VEGFA and dopa-responsive dystonia due to sepiapterin reductase deficiency: Patients with SRD are mainly affected by persistently high levels of retinal inflammatory factors and hypoxia-ischemia, which involve RPE function and restrict fluid transfer, causing fluid to accumulate in the outer layers of the retina and having a greater impact on the EZ and the ELM.[24] It is believed that the pathological mechanism of SRD patients is not only an increase in VEGF levels but also abnormal RPE function.