Retinopathy in patients with sickle cell trait

Thrombosis risk with haemoglobin C trait and haemoglobin C disease: A systematic review

The thrombotic risk with haemoglobin C trait (HbAC) or haemoglobin C disease (HbCC) is unclear. However, individuals with HbCC have demonstrated chronic haemolysis, higher blood viscosity and altered rheology when compared to individuals with wild-type haemoglobin (HbAA). These physiological alterations may theoretically translate to increased risk of thrombosis; therefore, a systematic literature review was performed to investigate the possible association between HbAC and/or HbCC and thrombosis. Twenty-two studies met inclusion criteria representing 782 individuals with HbAC (n = 694) or HbCC (n = 88). Fifteen studies described the presence/absence of venous thromboembolism (VTE) in patients with HbAC (n = 685) or HbCC (n = 79), while seven studies described patients with HbAC (n = 9) or HbCC (n = 9) and arterial thrombosis. Most (n = 20) studies were case reports or case series; however, two studies suggested a potential increased VTE risk with HbAC compared to HbAA in (i) all patients (OR 2.2, 95% CI: 0.9-5.5) and in (ii) pregnant individuals (RR 3.7, 95% CI 0.9-16). This review is the largest assessment of patients with HbC trait or disease and thrombosis to date; despite its limitations, the findings suggest HbC may be a predisposing risk factor to thrombosis. Prospective cohort studies are warranted to definitively elucidate the risk of thrombosis in this population.

Rare Cause of Acute Loss of Vision in a Patient With Sickle Cell Trait

Sickle cell disease (SCD) is a prevalent inherited blood disorder with various ocular manifestations, including sickle cell retinopathy (SCR), characterized by retinal microcirculation impairment and ischemic complications. We present the case of a 21-year-old male with sickle cell trait who experienced a sudden, painless loss of vision in his left eye. Ophthalmologic examination revealed vitreous hemorrhage and neovascularization, indicating SCR. Initial treatment with hydroxyurea and exchange transfusions led to partial improvement. However, due to persistent vitreous hemorrhage, the patient underwent a vitrectomy. The sickle cell trait affects a large global population, and its retinopathy is a rare but severe complication. The pathogenesis and risk factors for SCR are similar to those for SCD. The diagnosis of SCR is established through fundoscopic examination and graded based on Goldberg's classification. Management involves a multidisciplinary approach targeting systemic illness and visual defects, including hydroxyurea, photocoagulation, anti-vascular endothelial growth factors, and vitrectomy. Awareness, early diagnosis, and timely intervention are essential to preventing vision-threatening complications in sickle cell trait patients with SCR.

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.

Retinopathy in Egyptian patients with sickle cell disease: A cross-sectional study

Sickle cell disease (SCD) is a disorder that causes red blood cells to become sticky and rigid. Sickle cells can block blood flow in small blood vessels depriving the eye of oxygen and cause damage. This is called sickle retinopathy that can progress to severe proliferative sickle cell retinopathy, bleeding into the eye, detachment of the retina or even loss of vision.To assess ocular manifestations and detect frequency of retinopathy in patients with SCD.Cross-sectional study was conducted on 32 patients with SCD. They were 22 males and 10 females with mean age of 12 years. Routine investigations as well as ophthalmological examination including visual acuity, fluorescein angiography and optical coherence tomography were done.We found that 8 patients (25%) suffered from proliferative retinopathy, 10 patients (31%) showed tortuous retinal veins, while 14 patients (44%) were normal. All patients showed macular thinning on optical coherence tomography examination.We concluded that frequency of retinopathy in patients with SCD is more than expected and it was higher in patients who started transfusion at a later age. More attention should be paid for this problem and close observations and follow up is strongly needed.

Sickle Cell Trait Presenting as Unilateral Proliferative Retinopathy and Macular Thinning in a Pregnant Woman

Background

To report a case of a pregnant woman with sickle cell trait (SCT) who presented with unilateral proliferative sickle cell retinopathy. Case Presentation. A 26-year-old otherwise healthy pregnant woman presented with the complaint of visual loss in her left eye. The funduscopic examination showed vitreous hemorrhage, sea fan neovascularization, and pale optic disc. Optical coherence tomography revealed macular inner retinal layer thinning and foveal splaying (saucerization of the foveal pit). The investigations, including hemoglobin electrophoresis, verified the diagnosis of sickle cell trait. Blood pressure, fasting blood glucose tests, and tuberculin skin tests were normal. We treated the patient by peripheral retinal photocoagulation over the area of nonperfusion.

