Interocular asymmetry of foveal avascular zone morphology and parafoveal capillary density in sickle cell retinopathy.
- 作者列表："Zhou DB","Scott AW","Linz MO","Han IC","Castanos MV","Lynch G","Andrade Romo JS","Linderman RE","Carroll J","Rosen RB","Chui TY
OBJECTIVES:To examine interocular asymmetry of foveal avascular zone (FAZ) and parafoveal capillary density metrics in sickle cell retinopathy (SCR) using optical coherence tomography angiography (OCT-A). METHODS:This cross-sectional, retrospective study evaluated SCR patients and unaffected controls who underwent 3x3mm macular OCT-A imaging using a spectral domain-OCT system. FAZ (area, perimeter, and acircularity index) and parafoveal capillary density metrics were computed for both eyes of each participant. In unaffected controls, interocular difference in FAZ and parafoveal capillary density metrics were evaluated using Bland-Altman plots. SCR patients with interocular difference outside the upper 97.5% and lower 2.5% limits of agreement from controls were defined as having interocular asymmetry. Area under receiver operating characteristic curve (AROC) was also performed to determine the ability of the absolute interocular difference to differentiate between subjects with SCR-including non-proliferative SCR (NP-SCR) and proliferative SCR (P-SCR)-and unaffected controls. RESULTS:Thirty-one patients with SCR (21 NP-SCR and 10 P-SCR) and 14 race-matched and age-matched controls were included for analysis. Interocular asymmetry was seen for all FAZ and parafoveal capillary density metrics in NP-SCR and P-SCR subjects. SCR subjects showed greater disease severity in the left-eye for FAZ and parafoveal capillary density metrics. CONCLUSIONS:NP-SCR and P-SCR patients demonstrated quantifiable interocular asymmetry in FAZ and parafoveal capillary density metrics compared to unaffected subjects, with left-eye predominance in disease severity.
目的: 使用光学相干断层扫描血管造影术 (oct-a) 检查镰状细胞视网膜病变 (SCR) 中黄斑中心静脉无血管区 (FAZ) 和视网膜旁毛细血管密度指标的眼间不对称性。 方法: 这项横断面、回顾性研究评估了使用谱域OCT系统进行3x3mm黄斑OCT-A成像的SCR患者和未受影响的对照者。计算每名参与者双眼的FAZ (面积、周长和无血管指数) 和旁毛细血管密度指标.在未受影响的对照中，使用Bland-Altman图评估FAZ和副毛细血管密度度量的眼间差异。将眼间差异超出对照一致上限97.5% 和下限2.5% 的SCR患者定义为具有眼间不对称性。还进行了受试者工作特征曲线下面积 (AROC) 以确定绝对眼间差异区分具有SCR (包括非增殖性SCR (np-scr) 和增殖性SCR (p-scr)) 的受试者与未受影响的对照的能力。 结果: 31例SCR患者 (21例np-scr和10例P-SCR) 和14例种族匹配和年龄匹配的对照被纳入分析。在np-scr和P-SCR受试者中，所有FAZ和副毛细血管密度指标均观察到眼间不对称。SCR受试者在FAZ和副毛细血管密度指标的左眼中显示出更大的疾病严重程度。 结论: 与未受影响的受试者相比，np-scr和p-scr患者在FAZ和副毛细血管密度指标中表现出可量化的眼间不对称，其中左眼在疾病严重程度上占优势。
METHODS:BACKGROUND:Thalassemia is one of the most common monogenetic diseases in the south of China and Southeast Asia. Hemoglobin Bart's hydrops fetalis syndrome was caused by a homozygous Southeast Asian deletion (-/-) in the HBA gene. Few studies have proved the potential of screen for Bart's hydrops fetalis using fetal cell-free DNA. However, the number of cases is still relatively small. Clinical trials of large samples would be needed. OBJECTIVE:In this study, we aimed to develop a noninvasive method of target-captured sequencing and genotyping by the Bayesian method using cell-free fetal DNA to identify the fetal genotype in pregnant women who are at risk of having hemoglobin Bart hydrops fetalis in a large-scale study. STUDY DESIGN:In total, 192,173 couples from 30 hospitals were enrolled in our study and 878 couples were recruited, among whom both the pregnant women and their husbands were detected to be carriers of Southeast Asian type (-/αα) of α-thalassemia. Prenatal diagnosis was performed by chorionic villus sampling, amniocentesis, or cordocentesis using gap-polymerase chain reaction considered as the golden standard. RESULTS:As a result, we found that the sensitivity and specificity of our noninvasive method were 98.81% and 94.72%, respectively, in the training set as well as 100% and 99.31%, respectively, in the testing set. Moreover, our method could identify all of 885 maternal samples with the Southeast Asian carrier and 36 trisomy samples with 100% of sensitivity in T13, T18, and T21 and 99.89% (1 of 917) and 99.88% (1 of 888) of specificity in T18 and T21, respectively. CONCLUSION:Our method opens the possibility of early screening for maternal genotyping of α-thalassemia, fetal aneuploidies in chromosomes 13/18/21, and hemoglobin Bart hydrops fetalis detection in 1 tube of maternal plasma.
METHODS:OBJECTIVES:Sickle cell disease (SCD) is a serious illness with disabling acute and chronic pain that needs better therapies, but insufficient patient participation in research is a major impediment to advancing SCD pain management. The purpose of this article is to discuss the challenges of conducting an SCD study and approaches to successfully overcoming those challenges. DESIGN:In a repeated-measures, longitudinal study designed to characterize SCD pain phenotypes, we recruited 311 adults of African ancestry. Adults with SCD completed 4 study visits 6 months apart, and age- and gender-matched healthy controls completed 1 visit. RESULTS:We recruited and completed measures on 186 patients with SCD and 125 healthy controls. We retained 151 patients with SCD with data at 4 time points over 18 months and 125 healthy controls (1 time point) but encountered many challenges in recruitment and study visit completion. Enrollment delays often arose from patients' difficulty in taking time from their complicated lives and frequent pain episodes. Once scheduled, participants with SCD cancelled 49% of visits often because of pain; controls canceled 30% of their scheduled visits. To facilitate recruitment and retention, we implemented a number of strategies that were invaluable in our success. CONCLUSION:Patients' struggles with illness, chronic pain, and their life situations resulted in many challenges to recruitment and completion of study visits. Important to overcoming challenges was gaining the trust of patients with SCD and a participant-centered approach. Early identification of potential problems allowed strategies to be instituted proactively, leading to success.
METHODS:OBJECTIVES:Sickle cell anemia is the commonest genetic disorder in India, and the frequency of the sickle cell gene is very high in the remote tribal areas where facilities are generally limited. Therefore, a rapid and affordable point-of-care test for sickle cell disease is needed. METHODS:The diagnostic accuracy of HemoTypeSC was evaluated against automated high-performance liquid chromatography (HPLC) as the gold standard for its efficacy in a newborn screening program. RESULTS:A total of 1,559 individuals (980 newborns and 579 adults) from four participating centers were analyzed by both methods. HemoTypeSC correctly identified 209 of 211 total hemoglobin (Hb) SS cases, for a 99.1%/99.9% total HbSS sensitivity/specificity. Overall, HemoTypeSC exhibited sensitivity and specificity of 98.1% and 99.1% for all possible phenotypes (HbAA, HbAS, and HbSS) detected. HPLC is relatively expensive and not available in most laboratories in remote tribal areas. CONCLUSIONS:We conclude that the rapid, point-of-care testing device HemoTypeSC test is suitable for population and newborn screening for the HbS phenotype.