Abstract
ObjectivesTo 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).MethodsThis 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.ResultsThirty-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.ConclusionsNP-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.
Highlights
Sickle cell disease is an autosomal recessive hemoglobinopathy that affects nearly 100,000 people in the US [1]
Interocular asymmetry was seen for all foveal avascular zone (FAZ) and parafoveal capillary density metrics in NP-sickle cell retinopathy (SCR) and proliferative SCR (P-SCR) subjects
Interocular asymmetry in sickle cell retinopathy was provided by the New York Eye and Ear Infirmary Foundation (RBR, TYC), the Marrus Family Foundation (RBR) , the Wise Family Foundation (RBR) , the Geraldine Violett Foundation (RBR), the Edward N. & Della L
Summary
Sickle cell disease is an autosomal recessive hemoglobinopathy that affects nearly 100,000 people in the US [1]. Disease pathophysiology involves misfolding of the beta subunit of hemoglobin, a protein responsible for intravascular oxygen transport. Modified beta-hemoglobin contains exposed hydrophobic regions that facilitate protein polymerization and subsequent erythrocyte deformation, under conditions of cellular stress and deoxygenation [2]. Resulting changes to erythrocyte structure and elasticity impact intercellular processes that mediate inflammation, oxidative injury, endothelial adhesion, and nitric oxide metabolism [3]. These mechanisms increase the risk of vaso-occlusive episodes at various circulatory pathways. This leads to high phenotypic variability in both organ involvement and disease burden [2]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
