Diabetic Retinopathy

Diabetic Retinopathy

Topic Overview

What is diabetic retinopathy?

Retinopathy is a
disease of the retina. The
retina is the nerve layer that lines the back of your
eye. It is the part of your eye that "takes pictures" and sends the images to
your brain. Many people with diabetes get retinopathy. This kind of retinopathy
is called
diabetic retinopathy (retinal disease caused by
diabetes).

Diabetic retinopathy can lead to poor vision and even
blindness. Most of the time, it gets worse over many years. At first, the blood
vessels in the eye get weak. This can lead to blood and other liquid leaking
into the retina from the blood vessels. This is called nonproliferative retinopathy. And this is the most common retinopathy. If the fluid leaks into the center of your eye, you may have blurry vision. Most people with nonproliferative retinopathy have no symptoms.

If blood sugar levels stay high, diabetic retinopathy
will keep getting worse. New blood vessels grow on the retina. This may sound
good, but these new blood vessels are weak. They can break open very easily,
even while you are sleeping. If they break open, blood can leak into the middle
part of your eye in front of the retina and change your vision. This bleeding
can also cause scar tissue to form, which can pull on the retina and cause the
retina to move away from the wall of the eye (retinal detachment). This is called proliferative retinopathy. Sometimes people don't have symptoms until it is too late to treat them. This is why having eye exams regularly is so important.

Retinopathy can also cause swelling of the
macula of the eye. This is called
macular edema. The
macula is the middle of the retina, which lets you see
details. When it swells, it can make your vision much worse. It can even cause
legal blindness.

What causes diabetic retinopathy?

If you are not able to keep your blood sugar
levels in a target range, it can cause damage to your blood vessels. Diabetic retinopathy
happens when high blood sugar damages the tiny blood vessels of the
retina.

When you have diabetic retinopathy, high blood pressure
can make it worse. High blood pressure can cause more damage to the weakened
vessels in your eye, leading to more leaking of fluid or blood and clouding more of your vision.

What are the symptoms?

Most of the time, there
are no symptoms of diabetic retinopathy until it starts to change your vision.
When this happens, diabetic retinopathy is already severe. Having your eyes
checked regularly can find diabetic retinopathy early enough to treat
it and help prevent vision loss.

If you notice problems with your
vision, call an eye doctor (ophthalmologist) right away. Changes in
vision can be a sign of severe damage to your eye. These changes can include
floaters, pain in the eye, blurry vision, or new vision loss.

How is diabetic retinopathy diagnosed?

An eye
exam by an eye specialist (ophthalmologist or optometrist) is the only way to
detect diabetic retinopathy. Having a dilated eye exam regularly can help find
retinopathy before it changes your vision. On your own,
you may not notice symptoms until the disease becomes severe.

Can diabetic retinopathy be prevented?

You can
lower your chance of damaging small blood vessels in the eye by keeping your
blood sugar levels and blood pressure levels within a target range. If you
smoke, quit. All of this reduces the risk of damage to the retina. It can also
help slow down how quickly your retinopathy gets worse and can prevent future
vision loss.

If you have a dilated eye exam regularly, you and
your doctor can find diabetic retinopathy before it has a chance to get worse.
For most people, this will mean an eye exam every year. Finding retinopathy early gives you a better chance of avoiding vision loss and
blindness.

How is it treated?

Surgery, laser treatment, or
medicine may help slow the vision loss caused by diabetic retinopathy. You may
need to be treated more than once as the disease gets worse.

Frequently Asked Questions

Learning about diabetic retinopathy:

Being diagnosed:

Getting treatment:

Ongoing concerns:

Living with diabetic retinopathy:

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Cause

Diabetes damages small blood vessels
throughout the body, leading to reduced blood flow. When these changes affect
the tiny blood vessels in the eyes,
diabetic retinopathy may occur.

In the
early stage of diabetic retinopathy, tiny blood vessels in the eye weaken and
develop small bulges that may burst and leak into the
retina. Later, new fragile blood vessels grow on the
surface of the retina. These blood vessels may break and bleed into the eye,
clouding vision and causing scar tissue to form.

