Quantitative analysis of retinal microcirculation in children with hyperopic anisometropic amblyopia: an optical coherence tomography angiography study

Effects of environmental enrichment on GLUT expression in the visual cortex of amblyopic rats

OBJECTIVE

To investigate the potential changes of glucose metabolism and glucose transporter protein (GLUT) in the visual cortex of formally deprived amblyopic rats, as well as the effects of enriched environments on the levels of nerve conduction and glucose metabolism in the visual cortex of amblyopic rats.

METHODS

36 rats were randomly divided into three groups: CON + SE (n = 12), MD + SE (n = 12) and MD + EE (n = 12). The right eyelids of both MD + SE and MD + EE groups were sutured. After successful modelling, the MD + EE group was maintained in an enriched environment, and the other two groups were kept in the same environment. Pattern visual evoked potentials (PVEP) was used to confirm models' effect, glucose metabolism was analyzed by Micro-PET/CT (18F-FDG), and the protein as well as mRNA expression levels of GLUT were detected by Western Blot and quantitative RT-PCR (quantitative Reverse Transcription-Polymerase Chain Reaction) analyses, site of GLUT expression by immunofluorescence (IF).

RESULTS

After suture modelling, both the MD + EE and MD + SE groups objective visual nerve conduction function decreased, the glucose metabolism in the visual cortex was markedly lower. After the enriched environment intervention, it recovered in the MD + EE group. The expression levels of GLUT1 and GLUT3 were increased in the MD + EE group in comparison with the MD + SE group. GLUT1 was primarily expressed on astrocytes and endothelial cells, but GLUT3 was mainly expressed on neurons.

CONCLUSION

Enrichment of the environment exhibited a therapeutic effect on amblyopia, which could be related to the enhancement of glucose metabolism and GLUT expression in the visual cortex.

Longitudinal evaluation of macular vascular density alterations in unilateral amblyopic children undergoing therapy: An optical coherence tomographic angiography study

Importance

Understanding the pathophysiology of the macula in amblyopic eyes is an active research area.

Objective

To correlate macular retinal vascular density changes with best-corrected visual acuity changes following occlusion therapy for amblyopia in children.

Design

A prospective cohort study of children visiting the Pediatric Ophthalmology Division of our institution between January 2020 and January 2022 was conducted.

Setting

A specialist eye hospital in Saudi Arabia.

Participants

Thirty children with unilateral amblyopia.

Exposure

Occlusion therapy for amblyopia.Main Outcome and Measures: Best corrected visual acuity (logMAR) before and at each of the four optical coherence tomographic angiographies was compared in amblyopic and fellow eyes. The effect of pretreatment determinants on the correlation between best-corrected visual acuity and retinal vascular density changes was reviewed.

Results

In this cohort of 30 amblyopic and 30 fellow eyes from 30 children (mean age 8.7 ± 1.4 years; male: female 18:12. The best-corrected visual acuity improved from a median of 0.6 (interquartile range 0.5; 1.1) pretreatment to a median of 0.4 (interquartile range 0.2; 0.6) posttreatment in amblyopic eyes, and from a median of 0.1 to 0.05 in the fellow eyes. The total percentage change in retinal vascular density in the amblyopic eye was significantly higher than that in the fellow eye (Z = -1.92, P = 0.05). The change in best-corrected visual acuity in the amblyopic eye after a median of 98 months (interquartile range, 69-126 months) of intervention was significantly correlated with the refraction-adjusted change in retinal vascular density (B = -0.03, 95 % confidence interval -0.04, -0.02, P < 0.001) and was influenced by strabismus (B = -0.46, 95 % confidence interval -0.59, -0.34, P < 0.001), type of amblyopia (B = 0.24, 95 % confidence interval 0.12, 0.36, P < 0.001), duration of occlusion (B = -0.43, 95 % confidence interval -0.65, -0.22, P < 0.001), and occlusion compliance (B = 0.24, 95 % confidence interval 0.11, 0.36, P < 0.001).

Conclusions

and Relevance: The RVD in amblyopic eyes in the first six months of therapy was significantly lower than that in fellow eyes, but not in subsequent assessments.

Evaluation of Ganglion Cell-Layer Complex and Macular Vessel Density in Amblyopic Eyes with Optical Coherence Tomography Angiography

Purpose: This study aimed to compare and quantify the ganglion cell complex (GCC), macular thickness, and vessel density (VD) in amblyopic eyes and their corresponding fellow eyes using optical coherence tomography angiography (OCTA). Methods: This cross-sectional study analyzed 32 unilateral amblyopic patients, examining both of their eyes. The study assessed parameters such as GCC thickness, macular thickness (total, inner, and outer layers), and VD in the optic nerve and macular region using spectral-domain OCTA. Results: This study analyzed data from 30 unilateral amblyopic patients with a mean age of 28.7 ± 18.3 years. Amblyopic eyes had lower mean best-corrected visual acuity compared with healthy eyes. However, no significant differences were found in retinal nerve fiber layer (RNFL) thickness, GCC thickness, and overall retinal thickness between amblyopic and fellow eyes when accounting for factors such as axial length and signal strength index. In patients older than 30 years, amblyopic eyes had a higher global loss volume (GLV) compared with fellow eyes (p = 0.02). In addition, blood VD within the optic disc and superficial/deep capillary plexuses in different macular regions were significantly lower in amblyopic eyes compared with fellow eyes. Conclusions: This study found significant differences in VD and the GLV index between amblyopic eyes and healthy eyes, particularly in older patients. However, there were no notable differences in macular thickness and RNFL thickness. Further research is needed to determine the clinical relevance of these findings.

