Sickle Cell Maculopathy: Microstructural Analysis Using OCTA and Identification of Genetic, Systemic, and Biological Risk Factors.

PURPOSE: To identify genetic, systemic, and biological factors associated with the occurrence of sickle cell maculopathy (SCM). To evaluate microvascular macular alterations using optical coherence tomography angiography (OCTA) in sickle cell disease (SCD). DESIGN: Cross-sectional study. METHODS: One hundred fifty-one eyes of 78 adult SCD patients (43 HbSS, 30 HbSC, 4 S/ß+, and 1 HbS Lepore) and 40 eyes of 20 healthy controls underwent spectral-domain optical coherence tomography (SDOCT) and OCTA using Spectralis HRA+OCT (Heidelberg Engineering, Heidelberg, Germany). We analyzed the occurrence of SCM, the foveal avascular zone (FAZ) area, and the severity of macular ischemia and studied their relationships with genetic, systemic, and biological parameters using multivariate logistic regression analysis. RESULTS: Maculopathy occurred in 66 eyes (44%), and more frequently in HbSS patients (71%, P = .004). Multivariate analysis identified HbSS genotype and lower prothrombin ratio (PR) as independently associated with SCM (P = .01). Proliferative sickle cell retinopathy was also associated with SCM (P = .02). FAZ enlargement was associated with higher lactate dehydrogenase level (P = .02). Macular ischemia was more severe in patients with lower hemoglobin level (P = .004) and lower PR (P = .01). No flow areas were identified with OCTA even in eyes with no macular thinning (36 eyes, 42%) and appeared more frequently in the temporal superior subfield (36%). CONCLUSIONS: HbSS genotype, abnormal coagulation and hemolysis increase the risk of SCM. OCTA provides valuable criteria to identify potential risk factors of SCM. OCTA also improves detection of early microvascular changes before the onset of macular thinning.

Proliferative retinopathy and maculopathy are two independent conditions in sickle cell disease: Is there a role of blood rheology?1.

OBJECTIVE: Our study investigated the prevalence of retinopathy and maculopathy in sickle cell patients and tested the association between these two conditions. In addition, we tested whether hematological and hemorheological parameters, as well as genotype, were involved in the development of these two conditions. METHODS: Seventy sickle cell adult patients were recruited: 37 with sickle cell anemia (SCA) and 33 with sickle cell hemoglobin C disease (SCC). All patients underwent retinal examination and macular ocular coherence tomography. Blood was sampled for the measurements of hematological and hemorheological parameters. RESULTS: Twenty-six patients had maculopathy and 30 had retinopathy with no significant difference between SCA and SCC patients. No association between the presence of retinopathy and maculopathy was detected. RBC aggregation was higher and RBC deformability lower at 3 Pa in SCA patients. Blood viscosity and hematocrit were higher in SCC than in SCA patients. However, no association was found between biological parameters and the ocular complications studied. CONCLUSIONS: Our study showed that retinopathy and maculopathy are common in sickle cell disease. Nevertheless, we found no association with hematological parameters, blood rheology or genotype.

Multifocal electroretinogram findings in sickle cell maculopathy.

BACKGROUND: The aim of the present work was to describe and compare multifocal electroretinogram findings (mfERG) between patients with sickle cell disease (SCD) without clinical sign of maculopathy and controls (HbAA). METHODS: Both HbSS (homozygous SCD) and HbSC (compound heterozygous SCD) patients, the two most frequent SCD genotypes, were included. All individuals underwent a full ophthalmologic examination (with a fundoscopy), a spectral domain ocular coherence tomography (SD-OCT) and a mfERG. RESULTS: A total of 86 subjects were included: 54 SCD patients (107 eyes) with 32 HbSS (63 eyes) and 22 HbSC (44 eyes) and 32 controls (64 eyes). None of the eyes showed retinal clinical abnormalities. SD-OCT analysis showed that macular thickness was statistically lower in SCD eyes than in controls. mfERG analysis demonstrated a significant reduction of N1 (initial-negative deflection), and P1 (positive peak) response amplitude densities of HbSS eyes compared to HbAA eyes from the centre (<2°) and to the periphery (>15°). Implicit time response was also reduced in the centre (<2°). N1 and P1 response amplitude densities of HbSC eyes were significantly lower than those of HbAA eyes from the centre (<2°) to the periphery (>15°). N1 implicit time was statistically reduced in HbSS compared to HbSC eyes. CONCLUSION: Our study is the first one to describe macular electrophysiological dysfunction in SCD patients. Moreover, we confirm that SCD maculopathy is equally frequent in HbSS and HbSC.