Deep Foveal Avascular Zone Research Articles

Alterations in optical coherence tomography and optical coherence tomography angiography findings in children with partial biotinidase deficiency.

The aim of the study was to investigate whether retinal neurovascular structural impairment in children with partial biotinidase deficiency (BD) could be detected early via optical coherence tomography (OCT) and OCT angiography (OCTA). Eighty patients with partial BD and 80 control cases without any known systemic or ocular diseases were enrolled in this prospective study. Retinal neurovascular structures in the macular and optic disc regions were examined in using OCT and OCTA. Data from subjects with partial BD were compared with data from healthy controls. A statistically significant decrease in the vessel density (VD) was observed in both superior and inferior parts of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) in the partial BD patient group compared with the control group (p<0.05). A significant decrease in the VD was also observed in the superior and inferior peripapillary SCP-DCP regions of the optic disc area in the patients with partial BD (p<0.05). Both the superficial and deep foveal avascular zone (FAZ) areas were significantly enlarged in the partial BD group with respect to the control group (p=0.026, p=0.021 respectively). In the partial BD patients, the vascular density in the macula and optic disc region is decreased in childhood, when compared to the control group. In patients with partial BD, it would be very useful to detect the early neurovascular changes that may occur during the course of the disease by means of a noninvasive technique such as OCTA.

The Role of Widefield Optical Coherence Tomography Angiography in Assessing the Severity of Diabetic Retinopathy.

Physicians need an accurate understanding of diabetic retinopathy (DR) severity to optimally manage patients. The aim of this prospective study is to correlate the severity of macular and peripheral retinal vascular abnormalities seen on widefield (WF) optical coherence tomography angiography (OCTA) with DR grading based on WF fundus photography. The study included 150 eyes from 82 patients with treatment-naïve DR. All patients were imaged with WF fundus photography and swept-source WF OCTA. Quantitative and qualitative analyses of the foveal avascular zone (FAZ) size and shape, and measurement of capillary nonperfusion (CNP) areas, were performed from the OCTA images. The mixed-effects model was used to compare the DR grading from WF photography with the vascular changes seen on WF-OCTA, and Bonferroni correction was applied to the gradings. The mean [± standard deviation (SD)] age of patients was 55.5 (± 9.4) years. The WF-OCTA showed that an increasing size of the FAZ (from 0.442 (± 0.059) µm to 0.933 (± 0.086) µm) correlated with increasing severity of the DR (as determined with WF photography). The deep capillary plexus, FAZ size, and CNP areas in eyes with proliferative diabetic retinopathy (PDR) differed from those with mild nonproliferative diabetic retinopathy (NPDR) (p < 0.001). Most eyes with severe nonproliferative DR were found to have CNP in four quadrants [superficial capillary plexus (SCP) 60%, deep capillary plexus (DCP) 50%]. The WF-OCTA detected subtle neovascularization of the disc (NVD) in 7 eyes (10%) and neovascularization elsewhere (NVE) in 13 eyes (18%) that had been diagnosed with only moderate NPDR on WF photography. FAZ and CNP areas as measured by WF-OCTA correlate with DR severity. WF-OCTA can also detect subtle NVE and NVD that cannot be seen with fundus photography.

Evaluation of Long-term Posterior Segment Parameters in Children Who Had Recovered From Multisystem Inflammatory Syndrome.

To evaluate long-term posterior segment findings in children recovering from multisystemic inflammatory syndrome (MIS-C) associated with severe acute respiratory syndrome coronavirus 2. Our study included 22 patients who were admitted to an intensive care unit with a diagnosis of MIS-C between November 2021 and March 2022, and 25 healthy controls. The study included pediatric patients who had an eye examination an average of 12.35 ± 2.18 months after recovery from MIS-C. Detailed eye examinations and measurements of all participants were obtained retrospectively from patient files. Posterior segment parameters were measured using swept-source optical coherence tomography (OCT) and OCT-angiography (OCT-A); these parameters included peripapillary retinal nerve fiber layer (pRNFL) thickness, central macular thickness (CMT), subfoveal choroidal thickness (SCT), macular vascular densities (VD), and foveal avascular zone (FAZ) area. Mean age was 9.7 ± 3.6 years in the MIS-C group and 10.6 ± 2.8 years in the healthy control group (P = 0.316). There were no statistically significant differences between the MIS-C group and the healthy control group in terms of pRNFL thickness, CMT, and SCT. However, in the MIS-C group, the macular superficial vascular plexus and deep vascular plexus showed significantly lower VD in the superior, inferior, nasal, and temporal quadrants compared to the healthy controls (P < 0.05 for all). A comparison of the superficial and deep FAZ area parameters of both groups showed no statistically significant difference (P > 0.05). We showed that patients who had recovered from MIS-C had retinal vascular damage at the long-term follow-up. Following up with these patients after recovery with OCT and OCT-A, which are noninvasive methods commonly used in the detailed evaluation of the posterior segment of the eye, could be beneficial for understanding the long-term effects of MIS-C on retinal microvasculature. [Ophthalmic Surg Lasers Imaging Retina 2024;55:518-526.].

