1 using a table of random numbers into the ranibizumab monotherapy group and the SMPL combined with ranibizumab therapy group. We compared the changes of best-corrected visual acuity, central macular thickness measured by optical coherence tomography and optical coherence tomography angiography parameters, including the vessel density of the superficial and deep capillary plexus (DCP), foveal avascular zone size and peripapillary vessel density, at baseline, 6 and 12 months after the treatment. After 12 months of follow-up, fundus fluorescein angiography results, adverse events, and the number of injections or laser therapies were recorded. The Fisher's exact test and group t-test were used for statistical analysis. Results: Seventy-two patients (72 eyes) were enrolled, with a mean age of (61.1±8.2) years. Patients in the combination therapy group included 19 males and 17 females, while patients in the ranibizumab monotherapy group were 17 males and 19 females. There was no statistically significant difference in baseline characteristics between the two groups (P>0.05). A significant improvement in best-corrected visual acuity was shown in both groups at 6 and 12 months [(58.5±12.9) and (58.2±12.2) ETDRS letters in the combination therapy group, and (63.3±13.1) and (63.8±12.5) ETDRS letters in the ranibizumab monotherapy group]. A significant reduction in central macular thickness was shown in both groups at 6 and 12 months [(451.0±185.5) and (380.4±159.3)μm in the combination therapy group, and (387.5±135.5) and (372.8±146.1)μm in the ranibizumab monotherapy group]. However, there was no significant difference between groups at each timepoint (all P>0.05). At 12 months, the vessel density of the superficial capillary plexus showed no statistical difference compared to the baseline value in each group or between groups (42.6%±5.9% in the ranibizumab monotherapy group and 42.2%±5.5% in the combination therapy group, P>0.05). The vessel density of the DCP in the combination therapy group significantly increased to 47.5%±5.6% at 12 months, significantly different from that in the ranibizumab group (43.4%±5.1%; P<0.05). The foveal avascular zone size in the ranibizumab monotherapy group reduced to (0.32±0.13) mm2, significantly different from that in the combination therapy group [(0.34±0.16) mm2] at 12 months (P<0.05). Patients in the ranibizumab monotherapy group received (7.3±2.5) intravitreal injections, while patients in the combination therapy group received 3 injections. No unfavorable outcomes on fundus fluorescein angiography or systemic or topical severe adverse events were observed during the follow-up. Conclusions: The SMPL combined with intravitreal ranibizumab injections was effective and safe in treating DME patients. The combination treatment significantly reduced the number of injections and improved the vessel density of the DCP and macular ischemia, compared to the ranibizumab monotherapy.

Changes in peripapillary and macular vasculature measured by optical coherence tomography angiography and their clinical correlation in patients with optic neuritis due to multiple sclerosis

Aim To document changes in the peripapillary vascular network and retinal vascular plexuses in patients with optic neuritis (ON) due to multiple sclerosis (MS) and compare it with healthy individuals. Settings and design A prospective comparative case–control study performed at the Ophthalmology Department of a tertiary-level university hospital, between November 2020 and November 2022. Patients and methods In all, 26 eyes of 26 patients with ON caused by MS and 26 eyes of 26 sex-matched and age-matched healthy controls. We used optical coherence tomography AngioVue Enhanced Microvascular Imaging System aiming to quantify and compare microvasculature changes in the macula and peripapillary region between the two groups. Results We found a statistically significant decrease in the superficial and deep vessel density in the macular area in patients with ON compared with the healthy controls. Superficial vessel density in the macular area in the healthy ones was 49.90±3.4, while in those with MS was 44.09±4.9 (P&lt;0.001). Deep vessel density in the macular area in patients without MS was 51.71±6.8 while in patients with MS was 45.51±5.7 (P&lt;0.001). Conclusion There is a decrease in superficial and deep vessel density and radial peripapillary vessel density in patients with ON caused by MS in comparison to healthy controls.

Optic nerve head alterations after COVID-19: an optical coherence tomography angiography-based longitudinal study.

