Optical Coherence Tomography Angiography and Ultra-widefield Fluorescein Angiography for Early Detection of Adolescent Sickle Retinopathy

Advances in sickle cell retinopathy screening techniques, tests, and practices: A systematic review

Sickle cell retinopathy (SCR) is a progressive, sight-threatening ophthalmic complication of sickle cell disease (SCD). Current SCR screening focuses on the detection of pathologic sea fan neovascularization, the first sign of proliferative sickle cell retinopathy (PSR). If untreated, PSR can lead to severe visual impairment and blindness through progression to vitreous hemorrhage and/or retinal detachment. SCR screening with dilated fundus examination (DFE) is recommended every 1-2 years starting at age 10, but data underlying this recommendation are of poor quality and based upon expert consensus. We performed a systematic review to characterize imaging techniques, laboratory-based tests, and clinical practices for SCR screening. This PROSPERO-registered systematic review included relevant texts identified through predetermined searches in online databases. Collected test accuracy data facilitated the calculation of likelihood ratios. Forty-four studies evaluating 4928 patients were included. DFE demonstrated moderate test accuracy (LR+ of 8.0, LR- of 0.3). Ultra-widefield-fundus photography demonstrated superior accuracy (LR+ 32.5, LR- 0.03). Optical coherence tomography angiography applications were highly accurate for PSR identification (machine learning LR+ 32.5, LR- 0.03; human grader LR+ 2.8-213.1, LR- 0.1-0.2). Most techniques and tests were more accurate at detecting PSR than staging SCR or detecting lower-grade SCR. Our findings support the integration of advanced image-based approaches, such as computer-based image analysis and ultra-wide-field fundus imaging, for SCR screening in SCD patients given the superior accuracy in PSR detection compared with the current standard of care. Rigorous SCR screening implementation studies are needed to support evidence-based SCR screening recommendations.

Optical Coherence Tomography Angiography of Macular Microangiopathy in Children With Sickle Cell Disease

In this study, we identified the presence of sickle cell maculopathy and determined correlations between hemolysis indicators and systemic and ocular manifestations in children with sickle cell disease (SCD). Thirty-three patients with SCD 5 to 18 years of age underwent optical coherence tomography angiography (OCTA) as part of a thorough eye examination. The hematological indices and clinical data (hemoglobin, fetal hemoglobin, mean corpuscular volume, and frequency of sickle cell-associated complications and therapy) were collected. The SCD group contained 33 patients (66 eyes), and the control group contained 36 healthy participants (72 eyes). The SCD group had significantly thinner parafoveal thickness ( P =0.041) and significantly smaller parafoveal volume ( P =0.041) than the controls. The SCD group had lower deep capillary plexus density than the controls ( P =0.029). The SCD group had significantly smaller flow areas than the controls ( P <0.001). The foveal avascular zone (FAZ) perimeter, foveal density, and FAZ area in the entire retina did not differ significantly between the groups ( P >0.05). The platelet level was negatively correlated with parafoveal and perifoveal thickness and density. OCTA detected early macular microvascular changes in children and adolescents with asymptomatic SCD.

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.

LONGITUDINAL ANALYSIS OF MICROVASCULAR CHANGES IN SICKLE CELL DISEASE USING SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

PURPOSE

To analyze the changes in macular vascular densities (VDs) and foveal avascular zone (FAZ) over a 6-year period using swept-source optical coherence tomography angiography in patients with sickle cell disease compared with unaffected control subjects.

METHODS

Thirty eyes of patients with sickle cell disease and 12 eyes of unaffected control subjects matched for age and ethnicity were examined at a 6-year interval using the same imaging protocol, including ultra-wide-field angiography, swept-source OCT, and 3 × 3-mm optical coherence tomography angiography. The macular VD and FAZ were measured on ImageJ software according to previously reported algorithms.

RESULTS

In sickle cell eyes, the mean FAZ significantly increased ( P < 0.01), and the VD decreased in the foveal (within a circle of 1.5 mm in diameter around the foveal center) and temporal areas in both the superficial and the deep capillary plexuses ( P < 0.01). The VD did not change over time in the parafoveal area (annulus between two circles of 1.5 and 3 mm in diameter) and in the superior, inferior, and nasal sectors. No worsening of peripheral retinopathy was observed in the cohort during the follow-up, except for one eye that developed sea-fan. In the control eyes, no microvascular change was observed over time in FAZ size and VD.

CONCLUSION

These longitudinal optical coherence tomography angiography findings in patients with sickle cell disease showed an enlargement of the FAZ and a decrease in VD in the temporal and perifoveal regions despite the absence of progression of peripheral retinopathy, suggesting a worsening of the macular nonperfusion over time in sickle cell disease.

