Assertion: diabetic retinopathy's stage | /r/HasAspect | symptom
Facets:
value: often
type: TEMPORAL
Source sentences:
text: The first stage, called non-proliferative diabetic retinopathy (NPDR), has no symptoms.
text: The first stage of diabetic retinopathy, known as non- proliferative retinopathy or background retinopathy, often has no noticeable signs or symptoms, although retinal swelling may be present.