Proliferative Sickle Cell Retinopathy Research Articles

The molecular mechanism responsible for HbSC retinopathy may depend on the action of the angiogenesis-related genes ROBO1 and SLC38A5

HbSC disease, a less severe form of sickle cell disease, affects the retina more frequently and patients have higher rates of proliferative retinopathy that can progress to vision loss. This study aimed to identify differences in the expression of endothelial cell-derived molecules associated with the pathophysiology of proliferative sickle cell retinopathy (PSCR). RNAseq was used to compare the gene expression profile of circulating endothelial colony-forming cells from patients with SC hemoglobinopathy and proliferative retinopathy (n = 5), versus SC patients without retinopathy (n = 3). Real-time polymerase chain reaction (qRT-PCR) was used to validate the RNAseq results. A total of 134 differentially expressed genes (DEGs) were found. DEGs were mainly associated with vasodilatation, type I interferon signaling, innate immunity and angiogenesis. Among the DEGs identified, we highlight the most up-regulated genes ROBO1 (log2FoldChange = 4.32, FDR = 1.35E-11) and SLC38A5 (log2FoldChange = 3.36 FDR = 1.59E-07). ROBO1, an axon-guided receptor, promotes endothelial cell migration and contributes to the development of retinal angiogenesis and pathological ocular neovascularization. Endothelial SLC38A5, an amino acid (AA) transporter, regulates developmental and pathological retinal angiogenesis by controlling the uptake of AA nutrient, which may serve as metabolic fuel for the proliferation of endothelial cells (ECs) and consequent promotion of angiogenesis. Our data provide an important step towards elucidating the molecular pathophysiology of PSCR that may explain the differences in ocular manifestations between individuals with hemoglobinopathies and afford insights for new alternative strategies to inhibit pathological angiogenesis.

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.

Evaluation of peripheral blood inflammatory biomarkers in sickle cell disease with and without retinopathy.

The aim of this study was to evaluate the clinical significance of blood-cell associated inflammation markers in patients with sickle cell disease (SCD) and sickle cell retinopathy (SCR). Neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), monocyte to lymphocyte ratio (MLR), systemic immune inflammation index (SIII), systemic inflammation response index (SIRI), systemic inflammation modulation index (SIMI) and aggregate systemic inflammation index (AISI) were calculated. This study included 45 healthy controls (Group 1) and 100 SCD (Group 2). Patients in Group 2 were then divided into two groups: without SCR (Group 3) and with SCR (Group 4), and patients with SCR (Group 4) were further divided into two groups: non-proliferative sickle cell retinopathy (NPSCR) (Group 5) and proliferative sickle cell retinopathy (PSCR) (Group 6). The mean values for NLR, PLR, SIII, SIRI, AISI, and SIMI were significantly higher in Group 2 compared to Group 1 (p = 0.011 for NLR, p = 0.004 for SIII, and p < 0.001 for others). Furthermore, AISI and SIMI parameters demonstrated statistically significant discriminatory power to distinguish Group 5 from Group 6 (p = 0.0016 and p = 0.0006, respectively). Given the critical role of inflammatory mechanisms in the pathogenesis of SCD and its related complications, the assessment of blood-cell-associated inflammatory markers may present a pragmatic and advantageous approach to the clinical oversight and therapeutic intervention of SCD.

Evaluation of peripheral blood inflammatory biomarkers in sickle cell disease with and without retinopathy.

The aim of this study was to evaluate the clinical significance of blood-cell associated inflammation markers in patients with sickle cell disease (SCD) and sickle cell retinopathy (SCR). Neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), monocyte to lymphocyte ratio (MLR), systemic immune inflammation index (SIII), systemic inflammation response index (SIRI), systemic inflammation modulation index (SIMI) and aggregate systemic inflammation index (AISI) were calculated. This study included 45 healthy controls (Group 1) and 100 SCD (Group 2). Patients in Group 2 were then divided into two groups: without SCR (Group 3) and with SCR (Group 4), and patients with SCR (Group 4) were further divided into two groups: non-proliferative sickle cell retinopathy (NPSCR) (Group 5) and proliferative sickle cell retinopathy (PSCR) (Group 6). The mean values for NLR, PLR, SIII, SIRI, AISI, and SIMI were significantly higher in Group 2 compared to Group 1 (p = 0.011 for NLR, p = 0.004 for SIII, and p < 0.001 for others). Furthermore, AISI and SIMI parameters demonstrated statistically significant discriminatory power to distinguish Group 5 from Group 6 (p = 0.0016 and p = 0.0006, respectively). Given the critical role of inflammatory mechanisms in the pathogenesis of SCD and its related complications, the assessment of blood-cell-associated inflammatory markers may present a pragmatic and advantageous approach to the clinical oversight and therapeutic intervention of SCD.