To evaluate longitudinal changes in peripapillary vessel density (VD) following coronavirus disease 2019 (COVID-19) using optical coherence tomography angiography. As part of a prospective longitudinal observational study, we studied healthy individuals with a history of mild COVID-19 confirmed via real-time polymerase chain reaction. After recovery, we used the Optovue RTVue XR Avanti machine to perform optic nerve head (ONH) imaging. We also assessed the VD of all vessels and of small vessels in the disc and the radial peripapillary capillary (RPC) network at 1 and 3 months post-recovery. We included 17 patients (34 eyes; mean age: 36.9 ± 10.2 years, range: 24-62 years) who had recovered from COVID-19. No changes were observed in the ONH parameters. However, there was a noticeable trend of increased small vessel VD values in the RPC. These increases were significant for the peripapillary whole, superior hemifield, inferior-temporal, temporal-superior, and superior-temporal small vessels. Moreover, the evaluation of all vessel VD values in the RPC revealed a significant decrease in the inside disc and a significant increase in a grid-based inferior region. COVID-19 may affect VD of the RPC in the ONH, and should be considered in ONH evaluations.

Diagnostic ability of the combination of retinal microvasculature evaluation and static automated perimetry for early primary open-angle glaucoma.

To investigate the diagnostic ability of retinal superficial vasculature evaluation by optic coherence tomography angiography (OCTA) combined with visual field (VF) testing for early primary open-angle glaucoma (POAG). In this cross-sectional study, 84 participants were included, including 11 in the ocular hypertension (OHT) group, 11 in the preperimetric POAG (pre-POAG) group, 29 in the early POAG group and 33 in the control group. All participants underwent 6 × 6 mm2 scans of macula and optic nerved head by optic coherence tomography (OCT) and OCTA, along with white-on-white and blue-on-yellow VF testing by static automated perimetry. The ability of diagnosing early glaucoma by either various examinations separately or combination of examinations in both terms of function and structure was studied using the receiver operating characteristic (ROC) curve and the area under the curve (AUC). The superficial retinal vessel densities (VD) in peri-nasal, para-temporal, peri-temporal and peri-inferior regions around the macula, as well as vessel area densities (VAD) in all peripapillary regions, were significantly different among the four groups, with lower VD or VAD in the early POAG patients compared to the normal individuals. The diagnostic ability of peripapillary superficial retinal VAD alone or VF testing alone was limited for early POAG only. However, the combination of these two was more effective in distinguishing normal individuals from OHT subjects or pre-POAG patients without VF defects, with better performance than the combination of peripapillary retinal nerve fiber layer (RNFL) thickness and VF indicators. Peripapillary retinal vessel densities were generally lower in early POAG patients compared to normal individuals. The combination of peripapillary superficial retinal VAD by OCTA with white-on-white VF testing improved the ability to distinguish POAG patients at early stage without function impairment, which may help in providing reference and guidance for the following-up and treatment of suspected POAG patients.

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

To identify damage to the inner retinal layer and microvasculature in the peripapillary area according to the severity of diabetic retinopathy (DR). 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. The average pRNFL thicknesses were 96.2 ± 7.1, 94.1 ± 9.6, 92.0 ± 9.9, and 90.3 ± 12.4μm 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 ± 1.6mm-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. 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.

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. 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. BMI decreased significantly to 43.75 ± 4.4 kg/m2 postoperatively compared to 55.31 ± 5.1 kg/m2 preoperatively (p &lt; 0.05). A significant increase was observed in macular vessel density in the deep capillary plexus postoperatively (p &lt; 0.01). However, no significant postoperative increase occurred in macular vascular density in the superficial and intermediate capillary plexus (p &gt; 0.05). Moreover, there was no change in peripapillary vascular density (p &gt; 0.05). Postoperative thickening of the foveal, parafoveal, and perifoveal retinal layers was significant (p &lt; 0.001). No significant correlation was detected between BMI change and macular and peripapillary vessel density changes (p &gt; 0.05). 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?

AimTo 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 method21 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.ResultsThere 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).ConclusionThe 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.

Evaluation of optical coherence tomography angiography metrics in children and adolescents with type 1 diabetes: 4-year longitudinal study

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

Optical coherence tomography angiography for detection of microvascular changes in early diabetes: A systematic review and meta-analysis.

