Visual outcome of treating proliferative sickle cell retinopathy in 108 eyes

AIM

To report treatment methods and visual outcome of treating proliferative sickle cell retinopathy (PSCR).

DESIGN

Retrospective interventional.

METHODS

Review of PSCR eyes treated between 2017 to 2022. Patient demographics, fundus findings at presentation, genotype, PSCR stage, treatment used, and visual outcome were assessed.

RESULTS

108 eyes of 88 consecutive patients were studied. Male: Female 48:40. Mean age: 38.91 (SD:12.52) years. Genotype: sickle cell haemoglobin C (SC) 83 eyes (76.9%), sickle cell haemoglobin S (SS) 19 eyes (17.6%), and sickle cell trait (AS) 6 eyes (5.5%). PSCR stages: 3: 15 eyes (11.0%), 4: 74 eyes (67.0%), and 5: 19 eyes (22.0%). Treatment methods: Intravitreal Injection (IVI) of anti-vascular endothelial growth factor (VEGF) only (27 eyes,25%), scatter retinal laser photocoagulation (SRLP) only (7 eyes, 6.5%), Vitrectomy + SRLP (29 eyes, 26.9%), IVI + SRLP (25 eyes, 23.1%), and Vitrectomy + IVI + SRLP (20 eyes, 18.5%). The treatment used correlated with PSCR stage (p = 0.000). IVI only was mostly used to treat stage 4 (81.4%), and SRLP only was used for stages 3 (42.9%) and 5 (57.1%). IVI + SRLP treated eyes had the best pre- and post-treatment vision. Vitrectomy + SRLP treated eyes had the most improved vision. SRLP only had least visual improvement. Fundus findings correlated with visual outcome (p = 0.003); but stage of PSCR, genotype and treatment used had no correlation (P > 0.05).

CONCLUSION

Several options effectively treat PSCR. Visual outcome improved or remained same in 90.7% of treated eyes. Randomized controlled trials will determine the optimum treatment for each distinct presentation of PSCR. Treatment guidelines and a disease classification system of prognostic value are unmet needs.

Diagnostic Role of Oral Fluorescein Angiography in Pediatric Ambulatory Clinics

Oral ingestion of fluorescein can be done in ambulatory pediatric clinics. We show that oral ultra-widefield fluorescein angiography is a non-invasive approach to rapidly diagnose and manage a diverse set of pediatric retinal vascular diseases.

Tractional Retinal Detachment Related to Hemoglobin C Trait Retinopathy: A Case Report

Hemoglobin C (HbC) disease is an uncommon disease that is generally considered benign, causing only occasionally painless hematuria, osteomyelitis, and dental abnormalities. Ocular manifestations have rarely been described in these patients. Here we report a novel ophthalmological manifestation of the disease. A 20-year-old woman presented with progressive visual loss in her right eye due to tractional retinal detachment. The left eye was apparently normal, but wide-field fluorescence angiography showed mild peripheral ischemia with multiple vascular abnormalities. Vitrectomy was performed and the systemic workup revealed the presence of hemoglobinopathy C in heterozygous form. HbC disease can be sight-threating due to retinal proliferation, similar to sickle cell retinopathy. Patients affected with this disease should undergo regular surveillance. Ultra-wide angiography is a helpful examination to detect peripheral ischemia in the earlier stages.

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.

Routine Ophthalmological Examination Rates in Adults with Sickle Cell Disease Are Low and Must Be Improved

The American Academy of Ophthalmology and the National Heart, Lung and Blood Institute recommend patients with sickle cell disease (SCD) undergo dilated funduscopic exams (DFE) every 1-2 years to screen for sickle retinopathy. There is a paucity of data on the adherence rate to these guidelines; a retrospective study was performed to evaluate our institution's adherence. A chart review of 842 adults with SCD, seen 3/2017-3/2021 in the Montefiore healthcare system (All Patients), was done. Only about half of All Patients (n = 842) had >1 DFE during the study period (Total Examined Patients, n = 415). The Total Examined Patients were categorized as screening, those without retinopathy (Retinopathy-, n = 199), or follow-up, including individuals previously diagnosed with retinopathy (Retinopathy+, n = 216). Only 40.3% of screening patients (n = 87) had DFE at least biennially. As expected, there was a significant decrease in the average DFE rate of the Total Examined Patients after the COVID-19 pandemic started (13.6%) compared to pre-COVID (29.8%, p < 0.001). Similarly, there was a significant decrease in the screening rate of Retinopathy- patients from 18.6% on average pre-COVID to 6.7% during COVID (p < 0.001). This data shows the sickle retinopathy screening rate is low and innovative approaches may need to be employed to remedy this issue.