Evaluation of the effect of ocular dominance on macular microcirculation via swept-source optical coherence tomography angiography

PurposeTo determine the existence of differences in the retinal microcirculation of dominant and non-dominant eyes, as well as of interocular differences in macular microcirculation, using swept-source optical coherence tomography angiography (OCTA). MethodsIn total, 122 eyes of 61 individuals were enrolled in this cross-sectional study. Measurements were taken using the swept-source optical coherence tomography Triton device (Topcon Corp, Tokyo, Japan) coupled with non-invasive OCTA technology. Macular perfusion parameters were assessed, including superficial vascular complex, vascular density of the deep vascular complex, vascular density of the choriocapillaris vascular complex, superficial foveal avascular zone and deep foveal avascular zone. Ocular dominance was determined among individuals with healthy eyes using the hole-in-the-card test. ResultsOcular dominance was found in 68.9 % of right eyes and 31.1 % of left eyes. The mean age of the subjects was 34.45 ± 16.48 years (range: 18–73 years). We found that 16 (30.76 %) males and 22 (31.42 %) females had left-eye dominance (p > 0.05). None of the OCTA parameters differed between the eyes based on dominance (p > 0.05). Central macular thickness and sub-foveal choroidal thickness did not show significant differences (p > 0.05). When comparing interocular parameters, a significant difference was observed only in the inferior sector of the superficial vascular complex (p = 0.04). ConclusionThere was no significant difference in OCTA parameters between dominant and non-dominant eyes. There was no predominant interocular difference in the measurements.

Changes in foveal avascular zone parameters in individuals with prediabetes compared to normoglycemic controls: a systematic review and meta-analysis.

To investigate changes in foveal avascular zone parameters in individuals with prediabetes compared to normoglycemic controls. PUBMED, Scopus and Cochrane Library were searched for published articles comparing the foveal avascular zone between prediabetic individuals and normoglycemic controls as assessed by optical coherence tomography angiography (OCTA). Standardised Mean Difference (SMD) with 95% confidence interval (CI) was computed for the comparison. A total of seven studies were included in our analysis, 6 provided data for the superficial capillary plexus from 345 eyes of individuals with prediabetes and 347 eyes of controls and 4 provided data on the deep capillary plexus from 285 eyes from individuals with prediabetes and 325 eyes of controls. Foveal avascular zone (FAZ) area in the superficial capillary plexus was enlarged in individuals with prediabetes compared to normoglycemiccontrols (SMD = 0.23, 95% CI = 0.03-0.44, p = 0.03, I2 = 27%, 6 studies). There was no statistically significant change in the deep capillary plexus FAZ area between the two groups (SMD = 1.14, 95% CI = -0.06-2.34, p = 0.06, I2 = 97%, 4 studies). FAZ area in the superficial capillary plexus was larger in individuals diagnosed with prediabetes compared to normoglycemic controls. This finding suggests that prediabetes could induce retinal microvascular changes before the onset of clinical diabetes. More original studies are needed to validate the results of the current meta-analysis.

Comparison of the optical coherence tomography-angiography (OCT-A) vascular measurements between molecularly confirmed MODY and age-matched healthy controls.