To evaluate the effectiveness of optical coherence tomography angiography (OCTA) in detecting early intraocular microvascular changes in diabetic patients. A systematic study search was performed on PubMed, Medline, Embase, and the Cochrane Library, ranging from January 2012 to March 2023. Controlled studies compared diabetes mellitus (DM) patients with non-diabetic retinopathy (NDR) or patients with mild non-proliferative diabetic retinopathy (mild NPDR) to healthy people. These studies included parameters of OCTA such as foveal avascular zone (FAZ), vessel density of superficial capillary plexus (VDscp), vessel density of deep capillary plexus (VDdcp), and peripapillary VD. The relevant effect model was used according to the heterogeneity, and the mean difference and 95% confidence intervals were calculated. A total of 18 studies with 2101 eyes were eventually included in this meta-analysis. Our results demonstrated that early alterations of VDscp, VDdcp, and peripapillary VD in NDR patients had a significant difference compared with healthy people by OCTA (VDscp: WMD=-1.34, 95% CI: -1.99 to -0.68, P<0.0001. VDdcp: WMD=-2.00, 95% CI: -2.95 to -1.04, P<0.0001. Peripapillary VD: WMD=-1.07, 95% CI: -1.70 to -0.43, P=0.0010). However, there was no statistically significant difference in total FAZ between them (WMD=-0.00, 95% CI: -0.02-0.01, P=0.84). In addition, for patients with mild NPDR, OCTA could illustrate prominent changes in VDscp, VDdcp, and total FAZ compared with healthy people (VDscp: WMD=-6.11, 95% CI: -9.90 to -2.32, P=0.002. VDdcp: WMD=-4.26, 95% CI: -5.95 to -2.57, P<0.00001. FAZ: WMD=0.06, 95% CI: 0.01-0.11, P=0.03). In diabetic patients with or without retinopathy, the parameters of OCTA such as VDscp, VDdcp, and peripapillary vessel density were demonstrated as potential biomarkers in monitoring the early alterations of retinal microangiopathy, while total FAZ may have no significant changes in diabetic patients without retinopathy.

Assessment of Retinal Microvasculature and Choroidal Vascularity After Intra-arterial Chemotherapy for Retinoblastoma

PurposeTo evaluate changes in retinal microvascular density and choroidal vascularity in patients with retinoblastoma (RB) after intra-arterial chemotherapy (IAC). DesignRetrospective clinical cohort study. MethodsThis study included 12 unilateral RB eyes treated with IAC (RB tumour), 12 contralateral normal eyes (RB fellow), and 12 healthy controls. The macular retinal thickness and retinal microvascular structure, including foveal avascular zone (FAZ) area, the macular and peripapillary superficial vessel density (SVD) and deep vessel density (DVD), were measured by optical coherence tomography angiography (OCTA). The choroidal thickness (ChT) and choroidal vascularity, including total choroidal area (TCA), luminal area (LA), stromal area (SA) and Choroidal Vascularity Index (CVI), were measured by spectral-domain optical coherence tomography (SD-OCT). A comparison among the three groups was conducted, while the correlations among the parameters were analyzed. ResultsBetween the three cohorts, the foveal retinal thickness, the SVD, DVD, ChT, TCA, LA, SA and CVI were significantly lower in RB tumour compared to RB fellow and the control eyes (all P<0.01). There were no significant differences in the parameters between the contralateral and control eyes. The correlation analyses indicated a significant negative correlation between the total melphalan dose and foveal and parafoveal DVD, ChT, and LA. ConclusionsThe retinal microvascular density and choroidal vascularity were lower in unilateral RB treated with IAC, and seemed to be related to the total melphalan dose. Moreover there were no measurable changes in the contralateral eyes.

Measurement of retinal and optic nerve head blood flow in glaucomatous individuals compared to normal individuals: an optical coherence tomography angiography study

Study aim Identifing quantitative differences in retinal and optic nerve head blood flow detected by optical coherence tomography (OCT) angiography in moderately to severely affected glaucoma eyes of primary open angle type versus normal individuals. Patients and methods Comparative noninterventional observational prospective research has been performed on 28 eyes (16 individuals). Participants went through examination and imaging protocols. Data were collected during the period from January 2020 to May 2020. The study population was split into two cohorts: the first cohort included 14 eyes of nine individuals who suffered from glaucoma of open-angle type (moderately to severely affected), and the second cohort included 14 eyes of seven normal sex-matching and age-matching individuals. Results We documented a reduction in the vessel density of both the optic nerve head area (P&lt;0.001) and superficial retinal areas in glaucomatous eyes (P&lt;0.001), and this reduction shows statistical significance. Conclusion Quantitative OCT angiography analysis proved affection of both peripapillary and macular vessel density in glaucoma of open-angle type, signifying the OCT angiography role in understanding the disease’s underlying etiology.