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.

Abnormal Neurologic Findings in Patients With Sickle Cell Disease Without a History of Major Neurologic Events

Background and Objectives

Patients with sickle cell disease (SCD) are prone to symptomatic neurologic complications. Previous studies reported accrual of neural injury starting at early age, even without having symptomatic neurologic events. The aim of this study was to assess the prevalence and risk factors of abnormal neurologic findings in patients with SCD with no history of major symptomatic neurologic events.

Methods

Our study extracted patients diagnosed with SCD from the Cooperative Study of Sickle Cell Disease. Patients who underwent a neurologic evaluation were included in our analysis. Patients with previous documented major symptomatic neurologic events were excluded. We compared patients with SCD with abnormal neurologic findings with those without in terms of clinical and laboratory parameters using multivariate binary logistic regression.

Results

A total of 3,573 patients with SCD were included (median age = 11 [IQR = 19] years, male = 1719 [48.1%]). 519 (14.5%) patients had at least one abnormal neurologic finding. The most common findings in descending order were abnormal reflexes, gait abnormalities, cerebellar dysfunction, language deficits, nystagmus, abnormal muscle tone and strength, Romberg sign, Horner syndrome, and intellectual impairment. History of eye disease (odds ratio [OR] = 2.76, 95% confidence interval [CI] = 1.63-4.68) and history of osteomyelitis (OR = 2.55, 95% CI 1.34-4.84) were the strongest predictors of abnormal neurologic findings, followed by smoking (OR = 1.59, 95% CI 1.08-2.33), aseptic necrosis (OR = 1.57, 95% CI 1.06-2.33), hand-foot syndrome (OR = 1.48, 95% CI 1.04-2.12), and male sex (OR = 1.42, 95% CI 1.01-2.02).

Discussion

Neurologic deficits are relatively common in patients with SCD, even without documented major neurologic insults. They range from peripheral and ophthalmic deficits to central and cognitive disabilities. Patients with SCD should have early regular neurologic evaluations and risk factor modification, particularly actively promoting smoking cessation.

Proliferative Sickle Cell Retinopathy in the Retinal Periphery Detected by Ultra-Widefield Imaging: A Case Report

Sickle cell proliferative retinopathy usually presents first in the peripheral retina and the ability to extend and enhance our visualization of the peripheral retina would allow for superior clinical decision-making. In our practice, we had a 28-year-old patient diagnosed with major sickle cell disease of the homozygous type SS (HbSS) that presented with sickle cell proliferative retinopathy detected by ultra-widefield imaging in the nasal side of the left fundus. At follow-up, neovascularization was detected in the extreme nasal periphery of the left eye by ultra-widefield imaging fluorescein angiography with right gaze. The case was graded as Goldberg stage 3, and the patient was administered photocoagulation treatment. With further advancements in the quality and modality of peripheral retinal imaging, novel proliferative lesions can be detected and appropriately managed much earlier than was previously possible. Ultra-widefield imaging allows for the visualization of the central 200 degrees of the retina but, with gaze view, peripheral retina beyond 200 degrees can be reached.

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.

Incidence of eye complications among sickle cell disease patients in Jeddah, Saudi Arabia: A cross-sectional study

Introduction

Sickle cell disease (SCD) is a heritable blood disorder resulting in deformed, rigid red blood cells, rendering them more prone to vaso-occlusion. Ocular complications are known to affect multiple organs through the body's vasculature. Here, we evaluated the incidence of eye complications in patients with SCD at King Abdulaziz Medical City in Jeddah, Saudi Arabia.

Materials and methods

We used a cross-sectional approach and collected relevant medical data from nine patients with SCD. Ophthalmic assessment included visual acuity and an in-clinic dilated fundus examination. All patients were asked to attend the ophthalmology clinic to undergo optical coherence tomography (OCT) angiography, macular OCT scan, and fundus photography. The results of the imaging tests were interpreted by a certified ophthalmology consultant specializing in retinal diseases. Descriptive analyses of the results were also performed.

Results

The mean age of the nine patients was 24.78 ± 10.9 years. All patients were non-hypertensive, one had type 1 diabetes, and another had type 2 diabetes. Five patients had normal visual acuity, two had slight impairments in at least one eye, and two had moderate impairment in at least one eye. One of the nine patients exhibited retinal ischemia in the right eye despite normal macular thickness (visual acuity, OD, 6/30; OS, 6/21). The remaining eight patients showed no ocular abnormalities.

