ASSESSMENT OF MACULAR VASCULATURE OF CHILDREN WITH SICKLE CELL DISEASE COMPARED TO THAT OF HEALTHY CONTROLS USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

Early diagnosis of sickle cell retinopathy by using ocular coherence tomography in pediatric population (7-18 years) in central India

BACKGROUND

Sickle cell disease (SCD) is the commonest inherited blood disorder leading to complications occurring due to vaso-occlusion including sight-threatening retinopathy. Retinopathy can be managed if diagnosed early and vision loss can be prevented. Since, very less data are available from India, hence, this study was conducted in children (7-18 years) with SCD to diagnose retinopathy by using ocular coherence tomography (OCT) in subclinical stages.

METHODS

This cross sectional single-center study was performed in 7-18 years age group children with SCD without any visual symptoms. Enrolled participants underwent complete ophthalmological examination including macula and optic disc thickness measurements using Cirrus HD-OCT and results were analyzed.

RESULTS

Among 55 participants, none had visual impairment. Significant fundoscopy finding (nonproliferative sickle cell retinopathy/NPSR) was found in three patients (5.4%), thinning of central macula in four patients (7.27%), inner macula thinning in eight patients (14.5%), outer macula thinning in one patient (1.81%), retinal nerve fiber layer thinning in five patients (9%), ganglion cell layer to inner plexiform layer thinning in eight patients (14.54%). Overall NPSR was found in 5.4% patients detected with fundoscopy, whereas retinal layer thinning was found in 14 patients (25.4%) using OCT.

CONCLUSION

Despite of the significant prevalence of SCR, it is still underdiagnosed complication, leading to thinning of the retina from early ages; thus, its early diagnosis by regular screening using newer diagnostic methods can prevent progression to sight-threatening complications and provide better quality of life for these patients.

Optical coherence tomography angiography measurements in systemic lupus erythematosus: A systematic review and meta-analysis

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting various organs. Ocular involvement, particularly retinopathy, is common, emphasizing the significance of early detection. Optical coherence tomography angiography (OCTA), a non-invasive imaging technique, reveals microvascular changes, aiding SLE diagnosis and monitoring. This study evaluates OCTA's effectiveness in detecting SLE-related retinal alterations. A systemic search was undertaken across PubMed, Embase, and Scopus databases to identify studies presenting OCTA measurements in SLE patients compared to healthy controls. The meta-analysis, employing either fixed-effects or random-effects models based on heterogeneity levels, was conducted. Additionally, subgroup and sensitivity analyses, meta-regression, and quality assessments were carried out. Thirteen studies of 565 eyes in the SLE group and 560 eyes in the control group were included. The meta-analyses revealed that SLE patients had a significantly lower retinal vessel density in the superficial and deep capillary plexus layers, choriocapillaris flow area, and foveal avascular zone (FAZ) circularity index compared to healthy controls, but that there were no significant differences in the FAZ area and perimeter. These findings highlight how OCTA can provide a noninvasive assessment of SLE effects on the retinal microvasculature, potentially presenting a reliable biomarker for more precise detection of SLE and disease activity monitoring.

Retinal and Choroidal Vascularity Evaluation in Pediatric Radiologically Isolated Syndrome and Multiple Sclerosis

BACKGROUND

To assess vessel density (VD) and flow of retinal plexuses and peripapillary region related with the pediatric radiologically isolated syndrome (RIS) and multiple sclerosis (MS).

METHODS

We analyzed 24 eyes of 12 participants with the diagnosis of RIS, 24 eyes of 12 participants with the diagnosis of MS, and 26 eyes of 13 age- and sex-matched healthy controls in this prospective, cross-sectional study. The superficial capillary plexus (SCP) and deep capillary plexus, foveal avascular zone, and the flow of choriocapillaris were investigated using optical coherence tomography angiography.

