Thus, it may be necessary to diagnose AON after a period of observation, noting the problem is not behaving as expected for demyelinative disease. Pathogenesis
Approximately 1-2% of patients with defined SLE develop an optic neuropathy during the course of their disease. SLE-associated optic neuritis is rarely the presenting sign of the disease. The molecular pathogenesis is hypothesized, based on clinical features and the emerging understanding of mechanisms in SLE. Inflammation resulting from auto-antibodies, immune complexes, T-cells and complement, probably damages the components of the optic nerve, as well as the blood vessels (vasculitis). The resulting vasculitis causes a loss of blood supply to the nerve (ischemia). This combination of inflammation and ischemia may produce reversible changes such as demyelination alone, or more permanent damage axonal (necrosis), or a combination. The poor recovery of vision in AON despite anti-inflammatory treatment suggests that ischemia from the underlying vasculitis is an important component, but the details have not been established. It may be reasonable to consider that AON pathogenesis represents an incomplete expression of the SLE-associated optic neuropathy disease process. Diagnosis
Treatment
AON is a rare disease and the natural history of the disease process is not well defined. Unlike typical optic neuritis, there is no association with multiple sclerosis, but the visual prognosis for AON is worse than typical optic neuritis. Thus AON patients have different treatment, and often receive chronic immunosuppression. No formal recommendation can be made regarding the best therapeutic approach.
In anatomy, a persistent left superior vena cava is the most common variation of the thoracic venous system. It is present in between 0.3% and 0.5% of the population, and is an embryologic remnant that results from a failure to involute. Presentation
In persistent left superior vena cava, the left brachiocephalic vein does not develop fully and the left upper limb and head and neck drain into the right atrium via the coronary sinus.In isolation, the variation is considered benign, but is very frequently associated with cardiac abnormalities (e.g. ventricular septal defect, atrioventricular septal defect) that have a significant mortality and morbidity. It is more frequent in patients with congenital heart defects.The (right) superior vena cava is almost always unaffected by the presence of persistent left superior vena cava. Diagnosis
If an anomaly is detected during a routine ultrasound, a fetal echocardiogram is performed to determine whether a fetus has the condition. Otherwise, it is often unnoticed unless an extenuating circumstance warrants further examination of the heart, usually much later in life.CT and MRI scans in a parasagittal section may show a "pipe" sign where the left superior vena cava occurs. Treatment
If no other cardiac abnormalities are present, persistent left superior vena cava will not be treated, as it is usually asymptomatic and unharmful. If it drains into the left atrium, then deoxygenated blood enters the circulation to the body, and cyanosis may occur. References


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