OCT Angiography to Monitor Sickle Cell Retinopathy

Article: Mount Sinai Ophthalmologists Develop New Technique to Assess Progression of Sickle Cell Retinopathy
Source: New York Eye and Ear Infirmary of Mount Sinai, via EurekAlert  and EyeWire News
Published: May 11, 2021

Sickle cell patients on treatment (hydroxyurea)
showed fewer areas of retinal non-perfusion

Researchers developed a new technique using optical coherence tomography angiography (OCTA) to evaluate progression of sickle cell retinopathy before symptoms manifest as well as assess the efficacy of pharmacological treatment over time. OCT angiography is especially useful in monitoring of sickle cell disease, an inherited red blood cell disorder, in the sense that the visualization of blood flow can detect areas where the sickle-shaped cells clump together and cause local vascular damage, potentially leading to ischemia or hemorrhages. Their study involved 27 participants, 14 of whom were controls and 13 of whom had sickle cell disease with retinopathy of varying severity; some were on standard therapy (hydroxyurea) and others were not on treatment. The series of OCTA scans showed, unsurprisingly, that healthy participants had consistent blood flow with no or very minimal fluctuations. The untreated sickle cell patients, however, had substantially more intermittent vaso-occlusion (more flickering between scan images) than patients on treatment, indicating that treatment was effective. The investigators then used a computer algorithm to assess risk of retinal blood blockages based on flicker frequency and locations of flickering. The lead investigator explains, “We have added a new dimension to ocular imaging technology that no one has thought of before. For the first time, we have shown that by doing rapid, repeated retinal imaging of sickle cell patients, you can see microscopic changes in blood vessels and blood flow. The more the blood flow fluctuates across images, the more at risk patients are for a permanent blockage, which severely damage their eyesight.” The early detection of retinopathy in asymptomatic sickle cell patients could prevent irreversible vision loss when it's too late. Additionally, given a multitude of pharmacological treatments for sickle cell disease, monitoring the effectiveness of a particular drug regimen with OCTA can better inform the choice of drugs.

My rating of this study: ⭐⭐⭐

Zhou DB, Castanos MV, Pinhas A, et al. "Quantification of intermittent retinal capillary perfusion in sickle cell disease." Biomedical Optics Express.  12(5):2825-2840. 2021. https://doi.org/10.1364/BOE.418874