Conclusion

Of the nine patients with SCD, five showed no symptoms of ocular complications. One patient showed retinal ischemia in the right eye, despite a normal macular thickness. This study's results suggest routine ophthalmologic examination may not be able to detect or monitor macular or retinal abnormalities unless augmented with detailed imaging techniques.

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Out of nine patients with SCD, five patients exhibited normal visual acuity.

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One patient presented perifoveal retinal ischemia in the right eye.

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Results suggest augmenting routine ophthalmology screening with imaging techniques.

Retinal and choroidal thickness in pediatric patients with sickle cell disease: a cross-sectional cohort study

BACKGROUND

To measure the retinal/choroidal thicknesses in the macular area of asymptomatic pediatric patients with sickle cell disease (SCD).

METHODS

This cross-sectional cohort study included 40 children (79 eyes) with SCD and 19 control patients (36 eyes). All subjects underwent spectral-domain optical coherence tomography (SD-OCT) with enhanced-depth imaging OCT. Generalized Estimating Equations (GEE) were applied to compare the outcomes between groups. P ≤ 0.05 was considered significant.

RESULTS

The choroidal thickness in the macular area in the study subfields was significantly thinner in the SCD eyes compared with control eyes (subfoveal subfield and temporal parafoveal subfield, p < 0.0001; nasal parafoveal subfield, p < 0.0001 temporal perifoveal subfield, p < 0.0001; and nasal perifoveal subfield, p < 0.0001). The variations in the retinal thickness were not significant.

CONCLUSION

EDI-OCT showed that the macular choroidal thickness is thinner in asymptomatic pediatric patients with SCD.

The Impact of Optical Coherence Tomography in the Early Identification of Children with Sickle Cell Retinopathy

INTRODUCTION

Sickle cell disease is characterized by the production of abnormal hemoglobin, which affects hemoglobin molecule stability during hypoxia and leads to the formation of sickle cells, resulting in increased hematic viscosity, hemolysis, and microvascular blockage. Vasoocclusion is assumed to be the primary cause of vision-threatening retinopathy in sickle cell disease. The aim of this study was to improve the early detection of sickle cell retinopathy (SCR) in children with sickle cell disease (SCD) and investigate the link between systemic and ocular symptoms.

METHODS

This cross-sectional study comprised children with SCD. The patient files provided a detailed medical history. The laboratory tests included a blood count, reticulocyte count, and Hb electrophoresis. The slit lamp, fundus, optical coherence tomography (OCT), and optical coherence tomography angiography (OCTA) were all part of the ophthalmological examination.

RESULTS

The study comprised 15 children with sickle cell disease who met the inclusion and exclusion criteria, with a mean age of 11.15 ± 1.29 years. Nine of the children were males (60%) and six were females (40%). 8 (53.3%) of the children had Hb SS, three (20%) had Hb SC, three (20%) had Hb SB⁺, and one (6.7%) had Hb SB⁰. Four children (26.7%) had poor visual acuity. A fundus examination revealed significant abnormal findings in 12 of the 7 children's eyes (40 percent). Macular thinning was detected by OCT in 10 eyes of 7 children (33.3%). Flow voids at the deep retinal capillary plexus were detected by OCTA in 10 eyes of 7 children (33.3%). Longer disease duration, higher reticulocytic percent, more painful crises, and noncompliance with hydroxyurea medication were all linked to the existence of eye abnormalities on fundus examination and OCT.

CONCLUSION

OCTA can show early retinal damage in sickle cell patients with macular changes. Sickle cell retinopathy is usually associated with more severe disease.

Artificial intelligence for improving sickle cell retinopathy diagnosis and management

Sickle cell retinopathy is often initially asymptomatic even in proliferative stages, but can progress to cause vision loss due to vitreous haemorrhages or tractional retinal detachments. Challenges with access and adherence to screening dilated fundus examinations, particularly in medically underserved areas where the burden of sickle cell disease is highest, highlight the need for novel approaches to screening for patients with vision-threatening sickle cell retinopathy. This article reviews the existing literature on and suggests future research directions for coupling artificial intelligence with multimodal retinal imaging to expand access to automated, accurate, imaging-based screening for sickle cell retinopathy. Given the variability in retinal specialist practice patterns with regards to monitoring and treatment of sickle cell retinopathy, we also discuss recent progress toward development of machine learning models that can quantitatively track disease progression over time. These artificial intelligence-based applications have great potential for informing evidence-based and resource-efficient clinical diagnosis and management of sickle cell retinopathy.