SMARTQCSurgical Outcomes of Retinal Detachment Associated with Proliferative Sickle Cell Retinopathy

Purpose: To evaluate the long-term anatomic and visual outcomes in eyes with sickle cell retinopathy (SCR)-related retinal detachments (RDs). Methods: Patients who underwent surgery for SCR-related RDs at the Wilmer Eye Institute or Wills Eye Hospital between 2008 and 2020 and followed for at least 6 months post-operatively were retrospectively reviewed. The primary outcome was the rate of single surgery anatomic success (SSAS) and final reattachment. Results: This study included 30 eyes from 28 patients (16 female and 12 male) with tractional RD (TRD) (n=13), rhegmatogenous RD (RRD) (n=1), and combined TRD/RRD (n=16). Mean age was 42.1 ± 15.1 years. Mean follow-up duration was 47.8 ± 34.1 months. Twenty-five (83.3%) eyes underwent pars plana vitrectomy (PPV) and 5 (16.7%) eyes underwent PPV with scleral buckle (SB). SSAS was achieved in 21 (70.0%) eyes at 1 year. Final reattachment was achieved in 28 (93.3%) eyes (22 eyes [73.3%] without tamponade). Recurrence of RDs was significantly associated with male gender (P=0.041), absence of previous laser (P= 0.032), iatrogenic breaks (P=0.035), retinectomy (P=0.034), and SO tamponade (OR 7.857, P= 0.024). Overall, the logarithm of the minimum angle of resolution (logMAR) visual acuity improved from 1.53 ± 0.57 (Snellen equivalent, 20/678) to 1.15 ± 1.01 (20/283) at final visit (p = 0.03); however, eyes with recurrent RD did not achieve significant visual improvement. Conclusion: PPV to repair SCR-related RDs was effective in achieving anatomic success and improving vision in most eyes. SSAS is critical for optimizing visual outcomes.

Proliferative Sickle Cell Retinopathy: A Patient and a Physician's Perspective on Quality of Life and Quality of Eye Care.

The impact of visual impairment in the context of sickle cell disease is poorly understood. Despite the significant advancements over the past threedecades in retinal imaging and in the understanding of molecular mechanisms that drive retinal neovascularization, there has been little improvement in the management of proliferative sickle cell retinopathy. This article is co-authored by a patient impacted by proliferative sickle cell retinopathy. She highlights her personal experience of sight loss from proliferative sickle cell retinopathy and the impact on her daily life and mental health. Subsequent to diagnosis and management of proliferative sickle cell retinopathy, she continues to live with irreversible sight loss and provides crucial insight from a patient's perspective into the broad lack of high-quality educational materials online and lack of understanding of the disease within the clinical community. This article aims to provide a strong narrative to emphasize the need for further qualitative and quantitative research in this area, to bring about the holistic step-change required to improve visual outcomes and eyecare for people with sickle cell disease.

Sickle Eye Project: a cross-sectional, non-interventional study of the prevalence of visual impairment due to sickle cell retinopathy and maculopathy in the UK

IntroductionSickle cell disease (SCD) is one of the most common genetic disorders in the UK, with over 15 000 people affected. Proliferative sickle cell retinopathy (SCR) is a well-described complication...

Visual outcome of treating proliferative sickle cell retinopathy in 108 eyes.

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

Terminology for Retinal Findings in Sickle Cell Disease Research: A Scoping Review