RESULTS

Parafoveal VD and all subregion parameters in SCP were significantly decreased in the MS group compared with the controls, whereas only nasal and inferior VD were significantly decreased in the pediatric RIS group compared with the controls. Ganglion cell layer (GCL) thickness of all subregions of the inner ring was significantly decreased in the pediatric MS group compared with the control group. No significant difference was observed between the pediatric RIS group and the control group regarding thickness.

CONCLUSIONS

We showed lower parafoveal VD in all subregions of SCP in pediatric MS, whereas only parafoveal nasal and inferior VD were decreased in pediatric RIS. GCL thickness of inner ring was significantly decreased in the pediatric MS, whereas GCL thickness did not change in pediatric RIS. Therefore, a decrease of parafoveal nasal and inferior VD without a decrease in thickness implies an early impairment of microvasculature in the RIS before impairment of thickness and that microvascular alterations begin from highly vascular superficial parafovea.

Longitudinal Assessment of Macular Thickness and Microvascular Changes in Children with Sickle Cell Disease

PURPOSE

To longitudinally assess macular thickness and microvascular changes in children with sickle cell disease (SCD).

DESIGN

A retrospective consecutive series.

SUBJECTS

Children with SCD aged ≤ 18 years who had an ophthalmic examination at Boston Children's Hospital between January 1998 and August 2022.

METHODS

Qualitative and quantitative analyses of both OCT and OCT angiography (OCTA) images were performed.

MAIN OUTCOME MEASURES

Total retinal thickness measured on macular OCT, superficial capillary plexus and deep capillary plexus (DCP) vessel density (VD), and foveal avascular zone (FAZ) area measured on 6- × 6-mm OCTA scans.

RESULTS

International Classification of Diseases, 10th Revision, code search identified 303 pediatric SCD patients who underwent ophthalmic examination during the study period. OCT and OCTA images were acquired on 104 (17.2%) and 60 (9.9%) eyes at presentation and on 159 (26.2%) and 100 (16.5%) eyes at final visit, respectively. Overall, temporal retinal thinning was noted qualitatively in 35.6% of SCD patients at presentation and 39.6% at final visit. Of those patients with macular thinning, 94.6% and 90.5% had peripheral sickle cell retinopathy (SCR) at presentation and final visit. On quantitative OCT analysis, HbSS eyes had a lower retinal thickness in the fovea and temporal parafovea compared with HbSC (P < 0.05). Eyes with peripheral SCR had a larger FAZ at presentation compared with eyes without peripheral SCR (P = 0.004), a lower DCP VD at final visit in the inferior temporal macula (P = 0.03), and a higher DCP VD at final visit in the superior nasal macula (P = 0.01). Eighty eyes of 40 patients had OCT, and 34 eyes of 20 patients had both OCT and OCTA images acquired at both initial and final visits. At final visit, retinal thickness decreased at the fovea, inferior perifovea, and temporal perifovea compared with presentation (P < 0.05). In parallel, VD DCP in the superonasal quadrant increased at final visit (P = 0.03).

CONCLUSIONS

Macular retinal thinning was progressive and observed in eyes with and without peripheral SCR. Over time, there was a compensatory increase in DCP VD in the nasal macula on OCTA.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Identifying Clinical Predictors of Proliferative Sickle Cell Retinopathy

PURPOSE

To identify systemic and/or ophthalmologic predictors of proliferative sickle retinopathy.

METHODS

Cross-sectional study comparing clinical, laboratory, and structural choriorretinal aspects between sickle cell disease patients with and without proliferative retinopathy. Patients underwent complete systemic and ophthalmologic evaluation. Enhanced depth spectral domain optical coherence tomography with choroidal binarization and optic coherence tomography angiography were performed and choriorretinal vascular components were compared.