Proliferative Retinopathy Associated with Repeated High-Altitude Exposure in a Patient with Sickle Cell Trait

Broadhead Geoffrey K., Henry E. Wiley, David Peprah, Kenneth Olumba, and Alisa T. Thavikulwat. Proliferative retinopathy associated with repeated high-altitude exposure in a patient with sickle cell trait. High Alt Med Biol. 23:369-371, 2022.-Sickle cell trait (SCT), a carrier state characterized by one normal copy of the beta-globin gene (producing hemoglobin A) and one abnormal variant (producing hemoglobin S), is typically asymptomatic and very low risk for manifestations of hemoglobinopathy, including development of retinopathy. Reported cases of proliferative retinopathy in patients with SCT have occurred in the context of concurrent ocular or systemic disease. We report a case of an otherwise healthy patient with SCT who developed proliferative retinopathy requiring surgical intervention in the setting of significant exposure to high altitude through increased work hours as a flight attendant in the month leading to her presentation. Significant high-altitude exposure may contribute to development of retinopathy in patients with sickle trait. Practitioners should consider the possibility of sickle cell retinopathy in patients with sickle trait in these circumstances.

Nonmydriatic Ultra-Widefield Fundus Photography in a Hematology Clinic Shows Utility for Screening of Sickle Cell Retinopathy

PURPOSE

To determine the feasibility and accuracy of nonmydriatic ultra-widefield (UWF) fundus photographs taken in a hematology clinic setting for screening of sickle cell retinopathy (SCR) DESIGN: Prospective cohort study.

METHODS

This single-site study took place at the Johns Hopkins Sickle Cell Center for Adults and the Wilmer Eye Institute. The study population was 90 eyes of 46 consecutive adults with sickle cell disease (SCD). Bilateral nonmydriatic fundus photos taken by clinic personnel during the participants' routine hematology appointment were graded by 2 masked retina specialists at the Wilmer Eye Institute for the presence of nonproliferative SCR (NPSR) and proliferative sickle retinopathy (PSR). A third retina specialist adjudicated in cases of grader disagreement. All participants underwent the standard dilated fundus examination (DFE) within 2 years of acquisition of UWF photographs. The main outcome measure was the sensitivity and specificity of nonmydriatic UWF images for the detection of NPSR and PSR RESULTS: PSR was noted in 19 of 90 eyes that underwent DFE and in 9 of 67 gradable UWF images. Interrater agreement between the 2 graders was moderate, with κ = 0.65 (range 0.43-0.87) for PSR. For gradable UWF photos, the sensitivity and specificity of detecting SCR using the nonmydriatic photos compared with the DFE were 85.2% and 62.5% for NPSR, respectively, and 69.2% and 100% for detection of PSR, respectively. One participant required ophthalmic therapy in both eyes for active sea-fan neovascularization.

CONCLUSIONS

UWF imaging shows utility in screening for SCR and may help identify patients with PSR who require a DFE and who may benefit from treatment.

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.