The scar tissue
may pull on the retina, leading to
retinal detachment. Retinal detachment occurs when the
retina separates from the wall of
the eye. This can lead to vision loss.

Symptoms

You may have
diabetic retinopathy for a long time without noticing
any symptoms. Typically, retinopathy does not cause noticeable symptoms until
significant damage has occurred and complications have developed.

Symptoms of diabetic retinopathy and its complications may
include:

  • Blurred, double, or distorted vision or difficulty
    reading.
  • Floaters or spots in
    your vision.
  • Partial or total loss of vision or a shadow or veil
    across your field of vision.
  • Pain, pressure, or constant redness of the eye.

What Happens

Diabetic retinopathy begins as a mild disease. During the early stage of the
disease, the small blood vessels in the
retina become weaker and develop small bulges called
microaneurysms. These microaneurysms are the earliest signs of retinopathy and
may appear a few years after the onset of diabetes. They may also burst and
cause tiny blood spots (hemorrhages) on the retina. But they do not usually
cause symptoms or affect vision. This is called nonproliferative retinopathy. At this stage, treatment is not required.

As retinopathy progresses, fluid
and protein leak from the damaged blood vessels and cause the retina to swell.
This may cause mild to severe vision loss, depending on which parts of the
retina are affected. If the center of the retina (macula) is affected, vision loss can be severe.
Swelling and distortion of the macula (macular edema), which results from a
buildup of fluid, is the most common complication of retinopathy. Macular edema treatment usually works to stop and sometimes reverse your loss of vision.

In some people, retinopathy gets worse over the course of several years and progresses to proliferative retinopathy.
In these cases, reduced blood flow to the retina stimulates the growth
(proliferation) of fragile new blood vessels on the surface of the retina. As the new blood vessels
multiply, one or more complications may develop and damage the person's vision.
These complications can include:

  • The formation of scar tissue that pulls on the
    retina, which may lead to
    retinal detachment.
  • Bleeding inside the
    eye (preretinal or vitreous hemorrhage).
  • The growth of new blood
    vessels on the surface of the iris (rubeosis iridis), which eventually leads to a form of severe glaucoma called
    neovascular glaucoma.

Any of these later complications may cause severe,
permanent vision loss.

What Increases Your Risk

Your risk for diabetic retinopathy depends largely on two things:
how long you have had diabetes and whether or not you have kept good control of
your blood sugar.

You can control some risk factors, which are things that may
increase your risk for diabetic retinopathy and its complications. Risk factors
that you can control include:

  • Pregnancy. Women who
    have diabetes are at increased risk of developing retinopathy during pregnancy.
    In women who already have retinopathy when they become pregnant, the condition
    can become much worse during pregnancy. If you get pregnant, you will need to have an eye exam sometime during the first 3 months. You'll also need close follow-up during your pregnancy and for 1 year after you have your baby.footnote 1
  • Consistently high blood sugar. High blood sugar levels increase your risk of retinopathy. Keeping your blood
    sugar levels
    in a target range can reduce your risk for diabetic
    retinopathy and can slow the progression of the disease if it has already
    started.
  • High blood pressure. In general, people with diabetes who also have high blood
    pressure are more likely to develop complications that affect the blood vessels
    in the body, including those in the eyes.
  • Delayed diagnosis and treatment. Getting a dilated eye exam will not
    prevent retinopathy. But it may reduce your risk of severe vision loss from
    complications of retinopathy. By detecting it early, you can get treatment that can prevent vision loss and delay
    the progression of the disease.
  • Smoking. Although smoking
    has not been proved to increase the risk of retinopathy, smoking may make many
    of the other health problems faced by people with diabetes worse, including
    disease of the small blood vessels.

If you have type 2 diabetes and use the medicine
rosiglitazone (Avandia, Avandamet, Avandaryl) to treat your diabetes, you may
have a higher risk for problems with the center of the retina (the macula). The
U.S. Food and Drug Administration (FDA) and the makers of the drug have warned
that taking this medicine could cause swelling in the macula, which is called
macular edema.

