Non-proliferative sickle cell retinopathy (NPSCR)
Non-proliferative sickle cell retinopathy (NPSCR) can feature the following retinal manifestations:

Venous tortuousity is commonly observed in patients with homozygous HbSS sickle cell disease. Numerous diseases that feature blood hyperviscosity similar to sickle cell disease can manifest as retinal venous tortuousity. Tortuosity is caused by arteriovenous shunting from the retinal periphery. It can feature small bleeds of the retina known as intra-retinal hemorrhages, due to blockage of blood vessels by the sickled blood cells, thus triggering vessel wall necrosis. The resulting hemorrhages are initially bright red and oval shaped. As the hemorrhage ages over a period of days to weeks, the color then changes to a salmon hue known as a salmon patch. They are usually seen adjacent to the retinal arteriole. Bleeding in the deeper layers of the retina leads to the appearance of dark lesions known as black sunburst spots. These oval or round shaped pigmented spots are formed due to RPE proliferation. As the haemoglobin within the hemorrhage breaks down over time, yellow spots known as iridescent bodies are formed within the layers of the sensory retina. Maculopathy occurs in a significant portion of patients affected by sickle cell retinopathy. It is more prevalent in homozygous HbSS type sickle cell disease. The fovea can be found within the macula and is known as the center of the visual field. Maculopathy in sickle cell retinopathy is due to long term changes of capillaries that interact at the fovea.
Medical uses
In the United States, ravulizumab is indicated for the treatment of adults and children one month of age and older with paroxysmal nocturnal hemoglobinuria and for the treatment of adults and children one month of age and older with atypical hemolytic uremic syndrome (aHUS) to inhibit complement-mediated thrombotic microangiopathy (TMA).In the European Union, ravulizumab is indicated in the treatment of adults with paroxysmal nocturnal haemoglobinuria:

in people with haemolysis with clinical symptom(s) indicative of high disease activity
in people who are clinically stable after having been treated with eculizumab for at least the past six months. Names
Ravulizumab is the International Nonproprietary Name (INN). History
Ravulizumab was developed by Alexion Pharmaceuticals, Inc. It was engineered from eculizumab to have a longer-lasting effect.Ravulizumab was approved by the US Food and Drug Administration (FDA) in December 2018. In April 2019, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) recommended the granting of a conditional marketing authorization for ravulizumab. Ravulizumab was approved for medical use in the EU in July 2019. References
Further reading
Stern RM, Connell NT (2019). "Ravulizumab: a novel C5 inhibitor for the treatment of paroxysmal nocturnal hemoglobinuria". Ther Adv Hematol. 10: 2040620719874728. doi:10.1177/2040620719874728. PMC 6737867. PMID 31534662. External links
"Ravulizumab". Drug Information Portal. U.S. National Library of Medicine.