Monitoring retinal pathology and cerebral injury in sickle cell disease using spectral-domain optical coherence tomography in pediatric patients

PURPOSE

This study aimed to confirm the correlation between sickle cell disease (SCD) genotype and retinal damage identified by spectral-domain optical coherence tomography (SD-OCT), and examine a potential link between hypoxic ischemic injury in the retina and brain.

METHODS

In this prospective, observational case series, 117 patients (56 males) aged 5-20 years with SCD (36 SC, 68 SS, eight Sβ+ thalassemia, five Sβ0 thalassemia) underwent ophthalmologic examination including funduscopy and SD-OCT imaging. Comparison of SCD genotypes and association between ocular findings and cerebrovascular disease (CVD) in subjects with SS/Sβ0 genotype were investigated.

RESULTS

Visual acuity ranged from 20/20 to 20/40. On funduscopic exam, 16 of 117 (13.7%) had retinopathy; 69 of 117 (59.0%) showed inner retina thinning on SD-OCT. Patients with SS/Sβ0 showed a higher frequency of sickle cell retinopathy (SCR) change (68.5% vs. 47.2%), bilateral SCR (49.9% vs. 25.0%), and foveal involvement (15.1% vs. 0) than the SC genotype. While funduscopic findings in our cohort with SS/Sβ0 genotype showed no correlation with CVD, 20 of 21 patients with CVD had abnormal SD-OCT. Elevated reticulocyte percentage and aspartate aminotransferase are associated with SD-OCT changes and CVD.

CONCLUSIONS

SD-OCT was better than funduscopy in detecting retinal changes, higher frequency, and more extensive retinal changes in the more severe SCD genotypes SS and Sβ0 as compared with SC. The correlation between abnormal SD-OCT and CVD strongly suggests that retinal exam using SD-OCT may aid in detection and monitoring SCD-related CVD. Retinopathy may be another component of the hemolytic subphenotype of SCD.

Hemoglobinopathies: ocular manifestations in children and adolescents

Hemoglobinopathies are genetic disorders that lead to abnormal structure of the hemoglobin molecule. Sickle cell disease, the most common inherited blood disorder, is characterized by defective oxygen transport. Almost every part of the eye can be affected by sickle cell disease; however, proliferative sickle cell retinopathy is the primary cause of vision loss, either from vitreous hemorrhage or retinal detachment. Here we review the various manifestations of hemoglobinopathies on the eyes of children and adolescents, with a specific focus on sickle cell disease and its different phenotypes. Newer, more sensitive ophthalmological imaging modalities, including ultra-widefield fluorescein angiography, spectral-domain optical coherence tomography, and optical coherence tomography angiography, are available. These sensitive modalities allow for a more thorough examination of the retinal periphery where sickle cell retinopathy is often present. Utilization of such modalities will help with the early detection of the disease in children, which provide a better understanding of the pathogenesis of the disease and guide future screening and treatment regimens.

The effect of insulin pump therapy in retinal vasculature in type 1 diabetic patients

BACKGROUND/OBJECTIVES

Continuous subcutaneous insulin infusion (CSII) is a treatment for type 1 diabetes that improves metabolic control and reduces micro and macrovascular complications. The aim of this study was to compare the effect of CSII versus traditional multiple daily injections (MDI) therapy on retinal vasculature.

METHODS

We performed a prospective study with type 1 diabetic patients with no prior history of ocular pathology other than mild diabetic retinopathy. The patients were divided into two groups according to their therapeutic modality (CSII vs MDI). The retinal nerve fiber layers thickness and vascular densities were compared between groups in both macula and optic disc. The correlations between vascular density and clinical features were also determined. Statistical significance was defined as p < 0.05.

RESULTS

The study included 52 eyes, 28 in the insulin CSII group. The mean age was 36.66 ± 12.97 years, with no difference between groups (p = 0.49). The mean glycated hemoglobin (HbA1c) was found to be lower in the CSII group (7.1% ± 0.7 vs 7.5% ± 0.7 p < 0.01). The parafoveal vascular density was found to be higher in the CSII group (42.5% ± 0.4 vs 37.7% ± 0.6, p < 0.01). We found an inverse correlation between HbA1c value and parafoveal vascular densities (p < 0.01, r = -0.50).

CONCLUSION

We found that CSII provided better metabolic control than MDI and this seemed to result in higher parafoveal vascular density. As lower vascular density is associated with an increased risk of diabetic retinopathy, these results suggest that CSII could be the safest therapeutic option to prevent retinopathy.