To review the current sickle cell disease (SCD) literature to assess how "retinopathy" has been defined and to identify ocular outcomes that have been measured and described. A systematic scoping review of SCD literature was completed regarding ocular manifestations of SCD and vision outcomes across all medical specialties. Participants with SCD and control patients were included in our data extraction. We reviewed English-language literature from 2000 to 2021 for eligible studies by searching PubMed, Google Scholar, Embase, and the Cochrane library using terms to encompass SCD and ocular findings. Data collection included study information, patient characteristics, vision-related findings (inclusion criteria and/or study outcomes), and retinopathy characteristics (definition, when, how and by whom diagnosed). We identified 4006 unique citations and 111 were included in the analysis. Ophthalmologists were senior authors of about half (59/111; 53.2%) of the articles; most articles were published between 2016 and 2021 (71/111; 70.0%). The studies had been conducted primarily in North America (54/111; 48.6%) or Europe (23/111; 20.7%); designs were cross-sectional (51/111; 45.9%), prospective cohort (28/111; 25.2%), retrospective cohort (27/111; 24.3%), and case-control (4/111; 3.6%). Among studies reporting any retinopathy, it was commonly defined as a combination of nonproliferative sickle cell retinopathy and proliferative sickle cell retinopathy (PSR;52/87; 59.8%), infrequently as PSR only (6/87; 6.9%), or not defined at all (23/87; 26.4%). The Goldberg classification was used to grade retinopathy in almost half of the studies (41/87; 47.1%). Investigators reporting diagnostic methods used clinical fundus examination (56/111; 50.4%), OCT (24/111; 21.6%), fluorescein angiography (20/111; 18.0%), ultrawidefield fundus photographs (15/111; 13.5%), and OCT angiography (10/111; 9.0%), or did not report methods (28/111; 25.2%). There are inconsistencies in documentation of methods and outcomes in studies of SCD ophthalmic findings. Particularly concerning is the lack of documentation of ophthalmic examination methods, qualifications of examiners, and clarity and specificity of sickle cell retinopathy definitions. With the increase in SCD treatment research and novel systemic therapies available, it is important to adopt clear and consistent descriptions and rigorous data collection and reporting of ophthalmic outcomes in SCD studies. The authors have no proprietary or commercial interest in any materials discussed in this article.

Identifying Clinical Predictors of Proliferative Sickle Cell Retinopathy

Purpose To identify systemic and/or ophthalmologic predictors of proliferative sickle retinopathy. Methods Cross-sectional study comparing clinical, laboratory, and structural choriorretinal aspects between sickle cell disease patients with and without proliferative retinopathy. Patients underwent complete systemic and ophthalmologic evaluation. Enhanced depth spectral domain optical coherence tomography with choroidal binarization and optic coherence tomography angiography were performed and choriorretinal vascular components were compared. Results Forty-five eyes from 45 sickle cell patients were included. Ninety-one percent of patients were diagnosed with sickle cell retinopathy, 29% with proliferative retinopathy. Mean corpuscular volume, lactate dehydrogenase, and percentage of fetal hemoglobin were reduced in the subgroup of patients with proliferative retinopathy when compared with patients without proliferative retinopathy (p ≤ 0.001; p = 0.04; p ≤ 0.001, respectively). The best predictor of proliferative retinopathy was mean corpuscular volume (AUC = 0.842; p = 0.001), followed by the percentage of fetal hemoglobin (AUC = 0.763, p = 0.009) and lactate dehydrogenase (AUC curve = 0.706; p = 0.039). No differences were found between groups in the quantitative analysis of retinal vascularization using OCTA and choroidal vascularization using OCT (p ≥ 0.05). Conclusion Fetal hemoglobin and mean corpuscular volume may be good predictors of proliferative sickle retinopathy. The association between proliferative retinopathy and reduced levels of lactate dehydrogenase and mean corpuscular volume points to hypoxia and not hemolysis as a possible driving force in its pathophysiology.

Natural history and rate of progression of retinopathy in adult patients with sickle cell disease: an 11-year follow-up study.

Sickle cell retinopathy (SCR) is a complication of sickle cell disease (SCD). Proliferative SCR (PSCR) can lead to severe visual impairment due to vitreous hemorrhage or retinal detachment. Knowledge of risk factors for progression and complications of SCR is limited. The aim of this study is to describe the natural history of SCR and to identify risk factors for progressive SCR and development of PSCR. We retrospectively analyzed disease progression in 129 patients with SCD with a median follow-up period of 11 years (interquartile range, 8.5-12). Patients were divided in 2 groups. The genotypes hemoglobin SS (HbSS), HbSβ0-thalassemia, and HbSβ+-thalassemia were grouped together (n= 83; 64.3%), whereas patients with HbSC (n= 46; 35.7%) were grouped separately. Progression of SCR was observed in 28.7% (37 of 129) of patients. Older age (adjusted odds ratio [aOR], 1.073; 95% confidence interval [CI], 1.024-1.125; P= .003), HbSC genotype (aOR, 25.472; 95%CI, 3.788-171.285; P≤0.001), and lower HbF (aOR, 0.786; 95%CI, 0.623-0.993; P= .043) were associated with PSCR at end of follow-up. Lack of any SCR at end of follow-up was associated with female sex (aOR, 2.555; 95%CI, 1.101-5.931; P= .029), HbSS/HbSβ0/HbSβ+ genotype (aOR, 3.733; 95%CI, 1.131-12.321; P= .031), and higher HbF levels (aOR, 1.119; 95%CI, 1.007-1.243; P= .037). Differentiated strategies for screening and follow-up of SCR could be considered for patients at low or high risk.