Imaging Assessment of Peripapillary Vessel Diameters in Postmortem Eyes.

Proof of concept of ex vivo retinal vessel diameter measurements in human postmortem eyes. En face near-infrared (IR) images and optical coherence tomography (OCT) of the optic nerve head (ONH) were captured ex vivo with a Heidelberg Engineering Spectralis (Spectralis, version 7.0.4, Image Capture Module, version 1.2.4, Heidelberg Heidelberg, Germany) device, using a custom-made eye chamber holding and positioning the eyes during the image process. Thirty-two formaldehyde-fixated eyes of 16 patients were imaged. In the IR images, two independent graders measured retinal vessel diameters at the intersection of a drawn circle centered on the ONH with diameters of 2.0 mm and 3.4 mm, respectively. The anatomically corresponding measurements between both graders were statistically analyzed using a Wilcoxon signed-rank test. A total of 246 matched measurements of both graders were analyzed across all 32 imaged eyes. Statistically significant differences between the graders were found for arterioles at 2 mm from the ONH. The other measurements did not show statistically significant intergrader differences. The mean values for arteriole diameters were 72.2 µm at 2.0 mm and 61.5 µm at 3.4 mm for grader 1, and 66.4 µm at 2.0 mm and 63.2 µm at 3.4 mm for grader 2. The mean diameter for venules were 75.5 µm at 2.0 mm and 79.3 µm at 3.4 mm for grader 1, and 67.4 µm at 2 mm and 79.1 µm at 3.4 mm for grader 2. To the best of our knowledge, this is the first study to present IR image-based retinal vessel diameters in ex vivo postmortem eyes. Retinal IR/OCT imaging is possible, and measurements are reproducible in formaldehyde-fixated human eyes. Fixation artefacts result in lower image quality, and this can impose challenges in correctly detecting, classifying, and measuring retinal vessels.

Effect of treatment with carteolol and latanoprost in newly diagnosed primary open-angle glaucoma on peripapillary vessel density.

In a previous follow-up of glaucoma patients taking carteolol or latanoprost, we found a greater progression of visual field changes with the prostaglandin than the betablocker. In the present study we compared the impact of carteolol and latanoprost on peripapillary vessel density in newly diagnosed primary open-angle glaucoma (POAG) patients. The study consisted of two groups of POAG patients. There were 46 patient eyes treated with carteolol (Carteol LP 2%) in the first group and 52 eyes treated with latanoprost (Xalatan 0.005%) in the second. Intraocular pressure (IOP), vessel density (VD) and visual field were assessed in all patients. VD was measured peripapillary by optical coherence tomography angiography (OCTA) with the Avanti RTVue XR in eight segments: Inferior Temporal - IT (1); Temporal Inferior -TI (2); Temporal Superior - TS (3); Superior Temporal - ST (4); Superior Nasal - SN (5); Nasal Superior - NS (6); Nasal Inferior - NI (7) and Inferior Nasal - IN (8). The measurements were compared before and after three months of treatment. The visual field was examined with a fast threshold glaucoma program using a Medmont M 700 instrument from Medmont International Pty Ltd. and only when a diagnosis of POAG was done. The overall defect (OD) was assessed. Before treatment, there was no difference between groups in either OD or VD. After treatment, there was a decrease in IOP in both groups. In the carteolol-treated group, the mean decrease was 5.8 mmHg and in the latanoprost-treated eyes, the mean decrease was 7 mmHg. The difference was not statistically significant (P=0.133). After treatment with carteolol, there was a statistically significant increase in VD in segments 4, 5 and 6. After latanoprost treatment, VD was statistically significantly improved only in segment 5. A greater increase in VD values was found in eyes treated with carteolol than in eyes treated with latanoprost. Carteolol had a better effect on vessel density than latanoprost.