Plexus-specific retinal vascular anatomy and pathologies as seen by projection-resolved optical coherence tomographic angiography

Optical coherence tomographic angiography (OCTA) is a novel technology capable of imaging retinal vasculature three-dimensionally at capillary scale without the need to inject any extrinsic dye contrast. However, projection artifacts cause superficial retinal vascular patterns to be duplicated in deeper layers, thus interfering with the clean visualization of some retinal plexuses and vascular pathologies. Projection-resolved OCTA (PR-OCTA) uses post-processing algorithms to reduce projection artifacts. With PR-OCTA, it is now possible to resolve up to 4 distinct retinal vascular plexuses in the living human eye. The technology also allows us to detect and distinguish between various retinal and optic nerve diseases. For example, optic nerve diseases such as glaucoma primarily reduces the capillary density in the superficial vascular complex, which comprises the nerve fiber layer plexus and the ganglion cell layer plexus. Outer retinal diseases such as retinitis pigmentosa primarily reduce the capillary density in the deep vascular complex, which comprises the intermediate capillary plexus and the deep capillary plexus. Retinal vascular diseases such as diabetic retinopathy and vein occlusion affect all plexuses, but with different patterns of capillary loss and vascular malformations. PR-OCTA is also useful in distinguishing various types of choroidal neovascularization and monitoring their response to anti-angiogenic medications. In retinal angiomatous proliferation and macular telangiectasia type 2, PR-OCTA can trace the pathologic vascular extension into deeper layers as the disease progress through stages. Plexus-specific visualization and measurement of retinal vascular changes are improving our ability to diagnose, stage, monitor, and assess treatment response in a wide variety of optic nerve and retinal diseases. These applications will be further enhanced with the continuing improvement of the speed and resolution of the OCT platforms, as well as the development of software algorithms to reduce artifacts, improve image quality, and make quantitative measurements.

Sickle Cell Maculopathy: Prevalence, Associations and Impact on Visual Acuity

AIMS

To investigate the prevalence of sickle cell maculopathy (SCM), and associations with age, sex, genotype, proliferative sickle cell retinopathy (PSR) stage, and the impact on visual acuity.

METHODS

Age, sex, and visual acuity were recorded and spectral domain OCT and ultra-wide-field images of the macula and retina were reviewed in a consecutive series of 74 adults with sickle cell disease.

RESULTS

The median age was 37 years (range 19-73 years) and 36 cases (48.6%) were male. SCM was present in at least 1 eye of 40 cases (54.1%) or in 67 of all eyes (42.3%). SCM prevalence was 54.8%, 62.5%, and 25% for the HbSS, HbSC, and HbS/BThal or other genotypes, respectively. SCM was observed in 41 (39.4%) of the eyes with PSR stages 0, 1, and 2, and in 21 (51.2%) of the eyes with PSR stages 3, 4, and 5, respectively. Mild visual impairment or worse was present in 3 eyes (4.8%) with SCM but this was secondary to other pathology.

CONCLUSION

SCM is a frequent finding in the eyes of adults with sickle cell disease. The prevalence is similar for the HbSS and HbSC genotypes and is not related to the PSR stage. High-contrast distance visual acuity is typically preserved.

Retinal ultra-wide-field colour imaging versus dilated fundus examination to screen for sickle cell retinopathy

PURPOSE

To compare ultra-wide-field colour fundus imaging (UWFI) to dilated fundus examination (DFE) for the screening of sickle cell retinopathy (SCR).

DESIGN

This study is a prospective, blinded, multicentre case series.

PARTICIPANTS

This study included two groups: an adult group (n=268 eyes) and a paediatric group (n=168 eyes). Sickle cell disease (SCD) types included haemoglobin S homozygous (HbSS), haemoglobin S and C (HbSC) and Hb S with β-thalassaemia (HbSß-Thal).

METHODS

Participants underwent DFE and UWFI. Each eye received three independent grades (1-4), documented by three graders: clinical grader, image grader 1 and image grader 2. Three clinically relevant diagnostic thresholds were determined. Based on these thresholds, the sensitivity, specificity, positive predictive value and negative predictive value for all three graders were calculated relative to each other as reference tests.

RESULTS

HbSC was associated with the most advanced SCR grades. When compared to the clinical grader, image grader 1 and image grader 2 consistently detected more SCR and higher SCR grades in both adult and paediatric groups. In both groups, image grader 1 and image grader 2 identified twice as many cases of capillary occlusion/anastomosis than clinical grader. To detect the presence of any proliferative SCR, image grader 1 and image grader 2 had a sensitivity of 82%, 71% in the paediatrics group and 90% and 72% in the adult group. The clinical grader sensitivity was 52% in the paediatrics group and 53% in the adult group.

