We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What Is AV Nicking?

Mary McMahon
Updated: Feb 09, 2024

Arteriovenous (AV) nicking is a phenomenon seen in the eye, usually in association with hypertensive retinopathy. Patients with this condition experience retinal damage as a result of chronic high blood pressure. If it is not addressed, they could be at risk of vision loss and other serious complications, like cardiac problems caused by the sustained hypertension. An ophthalmological exam can show signs of AV nicking, also known as the Gunn sign, and pictures can be taken for the record or for evaluation by another health care professional.

In this clinical sign, at the point where one of the venules in the eye crosses an arteriole, the venule has a bulged, hourglass-like appearance. There are a number of theories to explain this phenomenon, including physical compression from the thickened walls of the artery and cellular changes that may occur with chronic high blood pressure. Whatever the cause, it can precede an occlusion, where the venule is partially blocked and cannot carry blood. This exposes the patient to the risk of serious complications.

Examination of the eye to identify AV nicking can be performed by introducing a bright light through the pupil to visualize the retina, and magnifying with the assistance of a lens. The eye may be dilated to make it easier to see as much of the retina as possible, and injectable dyes can be used to enhance contrast if the care provider thinks this may be helpful. Signs of AV nicking are usually very easy to spot, thanks to the distinctive bulges. Images can help care providers track changes in the eye over time, which may be important if they want to assess response to treatment.

When AV nicking develops, this indicates that ongoing damage is occurring and the patient needs to address the cause. High blood pressure is usually the culprit. Treatments can include diet and exercise modifications to determine if it is possible to lower blood pressure naturally. Medications are also available and may be recommended if the patient doesn’t respond to initial treatment. High blood pressure can increase the risk of not just retinopathy, but also glaucoma and damage to the optic nerve.

Patients with advanced hypertensive retinopathy typically have more signs in addition to the AV nicking. These can include cotton wool spots, areas of smeared vision across the eye, as well as blurred vision. Other clinical signs of high blood pressure may be present as well, like kidney damage and heart problems.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a WiseGeek researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Related Articles

Discussion Comments
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.