Polymorphisms in Inflammatory Genes Modulate Clinical Complications in Patients With Sickle Cell Disease

Sickle cell disease (SCD), the most common monogenic disease worldwide, is marked by a phenotypic variability that is, to date, only partially understood. Because inflammation plays a major role in SCD pathophysiology, we hypothesized that single nucleotide polymorphisms (SNP) in genes encoding functionally important inflammatory proteins might modulate the occurrence of SCD complications. We assessed the association between 20 SNPs in genes encoding Toll-like receptors (TLR), NK cell receptors (NKG), histocompatibility leukocyte antigens (HLA), major histocompatibility complex class I polypeptide-related sequence A (MICA) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), and the occurrence of six SCD clinical complications (stroke, acute chest syndrome (ACS), leg ulcers, cholelithiasis, osteonecrosis, or retinopathy). This study was performed in a cohort of 500 patients. We found that the TLR2 rs4696480 TA, TLR2 rs3804099 CC, and HLA-G, rs9380142 AA genotypes were more frequent in patients who had fewer complications. Also, in logistic regression, the HLA-G rs9380142 G allele increased the risk of cholelithiasis (AG vs. AA, OR 1.57, 95%CI 1.16-2.15; GG vs. AA, OR 2.47, 95%CI 1.34-4.64; P = 0.02). For SNPs located in the NKG2D loci, in logistic regression, the A allele in three SNPs was associated with a lower frequency of retinopathy, namely, rs2246809 (AA vs. GG: OR 0.22, 95%CI 0.09-0.50; AG vs. GG: OR 0.47, 95%CI 0.31-0.71; P = 0.004, for patients of same origin), rs2617160 (AT vs. TT: OR 0.67, 95%CI 0.48-0.92; AA vs. TT: OR 0.45, 95%CI 0.23-0.84; P = 0.04), and rs2617169 (AA vs. TT: OR 0.33, 95%CI 0.13-0.82; AT vs. TT: OR 0.58, 95%CI 0.36-0.91, P = 0.049, in patients of same SCD genotype). These results, by uncovering susceptibility to, or protection against SCD complications, might contribute to a better understanding of the inflammatory pathways involved in SCD manifestations and to pave the way for the discovery of biomarkers that predict disease severity, which would improve SCD management.

Quantitative optical coherence tomography angiography: A review

As a new optical coherence tomography (OCT) modality, OCT angiography (OCTA) provides a noninvasive method to detect microvascular distortions correlated with eye conditions. By providing unparalleled capability to differentiate individual plexus layers in the retina, OCTA has demonstrated its excellence in clinical management of diabetic retinopathy, glaucoma, sickle cell retinopathy, diabetic macular edema, and other eye diseases. Quantitative OCTA analysis of retinal and choroidal vasculatures is essential to standardize objective interpretations of clinical outcome. Quantitative features, including blood vessel tortuosity, blood vessel caliber, blood vessel density, vessel perimeter index, fovea avascular zone area, fovea avascular zone contour irregularity, vessel branching coefficient, vessel branching angle, branching width ratio, and choroidal vascular analysis have been established for objective OCTA assessment. Moreover, differential artery–vein analysis has been recently demonstrated to improve OCTA performance for objective detection and classification of eye diseases. In this review, technical rationales and clinical applications of these quantitative OCTA features are summarized, and future prospects for using these quantitative OCTA features for artificial intelligence classification of eye conditions are discussed.

Central Mini-tenotomy and Environmental Modifications to Correct "Macular Diplopia" due to Sickle Cell Retinopathy in a Resource-limited Setting

Epiretinal membrane causing binocular diplopia, also denoted "macular diplopia," is a well-established entity, which is often difficult to treat. Mini-tenotomy is a surgical procedure to treat diplopia due to small-angle deviations. In this case report, we describe the successful management of a patient with "macular diplopia" secondary to sickle cell retinopathy using a central mini-tenotomy of the left superior rectus muscle and environmental adaptations to diminish peripheral retinal fusion.

Sensitivity and Specificity of Ultrawide-Field Fundus Photography for the Staging of Sickle Cell Retinopathy in Real-Life Practice at Varying Expertise Level