RESULTS

Forty-five eyes from 45 sickle cell patients were included. Ninety-one percent of patients were diagnosed with sickle cell retinopathy, 29% with proliferative retinopathy. Mean corpuscular volume, lactate dehydrogenase, and percentage of fetal hemoglobin were reduced in the subgroup of patients with proliferative retinopathy when compared with patients without proliferative retinopathy (p ≤ 0.001; p = 0.04; p ≤ 0.001, respectively). The best predictor of proliferative retinopathy was mean corpuscular volume (AUC = 0.842; p = 0.001), followed by the percentage of fetal hemoglobin (AUC = 0.763, p = 0.009) and lactate dehydrogenase (AUC curve = 0.706; p = 0.039). No differences were found between groups in the quantitative analysis of retinal vascularization using OCTA and choroidal vascularization using OCT (p ≥ 0.05).

CONCLUSION

Fetal hemoglobin and mean corpuscular volume may be good predictors of proliferative sickle retinopathy. The association between proliferative retinopathy and reduced levels of lactate dehydrogenase and mean corpuscular volume points to hypoxia and not hemolysis as a possible driving force in its pathophysiology.

Temporal macular thinning and vessel density correlation in children and young adults with sickle cell disease

Optical coherence tomography angiography (OCTA) is a recent noninvasive imaging technology that has proved to provide a comprehensive evaluation of retinal vascular abnormalities in adult patients with sickle cell disease (SCD). However, the pediatric population remains less studied. The purpose of this study is to evaluate the correlation between temporal vessel density (VD) in OCTA and temporal macular thinning in optical coherence tomography (OCT) in children and young adults with SCD. We reviewed medical records, OCT and OCTA (Spectralis®) scans from a sample of 32 eyes from 16 patients (7 female + 9 male) under 25 years old. The OCT macular thickness data and OCTA image data were processed using Python 3.9 programming language, and statistical analysis was performed. Pearson Correlation Coefficient between macular thickness and VD for inner and outer temporal areas was 0.47 (p-value = 0.006) and 0.74 (p-value < 0.001), respectively. A t-test was also performed to prove that there is a statistically significant VD difference in patients with higher and lower macular thickness (p < 0.001). These results show that children with outer temporal macular thinning on OCT have lower outer temporal VD on OCTA suggesting that microvascular insults may lead to chronic ischemic changes in the inner retinal layers.

Subclinical Retinal Capillary Abnormalities in Juvenile Systemic Lupus Erythematosus without Ocular Involvement

PURPOSE

This study aimed to evaluate subclinical retinal microvascular changes with OCTA in juvenile systemic lupus erythematosus (JSLE) patients without ocular involvement.

METHODS

Ten eyes of 10 JSLE and 13 eyes of 13 age and sex-matched healthy controls (HCs) were enrolled. The superficial (SCP) and deep capillary plexus (DCP), FAZ parameters, the flow area of the outer retina, and choriocapillaris were evaluated using OCTA.

RESULTS

All vessel density (VD) parameters in DCP were significantly lower in JSLE group compared to HCs. There was no significant difference between the groups in VD parameters of both SCP and ONH, FAZ, outer retina and choriocapillaris flow area. All DCP VD parameters showed a good ability to differentiate JSLE from HCs.

CONCLUSION

OCTA could detect retinal vascular impairment in the deep macular region in JSLE patients with normal ocular examination. Furthermore, all DCP VD parameters have a good ability to discriminate JSLE from HCs.

Evaluation of subclinical retinal microvascular changes in systemic lupus erythematosus patients using optical coherence tomography angiography and its relationship with disease activity

Objective

This study aimed to investigate subclinical retinal microvascular changes with optical coherence tomography angiography (OCTA) in patients with systemic lupus erythematosus (SLE) and healthy controls (HCs), and to evaluate the relationship between OCTA findings and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K).

Materials and Methods

In this study, 47 eyes of SLE and 41 eyes of healthy control (HC) were evaluated. The SLE patients were divided into two subgroups: low disease activity (LDA) (SLEDAI≤5) and high disease activity (HDA) (SLEDAI>6). The results of OCTA were compared between SLE patients and HCs as well as the SLE subgroups. The relationship between OCTA results and SLEDAI-2K was evaluated.