Comparison of Retinal and Choroidal Microvasculature Changes in Monocular Amblyopic and Non-amblyopic Eyes following Short-term Patch Occlusion Treatment

PURPOSE

Our objective was to investigate whether there were differences in the short-term changes of retinal and choroidal microvasculature between amblyopic and non-amblyopic eyes after patch occlusion treatment in patients with monocular amblyopia. Additionally, we aimed to determine if these changes were associated with improvements in clinical parameters.

METHODS

We conducted a retrospective, longitudinal paired-eye case-control study by analyzing the medical records of patients under the age of 12 who had monocular amblyopia and underwent patch occlusion treatment for a duration of 2 to 12 months. Using optical coherence tomography angiography images, we compared the foveal avascular zone width, retinal blood vessel density (VD), choroidal thickness (CT), and choroidal vascularity index (CVI) in amblyopic and non-amblyopic eyes before and after patch occlusion treatment. We analyzed the correlations between the aforementioned parameters and changes in best-corrected visual acuity (BCVA) and stereopsis.

RESULTS

Overall, 114 eyes from 57 patients were enrolled. At baseline, parafoveal superficial plexus VD, foveal and parafoveal deep capillary plexus VD (DCPD) were lower by 0.994 ± 3.312% (p = .026), 2.403 ± 8.273% (p = .033), and 2.469 ± 4.095% (p < .001), respectively; CT was thicker by 30.6 ± 90.7 μm (p = .014); and CVI was higher by 1.920 ± 3.432% (p < 001) in the amblyopic eyes than in the non-amblyopic eyes. Following short-term patch occlusion treatment, foveal and parafoveal DCPD increased by 1.264 ± 3.829% (p = .017) and 1.028 ± 3.662% (p = .036), respectively, CT thinned by 15.5 ± 51.5 μm (p = .019), and CVI decreased by 1.296 ± 3.997% (p = .018) in the amblyopic eyes. Following patch occlusion treatment, as the foveal DCPD decreased and CVI increased, the BCVA improved (p = .017 and .035, respectively).

CONCLUSION

Following patch occlusion treatment, increased foveal DCPD and decreased CVI were associated with improved BCVA.

A variation of foveal morphology in a group of children with hypermetropia

PURPOSE

During routine eye examinations, we noticed widened and flattened foveal pits with loss of normal V-shaped foveal profile and a pseudohole-like appearance in some otherwise healthy hypermetropic children. Our purpose was to describe clinical significance and multimodal imaging features of this incidental finding.

METHODS

Prospectively, 25 eyes of 13 hypermetropic children with these foveal changes and 36 eyes of 19 hypermetropic children with normal foveal appearance were enrolled. The macular thickness measurements and foveal parameters including pit diameter, depth, base, and area obtained by optical coherence tomography (OCT) (Heidelberg Spectralis, Heidelberg Engineering, Heidelberg, Germany), macular superficial and deep vessel density (VD) and foveal avascular zone values obtained by optical coherence tomography angiography (Avanti RTVue‑XR; Optovue, Fremont, CA, USA) were noted. The correlations of these parameters with visual function were evaluated.

RESULTS

In the study group, significantly widened and flattened pit contours with decreased central foveal thickness (p = 0.01), and increased distance between foveal edges (p < 0.001) were observed. While the whole image superficial macular VD was similar between the groups (p = 0.74), a significant decrease in deep macular VD was observed in the study group (p = 0.01). None of these changes were correlated with visual acuity.

CONCLUSION

Wider and flattened foveal pits described here represent a newly defined variation in healthy hypermetropic children. Although a correlation with visual acuity was not evident, these changes in foveal profile are shown to be related with macular microvascular changes in deep capillary plexus. Awareness of these morphologic changes will help clinicians in the differential diagnosis of macular pseudohole.

Evaluation of Retinal Microvascular Features in Patients with Amblyopia Based on Optical Coherence Tomography Angiography: A Systematic Review and Meta-Analysis

BACKGROUND

The performance of optical coherence tomography angiography (OCTA) in macular microvasculature of patients with amblyopia has been widely studied, but these studies have yielded different and controversial results.

OBJECTIVES

The aim of this study is to investigate retinal microvascular features in patients with amblyopia undergoing OCTA.

METHODS

PubMed, Embase, and Web of Science were searched for published articles comparing the retinal microvascular features between individuals with amblyopia and controls until April 2022. The mean difference with a 95% confidence interval was used to assess continuous variables.

RESULTS

The analysis included 17 studies. The whole vessel density of the superficial capillary plexus (SCPVD) was lower in amblyopic eyes (AE) than in normal eyes (NE) in 3 × 3 mm2 scans, while the perifoveal vessel density of superficial and deep capillary plexus was lower in 6 × 6 mm2 scans. The whole, parafoveal vessel density of deep capillary plexus (DCPVD) and parafoveal SCPVD were lower in both scans. The comparison between AE and fellow eyes (FE) revealed no statistical difference in all quadrants except the parafoveal and perifoveal SCPVD and the foveal DCPVD. Additionally, SCPVD in all quadrants except the fovea and DCPVD in all quadrants except the parafoveal were higher in FE compared to NE. No significant difference was found in the foveal avascular area between AE and NE, AE and FE, or NE and FE.