Widefield oct-angiography-based classification of sickle cell retinopathy.

To assess the capillary non-perfusion in different concentric sectors on widefield optical coherence tomography angiography (WF-OCTA) and to correlate the ratio of non-perfusion (RNP) to the severity of sickle cell retinopathy (SCR). This retrospective, cross-sectional study included eyes of patients with various sickle cell disease (SCD) genotypes having undergone WF-OCTA and ultra-widefield color fundus photography (UWF-CFP). Eyes were grouped as no SCR, non-proliferative SCR or proliferative SCR. RNP was assessed on WF-OCTA montage in different field-of-view (FOV) sectors centered on the fovea: 0-10-degrees circle excluding the foveal avascular zone, the 10-30-degrees circle excluding the optic nerve, the 30-60-degrees circle, and the full 60-degrees circle. Forty-two eyes of twenty-eight patients were included. Within each SCR group, mean RNP of the FOV 30-60 sector was higher than all other sectors (p < 0.05). Mean RNP of all sectors were significatively different between no SCR group and proliferative SCR group (p < 0.05). To distinguish no SCR versus non-proliferative SCR FOV 30-60 had a good sensitivity and specificity of 41.67% and 93.33%, respectively (cutoff RNP > 22.72%, AUC = 0.75, 95% CI 0.56-0.94, p = 0.028). To differentiate non-proliferative versus proliferative SCR, FOV 0-10 had good sensitivity and specificity of 33.33% and 91.67%, respectively (cutoff RNP > 18.09, AUC = 0.73, 95% CI 0.53 to 0.93, p = 0.041). To discern no SCR versus proliferative SCR, all sectors had optimal sensitivity and specificity (p < 0.05). WF OCTA-based RNP provides non-invasive diagnostic information regarding the presence and severity of SCR, and correlates with disease stage in certain FOV sectors.

Comparative transcriptome analysis of endothelial progenitor cells of HbSS patients with and without proliferative retinopathy.

Among sickle cell anemia (SCA) complications, proliferative sickle cell retinopathy (PSCR) is one of the most important, being responsible for visual impairment in 10-20% of affected eyes. The aim of this study was to identify differentially expressed genes (DEGs) present in pathways that may be implicated in the pathophysiology of PSCR from the transcriptome profile analysis of endothelial progenitor cells. RNA-Seq was used to compare gene expression profile of circulating endothelial colony-forming cells (ECFCs) from HbSS patients with and without PSCR. Furthermore, functional enrichment analysis and protein-protein interaction (PPI) networks were performed to gain further insights into biological functions. The differential expression analysis identified 501 DEGs, when comparing the groups with and without PSCR. Furthermore, functional enrichment analysis showed associations of the DEGs in 200 biological processes. Among these, regulation of mitogen-activated protein (MAP) kinase activity, positive regulation of phosphatidylinositol 3-kinase (PI3K), and positive regulation of Signal Transducer and Activator of Transcription (STAT) receptor signaling pathway were observed. These pathways are associated with angiogenesis, cell migration, adhesion, differentiation, and proliferation, important processes involved in PSCR pathophysiology. Moreover, our results showed an over-expression of VEGFC (vascular endothelial growth factor-C) and FLT1 (Fms-Related Receptor Tyrosine Kinase 1) genes, when comparing HbSS patients with and without PSCR. These results may indicate a possible association between VEGFC and FLT1 receptor, which may activate signaling pathways such as PI3K/AKT and MAPK/ERK and contribute to the mechanisms implicated in neovascularization. Thus, our findings contain preliminary results that may guide future studies in the field, since the molecular mechanisms of PSCR are still poorly understood.

5596737 RETINOPATHY IN EGYPTIAN PATIENTS WITH SICKLE CELL DISEASE

Background: 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. Aim: To assess ocular manifestations and detect frequency of retinopathy in patients with SCD. Methods: 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. Results: 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. Conclusion: 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.