Results

There were no differences in foveal avascular zone (FAZ) areas between the SLE patients and HCs. Central foveal thickness (CFT) was lower in SLE patients ( p = .046). Superficial capillary plexus (SCP) vessel density (VD) in SLE patients was significantly lower only in the foveal area compared to that in HCs ( p = .006). Deep capillary plexus (DCP) VD in SLE patients was significantly lower in all areas except the temporal parafoveal area compared to that in the HCs. There was no statistically significant difference between SLE groups with LDA and HDA in FAZ or any of the other areas, including SCP and DCP. When the correlation between OCTA findings and SLEDAI-2K was examined, both SCP and DCP VD were found to be negatively correlated.

conclusions

It was observed that DCP VDs were affected in SLE patients with LDA, and SCP VDs were also affected in addition to DCP with HDA. This suggests that DCP may be the first capillary plexus to be comprised in SLE. VDs were negatively correlated with disease activity. It was concluded that OCTA can be a useful tool in assessing subclinical retinal microvascular pathology and disease activity in patients with SLE.

The Impact of Axial Eye Growth on Foveal Avascular Zone Measurements in Children

SIGNIFICANCE

Foveal avascular zone (FAZ) area is a frequently used biomarker in diseases impacting the retinal vasculature in pediatric populations. Variation in axial length between individuals results in differences in lateral image scale, which affect the accuracy of FAZ area measurements. Accordingly, changes in axial length over time within individual children would affect estimates of FAZ area change.

PURPOSE

This study aimed to quantify how changes in axial length over time affect estimates of FAZ area change using optical coherence tomography angiography (OCT-A) images.

METHODS

Twenty pediatric participants (<18 years old) and 40 adult participants were imaged on Optovue's Avanti system (Fremont, CA) and had axial length measurements acquired at two time points. The FAZ was segmented twice using the OCT-A image at each time point. Foveal avascular zone area was estimated at both time points using the assumed/fixed axial length of the OCT-A device (unscaled) and using the participant's axial length (scaled). Changes in FAZ area over time were compared between the pediatric and adult groups using both unscaled and scaled data.

RESULTS

The average ± standard deviation follow-up time was 3.35 ± 1.66 years for the pediatric group and 2.90 ± 1.65 years for the adult group. Using unscaled data, FAZ area seemed to decrease between visits in the pediatric group (P = .004), whereas the FAZ area increased between visits in the adult group (P = .003). When correctly scaled data were used, the FAZ area still increased between visits for the adult group (P < .001), although the FAZ area no longer showed a significant change between visits for the pediatric group (P = .37). When comparing the normalized FAZ area change across visits between unscaled and scaled data, a significant difference was found between the adult and pediatric groups (P < .001).

CONCLUSIONS

Scaled data should be used when measuring FAZ area in pediatric populations, especially in longitudinal studies.

Co-occurrence of sickle cell disease and oculocutaneous albinism in a Congolese patient: a case report

BACKGROUND

Sickle cell disease and oculocutaneous albinism are rare autosomal recessive disorders both related to mutations on chromosome 11. The diagnosis of patients suffering from both pathologies is necessary to enable dedicated monitoring of any complications at the ophthalmic and skin level. However, few cases are described in the literature.

CASE PRESENTATION

A 14-month-old Congolese male child affected by oculocutaneous albinism, presented with pallor and jaundice. Blood indices revealed severe hemolytic anemia, which led to the diagnosis of sickle cell disease. The patient received a blood transfusion and close follow-up.

CONCLUSIONS

The co-inheritance of sickle cell disease and oculocutaneous albinism is a reality in the Democratic Republic of Congo, although it is rarely described. Given the current state of our knowledge, specific surveillance, specifically regarding cutaneous and ophthalmological complications, should be offered in this particular population. To enable this dedicated follow-up, sensitization to screening for sickle cell anemia in albino individuals should be carried out.