CONCLUSIONS

The retinal vessel density of superficial and deep capillary plexus in AE and FE was lower than in NE, and differences were more likely discovered using 6 × 6 mm2 scans. Consequently, OCTA might be explored as a diagnostic tool to identify and monitor patients with amblyopia.

Microvasculature evaluation of anisometropic amblyopia children by Angio-OCT

To compare and assess the choroidal and retinal microstructural vascularity in amblyopic eyes with the fellow eyes in anisometropic amblyopic children using angiography optical coherence tomography (Angio-OCT). Twenty-seven children (54 eyes; 5.59 ± 1.08 years old; 59.3% girls) were enrolled in this study. Choroidal thickness (CT) was measured with the use of the enhanced depth imaging mode in Angio-OCT. Parafoveal/peripapillary vascular density indices and the foveal avascular zone (FAZ) size were analyzed by MATLAB code programming on Angio-OCT images. The mean FAZ size of the amblyopic eyes were larger both in superficial and deep capillary plexus layer (SCPL/DCPL). Compared with the contralateral eyes (BCVA were normal), all the vascular density indices of SCPL and DCPL in the parafoveal and peripapillary zones were lower in the amblyopic eyes, however, the difference was insignificant (p > 0.05). No significant decrease was observed in four quadrants analyses of the amblyopic eyes (p > 0.05). Except for the measurement at 2000 µm and 1500 µm from the fovea in temple, CT in amblyopic eyes were significantly thicken than the fellow eyes (p < 0.05). Compared with the fellow eyes, the CT of certain areas were thicker in the amblyopic eyes. Though the FAZ size of the amblyopic eyes was larger in SCPL/DCPL layers, the retinal vascular density indices in SCPL/DCPL were lower in amblyopia eyes without statistical difference. Angio-OCT may be an effective way to evaluate the status of the choroidal and retinal vascular system in amblyopic children.

Analysis of Retinal Microvasculature Features in Amblyopic Eyes: A Meta-Analysis

BACKGROUND

Amblyopia is a common cause of visual disorder with several changes in retinal structure and vessel. To date, alterations in retinal microvasculature features in amblyopia have yielded inconsistent results.

OBJECTIVES

This meta-analysis aimed to evaluate retinal vessel density (VD) in amblyopic patients using optical coherence tomography angiography (OCTA).

METHODS

PubMed, Web of Science, Embase, and Cochrane Library databases were systematically searched for published articles comparing retinal microvasculature characteristics in patients with amblyopia and controls. Continuous variable outcomes were assessed using the mean difference (MD) with a 95% confidence interval. Review Manager Version 5.30 was used for the analysis.

RESULTS

Thirteen qualified articles were pooled in this meta-analysis. Compared with controls, the foveal whole en face VD of superficial capillary plexus (SCP) and deep capillary plexus (DCP) of patients as measured by 3 × 3-mm scans were significantly lower in amblyopia eyes (MD: -1.37, p = 0.0003; MD: 1.70, p < 0.00001, respectively). Similarly, in the 6 × 6-mm scans, foveal whole en face VD of the SCP and DCP were remarkably lower in amblyopia eyes than in controls (MD: -2.24, p = 0.03; MD: -5.08, p = 0.04, respectively). The parafoveal VD of SCP in 3 × 3-mm scans (MD: -1.96, p < 0.00001) was also lower in amblyopic patients than in controls. Similarly, in 6 × 6-mm scans, amblyopia eyes showed a significant decrease and a trending decrease in the parafoveal VD of the SCP (MD: -3.85, p = 0.007) and DCP (MD: -3.03, p = 0.10), respectively. For whole radial peripapillary capillary (RPC), VD was significantly reduced in amblyopic patients compared to controls (MD = -0.83, p < 0.00001). In addition, the deep foveal avascular zone (FAZ) was larger in amblyopic eyes than in the controls (MD = 0.55, p = 0.007).

CONCLUSIONS

Our data suggest that whole foveal and parafoveal VD and RPC whole VD were reduced in patients with amblyopia. Moreover, our results reveal that the FAZ is larger in amblyopic patients. Consequently, OCTA may have the potential for diagnosing and monitoring patients with amblyopia.

Microvascular assessment of macula, choroid, and optic disk in children with unilateral amblyopia using OCT angiography

PURPOSE

To investigate the microvascular changes of macula, choroid, and optic disk in children with unilateral amblyopia.

METHODS

This prospective cross-sectional study involved 39 unilateral amblyopic children and 39 age- and sex-matched heathy participants who served as control. Vessel densities of the superficial and deep capillary plexuses (SCP and DCP), foveal avascular zone (FAZ) area, macular thickness, optic disk vessel density, retinal nerve fiber layer (RNFL) thickness, choriocapillaris vessel density, and subfoveal choroidal thickness were evaluated by OCT angiography (OCTA). Meanwhile, the correlations of microvascular perfusion and structural changes of macula, choroid, and optic disk were analyzed.