When To Call a Doctor

Call your doctor immediately if you have
diabetes and notice:

  • Floaters in
    your field of vision. Floaters often appear as dark specks, globs, strings, or
    dots. A sudden shower of floaters may be a sign of a
    retinal detachment, which is a serious complication of
    diabetic retinopathy.
  • A new visual defect, shadow, or curtain across part of your
    vision. This is another sign of retinal detachment.
  • Eye pain or a
    feeling of pressure in your eye.
  • New or sudden vision loss. The
    sudden onset of partial or complete vision loss is a symptom of many disorders
    that can occur within or outside the eye, including retinal detachment or
    bleeding within the eye. Sudden vision loss is always a medical
    emergency.

Watchful waiting

Watchful waiting is not an option if you have
diabetes and notice changes in your vision.

If you have type 2 diabetes,
even if you do not have any symptoms of eye disease, you still need to have
your eyes and vision checked regularly by an eye specialist (ophthalmologist
or optometrist). If you wait until you have symptoms, it is more likely that
complications and severe damage to the
retina will have already developed. These may be harder to treat and may result in permanent vision loss.

If you have type 1 diabetes, are age 10 or older, and were diagnosed 5 or more years ago, you should have your eyes checked even if you don't have symptoms. If you wait until you have symptoms, it is more likely that complications and severe damage to the retina will have happened. These may be harder to treat. And the damage may be permanent.

Watchful waiting is not an option if you already
have diabetic retinopathy but do not have symptoms or vision loss. You will
need to return to your ophthalmologist for frequent evaluations (every few
months in some cases) so that your doctor can closely monitor changes in your
eyes. There is no cure for the disease. But treatment can slow its progression.
Your ophthalmologist can tell you how often you need to be evaluated.

Who to see

People who have diabetes need to see a doctor who
specializes in eye care for their eye evaluations.

If you have
diabetic retinopathy and need laser treatment or
surgery, you need to consult an ophthalmologist who specializes in treating the
retina and has special training in the care of eye
disease caused by diabetes.

To prepare for your appointment, see the topic Making the Most of Your Appointment.

Exams and Tests

Diabetic retinopathy can be detected during a dilated eye exam by an
ophthalmologist or
optometrist. An exam by your primary doctor, during
which your eyes are not dilated, is not an adequate substitute for a full exam
done by an ophthalmologist. Eye exams for people with
diabetes can include:

  • Visual acuity testing. Visual acuity testing measures the eye's ability to focus and
    to see details at near and far distances. It can help detect vision loss and
    other problems.
  • Ophthalmoscopy and slit lamp exam.
    These tests allow your doctor to see the back of the eye and other structures
    within the eye. They may be used to detect clouding of the lens (cataract), changes in the
    retina, and other problems.
  • Gonioscopy. Gonioscopy is used to find out whether the
    area where fluid drains out of your eye (called the
    drainage angle) is open or closed. This test is done
    if your doctor thinks you may have
    glaucoma, a group of eye diseases that can cause
    blindness by damaging the
    optic nerve.
  • Tonometry.
    This test measures the pressure inside the eye, which is called intraocular
    pressure (IOP). It is used to help detect glaucoma. Diabetes can increase your
    risk of glaucoma.

Your doctor may also do a test called
an optical coherence tomography (OCT) to check for fluid in your retina. Sometimes a fluorescein angiogram is done to check for and locate leaking
blood vessels in the retina, especially if you have symptoms, such as blurred
or distorted vision, that suggest damage to or swelling of the retina.

Fundus photography can track changes in the eye over time in people who
have diabetic retinopathy and especially in those who have been treated for it.
Fundus photography produces accurate pictures of the back of the eye (the
fundus). An eye doctor can compare photographs taken at different times to
watch the progression of the disease and find out how well
treatment is working. But the photos do not take the place of a full eye exam.