Retinochoroidal vascular plexuses in patients with iron deficiency anaemia

Clinical relevance: Optical coherence tomography angiography (OCT-A) may enable the identification of alteration in the retinochoroidal microvasculature in patients with iron deficiency anaemia.Background: To investigate the presence of macular microvascular alterations in females with IDA by using OCT-A.Methods: This is a cross-sectional comparative study. Forty patients with IDA and 35 age-matched healthy women underwent a complete ophthalmologic examination and OCT-A imaging. Foveal avascular zone parameters and the vessel density in the superficial (SCP) and deep capillary plexus (DCP) were calculated using automated software. All measurements were compared between groups. Correlations between the OCT-A metrics and haematological laboratory parameters were evaluated.Results: Compared to healthy subjects, IDA patients revealed significantly decreased vessel density of the SCP in all parafoveal quadrants (p < 0.05). In contrast, vessel density analysis in DCP has shown no statistically significant difference in all parafoveal quadrants (p > 0.05). Although foveal vessel density in both SCP and DCP were higher in the IDA group, only the foveal vessel density in DCP was significantly higher than controls (p = 0.001). The mean values of the foveal avascular zone area and perimeter and choriocapillaris flow area were significantly lower in the IDA group (p < 0.05). The parafoveal vessel density in SCP, foveal avascular zone area, and choriocapillaris flow area were positively correlated with haematological parameters including haemoglobin, haematocrit, mean corpuscular haemoglobin, and mean corpuscular volume (p < 0.01).Conclusion: Patients with IDA had decreased parafoveal vessel density in the SCP, but not the DCP. Foveal avascular zone metrics and choriocapillaris flow area measurements were significantly lower in IDA.

Evaluation of retinal vascularization by optical coherence tomography angiography (OCTA) in rheumatoid arthritis, and its relationship with disease activity

PURPOSE

To measure the retinal capillary density quantitatively with optical coherence tomography angiography (OCTA) in patients with rheumatoid arthritis (RA) and healthy controls (HCs), and to evaluate the relationship between OCTA findings and RA disease activity.

METHODS

In this cross-sectional study, 106 eyes of RA patients and 71 eyes of HCs were evaluated. RA patients were divided into inactive (DAS28 < 3.2) and active (DAS28 ≥ 3.2) subgroups. Retinal capillary plexus density (CPD) was obtained from the superficial capillary plexus (SCP), deep capillary plexus (DCP), and radial peripapillary capillary (RPC).

RESULTS

In RA patients and HCs, the CPD (%) was 50.99 ± 3.30 and 52.08 ± 2.36 (p = .013) in the SCP, 55.65 ± 5.73 and 57.53 ± 4.60 (p = .019) in the DCP, and 49.98 ± 2.25 and 49.93 ± 2.25 (p = .947) in the RPC blood supply regions, respectively. In inactive and active RA patients, the CPD (%) was 51.01 ± 2.92 and 50.97 ± 3.73 (p = .947) in the SCP, 55.02 ± 5.70 and 56.40 ± 5.74 in the DCP (p = .229), and 50.34 ± 2.23 and 49.55 ± 2.22 (p = .079) in the RPC blood supply regions, respectively. DAS28 was negatively correlated with CPD in RPC blood supply region (Rho = -0.272, p = .006).

CONCLUSION

In RA, retinal CPD in the macula is lower than HCs. Although retinal CPD is not generally different in active and inactive RA patients, capillaries in the optic disc may be affected by disease activity.

Effects of iron deficiency anemia on peripapillary and macular vessel density determined using optical coherence tomography angiography on children

PURPOSE

To evaluate retinal vascular parameters by optical coherence tomography angiography (OCT-A) in iron deficiency anemia (IDA).

METHODS

Thirty-two patients with IDA (study group) and 30 healthy children (control group) were enrolled in the study. All subjects underwent a complete ocular examination. OCT-A scans were performed in a 6 × 6 mm area centered on the macula. Foveal avascular zone (FAZ), non-flow area (NFA), FAZ perimeter (PERIM), acircularity index (AI) of FAZ, and foveal density (FD) were measured in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). SCP and DCP were also scanned centered on the optic disk. Hemoglobin (Hb), mean corpuscular volume (MCV), serum iron, total iron-binding capacity (TIBC), and ferritin were also studied and compared for both groups.