Conclusion

Even though the sickle cell trait is generally considered as a milder form of sickle cell disease without severe retinal manifestations, pregnancy should be considered as a trigger that can induce proliferative changes and foveal splaying in this group of patients.

Deep Learning Detection of Sea Fan Neovascularization From Ultra-Widefield Color Fundus Photographs of Patients With Sickle Cell Hemoglobinopathy

Importance

Adherence to screening for vision-threatening proliferative sickle cell retinopathy is limited among patients with sickle cell hemoglobinopathy despite guidelines recommending dilated fundus examinations beginning in childhood. An automated algorithm for detecting sea fan neovascularization from ultra-widefield color fundus photographs could expand access to rapid retinal evaluations to identify patients at risk of vision loss from proliferative sickle cell retinopathy.

Objective

To develop a deep learning system for detecting sea fan neovascularization from ultra-widefield color fundus photographs from patients with sickle cell hemoglobinopathy.

Design, Setting, and Participants

In a cross-sectional study conducted at a single-institution, tertiary academic referral center, deidentified, retrospectively collected, ultra-widefield color fundus photographs from 190 adults with sickle cell hemoglobinopathy were independently graded by 2 masked retinal specialists for presence or absence of sea fan neovascularization. A third masked retinal specialist regraded images with discordant or indeterminate grades. Consensus retinal specialist reference standard grades were used to train a convolutional neural network to classify images for presence or absence of sea fan neovascularization. Participants included nondiabetic adults with sickle cell hemoglobinopathy receiving care from a Wilmer Eye Institute retinal specialist; the patients had received no previous laser or surgical treatment for sickle cell retinopathy and underwent imaging with ultra-widefield color fundus photographs between January 1, 2012, and January 30, 2019.

Interventions

Deidentified ultra-widefield color fundus photographs were retrospectively collected.

Main Outcomes and Measures

Sensitivity, specificity, and area under the receiver operating characteristic curve of the convolutional neural network for sea fan detection.

Results

A total of 1182 images from 190 patients were included. Of the 190 patients, 101 were women (53.2%), and the mean (SD) age at baseline was 36.2 (12.3) years; 119 patients (62.6%) had hemoglobin SS disease and 46 (24.2%) had hemoglobin SC disease. One hundred seventy-nine patients (94.2%) were of Black or African descent. Images with sea fan neovascularization were obtained in 57 patients (30.0%). The convolutional neural network had an area under the curve of 0.988 (95% CI, 0.969-0.999), with sensitivity of 97.4% (95% CI, 86.5%-99.9%) and specificity of 97.0% (95% CI, 93.5%-98.9%) for detecting sea fan neovascularization from ultra-widefield color fundus photographs.

Conclusions and Relevance

This study reports an automated system with high sensitivity and specificity for detecting sea fan neovascularization from ultra-widefield color fundus photographs from patients with sickle cell hemoglobinopathy, with potential applications for improving screening for vision-threatening proliferative sickle cell retinopathy.

[Sickle cell trait complications: A case series of 6 patients]

INTRODUCTION

Patients with sickle cell trait (SCT) are commonly considered as asymptomatic carriers. However, some clinical manifestations may occur.

METHODS

Here we present a retrospective descriptive study about SCT subjects with at least one complication diagnosed in a sickle cell disease referral center, in Paris, between 2008 and 2019. We also performed a literature review on the complications of SCT subjects.

RESULTS

Six patients (between 19 and 65 years old) were included. SCT was already known only for 4 of them at the time of the complication. Four patients presented with a splenic infarct after a stay in high altitude or a plane trip, one of them was associated with papillary necrosis; one patient had isolated papillary necrosis, and the last one had splenic sequestration. These complications happened for most of them after exposure to an unusual situation of hypoxia or deshydratation. Five out of 6 patients had a marked elevated C reactive protein.

CONCLUSION

SCT may cause acute ischemic complications in a context of prolonged hypoxia or dehydration. The most commonly reported are the splenic infarct and the renal papillary necrosis. A study of hemoglobin should be considered in these clinical situations in patients with compatible ethnic origin.