Technique and Outcomes of Vitreoretinal Surgery for Complications of Proliferative Sickle Cell Retinopathy

Technique and Outcomes of Vitreoretinal Surgery for Complications of Proliferative Sickle Cell Retinopathy

A review of outcomes of laser photocoagulation for Goldberg stage 3 proliferative sickle cell retinopathy

Topic: A review of outcomes of laser photocoagulation for Goldberg stage 3 proliferative sickle cell retinopathy (PSR) in a Eye Foundation Hospital. Aims and objectives: To report regression of retina neovascularization and visual outcomes after prophylactic scatter retina laser photocoagulation for Goldberg stage 3 PSR in a tertiary private hospital in sub-Saharan Africa. Methods: A retrospective review of case files of patients who were treated with prophylactic scatter retina laser photocoagulation between January 2017 and June 2022 following a diagnosis of PSR in a Eye Foundation Hospital, Ikeja, Lagos, Nigeria, was done. Results: A total of 124 eyes of 62 patients with PSR were seen within the period under consideration. A majority of patients (49 (79.0%)) had hemoglobin (Hb) genotype SC, while 13 patients (21%) were Hb genotype SS. At presentation, 29 eyes (23.3%) had Goldberg stage 2 PSR, 55 eyes (44.4%) had Goldberg stage 3 PSR, 27 eyes (21.8%) had stage 4 PSR, while 13 eyes (10.5%) had stage 5 PSR. All 55 eyes (49.2%) with stage 3 PSR were treated with prophylactic retina laser photocoagulation. At the patients’ last clinic visit, 34 eyes (61.8%) had the same visual acuity (VA) as at presentation, 11 eyes (20%) had improvements in VA, while 10 eyes (18.2%) had worse VA. Laser treatment success (regression of seafan neovascularization) was seen in 50 eyes (90.9%), while five eyes (8.1%) had unsuccessful laser treatment. Conclusion: A high percentage (90.9%) of resolution of retina neovascularization secondary to PSR at stage 3 of Goldberg’s classification was seen after prophylactic scatter retina laser photocoagulation in our group of evaluated patients. Most patients (81.8%) maintained or had improvements in their visual acuities over the period of follow-up. More clinical research is required to further evaluate outcomes of laser photocoagulation for PSR.

Natural History and Rate of Progression of Retinopathy in Patients with Sickle Cell Disease: An 11-Year Retrospective Follow-up Analysis

Background: Sickle cell disease (SCD) is characterized by chronic hemolysis and recurrent vaso-occlusion, resulting in tissue ischemia and organ damage. The retina is very sensitive to ischemic damage, which can result in sickle cell retinopathy (SCR). SCR can be divided into non-proliferative SCR (NPSCR) and proliferative SCR (PSCR). The proliferative form can be complicated by severe visual impairment due to vitreous haemorrhage and retinal detachment. With respect to retinopathy, different opinions exist about the necessity of regular screening. Knowledge of the natural history and risk factors for progression of SCR and subsequent complications is limited. Therefore, it would be helpful to determine the cumulative incidence of SCR in a large population of adult patients and to identify risk factors for progression and vision threatening complications. Aims: The aim of our study is to describe the natural history of SCR in a systematically analysed cohort of patients with SCD and to identify risk factors for the development of PSCR. Methods: In our retrospective cohort study, we recruited all patients with SCD (HbSS, HbSC, HbSβ0 and HbSβ+) attending the departments of Haematology and Ophthalmology of our tertiary academic hospital between 2006 and 2011. Patients lost to follow-up were excluded. Clinical, ophthalmologic and laboratory data were systematically collected and retrospectively analysed. Univariate and multivariate binary logistic regressions were used to identify associations between clinical and laboratory variables and progression to PSCR. Results: 129 SCD patients were included with a median follow-up of 11 years (IQR = 8.5-12). The median age at the end of follow-up was 34 years (IQR = 28-45). HbSS/HbSβ0/HbSβ+ genotype was present in 64.3% (83/129) of the patients and HbSC genotype was present in 35.7% (46/129). Progression of SCR during follow-up was seen in 28.7% (37/129) of the patients. Male sex was the only predictor for progression of SCR (aOR: 2.535, 95% CI: 1.152-5.579, p = 0.021). Age (aOR: 1.073, 95% CI: 1.024-1.125, p = 0.003) and HbSC genotype (aOR: 35.796, 95% CI: 7.444-172.125, p <0.001) were associated with PSCR at end of follow-up. Hb level and microalbuminuria were no independent risk factors for PSCR or progression to PSCR (p > 0.05). Lack of any SCR at end of follow-up was associated with female sex (aOR: 3.440, 95% CI: 1.523-7.774, p = 0.003) and HbSS/HbSβ0/HbSβ+ genotype (aOR: 6.419, 95% CI: 2.352-17.519, p = <0.001). Conclusion: Progression of SCR was seen in more than a quarter of the patients. Age and HbSC genotype were associated with progression to PSCR at end of follow-up. Female SCD patients and patients with HbSS/HbSβ0/HbSβ+ genotype were at significant lower risk of developing SCR than other patients. Given the high rate of progression of SCR, screening of SCR remains important, but differentiated strategies for screening and follow-up of SCR could be considered for low-risk or high-risk patients. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Risk factors associated with sickle cell retinopathy: findings from the Cooperative Study of Sickle Cell Disease

