retinopathy signs and symptomshypertensive retinopathy symptomsmyopic astigmatism definitionearly signs of diabetic retinopathybackground retinopathy symptomsmyopic vision definitiondefine myopicautoimmune retinopathy symptomsretinopathy of prematurity symptomsthe meaning of myopicproliferative retinopathy symptomscentral serous retinopathy symptoms