Purpose: To evaluate the sensitivity and specificity of ultrawide-field fundus photography (UWF-FP) for the detection and classification of sickle cell retinopathy (SCR) by ophthalmologists with varying degrees of expertise in retinal disease. Methods: Patients presenting with sickle cell disease (SCD) in the Créteil University Eye Clinic, having undergone UWF-FP and ultrawide-field fluorescein angiography (UWF-FA) on the same day, were retrospectively included. Eyes with previous retinal photocoagulation were excluded. SCR was graded independently by UWF-FP and UWF-FA using Goldberg classification by two ophthalmologists with varying expertise levels. Results: Sixty-six eyes of 33 patients were included in the study. The sensitivity of UWF-FP for the detection of proliferative SCR was 100%, (95% confidence interval [CI95%] 76.8–100) for the retinal specialist and 100% (CI95% 71.5–100) for the ophthalmology resident. The specificity of UWF-FP for the detection of proliferative SCR was 100% (CI95% 92.7–100) for the retinal specialist and 98.1% (CI95% 89.7–100) for the ophthalmology resident. Conclusions: UWF-FP is a valuable exam for proliferative SCR screening, with excellent sensitivity and specificity and a good inter-grader agreement for ophthalmologists with various degree of skills, and is easy to use in a real-life setting.

Awareness of Ocular Manifestations, Complications, and Treatment of Sickle Cell Disease in the Eastern Province of Saudi Arabia: A Cross-Sectional Study

AIM:

This study aims to assess the level of awareness about the effect of sickle cell disease (SCD) on the eye and vision and factors influencing SCD awareness.

SUBJECTS AND METHODS:

The study design was cross-sectional and was carried out in 2018 among the general population in the Eastern province of Saudi Arabia. It was conducted using an online, validated questionnaire, after obtaining consent from the participants. The outcome variable was 557. The level of awareness was correlated to demographic information.

RESULTS:

The study population was 557 Saudi adults. 84 were male and 473 female. Their mean age was 22 ± 23 years. Majority of the participants (57.3%) were not aware that SCD could affect the eye and vision. There was no difference in the knowledge regarding ocular complications of SCD among different ages and sexes.

CONCLUSIONS:

The result of this study indicates the need for raising the knowledge regarding the disease, its ocular complications, screening methods, and management. Health educations campaigns would be an effective tool in increasing SCD awareness.

Supervised Machine Learning Based Multi-Task Artificial Intelligence Classification of Retinopathies

Artificial intelligence (AI) classification holds promise as a novel and affordable screening tool for clinical management of ocular diseases. Rural and underserved areas, which suffer from lack of access to experienced ophthalmologists may particularly benefit from this technology. Quantitative optical coherence tomography angiography (OCTA) imaging provides excellent capability to identify subtle vascular distortions, which are useful for classifying retinovascular diseases. However, application of AI for differentiation and classification of multiple eye diseases is not yet established. In this study, we demonstrate supervised machine learning based multi-task OCTA classification. We sought (1) to differentiate normal from diseased ocular conditions, (2) to differentiate different ocular disease conditions from each other, and (3) to stage the severity of each ocular condition. Quantitative OCTA features, including blood vessel tortuosity (BVT), blood vascular caliber (BVC), vessel perimeter index (VPI), blood vessel density (BVD), foveal avascular zone (FAZ) area (FAZ-A), and FAZ contour irregularity (FAZ-CI) were fully automatically extracted from the OCTA images. A stepwise backward elimination approach was employed to identify sensitive OCTA features and optimal-feature-combinations for the multi-task classification. For proof-of-concept demonstration, diabetic retinopathy (DR) and sickle cell retinopathy (SCR) were used to validate the supervised machine leaning classifier. The presented AI classification methodology is applicable and can be readily extended to other ocular diseases, holding promise to enable a mass-screening platform for clinical deployment and telemedicine.

Hemoglobin level and macular thinning in sickle cell disease

Purpose: To study the relationship between complete blood count (CBC) indices over time, particularly serum hemoglobin (Hb) levels, and severity of macular thinning on spectral domain optical coherence tomography (SD-OCT) in patients with sickle cell disease (SCD).

Methods: This is a single-center, retrospective analysis of 141 consecutive SCD patients over a 10-year period, of which 40 patients (79 eyes) had SD-OCT imaging of the macula and 29 (58 eyes, mean age 17.5 years) were eligible for the study. Investigators reviewed electronic medical records for documentation of retinopathy stage, disease genotype, CBC values, and SD-OCT imaging. SD-OCT parameters and CBC values were compared between different retinopathy stages and disease genotypes. Regression analyses were performed on SD-OCT parameters and CBC values.