RESULTS

The vessel density of SCP and DCP in the whole macula in the amblyopic group was significantly lower than that in the control group after adjusting for age, axial length, and spherical equivalents (all P < 0.05). FAZ area, macular thickness, RNFL thickness, and the optic disk vessel density were not statistically different between the amblyopic group and the control group (all P > 0.05). Subfoveal choroidal thickness of amblyopic eyes was significantly higher than that of control eyes(P = 0.032). Choriocapillaris flow void (FV) in the amblyopic group was greater than that in the control group (P = 0.013). Significant differences were observed between the fellow eyes and the control eyes in choriocapillaris FV and subfoveal choroidal thickness (P = 0.011 and P = 0.042, respectively). Foveal SCP and DCP vessel density in all studied eyes were positively correlated with the whole macular thickness, respectively (r = 0.556 and r = 0.627, respectively, both P < 0.001). Whole SCP and DCP vessel density in the amblyopic eyes were negatively correlated with choriocapillaris FV (r = -0.723, P < 0.001; r = -0.512, P = 0.001, respectively).

CONCLUSION

Children with amblyopic eyes have attenuated macular and choriocapillaris perfusion. There is a need for future studies that will investigate the pathophysiology of amblyopia in children by OCTA.

Optical coherence tomographic angiography in children with anisometropic amblyopia

OBJECTIVES

To observe and compare the difference in retinal perfusion using optical coherence tomography angiography (OCTA) between anisometropic amblyopia in children and fellow eyes as well as age-matched controls.

METHODS

A total of 16 children with anisometropic amblyopia and 19 age-matched healthy subjects were enrolled. All participants underwent OCTA examination, with 3 mm × 3 mm and 6 mm × 6 mm scans in the macular region. Perfusion parameters of the superficial retinal layer were measured by built-in software, including the macular foveal avascular zone (FAZ) area, perimeter and circularity, as well as the vessel length density (VLD) and perfusion density (PD) of the foveal, parafoveal and perifoveal regions.

RESULTS

Among the 16 patients with anisometropic amblyopia, the FAZ area was significantly higher in diseased eyes (P = 0.027) than in fellow eyes. The VLD and PD of the foveal average and the VLD of the nasal quadrant of the perifoveal region in anisometropic amblyopic eyes were significantly lower than those in fellow eyes (P < 0.05). The VLD of the parafoveal average, the superior, temporal, inferior and nasal quadrants of the parafoveal region, and the nasal quadrant of the perifoveal region in anisometropic amblyopic eyes were significantly lower than those in healthy controls (P < 0.05). The PD of the parafoveal average, and the inferior quadrant of the parafoveal region in anisometropic amblyopic eyes were significantly lower than those in healthy controls (P < 0.05). The VLD of the parafoveal average, the superior, inferior and nasal quadrants of the parafoveal region, and the nasal quadrant of the perifoveal region in fellow eyes were significantly lower than those in healthy controls (P < 0.05). The PD of the parafoveal average, and the inferior quadrant of the parafoveal region in fellow eyes were significantly lower than those in healthy controls (P < 0.05).

CONCLUSIONS

The macular vessel density of the superficial capillary plexus is lower in anisometropic amblyopic children than in age-matched healthy children. Compared with the fellow eye, the perfusion of the amblyopic eye in children with anisometropic amblyopia also decreases.

Treatment Outcome of Occlusion for Unilateral Amblyopia in Saudi Children 6-12 Years Old

PURPOSE

The purpose of this study was to estimate the rate and review determinants of successful therapy for unilateral amblyopia in children.

METHODS

This prospective cohort consisted of Saudi children aged 6-12 who received amblyopia therapy between 2020 and 2022. Best-corrected visual acuity (BCVA) in the amblyopic eye improved to reach the BCVA of the fellow eye at follow-up visits, or BCVA in the amblyopic eye improved and remained stable over three follow-up visits. Demographic and ocular characteristics were associated with the outcome.

RESULTS

In 30 children, the median BCVA at presentation and the last follow-up was 0.8 logMAR (interquartile range [IQR]: 0.6; 1.0) and 0.45 logMAR (IQR: 0.3; 0.6), respectively. The success rate of amblyopia therapy was 80% (95% confidence interval: 65.7; 94.3). It was 100%, 76.5%, and 77.8% in eyes with anisometropic, strabismic, and mixed types of amblyopia, respectively. Amblyopia grade (P = 0.177), type of amblyopia (P = 0.96), and spectacles as therapy in the past (P = 0.09) were not significantly associated with the successful out. The duration of follow-up was significantly longer in those with unsuccessful outcomes (P = 0.05). Excellent compliance for occlusion was observed in 62.5% of children with successful outcomes. In 14 (46.7%) children, BCVA was ≤0.3 logMAR BCVA at the last follow-up. Two-line improvement in amblyopic eyes was in 26 (86.7%) children at the last follow-up compared to BCVA at presentation.

CONCLUSION

Occlusion therapy complemented using glasses in older children also significantly improved visual recovery in amblyopic eyes.