BackgroundSickle cell retinopathy (SCR) is one of the most important ocular manifestations of sickle cell disease (SCD). This study aims to assess the prevalence of SCR in SCD, identify risk factors for its development and progression to proliferative sickle cell retinopathy (PSCR), and evaluate the potential implications of these results on clinical practice.MethodsThis research is a secondary analysis of patients diagnosed with SCD from the epidemiological, multicenter Cooperative Study of Sickle Cell Disease (CSSCD). We included all patients who completed a full ophthalmic evaluation. We identified clinical and laboratory SCD characteristics associated with SCR using multivariate logistic regression models. Proliferative sickle cell retinopathy (PSCR) was diagnosed according to the Goldberg classification system.ResultsOf the 1904 study participants with SCD who met the inclusion criteria, 953 (50.1%) had retinopathy; of which 642 (67.3%) had bilateral disease. SCR was associated with older age (p < 0.001), history of smoking (p = 0.001), hematuria (p = 0.050), and a lower hemoglobin F (HbF) level (p < 0.001). PSCR risk increased with smoking (p = 0.005), older age (p < 0.001) higher hemoglobin level (p < 0.001) and higher white blood cell count (p = 0.011). Previous blood transfusion (p = 0.050), higher reticulocyte count (p = 0.019) and higher HbF level (p < 0.001) were protective factors against the development of PSCR. Ocular symptoms were associated with progression to PSCR in patients with SCR (p = 0.021).ConclusionIn this cohort of individuals with SCD, half of the participants had signs of SCR. Smoking and blood hemoglobin level were the two modifiable risk factors associated with increased retinopathy progression. Screening to identify the different stages of retinopathy, actively promoting smoking cessation, and optimizing the hematological profile of patients with SCD should guide treatment protocols designed to prevent the vision-threatening complications of the disease.

Analysis of Best Management of Proliferative Sickle Cell Retinopathy in An African PopulationA Retrospective Analytical Study

Introduction: Visual impairment in Proliferative Sickle Cell Retinopathy (PSCR) starts with neovascularisation. Treatment armamentaria including diathermy, retinopexy, Autoinfarction (AI), surgical procedures and Intravitreal Anti-Vascular Endothelial Growth Factors Injections Monotherapy (AEGFM) have been applied. Some outcomes led to blindness but data on how effective AEGFM is in treating PSCR is lacking in several publications. Aim: To assess outcome and complication profile of large series of patients who underwent AEGFM after being diagnosed with PSCR. Materials and Methods: This was a retrospective analytical study conducted from October 2020 on records of patients who underwent AEGFM and other treatment on account of PSCR at Department of Ophthalmology, 37 Military Hospital, Accra, Ghana. The records were reviewed retrospectively for visual outcomes and complications. Patients’ demographic data, indications of treatment, best corrected preoperative and postoperative visual acuities, complications of surgery and length of follow-up were collected and analysed using chi-square and paired t-tests. Results: A total of 80 eyes of 40 patients (36 males and 4 females) were identified. Mean age during AEGFM (72 eyes) and vitreoretinal surgery (8 eyes) was 31.7±9.3 years (range 26-56 years) with mean follow-up period of 6±1 years (range 5-7 years). A total of 70 (87.5%), 2 (2.5%) and 8 eyes (10%) had improvement, maintenance and worsening of final visual acuities, respectively. A total of 8 (16%) eyes developed postoperative complications from retinal surgeries with Proliferative Vitreoretinopathy (PVR) being the most common. Forty (50%) eyes with old retinal Laser Photocoagulation (LP) scars reported with fresh elevated Sea Fans (SF) and Vitreous Haemorrhage (VH). LP is therefore a major source of SF formation and VH in PSCR. Conclusion: AEGFM is better treatment than other available modalities in management of undetached PSCR.

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.