Early detection

Early detection and treatment of diabetic retinopathy can help prevent vision loss. For people in whom
diabetic retinopathy has not been diagnosed, the American Diabetes Association
recommends that screening be done based on the following guidelines:footnote 1

  • People with
    type 1 diabetes who are age 10 and older should have
    a dilated eye exam within 5 years after diabetes is diagnosed and then every
    year.
  • People with
    type 2 diabetes should have an exam as soon as
    diabetes is diagnosed and then every year.
  • If your eye exam results are normal, your doctor may consider
    follow-up exams less often. For example, you may have an exam every 2 years. But if you are diagnosed with retinopathy, you may need frequent eye exams.
  • Women who have type 1 or type 2 diabetes and who are planning to become pregnant should
    have an exam before becoming pregnant, if possible, and then once during the
    first 3 months (first trimester) of pregnancy. The eye doctor can decide
    whether you need further screening for retinopathy during pregnancy based on
    the results of the first-trimester exam.

Note: Pregnant women who develop
gestational diabetes are not at risk for diabetic
retinopathy and do not need to be screened for it. (But women who develop
gestational diabetes during pregnancy have a greater chance of developing type
2 diabetes later in life, which can put them at increased risk for retinopathy
and other eye problems.)

People who have diabetes are also at
increased risk for other eye diseases, including
glaucoma and
cataracts. Regular dilated eye exams can help detect these
diseases early and prevent or delay vision loss.

Treatment Overview

There is no cure for
diabetic retinopathy. But
laser treatment (photocoagulation) is usually very
effective at preventing vision loss if it is done before the
retina has been severely damaged. Surgical removal of
the
vitreous gel (vitrectomy) may also help improve vision
if the retina has not been severely damaged. Sometimes injections of an anti-VEGF (vascular endothelial growth factor) medicine or an anti-inflammatory medicine help to shrink new blood vessels in proliferative diabetic retinopathy. Because symptoms may not develop
until the disease becomes severe, early detection through regular screening is
important. The earlier retinopathy is detected, the easier it is to treat and
the more likely vision will be preserved.

You may need treatment for diabetic retinopathy if:

  • It has affected the center (macula) of the retina.
  • Abnormal new blood vessels have started to appear.
  • Your side
    (peripheral) vision has been severely damaged.

If the macula has been damaged by
macular edema, anti-VEGF medicine, such as Lucentis, may help. Steroids may be injected into the eye. Sometimes an implant, such as Iluvien, may be placed in the eye to release a small amount of corticosteroid over time. If the retina hasn't been severely damaged, laser treatment or vitrectomy may help with macular edema.

Surgical removal of
the vitreous gel (vitrectomy) is done when there is bleeding (vitreous
hemorrhage) or
retinal detachment, which are rare in people with
early-stage retinopathy. Vitrectomy is also done when severe scar tissue has
formed.

Treatment for diabetic retinopathy is often very effective
in preventing, delaying, or reducing vision loss. But it is not a cure for the
disease. People who have been treated for diabetic retinopathy need to be
monitored frequently by an eye doctor to check for new changes in their eyes.
Many people with diabetic retinopathy need to be treated more than once as the
condition gets worse.

Also, controlling your blood sugar levels is
always important. This is true even if you have been treated for diabetic
retinopathy and your eyes are better. In fact, good blood sugar control is
especially important in this case so that you can help keep your retinopathy
from getting worse.

Ideally, laser treatment should be done early
in the course of the disease to prevent serious vision loss rather than to try
to treat serious vision loss after it has already developed.

People with diabetes who have any signs of retinopathy need to be
examined as soon as possible by an
ophthalmologist.

Prevention

There are steps you can take to reduce your
chance of vision loss from
diabetic retinopathy and its complications:

