What is Peripapillary Atrophy?
Peripapillary atrophy is an area of thinned, degenerated tissue around the optic nerve. The optic nerve is the structure in the back of the eye that connects the eye to the brain. Peripapillary atrophy means that the area of tissue around the optic nerve that is normally pink and healthy, becomes yellow or black. This causes an abnormal appearance of the optic nerve and changes the color of the tissue surrounding the optic nerve. Peripapillary atrophy may either be white, yellow, or black in color, depending on the type.
There are different types of peripapillary atrophy, including choroidal crescent, RPE crescent, and scleral crescent. It is more likely to happen in eyes with a high nearsighted prescription (such as -7.00). However, an increase in the size of the peripapillary atrophy over time can be a sign of glaucoma. When the eye doctor sees peripapillary atrophy around your optic nerve, they will examine your eyes carefully for glaucoma.
- Peripapillary atrophy is an area of thinned or degenerated tissue around the optic nerve, which connects the eye to the brain.
- Peripapillary atrophy may be associated with glaucoma or a high nearsighted prescription.
- Peripapillary atrophy is assessed during a dilated eye exam.
Understanding Peripapillary Atrophy
In medical terminology, peri translates to ‘surrounding’ and papillary translates to ‘optic nerve’. The literal translation of peripapillary is ‘surrounding the optic nerve’. Peripapillary atrophy is present when the tissue around the optic nerve is thin, stretched out, or degenerated. When there is peripapillary atrophy, the color of the tissue will change. The tissue is no longer pink and healthy like it normally should be. Instead, peripapillary atrophy looks white, yellow, or black.
The optic nerve connects the eye to the brain, and relays visual information. Peripapillary atrophy around the optic nerve describes thinning of the layers of the retina, around the borders of the optic nerve. Typically, peripapillary atrophy is benign.
When there is a large area of peripapillary atrophy, or if the area is getting larger over time, it may be a sign of glaucoma. Eyes with glaucoma often have larger areas of peripapillary atrophy, and they increase in size over time. Glaucoma is an eye disease that leads to progressive damage to the optic nerve and causes peripheral vision loss. It is important to get an annual dilated eye exam to detect the presence of peripapillary atrophy and assess the risk of glaucoma.
Peripapillary Atrophy in Myopic Eyes: Beta and Gamma
Peripapillary atrophy may be divided into an ‘alpha zone’ and a ‘beta zone.’ The beta zone refers to the inner zone, closest to inside of the optic nerve. The beta zone of peripapillary atrophy is present in 15% to 20% of normal eyes, so it might not always be concerning. However, the beta zone is larger and more common in glaucoma. A beta zone of peripapillary atrophy is associated with vision loss, bleeding on the optic nerve, and thinning of the optic nerve — signs that indicate that glaucoma is damaging the optic nerve.
Eyes with a high amount of nearsightedness (such as -7.00) also have a larger ‘beta zone’ of peripapillary atrophy. High nearsightedness is defined as a glasses prescription of -6.00 D or greater. High nearsightedness can make it more difficult to diagnose glaucoma because both conditions cause similar changes to the optic nerve appearance. The best way to determine if eyes with nearsightedness have glaucoma is to test the peripheral vision using a visual field.
The ‘alpha zone’ of peripapillary atrophy is the outer zone, further away from the optic nerve, and typically does not indicate any eye diseases. An eye doctor can help classify whether the peripapillary atrophy is alpha zone or beta zone by doing a dilated eye exam and looking at the optic nerve.
Peripapillary Atrophy Grading
Alpha and beta zone
One way that doctors grade peripapillary atrophy is by identifying the ‘alpha zone’ and the ‘beta zone’. The risk of glaucoma can be assessed by taking photos of the optic nerve and seeing if the peripapillary zone has changed over time. If there is change, the photos may show an enlargement of the beta zone of peripapillary atrophy. Photos are a valuable tool in assessing the risk of glaucoma over time, as glaucoma happens over the course of many years.
Area of peripapillary atrophy
The location of peripapillary atrophy is noted in your chart record. It may be on the top, bottom, left, or right of the optic nerve. The temporal side of the optic nerve is most likely to have peripapillary atrophy in normal eyes and nearsighted eyes. If there is peripapillary atrophy on the top or bottom of the optic nerve, it is more concerning for glaucoma.
Extent of peripapillary atrophy
The size of the peripapillary atrophy can be measured using the size of the optic nerve. For example, an eye doctor may note that the region of peripapillary atrophy is half the size of the optic nerve.
Scleral crescent (Elschnig’s ring)
Elschnig’s scleral ring is a white colored area of peripapillary atrophy. It occurs in the alpha zone and it is seen in normal, non-diseased eyes.
RPE (retinal pigment epithelial) crescent is a black colored, crescent-shaped area of peripapillary atrophy. It occurs in the alpha zone and it is seen in normal, non-diseased eyes.
Choroidal crescent is a yellow colored, crescent-shaped area of peripapillary atrophy. It occurs in the beta zone and is more common in eyes with glaucoma and high nearsightedness.