Previous structural, vascular density, and perfusion studies have mostly comprised type 1 and type 2 diabetes, even in the absence of retinopathy. The current study aimed to compare macular vessel density (VD) measurements between maturity-onset diabetes of the young (MODY) patients and controls. The macular VD of superficial, deep retina, and choriocapillaris (CC), and central macular thickness (CMT), foveal avascular zone (FAZ), FAZ perimetry, VD of the total retina at 300µm around the FAZ (FD), and acirculatory index (AI) measurements were taken and analyzed via OCT-A (RTVue XR 100-2 Avanti, AngioVue) and were compared between molecularly confirmed MODY (glucokinase (GCK) variants) patients and healthy controls. Twenty-five MODY patients and 30 healthy controls were included in the study. The mean plasma hemoglobin A1c level in the MODY group was 6.39 ± 0.38. The mean age was 13.8 ± 2.1 in the MODY group and was 12.6 ± 2.5years among controls. There was no significant difference in terms of the age, superficial and deep retinal VD, FAZ, FAZ perimetry, CMT, FD, or AI between the groups. Compared to the healthy controls, a slight but significant increase in the CC-VD was detected in the MODY group, but only in the parafoveal and perifoveal regions (p = 0.034, p = 0.009). The significant CC-VD increase in the MODY group might be associated with hyperglycemia and/or relatively poor and vulnerable peripheral vascular CC perfusion compared to the central. Previous thickness and VD results of childhood or adolescent diabetes were distributed in a wider range, suggesting that various factors, including some not yet clearly defined, may affect the choroidal vasculature independently of glycemia or as a contributing factor.

Retinal Microvasculature in Systemic Sclerosis Patients and the Correlation between Nailfold Capillaroscopic Findings and Optical Coherence Angiography Results.

Background: The comparison of retinal perfusion in the eyes of patients with systemic sclerosis (SSc) and in healthy controls using optical coherence tomography angiography (OCTA). The correlation between nailfold capillaroscopy results and OCTA findings among SSc. Methods: The study enrolled 31 patients with systemic sclerosis and 41 healthy controls. OCTA was performed in both groups to assess the retinal vasculature in the superficial (SCP) and deep (DCP) capillary plexuses and the foveal avascular zone (FAZ) area. Nailfold capillaroscopy (NC) was performed in SSc patients and compared to the FAZ area and the superficial and the deep vessel density. Results: In the SSc group, the parafoveal vessel density in DCP was significantly higher in relation to the mean value (p < 0.0001) and in each quadrant of the macula (p < 0.0001) compared to healthy subjects (p < 0.0001). The patients with early scleroderma patterns in capillaroscopy had a larger superficial and deep FAZ (p = 0.0104, p = 0.0076, respectively) than those with active and late patterns. There was a statistically significant difference in the FAZ when comparing early to active (p < 0.0001) and early to late scleroderma patterns (p < 0.0001). A statistically significant difference was found in the type of interstitial lung disease and the deep FAZ area (p = 0.0484). SSc patients with nonspecific interstitial pneumonia (NSIP) had a larger FAZ than those with usual interstitial pneumonia (UIP) (p = 0.0484). Moreover, NSIP cases had a higher parafoveal mean superficial vessel density than those with UIP (p = 0.0471). Conclusions: Our investigation showed that the peripheral microvascular system correlates with ocular microcirculatory impairment. The results indicate the important role of OCTA in the diagnosis, monitoring, and prognosis of microvascular changes in SSc.

Связь парацентральной острой срединной макулопатии и гипертонической болезни

Purpose. To study changes in retinal microcirculation and the prevalence of chronic paracentral acute middle maculopathy (PAMM) lesions in patients with mild hypertension. Participants. Twenty-seven patients (21 males and 6 females 50.3 ± 6.3 years) with mild hypertension without cardiovascular risk and 24 healthy subjects (15 males and 9 females, 46.3 ± 13.0 years) were included. Methods. The foveal avascular zone (FAZ) area, vessel density of superficial and deep capillary plexus were assessed using optical coherence tomography (OCT) angiography. The presence of chronic PAMM lesions was evaluated by the revision of cross-sectional OCT images of 6-mm volume scans. A chronic or resolved PAMM lesion was defined as inner nuclear layer thinning with outer plexiform layer disruption. Results. There was no difference between hypertensive and healthy group in baseline characteristics, vessel density of superficial capillary plexus, vessel density of deep capillary plexus and FAZ area. Chronic PAMM lesions were found in 88.9 % hypertensive patients and in 16.7 % healthy individuals. The odds ratio for the presence of chronic PAMM lesions in mild hypertension was 40.0 (p &lt; 0.001). Conclusion. Chronic PAMM lesions are highly prevalent in hypertensive patients and may represent the earliest changes in retinal microcirculation in mild hypertension, before changes in OCT angiography parameters have become apparent. Keywords: paracentral acute middle maculopathy, hypertension, optical coherence tomography

Mean Ocular Perfusion Pressure Effect During Pars Plana Vitrectomy on the Foveal Avascular Zone: A Pilot Study.