RESULTS

The mean age was 12.22 ± 4.48 years (ranged 5-18 years) in the study group and 12.37 ± 3.76 years (ranged 6-18 years) in the control group. The mean FAZ value was 0.290 ± 0.09 mm² in the study group and 0.298 ± 0.11 mm² in the control group. The mean NFA value was 0.477 ± 0.10 mm² in the study group and 0.486 ± 0.13 mm² in the control group (p > 0.05). FD and AI were not statistically significant between the study group and control group (p > 0.05). The mean value for SCP was statistically significant between the study group and control group (p < 0.05). The mean value for DCP was not significantly different between the study and control groups (p > 0.05). The mean values for capillary density on optic disk were also statistically significant between the study group and control group (p < 0.05). A negative correlation was found between serum iron, TIBC, and capillary plexus density (p < 0.05). A positive correlation was found between MCV and ferritin values and capillary plexus density (p < 0.05).

CONCLUSION

IDA had significantly lower capillary plexus density. We detected retinal microvascular changes in young IDA patients before significant ocular anomalies, especially ischemic changes, developed.

Foveal avascular zone and vessel density in children with attention deficit hyperactivity disorder

PURPOSE

To compare the retinal and choroidal microvasculature quantitatively via optical coherence angiography (OCTA) in children with attention deficit hyperactivity disorder (ADHD) who were under methylphenidate (MFD) treatment or newly diagnosed as ADHD and were not taking any medication.

METHODS

This was a cross-sectional, comparative, and observational study. The children who were between 6 and 17 years old and previously diagnosed as ADHD and were under MFD treatment or who were newly diagnosed as ADHD were included in the study. Optical coherence tomography angiography imaging was performed via OCT RT XR Avanti with AngioVue software (Optivue Inc, Freemont, CA). The main outcome measure of the study was OCTA parameters of the children with ADHD.

RESULTS

A total of 186 eyes of 186 patients were included in the study. There were 80 eyes in the control group (newly diagnosed) and 106 eyes in the treatment group (under MFD treatment). The mean duration of methylphenidate use in the treatment group was 33.9 ± 20.1 months (between 6 and 84 months). The choriocapillary flow area (p = 0.03), superficial parafoveal thickness (p = 0.01), and deep parafoveal thickness (p = 0.01) were statistically greater in the treatment group than the control group.

CONCLUSION

Most of the important OCTA parameters especially foveal avascular zone (FAZ) area and FAZ perimeter were similar in the two groups. There was a significant difference between the two groups in parafoveal thickness values which might point to a slight effect of MFD on retinal circulation.

Optical coherence tomography angiography findings in young β-thalassemia patients

PURPOSE

The purpose was to evaluate retinal vascular parameters by optical coherence tomography angiography in β-thalassemia major patients.

METHODS

Thirty-three patients with β-thalassemia major (study group) and 29 healthy children (control group) were enrolled in the study. All subjects underwent a complete ocular examination. The mean foveal avascular zone, non-flow area, foveal avascular zone perimeter, acircularity index of foveal avascular zone, foveal density, the superficial capillary plexus, and deep capillary plexus were scanned using 6 × 6 mm optical coherence tomography angiography scans centered on the macula. Superficial capillary plexus and deep capillary plexus were also scanned centered on the optic disk. We collected data on histories of patients, and hemoglobin and ferritin were also studied from both groups.

RESULTS

The mean age was 13.85 ± 4.69 years (range: 4-21 years) in β-thalassemia major group and 12.59 ± 3.66 years (range: 6-18 years) in the control group. The mean foveal avascular zone value was 0.265 ± 0.11 mm² in the study group and 0.296 ± 0.12 mm² in the control group. The mean non-flow area value was 0.468 ± 0.12 mm² in the study group and 0.479 ± 0.14 mm² in the control group (p > 0.05). Differences in the mean values for foveal density and acircularity index were statistically significant between the study group and control group (p < 0.05, p = 0.026, and p = 0.026, respectively). Superficial capillary plexus and deep capillary plexus were not a significant difference between the study and control groups in 6 × 6 mm scans on macula and 4.5 × 4.5 mm scans on optic disk area (p > 0.05). Acircularity index was negatively correlated (r = -0.292, p = 0.026), and foveal density was positively correlated with hemoglobin (r = 0.292, p = 0.026).

