Red cell exchange transfusion halts progressive proliferative sickle cell retinopathy in a teenaged patient with hemoglobin SC disease

Systemic medications for sickle cell disease and potential applications for sickle cell retinopathy

PURPOSE OF REVIEW

To review the literature evaluating systemic medications for treatment of sickle cell disease (SCD) and their applications for sickle cell retinopathy.

RECENT FINDINGS

Prior studies have demonstrated the efficacy of traditional systemic therapies in reducing the risk of development of sickle cell retinopathy. Since 2017, several new and promising disease-modifying therapies for sickle cell disease have been approved for clinical use, including the first genetic therapies such as exagamglogene autotemcel (exa-cel) and lovotibeglogene autotemcel (lovo-cel). These treatments have shown promising results for systemic management but are not widely utilized due to limited access and high cost. The efficacy of these therapies for the prevention of sickle cell retinopathy remains unknown and opens the door to new avenues for research. Furthermore, the role of systemic therapy for the management of hemoglobin SC (HbSC) disease, which has milder systemic effects but higher likelihood of causing retinopathy, remains poorly understood.

SUMMARY

Hydroxyurea has been a mainstay of systemic management of SCD with prior work suggesting its ability to reduce the likelihood of developing retinopathy. There are several new and potentially curative systemic therapies for SCD, though their role in retinopathy prevention and management has not been studied extensively. Future studies are necessary to understand the implications of these emerging therapies for sickle cell retinopathy.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

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.

Analysis of Retinal Thinning Using Spectral-domain Optical Coherence Tomography Imaging of Sickle Cell Retinopathy Eyes Compared to Age- and Race-Matched Control Eyes

PURPOSE

To determine whether the retina is thinner in sickle cell patients than in race- and age-matched controls, and, if it is thinner, whether there is any association with systemic diseases.

METHODS

Sickle cell and control (age- and race-matched) patients were prospectively enrolled from a university retina clinic into this observational study. Participants underwent visual acuity testing, slit-lamp biomicroscopy, dilated ophthalmoscopy, and spectral-domain optical coherence tomography imaging. Sickle cell retinal lesions, degree of vascular tortuosity, caliber of arteriovenous anastomosis, and stage of retinopathy were noted. Early Treatment Diabetic Retinopathy Study (ETDRS) subfield measurements were compared between sickle cell and control subjects and also among sickle cell hemoglobin subtypes. Associations between ETDRS subfield measurements and hemoglobin subtype, retinopathy stage, and systemic diseases were assessed.

RESULTS

A total of 513 sickle cell eyes (260 patients) and 75 control eyes (39 patients) had median visual acuities of 20/20. ETDRS central (P = .002), inner (nasal P = .009, superior P = .021, temporal P < .001, inferior P = .017), and temporal outer (P = .012) subfield measurements were thinner in sickle cell eyes compared to control eyes. Hemoglobin SS eyes had significantly thinner inner ETDRS subfield measurements compared to SC and SThal eyes. Retinal thinning in all subfields was associated with age (P = .017) for sickle cell and control eyes. No association was found between retinal thinning and hydroxyurea use or arteriovenous anastomosis caliber.

CONCLUSIONS

The macula is thinner in sickle cell eyes compared to control eyes; retinal thickness decreases with increasing age and sickle cell retinopathy stage and is most severe in hemoglobin SS subtypes. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

The past, present and future management of sickle cell retinopathy within an African context

Sickle cell retinopathy is a potentially blinding condition that affects young people in the working age group. This review looks at the past, present and future management of sickle cell retinopathy within an African context. After Sickle cell disease was first reported in 1910, some reports from Africa were pivotal in describing the retinal changes associated with the disease. It soon became obvious that there was a varied clinical picture and clinical course. Several landmark studies were carried out in Jamaica to help elucidate the complexities of the disease and outline appropriate clinical management. In most of the developed world, the clinical management of sickle cell disease has improved with concurrent improvement in outcomes. Currently resource constraints in most Sub-Saharan African countries where there is a high burden of disease means that the management of sickle cell retinopathy is fraught with numerous challenges. Future large scale trials in Africa shall hopefully help to better elucidate the mechanisms behind proliferative sickle retinopathy and help in the development of new and improved therapeutic pathways. The use of technology can help immensely in the screening of patients with sickle cell to detect early proliferative changes and if necessary treat accordingly.

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).

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.