Purpose: To evaluate the effect of mean ocular perfusion pressure on the foveal avascular zone (FAZ) area in eyes with successful retinal detachment (RD) surgery. Methods: This prospective pilot fellow eye-controlled study measured the intraoperative mean ocular perfusion pressure in eyes having surgery for rhegmatogenous RD (RRD). Postoperatively, the FAZ area was measured; the change was calculated as the difference in the FAZ area between the operated eye and the contralateral control eye. Results: The study comprised 8 patients with a mean age (±SD) of 53.38 ± 13.92 years. The mean superficial FAZ area was not different between operated eyes and control eyes, while the deep FAZ area was significantly larger in operated eyes. There was a strong negative correlation between the mean ocular perfusion pressure and the change in the deep FAZ area (Spearman ρ, -0.73; P = .04); the correlation between the mean ocular perfusion pressure and the change in the superficial FAZ area was not significant (Spearman ρ, -0.24; P = .57). A significant linear regression was found between the mean ocular perfusion pressure and the change in the deep FAZ area (R2 = 0.388). The predicted enlargement of the deep FAZ area was 0.03 mm with every 1 mm Hg decrease in the mean ocular perfusion pressure. Conclusions: Lower intraoperative mean ocular perfusion pressure is associated with enlargement of the deep FAZ area in eyes having successful RRD surgery.

Changes in retinal and choroidal thickness and vascular density in patients with systemic lupus erythematosus: Assessed by optical coherence tomography angiography.

The aim was to investigate the changes in retinal and choroidal thickness and vascular density in patients with systemic lupus erythematosus (SLE) using optical coherence tomography angiography (OCTA). Twenty-nine patients with SLE (29 eyes) and 25 control subjects (25 eyes) were enrolled. SLE activity was assessed using the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Retinal thickness (RT), inner retinal thickness (IRT), outer retinal thickness (ORT), choroidal thickness (ChT), retinal superficial vascular density (SVD), retinal deep vascular density (DVD), choriocapillary vascular density (CCVD), foveal avascular zone (FAZ), superficial FAZ (sFAZ), and deep FAZ (dFAZ) were measured using OCTA. The retinal and choroidal thickness and vascular density between the control group and SLE group were compared. The relationships between SLEDAI scores and the retinal and choroidal thickness and vascular density in SLE group were analyzed. The SVD was significantly increased, and the DVD and CCVD were significantly decreased in the SLE group compared to the control group (p < .05). The results of receiver operating characteristic (ROC) showed that the area under the curve (AUC) values of SVD, DVD, and CCVD were 0.873, 0.729, and 0.727, indicating a high accuracy in discriminating patients with SLE from controls. Correlation analysis showed that the SLEDAI scores were positively correlated with dFAZ (r = 0.589, p = .001) and FAZ (r = 0.451, p = .018), and negatively correlated with DVD (r = -0.491, p = .009) and CCVD (r = -0.521, p = .005). DVD and CCVD were decreased in the SLE and might be related to the disease activity. SVD, DVD, and CCVD may hold promise in the discovery of biomarkers for diagnosing SLE.

Evaluation of macular choroidal and microvascular network changes by activity scores and serum antibodies in thyroid eye patients and healthy subjects.

To investigate the choroidal thickness and the microvascular network changes around the macula in thyroid eye disease (TED) patients at different stages and the relationship of those changes with risk factors, serum antibodies and the severity of TED. A total of 85 participants were enrolled. All participants underwent ophthalmology and endocrinology examinations. Subfoveal choroidal thickness (SFCT), superficial (s) and deep (d) foveal avascular zone (FAZ) area, mean (m) and central (c) superficial vascular density (SVD), deep vascular density (DVD) measurements of the enrolled cases were performed with Topcon swept source optical coherence tomography (OCT)/OCT angiography (OCTA) DRI OCT Triton. Multiple linear regression analysis was used to explore the associations between SFCT, FAZ area, SVD, DVD and the relevant factors of TED. Those with active TED patients had higher c-DVD and m-DVD levels (P<0.05), however there is no statistically significant difference in SFCT between active and stable TED patients. Among the serum antibodies, it was observed that s-FAZ and d-FAZ increased, c-SVD and m-SVD decreased in patients with high thyroid stimulating hormone-receptor autoantibodies (TRAB) level, whereas SFCT thickened in patients with high levels of both TRAB and human thyroglobulin (hTG). There was no significant difference in SFCT, FAZ, SVD and DVD measurement at gender, between hyperthyroid and euthyroid patients and among those with or without thyroid papillary carcinoma. The results show that both disease activation and serum antibodies differentially affect both superficial and deep retinal vascular density. It has also been shown that high serum antibody levels affect choroidal thickness independent of clinical activity.