Retinal Artery Occlusion in Young Patients: A 6-Year Review

Purpose:

This article describes the characteristics, management, and etiology of retinal artery occlusions (RAOs) in young patients.

Methods:

A retrospective chart review of patients <50 years of age with ophthalmic and RAOs was conducted. Data were collected on demographics, clinical presentation, laboratory and imaging evaluation, management, and outcome.

Results:

Seventeen eyes of 15 patients younger than 50 (mean age, 34±8 years; 71% male, 29% female) with RAOs were identified. AOs included: 8 (47%) central RAOs (CRAOs), 5 (29%) branch RAOs (BRAOs), 3 (18%) ophthalmic AOs (OAOs), and 1 (6%) combined CRAO and vein occlusion (CRAO/CRVO). Logarithm of the minimum angle of resolution visual acuity (VA) at presentation was 2.6±4 (Snellen range 20/15 to no light perception). Systemic diseases in patients with BRAO included Susac disease (n = 1), sickle cell disease (n = 2), patent foramen ovale (PFO) (n = 1), and HIV (n = 1). CRAO was diagnosed in 4 patients after invasive surgery (3 after neurosurgery and 1 after cardiac surgery). Other patients had hypertension (n = 3), hypercoagulability due to uterine cancer (n = 1), and PFO (n = 1). OAOs were noted in 1 patient with Saturday night retinopathy and in 1 with ruptured internal carotid aneurysm at the level of the ophthalmic artery. Two eyes with CRAO were treated with tissue plasminogen activator (1 intraophthalmic artery through catheterization and 1 intravenously) without any change in final VA. In these patients, VA remained poor (VA hand motions – counting fingers) at 6 months or greater follow-up visits.

Conclusion:

RAO in young patients is uncommon. In this series, one-fourth of occlusions were seen during the perioperative period. A significant number of patients had concurrent uncontrolled hypertension. Other associated systemic findings included PFO, hypercoagulability, sickle cell disease, Susac disease, and HIV.

Sickle cell retinopathy: improving care with a multidisciplinary approach

Sickle cell retinopathy (SCR) is the most representative ophthalmologic complication of sickle cell disease (SCD), a hemoglobinopathy affecting both adults and children. SCR presents a wide spectrum of manifestations and may even lead to irreversible vision loss if not properly diagnosed and treated at the earliest. Over the past decade, multidisciplinary research developments have focused upon systemic, genetic, and ocular risk factors of SCR, enabling the clinician to better diagnose and manage these patients. In addition, newer imaging and testing modalities, such as spectral domain-optical coherence tomography angiography, have resulted in the detection of subclinical retinopathy related to SCD. Innovative therapy includes intravitreal injection of an anti-vascular endothelial growth factor (eg, Lucentis^® [ranibizumab] or Eylea^® [aflibercept]) which appears comparatively safe and efficient, and may be combined with laser photocoagulation (LPC) for proliferative SCR. The effect of LPC alone does not significantly lead to the regression of advanced SCR, although it helps in avoiding hemorrhage and sight loss. This comprehensive article is based on 10-years retrospective (2007–2017) studies. It aims to present advances and recommendations in SCR theranostics while pointing out the requirement of combinatorial approaches for better management of SCR patients. To reach this goal, we identified and analyzed randomized original and review articles, clinical trials, non-randomized intervention studies, and observational studies using specified keywords in various databases (eg, Medline, Embase, Cochrane, ClinicalTrials.gov).

A retinopathy in young patient with co-inheritance of heterozygous alpha + -thalassemia and sickle trait: a case report

Background

The retinopathy is an uncommon complication in individuals with sickle cell trait except for the cases of sickle cell trait associated with systemic arterial hypertension, diabetes mellitus, syphilis, tuberculosis and sarcoidosis.

Case Presentation

A retinopathy in a 16 year-old child with no history of consanguinity in the parents revealed a sickle S trait associated to heterozygous alpha thalassemia. His mother has Sickle cell anaemia (Hb SS) and his father is a carrier of heterozygous alpha-thalassemia status that it was unknown before.

Conclusion

This case report describes a proliferative retinopathy in a 16 year-old patient with co-inheritance of heterozygous alpha + −thalassemia and sickle trait.