Parafoveal and peripapillary vessel density in pediatric and juvenile craniopharyngioma patients

We assessed the retinal microvascular alterations detected by optical coherence tomography angiography (OCT-A) in pediatric and juvenile craniopharyngioma (CP) patients with chiasmal compression. We included 15 eyes of 15 pediatric or juvenile CP patients and 18 eyes of 18 healthy subjects. The evaluation of vessel density from the superficial retinal capillary plexus (SRCP), the deep retinal capillary plexus, and the radial peripapillary capillary (RPC) segments was obtained by OCT-A. The association between vessel density measures and functional and structural measurements was also analyzed. There were significant reductions in the nasal sector of the SRCP (p < 0.0001) and all sectors of the RPC segment vessel density (nasal, temporal, and superior; p < 0.0001, inferior; p = 0.0015) in CP patients postoperatively compared to the healthy subjects. The peripapillary retinal nerve fiber layer (r = 0.6602, p = 0.0074) and ganglion cell-inner plexiform layer thicknesses (r = 0.7532, p = 0.0030) were associated with RPC segment vessel density. Visual acuity (r = − 0.5517, p = 0.0330) and temporal visual field sensitivity loss (r = 0.5394, p = 0.0465) showed an association with SRCP vessel density. In pediatric and juvenile patients with CP, parafoveal and peripapillary vascular changes following chiasmal compression were observed. The changes in vascular structures were closely related to structural and functional outcomes.

Analysis of Macular Retinal Thickness and Microvascular System Changes in Children with Monocular Hyperopic Anisometropia and Severe Amblyopia

Objective

To study the changes of macular retinal thickness and microvascular system in children with monocular hyperopic anisometropia and severe amblyopia using optical coherence tomography angiography (OCTA) and to explore the value of OCTA in the diagnosis and treatment of amblyopia.

Methods

Thirty-two children with monocular hyperopic anisometropia and severe amblyopia who were treated in the Department of Ophthalmology of the First Affiliated Hospital of Gannan Medical College from January 2020 to December 2020 were included in the study. Eyes with amblyopia (n = 32) served as the experimental group, and the contralateral healthy eyes (n = 32 eyes) served as the control group. All children underwent comprehensive ophthalmological examination including slit lamp, eye position, visual acuity, optometry, eye movement, intraocular pressure, ocular axis, and fundus examination to rule out organic lesions. Macular 6 mm × 6 mm scans were performed on both eyes of all subjects by the same experienced clinician using an OCTA instrument. After ImageJ processing, the vessel density, inner layer, and full-layer retinal thickness (RT) of superficial retinal capillary plexus (SCP) were obtained. All data were analyzed by SPSS21.0 software, and a paired t-test was used for comparison between groups. P < 0.05 was considered to indicate statistical significance.

Results

The vessel densities of macular SCP in the amblyopia and control groups were 47.66 ± 2.36% and 50.37 ± 2.24% in the outer superior, 49.19 ± 2.64% and 51.44 ± 2.44% in the inner inferior, 49.63 ± 2.51% and 51.41 ± 3.03% in the outer inferior, and 45.56 ± 3.44% and 50.44 ± 3.52% in the outer temporal regions, respectively. The vessel density of macular SCP in the amblyopia group was significantly lower than that in contralateral healthy eyes in the outer superior, inner inferior, outer inferior, outer temporal, and central regions. There was no significant difference between the two groups in the inner superior, inner nasal, outer nasal, and inner temporal regions. The macular RT in the amblyopia group and the control group is 90.38 ± 6.09 μm and 87.56 ± 5.55 μm in the outer temporal, respectively. The RT in the macular inner layer in the outer temporal region of the amblyopia group was thicker than that of the control group (P < 0.05). There was no significant difference in the other eight regions between the two groups. The whole macular RT in the amblyopia group was thicker than that in the control group in nine regions, and the central area of macular RT in the amblyopia and control groups was 229.06 ± 6.70 μm and 214.50 ± 10.36 μm, respectively.

Conclusion

The OCTA results showed the overall RT of macula in 9 areas in the amblyopia group was thicker than that in the control group, which could show that the macular retinal thickness can be a potential way to distinguish the children with monocular hyperopic anisometropia and severe amblyopia.

Optical coherence tomography angiography in amblyopia: A critical update on current understandings and future perspectives

Optical coherence tomography angiography (OCTA) is a non-invasive tool to assess the retino-choroidal vasculature in vivo. It tracks the red blood cell movement and maps the vasculature in quick succession. In routine, diabetic retinopathy, age related macular degeneration, central serous chorioretinopathy, and others are commonly being studied to unveil its clinic role. On the other hand, amblyopia is a condition where the visual acuity is subnormal due to non-organic causes in the eye. But the OCTA studies till now have shown variable changes along retino-choroidal vasculature. Hence, to comprehend the existing literature knowledge, a systematic literature search was carried out and the original works describing novel findings in amblyopic eyes on OCTA were included. Upon detailed assessment, firstly, the disturbed vasculature along superficial retinal plexus, deeper retinal plexus, and choroidal plexus were evident in most untreated amblyopic eyes. However, such changes were not uniform, which is due to noted heterogenic patient profile, small sample size, biometric biases, non-uniform algorithms, and other factors. And to note, even in presence of such diverse changes, almost all the authors stated a plausible explanation for their notable changes. Secondly, the utility of OCTA in identifying vascular changes with standard treatments and segregation of visual beneficiaries from non-beneficiaries were possible. Hence, to conclude, OCTA is a valuable tool which can provide valuable useful insights into the amblyopic eyes during pre and post treatment periods. However, to gather more concrete evidence for clinical benefits, systematic, homogenous, and better structured clinical studies are mandated.