CONCLUSION

The UWFI is a sensitive tool to screen for SCR. It is superior to DFE in detecting capillary occlusion or anastomosis.

Visual cortex changes in children with sickle cell disease and normal visual acuity: a multimodal magnetic resonance imaging study

The visual system is primarily affected in sickle cell disease (SCD), and eye examination is recommended starting in late childhood. So far, to our knowledge, all studies have focused on the retina, neglecting the changes that might be present in the cortical portion of the visual system. We performed a multimodal magnetic resonance imaging (MRI) evaluation of the visual cortex in 25 children with SCD (mean age: 12·3 ± 1·9 years) and 31 controls (mean age: 12·7 ± 1·6 years). At ophthalmologic examination, 3/25 SCD children had mild visual acuity deficits and 2/25 had mild tortuosity of the retinal vessels. None showed optic pathway infarcts at MRI or Transcranial Doppler abnormal blood velocities, and 6/25 disclosed posterior cerebral artery stenosis (five mild and one severe) at MR-angiography. Compared to controls, SCD children had increased posterior pericalcarine cortical thickness, with a different trajectory of cortical maturation and decreased connectivity within medial and ventral visual neural networks. Our findings suggest that SCD affects the development and the tuning of the visual cortex, leading to anatomical and functional changes in childhood even in the absence of retinopathy, and set the basis for future studies to determine if these changes can represent useful predictors of visual impairment in adulthood, biomarkers of disease progression or treatment response.

Optical coherence tomography (OCT) and OCT angiography allow early identification of sickle cell maculopathy in children and correlate it with systemic risk factors

PURPOSE

To determine the presence of sickle cell retinopathy and maculopathy and to identify associations between markers of hemolysis and systemic and ocular manifestations in children affected by sickle cell disease.

METHODS

Eighteen children with sickle cell disease, aged 5-16 years, underwent complete eye examination including best-corrected visual acuity, slit-lamp biomicroscopy, ophthalmoscopy after pharmacological mydriasis, spectral-domain optical coherence tomography (SD-OCT), and optical coherence tomography angiography (OCTA). Blood test results and clinical history information were collected for each child, including fetal hemoglobin (HbF), hemoglobin (Hb), hematocrit (Htc), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), reticulocytes percentage (%ret), lactic dehydrogenase (LDH), total and direct bilirubin, glomerular filtration rate, number of painful crises, acute chest syndromes, and splenic sequestration. Therapeutic regimen and transfusion therapy were also evaluated.

RESULTS

Sixteen of 36 eyes (44.4%) had non-proliferative sickle cell retinopathy on ophthalmoscopic evaluation. No patients had proliferative sickle cell retinopathy. In 13 of 36 eyes (36.1%), SD-OCT and OCTA detected signs of sickle cell maculopathy. Nine eyes (25%) presented sickle cell retinopathy and maculopathy, 7 eyes (19.4%) sickle cell retinopathy alone, and 4 eyes (11.1%) sickle cell maculopathy alone. A statistically significant association was found between sickle cell retinopathy; lower levels of HbF, Hb, and Htc; and higher MCV and percentage of reticulocytes. Sickle cell maculopathy was associated with lower values of H and Htc and higher levels of reticulocytes and total bilirubin.

CONCLUSIONS

We identified early signs of sickle cell retinopathy and maculopathy in a pediatric population with SD-OCT and OCTA. These two retinal complications were more frequent in children with higher hemolytic rates.

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.

Wide-field imaging of sickle retinopathy

Background

Wide-field imaging is a newer retinal imaging technology, capturing up to 200 degrees of the retina in a single photograph. Individuals with sickle cell retinopathy commonly exhibit peripheral retinal ischemia. Patients with proliferative sickle cell retinopathy develop pathologic retinal neovascularization of the peripheral retina which may progress into sight-threatening sequelae of vitreous hemorrhage and/or retinal detachment. The purpose of this review is to provide an overview of current and future applications of wide-field retinal imaging for sickle cell retinopathy, and recommend indications for best use.

Main body

There are several advantages to wide-field imaging in the clinical management of sickle cell disease patients. Retrospective and prospective studies support the success of wide-field imaging in detecting more sickle cell induced retinal microvascular abnormalities than traditional non-wide-field imaging. Clinicians can easily capture a greater extent of the retinal periphery in a patient's clinical baseline imaging to follow the changes at an earlier point and determine the rate of progression over time. Wide-field imaging minimizes patient and photographer burden, necessitating less photos and technical skill to capture the peripheral retina. Minimizing the number of necessary images can be especially helpful for pediatric patients with sickle cell retinopathy. Wide-field imaging has already been successful in identifying new biomarkers and risk factors for the development of proliferative sickle cell retinopathy. While these advantages should be considered, clinicians need to perform a careful risk-benefit analysis before ordering this test. Although wide-field fluorescein angiography successfully detects additional pathologic abnormalities compared to traditional imaging, a recent research study suggests that peripheral changes differentially detected by wide-field imaging may not change clinical management for most sickle cell patients.