CONCLUSION

By using optical coherence tomography angiography, we detected foveal microvascular changes in young β-thalassemia patients before significant ocular anomalies development.

Retinal Thickness and Microvascular Changes in Children With Sickle Cell Disease Evaluated by Optical Coherence Tomography (OCT) and OCT Angiography

PURPOSE

To compare the severity of macular vascular changes in children with sickle cell disease (SCD) vs age- and race-matched controls.

DESIGN

Cross-sectional study.

METHODS

Children (<18 years old) with HbSS and HbS variant (HbSC and HbS thalassemia) genotypes, and their age- and race-matched controls, were recruited between January 2017 and December 2018. All subjects underwent optical coherence tomography angiography (OCTA) scans centered on the fovea and temporal macula. Retinal thickness, superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density (VD), and foveal avascular zone (FAZ) size were measured and compared between HbSS and HbS variant vs controls.

RESULTS

Thirty-four HbSS, 34 HbS variant (Goldberg staging 0-3 for SCD eyes), and 24 control eyes (total 48 children, aged 5-17 years) were included. Total VD (3-mm ETDRS circle) was lower in HbS variant eyes than in controls for both the SCP (42.9% vs 47.7%, P = .02) and DCP (47.4% vs 52.6%, P = .01). In HbSS eyes, VD was lower in the DCP (47.7%, P = .008) but not in the SCP (45.5%, P = .5), compared to controls. A higher proportion of HbSS (n = 18, 55%) than HbS variant eyes (n = 9, 26%) had pathologic areas of retinal thinning associated with SCP and DCP flow loss (P = .03). However, retinal thickness measurements and FAZ size did not differ between either HbSS or HbS variant group vs controls.

CONCLUSIONS

Children with SCD have similar retinal thickness but less dense vasculature on OCTA compared to age and race-matched controls, suggesting that microvascular insult may precede structural thinning.

Influence of mydriasis on optical coherence tomography angiography imaging in patients with age-related macular degeneration

Purpose

To evaluate the effect of topical mydriatic eye drops on optical coherence tomography angiography (OCTA) parameters in patients with age-related macular degeneration (AMD).

Methods

27 eyes of 27 patients suffering from AMD were included in this cross-sectional study. Patients with ≥-4.5 diopters spherical equivalent, corneal opacities or dense cataract preventing high-quality imaging were excluded. Whole-en-face scans of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in the central 3x3mm foveal region as well as whole-en-face and peripapillary scans of the radial peripapillary capillaries (RPC) were generated using OCTA (AngioVue®, Optovue). Imaging was first conducted with patients’ eyes in miosis, then in mydriasis after instillation of a dilating eye drop (0.5% tropicamide, 2.5% phenylephrine-HCl). Main outcome measures were flow density (FD), foveal avascular zone (FAZ), signal strength index (SSI) and motion artifact score (MAS).

Results

Our results reveal that in AMD patients there is no significant difference between FD measurements taken in miosis and those taken in mydriasis around the SCP (p = 0.198), DCP (p = 0.458), RPC whole-en-face (p = 0.275) and RPC peripapillary (p = 0.503). Measurements taken in these two states appear to be equivalent for assessment of FD (90%CI within ± 0.05). No significant difference was found either in the area of the FAZ (p = 0.338) or in the SSI (p = 0.371) before and after the instillation of tropicamide/phenylephrine. MAS was significantly lower after the application of mydriatic eye drops (p = 0.003).