Quantitative analysis of retinal and choroidal vasculature in patients with chorioretinal folds secondary to hyperopia

INTRODUCTION

There is a lack of information on quantitative parameters of optical coherence tomography angiography (OCTA) in cases of chorioretinal folds (CRF). The aim of this study was to compare OCTA retinal and choriocapillary vessel density (VD) between normal subjects and patients with CRF.

METHODS

We conducted an observational retrospective study. A total of 16 eyes of eight patients were recruited (eight eyes with CRF and eight control eyes). Data on best-corrected visual acuity (BCVA), refractive error, central macular thickness (CMT), central subfoveal thickness (CST), and OCTA findings (VD and foveal avascular zone (FAZ) area in superficial capillary plexus (SCP), middle capillary plexus (MCP), and deep capillary plexus (DCP), and VD in choriocapillaris (CC)) were recorded in each eye.

RESULTS

Compared with control group, CRF group showed decreased VD in the foveal region of SCP and MCP (p value 0.003 and 0.001), and increased VD in nasal region of SCP and MCP (p value 0.02 and 0.001), and in parafoveal area of MCP (p value 0.005). No differences were found in DCP and CC layers. Furthermore, we observed an enlargement of FAZ in CRF group at SCP and MCP slabs (p value <0.001 and 0.015). Respect to optical coherence tomography parameters, we demonstrated a thicker choroid in the CRF group (p value 0.002).

CONCLUSION

To the best of our knowledge, this is the first study reported in the literature quantifying VD of retinal capillary plexus and CC in a group of patients with a diagnosis of CRF secondary to hyperopia.

High body weight-related retinal vasculopathy in children with obesity

PURPOSE

To investigate the foveal avascular zone (FAZ) and the microvascular alterations in both macula and peripapillary region in obese children.

METHODS

We included a total of 222 eyes of 111 children (54 obese children and 57 healthy subjects). Capillary vessel density (VD) of superficial (SCP) and deep (DCP) retinal capillary plexuses were measured in macular slabs. Peripapillary region was also evaluated. The FAZ parameters were measured based on the whole retinal slab. A commercial optical coherence tomography-angiography system was used.

RESULTS

The mean ages were 13.33 ± 2.55 years (range, 8-17) and 13.41 ± 2.90 years (range, 7-18) in patients with obesity and healthy controls, respectively (p = 0.84). The mean area of the FAZ were 0.278 ± 0.10 mm2 and 0.272 ± 0.11 mm2 in children with obesity and in control participants, respectively (p = 0.68). There were significant increases in the superior region of the parafoveal VD of SCP (p = 0.008 for superior hemisphere and p = 0.003 for superior quadrant). There was no significant difference in any measure of the macular DCP and peripapillary region (p > 0.05, for all).

CONCLUSION

Increased vascular density measurements were found in the superior part of the parafoveal region of SCP in children with obesity. The results of the study should be taken into consideration during the course of the disease to define whole systemic response to obesity in childhood and will be of interest for pediatrician's clinical practice.

Macular Microvasculature and Associated Retinal Layer Thickness in Pediatric Amblyopia: Magnification-Corrected Analyses

Purpose

The purpose of this study was to characterize macular microvasculature and structural retinal layers using magnification-corrected optical coherence tomography angiography (OCTA) images in children with amblyopia.

Methods

This prospective cross-sectional study included 22 children with unilateral amblyopia (4–11 years of age) receiving spectral-domain OCTA. Vessel densities in foveal and parafoveal regions of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were measured in amblyopic and fellow eyes using a customized image analysis program correcting the scale of retinal image with axial length. Iowa Reference Algorithms (Iowa Institute for Biomedical Imaging) were used to measure mean thickness values of 10 intra-retinal layers rescaled for image size correction.

Results

Foveal and parafoveal vessel densities in amblyopic eyes were lower than that of the fellow eyes in the SCP (fovea: P = 0.006 and parafovea: P = 0.003) and the DCP (P = 0.024 and P = 0.025, respectively). Amblyopic eyes had significantly smaller foveal avascular zone (FAZ) area than fellow eyes (P < 0.001). There were significant differences in retinal layer thickness between paired eyes, particularly in the inner retina in both foveal and parafoveal regions; retinal nerve fiber layer (RNFL) (P = 0.024 and P = 0.095, respectively), ganglion cell layer (P < 0.001 and P = 0.008), inner plexiform layer (IPL; P = 0.12 and P = 0.037), inner nuclear layer (P = 0.005 and P = 0.005), and outer plexiform layer (OPL; P = 0.02 and P = 0.057), except in the foveal IPL, the parafoveal RNFL, and OPL.

Conclusions

Unilateral amblyopic eyes demonstrate reduced macular vessel density and thicker inner retinal layers compared with fellow eyes even after correcting for image magnification. Changes in macular microvasculature and structural layers may offer valuable insights in the development of amblyopia.