Effects of COVID-19 infection on retinal vascular density and choroidal thickness measured by optical coherence tomography angiography

AimThe present study evaluates the possible effects of COVID-19 on choroid thickness, the Foveal Avascular Zone (FAZ) and retinal vascular indices in the same individuals who had Optical Coherence Tomography (OCT) and Optical Coherence Tomography Angiography (OCTA) data prior to the COVID-19 pandemic. MethodsThe OCT and OCTA images of the same individuals with no known ophthalmic pathology who developed a COVID-19 infection were obtained were retrieved retrospectively from the database and compared with the repeated images of OCT and OCTA images 1–2 months after COVID-19 infection. ResultsEighty eyes of 40 patients (26 female [65%], 14 male [35%]) who had developed a prior Covid-19 infection were included in the study. When comparing the measurements of the same participants before and after Covid-19 infection, no significant difference was detected in the mean average choroidal thicknesses (p=0.998), average superficial (p=0.425) and deep (p=0.333) retinal vascular densities, and superficial (p=0.991) and deep (p=0.075) FAZ measurements. ConclusionsNo significant effect of COVID-19 on choroid thickness, FAZ or retinal vascular densities was noted in the present study, although there are some studies in literature with equivocal results.

Efficacy and safety of subthreshold micropulse laser in the treatment of acute central serous chorioretinopathy.

To analyze the efficacy and safety of subthreshold micropulse laser (SML) in the treatment of acute central serous chorioretinopathy (CSC). This is a retrospective case analysis study. Totally 58 eyes of 58 patients were enrolled, and they were divided into different groups. And 39 patients were treated with SML (SML group) and 19 patients were only observed (observation group). The follow-up period was 3mo after diagnosis. The best corrected visual acuity (BCVA), central retinal thickness (CRT), superficial retinal vascular density (SRVD), deep retinal vascular density (DRVD), the superficial and deep foveal avascular zone (FAZ) area, retinal light sensitivity (RLS), perfusion area of choroidal capillary layer (CCL), subfoveal choroidal thickness (SFCT) and fundus autofluorescence (FAF) were investigated. The BCVA, CRT, SRVD, DRVD, the superficial and deep FAZ area, RLS, SFCT of SML group were significantly improved at 3mo (all P<0.05). In the observation group, only CRT, DRVD and SFCT were improved (all P<0.05). Other research items in the observation group were not significantly different from baseline (all P>0.05). At the last follow-up, the BCVA and RLS in the SML group were better than those in the observation group, and CRT was lower, SRVD and DRVD, perfusion area of CCL were larger (all P<0.05). On FAF, no change of treatment spots was found after treatment. No structural laser damage was observed on optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA), and no choroidal neovascularization was observed. SML treatment of acute CSC can improve BCVA, RLS, and perfusion area of CCL, reduce CRT, increase SRVD and DRVD, and is safe.

A Reliable Criterion for the Correct Delimitation of the Foveal Avascular Zone in Diabetic Patients.

Manual segmentation of the Foveal Avascular Zone (FAZ) has a high level of variability. Research into retinas needs coherent segmentation sets with low variability. Retinal optical coherence tomography angiography (OCTA) images from type-1 diabetes mellitus (DM1), type-2 diabetes mellitus (DM2) and healthy patients were included. Superficial (SCP) and deep (DCP) capillary plexus FAZs were manually segmented by different observers. After comparing the results, a new criterion was established to reduce variability in the segmentations. The FAZ area and acircularity were also studied. The new segmentation criterion produces smaller areas (closer to the real FAZ) with lower variability than the different criteria of the explorers in both plexuses for the three groups. This was particularly noticeable for the DM2 group with damaged retinas. The acircularity values were also slightly reduced with the final criterion in all groups. The FAZ areas with lower values showed slightly higher acircularity values. We also have a consistent and coherent set of segmentations with which to continue our research. Manual segmentations of FAZ are generally carried out with little attention to the consistency of the measurements. A novel criterion for segmenting the FAZ allows segmentations made by different observers to be more similar.