Conclusions

Our findings reveal that neither measurements of FD nor measurements of the FAZ area changed significantly in AMD patients after the application of tropicamide/phenylephrine. Since MAS improved significantly in dilation, mydriatic examination is recommended. Nevertheless, a comparison of OCTA metrics from images taken with different pupil states (miosis versus mydriasis) is valid for clinical trials.

Relating retinal blood flow and vessel morphology in sickle cell retinopathy

Purpose

The purpose of the current study was to determine associations between retinal blood flow and vessel morphology metrics in sickle cell retinopathy (SCR) and healthy normal control (NC) subjects.

Methods

Optical coherence tomography angiography (OCTA) and Doppler OCT imaging were performed in 12 SCR (15 eyes) and 19 NC (26 eyes) subjects. Vessel tortuosity was measured using a dedicated image analysis algorithm applied to OCTA images. Vessel density and spacing between vessels were determined from OCTA images by a fractal dimension analysis method. Retinal blood flow was quantified using a phase-resolved technique applied to en face Doppler OCT images.

Results

There was a significant association between increased retinal blood flow and increased vessel tortuosity (P = 0.03). Furthermore, increased retinal blood flow was associated with increased vessel density (P = 0.03) and decreased spacing between small vessels (P = 0.01). There was no significant association between retinal blood flow and spacing between large vessels (P = 0.11). Vessel tortuosity and blood flow were increased, whereas spacing between small vessels was decreased in SCR compared to NC group (P ≤ 0.03). There were no significant differences in vessel density or spacing between large vessels between the SCR and NC groups (P ≥ 0.31).

Conclusions

Associations between retinal hemodynamics and vessel morphology were reported, providing better understanding of retinal pathophysiology and insight into potential quantitative biomarkers to evaluate SCR.

Prevalence and Onset of Pediatric Sickle Cell Retinopathy

PURPOSE

Children with sickle cell hemoglobinopathy (SCH) can demonstrate proliferative retinopathy with vision loss, but lack of consensus exists regarding screening regimens. We sought to determine the prevalence, age at onset, and risk factors associated with sickle cell retinopathy (SCR) to inform development of screening guidelines for asymptomatic children.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Children with SCH over a 4-year period.

METHODS

Prevalences of any retinopathy, nonproliferative retinopathy (NPR), and proliferative retinopathy (PR), determined as proportions of all children examined, were calculated. Subgroup analyses were completed by SCH genotype. Ages at first diagnosis were reported using standard descriptive statistics. The association of potential risk factors with retinopathy were assessed using univariate and multivariate linear and logistic regression.

MAIN OUTCOME MEASURES

Outcomes were prevalence, age at onset, and type of SCR, based on examination by an ophthalmologist. Markers of SCH severity (number of emergency room or hospital admissions for crises, number of blood transfusions, hydroxyurea therapy, transcranial Doppler-confirmed cerebral vasculopathy), genotype, gender, and race were evaluated as SCR risk factors.

RESULTS

Of 398 children (mean age, 9.6±4.6 years; range 0-18 years), 208 (52%) showed sickle cell homozygote (SS) genotype, 113 (28%) showed sickle cell hemoglobin C (SC) genotype, and 77 (19%) showed trait genotype. Forty-eight children (12.1%) demonstrated SCR, 44 of 398 children (11.1%; 95% confidence interval, 8.3%-14.5%) demonstrated NPR, and 9 of 398 children (2.3%; 95% confidence interval, 1.2%-4.2%) demonstrated PR. Prevalence was higher for SC than SS genotype for NPR (21% vs. 9%) and PR (5% vs. 1%); onset for SC genotype was earlier than that for SS genotype for NPR (youngest diagnosis 4.8 vs. 6.1 years) and PR (12.2 vs. 15.4 years). No other risk factors were associated significantly with SCR.

CONCLUSIONS

Clinical markers of SCH severity assessed were not associated with SCR and are not necessary for screening guidelines. Based on our study and literature review, although screening could begin at age 5 years for NPR, screening of children without ophthalmologic symptoms to identify treatment-requiring PR could begin later, at 9 years of age for SC and 13 years of age for SS.