Retinal changes in children and adolescents with sickle cell disease attending a paediatric hospital in Cairo, Egypt: risk factors and relation to ophthalmic and cerebral blood flow

BACKGROUND

Sickle cell disease (SCD) is characterised by occlusion of small blood vessels. This study aimed to assess retinal changes in patients with SCD and its correlation with time-averaged mean flow velocity (TAMV) in middle cerebral arteries (MCA) and ophthalmic arteries (OA).

METHODS

Sixty SCD patients (aged 3-18 years) attending a paediatric hospital in Cairo, Egypt, during March 2010 to November 2011, were compared with 30 healthy controls. All underwent clinical and fundus examination by indirect ophthalmoscopy, and assessment of TAMV in MCAs and OAs by transcranial Doppler, repeated 1 year later for those with conditional velocities.

RESULTS

HbS/β was diagnosed in 32 patients and HbSS in 28; 50 patients had normal fundus and 10 had bilateral non-proliferative retinopathy. Risk factors for retinopathy included HbSS, age, previous stroke, non-compliant hydroxyurea (HU) therapy, frequency of sickling crises and HbS level. TAMVs were increased in MCAs, but not in OAs, in sicklers. TAMVs in MCAs and OAs increased with non-compliant HU therapy, previous stroke, age, frequency of sickling crises and level of HbS. No significant interhemispheric difference was found.

CONCLUSION

Sickle retinopathy was correlated with TAMV in MCAs but not in OAs. A significant difference was found between initial and follow-up TAMVs in the MCAs, after 1 year of regular HU and transfusion therapy, in those with conditional velocities.

Retinal arterial occlusions in the young: systemic associations in Indian population

Purpose:

To determine the systemic associations in retinal arterial occlusions (RAO) in young Indian individuals less than 40 years of age.

Materials and Methods:

Case records of 32 patients (35 eyes) of less than 40 years, with non-traumatic RAO were analysed. All patients underwent detailed ophthalmic and systemic evaluation including hemogram, lipid profile, coagulation profile, vasculitis screening, carotid Doppler, echocardiogram.

Results:

In the study 21 were males and 11 were females. The age ranged from 11-39 years (Mean 27.6 ± 8.43). Nine (28%) patients were below 20 years of age. Among 35 eyes, 28 (80%) had central retinal artery occlusion (CRAO), three (8.6%) had branch retinal artery occlusion (BRAO), two (5.7%) each had cilio-retinal (CLAO) and hemi-retinal artery occlusion (HRAO). Vision ranged from no perception of light to 20/20. On systemic evaluation, in 21 (65.6%) patients a hypercoagulable state was responsible for the RAO. Conditions leading to a hypercoagulable state included hyperhomocysteinemia (21.9%), hyperlipidemia (15.6%), anticardiolipin antibody (6.2%), antiphospholipid antibody (6.2%), polycythemia, thrombocytosis, protein S deficiency, use of oral contraceptives and renal disorder (3.1% each). Six (18.7%) patients had cardiac valvular defects. Vasculitis screening was positive in three (9.4%) patients. Two (6.2%) had isolated systemic hypertension. In two (6.2%) patients no abnormality could be detected.

Conclusion:

The systemic associations of RAOs in the Indian population were distinctly different from those reported in the Western population. Hyperhomocysteinemia was the commonest association found. Whereas associations reported in the Western population such as cardiac abnormalities, coagulation disorders, hemoglobinopathies and oral contraceptive use were uncommon.

Southeast Asian ovalocytosis and a sickle cell trait in a young patient with sudden retinal stroke: a fortuitous association?

We report a case of retinal stroke in a patient from the Comoros Islands with both sickle cell trait and Southeast Asian ovalocytosis (SAO). Southeast Asian ovalocytosis is a dominantly inherited trait, frequent in Southeast Asia, caused by a 27 nucleotide deletion in the SLC4A1 gene that encodes band 3, leading to a decreased anion exchange but an increased cation leak across the erythrocyte membrane. We hypothesized that the red cell dehydration that can be induced by this cation leak can facilitate polymerization of Hb S [beta6(A3)Glu -->Val, GAG>GTG]. Southeast Asian ovalocytosis could then be a risk factor for rare microvascular complications in sickle cell trait.