Assessment of macular microvascular changes in children following treatment of anisometropic myopic amblyopia using optical coherence tomography angiography

PurposeTo evaluate macular microvascular changes in the form of foveal avascular zone (FAZ) area and vessel density in the superficial, deep capillary plexuses, and choriocapillaris using optical coherence tomography angiography (OCTA) in children with anisometropic myopic amblyopia before and after treatment.MethodsThis prospective observational study included 32 patients younger than 12 years old with anisomyopic amblyopia. OCTA was done before patients’ treatment with optical correction with or without patching and was repeated after successful amblyopia treatment. Outcomes included superficial, deep, and choriocapillaris vessel density (VD) and superficial and deep FAZ areas.ResultsThe study included 13 males (40.6%) and 19 females (59.4%), and the mean age was 9.52 ± 1.33 years. Fifty-three percent (53%) of patients needed only optical correction, and the remaining 47% needed additional patching therapy. After successful treatment, there was a significant improvement in amblyopic eyes in best-corrected visual acuity (p < 0.001), with higher VD values in superficial capillary plexuses (p < 0.001), deep capillary plexuses (p < 0.001), and foveal choriocapillaris (p = 0.030). In the glasses with patching subgroup, the difference between pre-treatment and post-treatment parameters revealed a significant improvement in vessel density in superficial retinal plexuses (foveal and parafoveal; p values 0.023 and < 0.001, respectively) and deep retinal plexuses (whole image, foveal, and parafoveal; p values 0.003, < 0.001, and 0.002, respectively). While amblyopic eyes treated with glasses alone had a significantly greater difference in choriocapillaris foveal VD (p value = 0.022).ConclusionAfter effective amblyopia treatment, amblyopic eyes exhibited improved best-corrected visual acuity and better macular perfusion along the superficial, deep vascular density, and choriocapillaris foveal VD.Clinical trial registrationCinicalTrials.gov Identifier: NCT05223153.

Associations between body mass index and choroidal thickness, superficial and deep retinal vascular indices, and foveal avascular zone measured by OCTA

AimThe present study explores the effects of Body Mass Index (BMI) on choroidal thickness, the deep and superficial retinal capillary plexuses, and the foveal avascular zone (FAZ). MethodsThe subjects in this prospective study were divided into five groups based on their calculated BMI. Choroidal thickness, superficial and deep retinal capillary plexuses, and FAZ were measured using enhance depth imaging (EDI) and optical coherence tomography angiography (OCTA). The groups were then compared and correlations with BMI were evaluated. ResultsThe study included 210 eyes of 105 subjects. The comparison of the BMI groups revealed a significant decrease in the mean choroidal thicknesses in the obese groups (p = 0.001), and a significant negative correlation between BMI and mean choroidal thickness (p = 0.02). The results of the analysis of the mean superficial and deep retinal capillary plexuses did not differ between the groups (p = 0.089, p = 0.808 respectively), while the deep FAZ measurements revealed a significant decrease in the obese groups (p = 0.003). ConclusionChoroidal thickness and deep FAZ are significantly negatively correlated with BMI, suggesting potential choroidal and retinal microvascular effects of obesity.

In vivo evaluation of macular microvasculature in childhood malnutrition using optical coherence tomography angiography.

To evaluate the microvascular alterations and foveal avascular zone (FAZ) changes in the foveal and parafoveal region in malnourished children. This cross-sectional study analyzed 168 eyes of 85 patients. The subjects were split into 3 groups based on their body mass index (BMI) percentiles and defined as Group 1 (BMI percentiles ≥95th, overnutrition group), Group 2 (BMI <5th percentile, undernutrition group) and Group 3 (BMI ≥5th and <85th percentile, control group). All subjects were examined with optical coherence tomography angiography (OCTA) to evaluate superficial capillary plexus (SCP), deep capillary plexus (DCP) vessel density (VD) and FAZ parameters. The retinal nerve fiber layer (RNFL), average macular ganglion cell-inner plexiform layer (GCL-IPL), inner limiting membrane-retinal pigment epithelium(ILM-RPE) thickness were evaluated using SD-OCT device. Age and gender did not statistically differ across groups (p=0.12 and p=0.92). Groups 1 and 2 were found to have significantly higher VD of the superior-hemisphere of the DCP levels than the control group (p=0.001). The control group's foveal VD of SCP was statistically higher than group 1's (p=0.012). Parafoveal VD was significantly increased in the superior of the SCP of group 1 and the lower hemisphere of the SCP of group 2 compared with the control group (p=0.02 and p=0.02, respectively). The mean FAZ perimeter, choriocapillaris flow area, RNFL, GCL-IPL and ILM-RPE thickness were similar between all groups. The childhood undernutrition and overnutrition may affect the density of retinal capillaries. Although the FAZ area and choriocapillary flow did not change, retinal capillary density tended to increase in malnutrition.