Assessment of Foveal Avascular Zone and Macular Vascular Plexus Density in Children With Unilateral Amblyopia: A Systemic Review and Meta-Analysis

Purpose: To examine the quantitative measurements of OCTA in children with amblyopia using the meta-analysis methodology. Methods: PubMed, Embase, and Cochrane library were searched for available papers up to March 2021. Weighted mean differences (WMD) were used to compare the retina parameters between the eyes with amblyopia and the contralateral eyes or healthy control eyes. Results: Twelve studies were included. When considering the parafovea, the microvessel density was reduced in amblyopic eyes compared with healthy control eyes in the superficial capillary plexus (SCP) in 6 × 6 volume scan (WMD = -2.12, 95%CI: -3.24, -0.99) but not SCP in 3 × 3 volume scan (WMD = -1.43, 95%CI: -2.96, 0.11). In the deep capillary plexus (DCP), amblyopia did not decrease vessel density in the 6 × 6 volume scan (WMD = -2.22, 95%CI: -5.86, 1.42; I ² = 79.6%, P = 0.008), but a difference was observed in the whole eye 3 × 3 (WMD = -1.95, 95%CI: -3.23, -0.67; I ² = 27.5%, P = 0.252). There were no significant differences in the foveal avascular zone area and foveal thickness between amblyopic eyes and healthy control eyes. There were no significant differences in microvessel density, foveal avascular zone area, and foveal thickness between amblyopic eyes and fellow eyes. Conclusion: According to OCTA, amblyopic eyes had lower vessel density in parafoveal SCP and DCP compared with healthy control eyes, but not compared with fellow eyes. There were no significant differences regarding the foveal avascular zone area and foveal thickness between amblyopic and non-amblyopic eyes.

Normative Data Assessment of Peripapillary and Macular Vessel Density and Foveal Avascular Zone Metrics Using Optical Coherence Tomography Angiography in Children

PURPOSE

To quantify the vessel density of the macula and optic disc and foveal avascular zone (FAZ) in healthy children and to evaluate the effects of age, gender, axial length, body mass index (BMI), and refractive errors on vessel density and FAZ.

METHODS

This study enrolled 92 eyes of 92 participants (42 boys and 50 girls). Optical coherence tomography angiography (OCTA) was performed using AngioVue (Avanti; Optivue). FAZ area, nonflow area, superficial and deep vessel density, FAZ perimeter, acircularity index of FAZ, foveal density, and radial peripapillary capillary vessel density were analyzed by gender. Correlations between the investigated OCTA parameters and age, axial length, and BMI were evaluated.

RESULTS

Girls had significantly larger nonflow and FAZ area than boys (P = .01 and .02). Superficial and deep vessel density at the fovea was significantly higher in boys compared to girls (P = .01 and .03). Inferior temporal and superior temporal Radial peripapillary capillary vessel densities were significantly higher in girls than boys (P = .01 and .03). No significant difference was found in the macular and optic disc vessel density measurements within refractive groups (P > .05, for all). Regarding the correlation of age with FAZ and vessel density parameters, only nonflow area was positively correlated with age (r = 0.22, P = .03).

CONCLUSIONS

This study provides normative data for children. Although boys had greater foveal vessel density, girls had greater FAZ area and nonflow area. Refractive status of the eye and BMI did not influence the OCTA parameters. Although nonflow area was positively correlated with age, other parameters were steady within the ages of 7 to 18 years. [J Pediatr Ophthalmol Strabismus. 2020;57(6):388-398.].

Foveal thickness, foveal microvasculature, and refractive error in children with asymmetric involvement of retinopathy of prematurity

OBJECTIVE

To evaluate foveal thickness, foveal microvasculature, and refractive error in children with asymmetric involvement of retinopathy of prematurity who had laser treatment in one eye and spontaneously regressed retinopathy of prematurity in the fellow eye.

METHODS

Totally, 17 children (34 eyes) with a history of asymmetric course of acute Zone II retinopathy of prematurity were assessed. Data on best-corrected visual acuity, refractive status, axial length, anterior chamber depth, and optical coherence tomography angiography findings were analyzed between treated and non-treated fellow eyes.

RESULTS

Treated eyes were more myopic than non-treated eyes (mean, -0.09 ± 1.86 diopters vs mean, 0.07 ± 0.98 diopters, p = 0.026). Compared to non-treated eyes, treated eyes had shallower anterior chamber depth (mean, 3.27 ± 0.24 mm vs mean, 3.55 ± 0.19 mm, p = 0.02). No significant difference was observed regarding optical coherence tomography angiography parameters between two eyes of the children. The mean central foveal thickness was found to be higher in treated eyes than in non-treated eyes (297.46 ± 22.03 vs 275.55 ± 18.45, p = 0.009). Higher number of laser spots were associated with decreased parafoveal superficial capillary plexus vessel density (r = -0.56, p = 0.02) and increased central foveal thickness (r = 0.62, p = 0.008).

CONCLUSION

Our results revealed no difference in optical coherence tomography angiography parameters between laser-treated and non-treated eyes in children with asymmetric involvement of Zone II retinopathy of prematurity except for a higher central foveal thickness in laser-treated eyes. Treated eyes were more myopic than the non-treated eyes. Number of laser applications during treatment had an impact on parafoveal superficial capillary plexus vessel density.

Quantitative analysis of macular and peripapillary microvasculature in adults with anisometropic amblyopia

INTRODUCTION

The aim of this study was to compare the macular and peripapillary capillary vessel density (CVD) and foveal avascular zone (FAZ) in amblyopic eyes of adults with their fellow eyes and with eyes of healthy controls using optical coherence tomography-angiography (OCT-A).