Results: Of the 58 eligible eyes (34HbSS, 18HbSC, 4HbSβ +thal, 2HbS βthal), 18 had PSR (proliferative sickle retinopathy), 14 had NPSR (nonproliferative sickle retinopathy), and 26 had NSR (no sickle retinopathy). Hb values were higher in SC group compared to SS group. Macular thickness in the temporal inner (Δ=26±33 um, p=0.01) and outer (Δ=21±30 um, p=0.02) subfields was higher in SC compared to SS group. Patients with SD-OCT thinning below the 5th percentile in the temporal outer subfields had lower recorded Hb nadirs (6.0±0.9) compared to those with thickness within the top 95th percentile (9.1±2.3). Regression analysis showed temporal macular thickness to be positively correlated with Hb values in the SS group.

Conclusion: Macular thinning observed on SD-OCT in SCD patients with SS genotype may be related to the level of anemia in this population.

Knowledge, beliefs and practices regarding sickle cell eye disease of patients at the sickle cell unit, Jamaica

Introduction

Sickle cell disease can result in visually threatening eye disease (proliferative sickle cell retinopathy). This can be prevented with timely eye screening. It is important for patients to understand their role. Our research is to determine the knowledge, beliefs and practices (KBP) regarding eye disease of Sickle Cell patients and the impact of genotype, demographic and socio-economic status.

Methods

Cross-sectional study at the Sickle Cell Unit, Jamaica during May 2016. Consecutive non-pregnant adults (>18 years of age) attendees, who were not acutely unwell, were invited to participate. A 26-item single interviewer administered questionnaire was used to obtain socio-demographic data, highest level of education completed, employment status, sickle cell genotype, if known, frequency of clinic attendance and patients' knowledge, beliefs and practices. Ten of these were yes/no questions, whereas eight required that they choose correct answers from four choices.

Results

One hundred subjects were recruited, 72% had homozygous SS disease. Their ages ranged from 18-63 years (mean 34.1 years, SD11.3). Fifty six percent were female. Most (75%) had achieved at least secondary education. The majority (62%) were unemployed. The mean belief score was 3.6/6(60%) and the mean knowledge and practice scores were 3.3/7(47%) and 2.2/5(44%) respectively. Milder genotypes had higher knowledge scores vs the more severe genotypes (4.0 vs 3.2, P=0.013). Only 28% had regular eye examinations; less than 50% had seen an ophthalmologist in the past year. Practice scores were higher in employed than in unemployed patients (2.6 vs 1.9, (P=0.04)). Employed patients were more likely than the unemployed to see their eye doctor for regular eye “examinations” (42.1% vs 19.4%, χ2=6.0, P=0.02). The practice and knowledge scores correlated (r²=0.363, P<0.001) and belief score (r²=0.304, P =0.002), except where 98% believed they should see an ophthalmologist annually, but only 42% did, and 21% had never.

Conclusion

Knowledge scores were fair, however, the practice was not always in keeping with knowledge.

The use of bevacizumab in pediatric retinal and choroidal disease: A review

The use of intravitreal bevacizumab in pediatric retinal and uveitic disease has become more widespread over the past decade. This article serves to outline the rationale underlying the use of intravitreal bevacizumab, and which disease entities it should be appropriately thought of as a primary or solo therapy, as opposed to an adjuvant one. Also presented is the relevant literature regarding each of these retinopathies.

Elevated fetal haemoglobin levels are associated with decreased incidence of retinopathy in adults with sickle cell disease

Among the many vascular complications of sickle cell disease (SCD), retinopathy is the most prevalent and represents a leading cause of blindness. Hydroxycarbamide therapy ameliorates many symptoms of SCD, and high fetal haemoglobin (HbF) levels have been shown to protect against the development of retinopathy in children with HbSS. Its effect on adults with SCD, who are at a much higher risk of developing retinopathy, has not been studied. We aimed to investigate the effect of hydroxycarbamide use and HbF level on sickle cell retinopathy development in adults. We performed a retrospective cross-sectional study and collected demographics, comorbidities, and ocular and haematological data from 300 adult sickle cell subjects examined at the Henkind Eye Institute at Montefiore Medical Center during a 5-year period, from October 2012 to November 2017. The cohort was comprised mainly of Black and Hispanic subjects with all SCD genotypes, aged 18-71 years. Results show that in HbSS patients treated with hydroxycarbamide, those with retinopathy had significantly lower HbF levels compared to patients without retinopathy (P = 0·018). Our study identified the optimal HbF cut-off point for retinopathy protection to be 14·87%. Thus, a HbF level of 15% appears to be the threshold above which the odds for developing retinopathy in SS patients are reduced by 50%.