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.

Distribution of the Retinal Microcirculation Based on the Morphology of Peripapillary Atrophy in High Myopia

Introduction: The objective of this study was to evaluate the retinal microvasculature of the optic nerve head and macula in high myopia (HM), investigate the association between the vascular parameters and peripapillary atrophy (PPA) deformation, and assess and identify the PPA morphology changes during the development of HM. Methods: One hundred sixty-seven right eyes from 167 HM patients were enrolled in this cross-sectional study. Using the optical coherence tomography angiography (OCTA) and fundus camera, we evaluated the following parameters: radian and type of PPA, intrapapillary vascular density (IVD), peripapillary vascular density (PVD), macular vascular density (MVD), and foveal avascular zone (FAZ). Based on the PPA radian, subjects were divided into four groups: the non-PPA, temporal PPA, advanced PPA, and annular PPA. At the same time, the above parameters were compared between the groups using analysis of variance (ANOVA) and least significant difference test. Results: Total enrolled patients were divided into the non-PPA group (22 eyes), temporal-PPA group (70 eyes), advanced-PPA group (60 eyes), and annular-PPA group (15 eyes). The results showed that the PVD in the annular-PPA group was smaller than that in the non-PPA group, especially in the superonasal, nasosuperior, nasoinferior, inferotemporal, temporoinferior, and superotemporal directions (F = 4.059, 5.014, 2.830, 4.798, 5.892, 3.439; p < 0.05). Notably, the PVD showcased the highest value in temporal, followed by that in superior and inferior, and the lowest in the nasal. Concerning the fovea deep macular vascular density, FAZ area, and subfoveal choroidal thickness in the annular-PPA group, they were less than those of the rest of the groups (p < 0.05). Conclusion: The retinal microvasculature differed significantly in HM according to the PPA morphology. In addition to PVD and SFCT, the PPA can also affect FAZ. Finally, we speculated that PVD demonstrated better predictability of myopic progression than MVD.

Vitrectomy in Diabetic Macular Edema:: A Swept-source OCT Angiography Study.

The foveal avascular zone (FAZ) has been reported to decrease after anti-VEGF injections in diabetic macular edema (DME) in the long term. This study aimed to present the changes in swept-source OCT angiography after vitrectomy in patients with DME. Retrospective interventional study. Thirty-five eyes were included (mean age: 62 years). Patients were followed for 12 months after vitrectomy with internal limiting membrane peeling for DME. The following parameters were measured: central retinal thickness (CRT), central choroidal thickness, superficial FAZ, deep FAZ (dFAZ), and vessel density in the superficial and deep retinal layers (dVD). The CRT and superficial FAZ significantly decreased after surgery (401 μm-338 μm; P<0.00, 401 μm-293 μm; P<0.001, respectively). Initial visual acuity (VA) improved from 20/160 (0.97 logarithm of the minimum angle of resolution [LogMAR]) to 20/80 (0.62 LogMAR) (P<0.001). The vessel density in the superficial retinal layers rate was 42.3% and decreased after surgery, reaching 41.6% at the end of the follow-up. The dVD rate 1 week after surgery was 28.9% and remained stable throughout the observation period. The most important prognostic factors for the final VA were preoperative VA and preoperative CRT, while the dFAZ and dVD at the time of edema resolution also correlated with the final VA. The superficial FAZ decreases after vitrectomy, which might indicate that vitrectomy has a protective effect on DME, similar to anti-VEGF injections. Prognostic factors for better final functional results are better initial VA and lower CRT before vitrectomy, in addition to a lower dFAZ diameter and a higher dVD at the moment of edema resolution. The author(s) have no proprietary or commercial interest in any materials discussed in this article.