METHODS

A total of 34 eyes of 17 patients with anisometropic amblyopia and 80 eyes of 40 age- and gender-matched healthy controls were included. CVD in superficial (SCP) and deep retinal capillary plexuses (DCP), peripapillary region, and FAZ were analyzed by OCT-A.

RESULTS

The median ages were 31 years (range 20-64) in patients with amblyopia and 34.5 years (range 24-65) in healthy controls (p = 0.242). The mean FAZ area measured was 0.329 ± 0.024 mm² in amblyopic eyes, 0.332 ± 0.025 mm² in fellow eyes, and 0.269 ± 0.015 mm² in control eyes (p < 0.05). The amblyopic eye of participants showed a decrease in CVD of SCP and DCP (p < 0.001, for all). The inside optic disk CVD measurements were lower in the amblyopic eyes than in the fellow eyes (p = 0.001) and healthy subjects (p = 0.015).

CONCLUSION

Significant differences in macular and peripapillary microvasculature were found in anisometropic amblyopic patients. The clinical significance of the results requires further investigation.

Comparison of Retinal Vascular Structure in Eyes With and Without Amblyopia by Optical Coherence Tomography Angiography

PURPOSE

To evaluate the retinal vascular structure in amblyopic eyes by optical coherence tomography angiography (OCTA).

METHODS

Thirty-seven eyes of 37 patients with anisometric amblyopia were compared with 37 eyes of 37 age- and gender-matched control subjects by OCTA in terms of superficial capillary plexus vessel density, deep capillary plexus vessel density, and foveal avascular zone.

RESULTS

The mean age was 12 ± 4.2 years in patients with amblyopia and 13 ± 6.1 years in individuals without amblyopia. Foveal superficial capillary plexus vessel densities were 20.49% ± 3.27%, 19.70% ± 3.82%, and 19.96% ± 3.84%, and parafoveal superficial capillary plexus vessel densities were 48.50% ± 3.64%, 49.01% ± 3.33%, and 48.9% ± 2.98% in amblyopic, fellow, and control eyes, respectively. The foveal deep capillary plexus vessel densities were 18.95% ± 3.76%, 18.6% ± 4.50%, and 19.29% ± 4.01%, and parafoveal deep capillary plexus vessel densities were 51.0% ± 4.21%, 51.85% ± 4.12%, and 52.03% ± 3.57% in amblyopic, fellow, and control eyes, respectively. Superficial and deep capillary plexus vessel densities in the foveal and parafoveal areas were not significantly different between the groups (P > .05). The parafoveal area was evaluated in quadrants. In the superior quadrant, superficial and deep capillary plexus parafoveal densities were significantly lower in amblyopic eyes (P < .05). No significant difference was observed in the foveal avascular zone between the groups (P > .05).

CONCLUSIONS

Although no significant vascular damage was demonstrated by OCTA in amblyopic eyes, localized defects may be specific for it. Additional studies are needed to evaluate any specific localization of vascular damage related to amblyopia. [J Pediatr Ophthalmol Strabismus. 2020;57(1):48-53.].

Assessment of Macular Microvasculature in Healthy Eyes of Infants and Children Using OCT Angiography

PURPOSE

To assess macular vasculature in healthy infants and children using OCT angiography (OCTA).

DESIGN

Prospective cross-sectional study.

PARTICIPANTS

One hundred thirty-five normal maculae of 89 healthy infants and children (mean age, 8.5±5.3 years; range, 9 weeks-17 years) treated at the Duke University Eye Center.

METHODS

We imaged 135 maculae of 89 pediatric patients using the standard Spectralis tabletop and investigational Spectralis with Flex module devices, both equipped with investigational OCTA software (Heidelberg Engineering, Heidelberg, Germany). OCT angiography images of the superficial vascular complex (SVC) and deep vascular complex (DVC) were analyzed for foveal avascular zone (FAZ) area and superficial and deep vessel density. We assessed effects of age, gender, race, axial length (AL), and central subfield thickness on FAZ and vessel density. Patients with both eyes imaged were assessed for agreement between the FAZ and vessel densities of the left and right eyes.

MAIN OUTCOME MEASURES

The FAZ area, as well as vessel area density (VAD) and vessel length density (VLD) in the SVC and DVC.

RESULTS

The FAZ varied significantly with race; white patients showed a significantly smaller FAZ than black patients (mean difference, 0.11 mm²; P = 0.004). The FAZ did not vary with age, gender, or AL (P > 0.05). In the SVC, VAD and VLD varied significantly with age (P < 0.001) and AL (R² = 0.46; P < 0.001) but not gender (P > 0.05). The SVC VLD was significantly different between races and ethnicities (P = 0.037), but VAD was not (P < 0.05). In the DVC, VAD and VLD also varied significantly with age (P < 0.001) and AL (R² = 0.46; P < 0.001) but not gender or race (P > 0.05). There was excellent agreement between the right and left eyes for FAZ (intraclass correlation [ICC], 0.97), SVC VLD (ICC, 1.00), and DVC VLD (ICC, 1.00).

CONCLUSIONS

Quantitative studies of pediatric perifoveal vasculature should consider age, race, and AL. In eyes with unilateral disease, the perifoveal vasculature in the unaffected eye may be used as a control comparison because there is excellent agreement between eyes.