[Interests of the examination of the fundus in general practice: review of 438 cases]

L'examen du fond d’œil fait partie du bilan de nombreuses maladies générales en dehors de l'ophtalmologie. L'objectif de notre travail était d’étudier les aspects cliniques et épidémiologiques des patients adressés pour un fond d’œil afin de montrer l'intérêtde cet examen. Il s'est agi d'une étude rétrospective descriptive des examens du fond d’œil durant la période de janvier 2011 à décembre 2013 dans un cabinet d'ophtalmologie d'une polyclinique à Bobo Dioulasso. Au cours de la période étudiée, 5942 consultations ont été enregistrées, dont 438 pour fond d’œil soit 7,37%. Il y avait 225 hommes et 213 femmes soit un sex ratio de 1,056. La tranche d’âge 40-59 ans représentait 54%. La fréquence des principaux motifs de la demande était l'hypertension artérielle 43,15% (N=189), le diabète 39,04% (N=171), l'association HTA et diabète 10,27% (N=45), et la drépanocytose 7,53% (N=33). Le fond d’œil était anormal chez 175 patients soit 36,23%. La rétinopathie hypertensive était retrouvée dans 42,73% des cas, la rétinopathie diabétique 25,92%, et la rétinopathie drépanocytaire 7,53%. L'examen du fond d’œil en médecine de ville présente un intérêt majeur, et permet de retrouver des anomalies chez plus d'un tiers des patients.

Monomethylfumarate induces γ-globin expression and fetal hemoglobin production in cultured human retinal pigment epithelial (RPE) and erythroid cells, and in intact retina

PURPOSE

Sickle retinopathy (SR) is a major cause of vision loss in sickle cell disease (SCD). There are no strategies to prevent SR and treatments are extremely limited. The present study evaluated (1) the retinal pigment epithelial (RPE) cell as a hemoglobin producer and novel cellular target for fetal hemoglobin (HbF) induction, and (2) monomethylfumarate (MMF) as an HbF-inducing therapy and abrogator of oxidative stress and inflammation in SCD retina.

METHODS

Human globin gene expression was evaluated by RT-quantitative (q)PCR in the human RPE cell line ARPE-19 and in primary RPE cells isolated from Townes humanized SCD mice. γ-Globin promoter activity was monitored in KU812 stable dual luciferase reporter expressing cells treated with 0 to 1000 μM dimethylfumarate, MMF, or hydroxyurea (HU; positive control) by dual luciferase assay. Reverse transcriptase-qPCR, fluorescence-activated cell sorting (FACS), immunofluorescence, and Western blot techniques were used to evaluate γ-globin expression and HbF production in primary human erythroid progenitors, ARPE-19, and normal hemoglobin producing (HbAA) and homozygous β(s) mutation (HbSS) RPE that were treated similarly, and in MMF-injected (1000 μM) HbAA and HbSS retinas. Dihydroethidium labeling and nuclear factor (erythroid-derived 2)-like 2 (Nrf2), IL-1β, and VEGF expression were also analyzed.

RESULTS

Retinal pigment epithelial cells express globin genes and synthesize adult and fetal hemoglobin MMF stimulated γ-globin expression and HbF production in cultured RPE and erythroid cells, and in HbSS mouse retina where it also reduced oxidative stress and inflammation.

CONCLUSIONS

The production of hemoglobin by RPE suggests the potential involvement of this cell type in the etiology of SR. Monomethylfumarate influences multiple parameters consistent with improved retinal health in SCD and may therefore be of therapeutic potential in SR treatment.