Grade 1: consists of a broadening of the arteriolar light reflex and concealment of the veins. The light reflex appears yellow - normal; it's enhancement can be misleading and should not be overemphasised.
Grade 2: grade 1 plus deflection of the veins at arteriovenous crossings.
Grade 3: grade 2 plus "copper wire" arterioles and marked arteriovenous crossing changes - banking of the vein where it appears distal to the crossing; tapering of the vein on either side of the crossing; and right-angled deflection of veins.
Grade 4: grade 3 changes plus "silver wire" arterioles and at times, occlusion of an arteriolar branch
Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page