Conclusions

While wide-field imaging may not carry a clinically significant direct benefit to all patients, it shows future promise in expanding our knowledge of sickle cell retinopathy. Clinicians may monitor peripheral retinal pathology such as retinal ischemia and retinal neovascularization over progressive time points, and use sequential wide-field retinal images to monitor response to treatment. Future applications for wide-field imaging may include providing data to facilitate machine learning, and potential use in tele-ophthalmology screening for proliferative sickle retinopathy.

Sickle cell retinopathy. A focused review

PURPOSE

To provide a focused review of sickle cell retinopathy in the light of recent advances in the pathogenesis, multimodal retinal imaging, management of the condition, and migration trends, which may lead to increased prevalence of the condition in the Western world.

METHODS

Non-systematic focused literature review.

RESULTS

Sickle retinopathy results from aggregation of abnormal hemoglobin in the red blood cells in the retinal microcirculation, leading to reduced deformability of the red blood cells, stagnant blood flow in the retinal precapillary arterioles, thrombosis, and ischemia. This may be precipitated by hypoxia, acidosis, and hyperosmolarity. Sickle retinopathy may result in sight threatening complications, such as paracentral middle maculopathy or sequelae of proliferative retinopathy, such as vitreous hemorrhage and retinal detachment. New imaging modalities, such as wide-field imaging and optical coherence tomography angiography, have revealed the microstructural features of sickle retinopathy, enabling earlier diagnosis. The vascular growth factor ANGPTL-4 has recently been identified as a potential mediator of progression to proliferative retinopathy and may represent a possible therapeutic target. Laser therapy should be considered for proliferative retinopathy in order to prevent visual loss; however, the evidence is not very strong. With recent development of wide-field imaging, targeted laser to ischemic retina may prove to be beneficial. Exact control of intraoperative intraocular pressure, including valved trocar vitrectomy systems, may improve the outcomes of vitreoretinal surgery for complications, such as vitreous hemorrhage and retinal detachment. Stem cell transplantation and gene therapy are potentially curative treatments, which may prevent retinopathy.

CONCLUSIONS

There is lack of evidence regarding the optimal management of sickle retinopathy. Further study is needed to determine if recent progress in the understanding of the pathophysiology and diagnosis of sickle retinopathy may translate into improved management and outcome.

Non-GVHD ocular complications after hematopoietic cell transplantation: expert review from the Late Effects and Quality of Life Working Committee of the CIBMTR and Transplant Complications Working Party of the EBMT

Non-graft-versus-host disease (non-GVHD) ocular complications are generally uncommon after hematopoietic cell transplantation (HCT), but can cause prolonged morbidity affecting activities of daily living and quality of life. Here we provide an expert review of non-GVHD ocular complications in a collaboration between transplant physicians and ophthalmologists through the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and the Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation. Complications discussed in this review include cataracts, glaucoma, ocular infections, ocular involvement with malignancy, ischemic microvascular retinopathy, central retinal vein occlusion, retinal hemorrhage, retinal detachment and ocular toxicities associated with medications. We have summarized incidence, risk factors, screening, prevention and treatment of individual complications and generated evidence-based recommendations. Baseline ocular evaluation before HCT should be considered in all patients who undergo HCT. Follow-up evaluations should be considered according to clinical symptoms, signs and risk factors. Better preventive strategies and treatments remain to be investigated for individual ocular complications after HCT. Both transplant physicians and ophthalmologists should be knowledgeable of non-GVHD ocular complications and provide comprehensive collaborative team care.

Early Macular Angiography among Patients with Glaucoma, Ocular Hypertension, and Normal Subjects

Purpose

To evaluate early macular circulation in open-angle glaucoma (OAG), normal-tension glaucoma (NTG), ocular hypertension (OHT), and healthy subjects via optical coherence tomography angiography (OCTA).

Methods

A retrospective cross-sectional study was conducted. Medical records were reviewed, and the patients who received OCTA examinations were divided into the OAG, NTG, OHT, and normal groups. The ophthalmic data including best-corrected visual acuity, spherical equivalent, intraocular pressure, central corneal thickness, central foveal thickness, visual field deviation, retinal nerve fiber layers thickness, and ganglion cell complex thickness were obtained from medical documents. For the macular area, the superficial vessel density (VD), deep VD, foveal avascular zone (FAZ), flow area of the outer retina, and flow area of the choriocapillaris were measured via OCTA and analyzed using the default vascular density analysis program in the same OCTA device.

Results

A total of 70 eyes from 70 patients were analyzed in the current study. Significant differences in the intraocular pressure, central corneal thickness, visual field deviation, retinal fiber layer thickness, and ganglion cell complex thickness were observed in the patients in the glaucoma group at their last visits. The OAG and NTG groups evinced a lower superficial VD than did the control group, while the NTG group had a lower deep VD than the control group. The NTG group also had a larger FAZ than did the OHT group. The flow area of the outer retina in the OAG group was low relative to those of the OHT and control groups. No difference in choriocapillaris perfusion was observed among the groups.

Conclusion

The OAG and NTG patients demonstrated impaired vasculature before significant disease development could be observed. Furthermore, the differences in macular circulation may be associated with differences in the courses of disease between the glaucoma and OHT patients.

High Healthcare Utilization in Adolescents with Sickle Cell Disease Prior to Transition to Adult Care: A Retrospective Study

BACKGROUND

The transition from pediatric to adult care in the US is often difficult for individuals with sickle cell disease (SCD). Young adults (18 to 25 years of age) have higher acute care utilization and an increased risk of poor outcomes. The current study was designed to provide greater insights into patients (16 to 18 years of age) with SCD prior to their transition to adult care.

OBJECTIVES

To describe current treatment patterns, pain crises prevalence, SCD-related complications, and healthcare resource utilization (HCRU) in 16-to-18-year-old patients with SCD.

METHODS

From 1/1/2015-6/30/2017 using MarketScan Databases, patients were included if they were 16 to 18 years old at the index date, had ≥1 inpatient or 2 outpatient SCD diagnosis claims during the identification period, and were continuously enrolled in the database for at least one year prior (baseline) and post index date. Outcomes included medications, disease management interventions, Charlson Comorbidity Index (CCI), vaso-occlusive (VOC) crises requiring healthcare visits, HCRU, and SCD complications.

RESULTS

1,186 patients were included; most (64.3%) were female. The mean CCI was 1.3 (SD: 0.7). In the overall cohort, patients experienced an average of 3.9 (SD: 4.2) VOCs and most patients (61.1%, n=725) had chronic complications during the one-year follow-up. Pulmonary disease (31.1%, n=369) was the most frequent complication; blood transfusions (mean: 8.4 [SD:7.0]) and iron-chelating therapies (mean: 8.6 [SD:10]) were the most common interventions and medications, respectively. In the 16 to 18 year old group, patients with SCD had 2.0 (SD = 2.3) hospital admissions, 3.4 (SD = 4.0) ER visits, and 5.0 (SD = 4.2) office visits.

CONCLUSIONS

Prior to transition to adult care, adolescents with SCD already have significant a cute and chronic disease-related complications, possibly contributing to frequent healthcare visits. Increased attention to this age group, including improvements in disease modifying therapy, are needed prior to transition to adult care systems to improve outcomes.

Non-Graft-versus-Host Disease Ocular Complications after Hematopoietic Cell Transplantation: Expert Review from the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and the Transplant Complications Working Party of the European Society for Blood and Marrow Transplantation

Non-graft-versus-host disease (GVHD) ocular complications are generally uncommon after hematopoietic cell transplantation (HCT) but can cause prolonged morbidity affecting activities of daily living and quality of life. Here we provide an expert review of non-GVHD ocular complications in a collaboration between transplantation physicians and ophthalmologists through the Late Effects and Quality of Life Working Committee of the Center for International Blood and Marrow Transplant Research and the Transplant Complications Working Party of the European Society of Blood and Marrow Transplantation. Complications discussed in this review include cataracts, glaucoma, ocular infections, ocular involvement with malignancy, ischemic microvascular retinopathy, central retinal vein occlusion, retinal hemorrhage, retinal detachment and ocular toxicities associated with medications. We summarize the incidence, risk factors, screening, prevention, and treatment of individual complications and generate evidence-based recommendations. Baseline ocular evaluation before HCT should be considered in all patients who undergo HCT. Follow-up evaluations should be considered according to clinical signs and symptoms and risk factors. Better preventive strategies and treatments remain to be investigated for individual ocular complications after HCT. Both transplantation physicians and ophthalmologists should be knowledgeable about non-GVHD ocular complications and provide comprehensive collaborative team care.