  • Control your blood sugar levels. Keep blood sugar levels
    in a target range by eating a healthful diet, frequently
    monitoring your blood sugar levels, getting regular physical exercise, and
    taking
    insulin or medicines for
    type 2 diabetes if prescribed.
  • Control your blood pressure. Retinopathy is more
    likely to progress to the severe form and macular edema is more likely to occur in people who
    have high blood pressure. It is not clear whether treating high blood pressure
    can directly affect long-term vision. But in general, keeping blood pressure
    levels in a target range can reduce the risk of many different complications of
    diabetes. For more information about how to control
    your blood pressure, see the topic High Blood Pressure.
  • Have your eyes examined by an eye specialist (ophthalmologist or optometrist) every year. Screening for diabetic retinopathy and other eye problems will not
    prevent diabetic eye disease. But it can help you avoid vision loss by allowing
    for early detection and treatment.
  • See an ophthalmologist if you have changes in your vision. Changes in
    vision—such as
    floaters, pain or pressure in the eye, blurry or
    double vision, or new vision loss—may be symptoms of serious damage to your
    retina. In most cases, the sooner the problem can be
    treated, the more effective the treatment will be.

The risk for severe retinopathy and vision loss
may be even less if you:

  • Don't smoke. Although smoking has not been proved to increase the risk of
    retinopathy, smoking may aggravate many of the other health problems faced by
    people with diabetes, including disease of the small blood
    vessels.
  • Avoid hazardous activities. Certain
    physical activities, like weight lifting or some contact sports, may trigger
    bleeding in the eye through impact or increased pressure. Avoiding these
    activities when you have diabetic retinopathy can help reduce the risk of
    damage to your vision.
  • Get adequate exercise. Exercise helps keep blood sugar levels in a target range, which can
    reduce the risk of vision damage from diabetic retinopathy. Talk to your doctor about what kinds of exercise are safe for
    you.

Surgery

Surgical treatment for diabetic retinopathy is removal of the
vitreous gel (vitrectomy). Vitrectomy does not cure the disease. But it may improve vision in people who
have developed bleeding into the vitreous gel (vitreous hemorrhage),
retinal detachment, or severe scar tissue formation.

Unfortunately, by the time some people are diagnosed with
retinopathy (especially late-stage retinopathy), it is often too late for
vitrectomy to provide much benefit. Even with treatment,
vision may continue to decline.

Early detection of retinopathy
through dilated eye exams can help you decide to have surgery when it is most
effective.

What to think about

After a person has had most of the vitreous gel removed by vitrectomy,
surgery to remove scar tissue or to repair a new retinal detachment may be
needed.

Vitrectomy may require an overnight hospital stay. But it is sometimes done
as outpatient surgery. Your eye doctor will determine if the surgery can be done with
local or general anesthesia.

Other Treatment

Laser treatment
(photocoagulation) can be an effective treatment for
diabetic retinopathy. But it does not cure the
disease. It can prevent, delay, and sometimes reverse vision loss. Without
either laser treatment or surgery, vision loss caused by diabetic retinopathy
and its complications may get worse until blindness occurs. So early treatment
is vital to slowing vision loss, which can happen quickly.

When
diabetic retinopathy causes bleeding (hemorrhage) into the
vitreous gel, extensive scar tissue formation, or
retinal detachment, surgical removal of the vitreous
gel (vitrectomy) may be needed before laser treatment is considered.

Unfortunately, by the time some people are diagnosed with diabetic
retinopathy, it is often too late for treatment to provide much benefit. Even
with treatment, vision will continue to decline.

Early detection
of retinopathy through dilated eye exams can provide the opportunity to have
laser treatment when it is most effective.

Other treatment choices

Laser photocoagulation uses the heat
from a laser to seal or destroy abnormal, leaking blood vessels in the
retina. It can cause the abnormal, weak blood vessels to shrink.

Some anti-VEGF (vascular endothelial growth factor) medicines, such as aflibercept and ranibizumab, can help treat macular edema from diabetic retinopathy.

What to think about

Pan-retinal
laser treatment is used to treat several spots on the retina during one or,
most often, two sessions. It reduces the risk of serious bleeding and the
progression of severe proliferative retinopathy.

Laser photocoagulation can result in some loss of vision,
because it destroys some of the nerve cells in the retina and can cause the abnormal blood vessels to go away. With pan-retinal
photocoagulation, this most often affects the outside (peripheral) vision,
because the laser is directed at that area. Your vision may be worse right
after treatment. But vision loss caused by laser treatment is mild compared
with the vision loss that may be caused by untreated retinopathy.

Other Places To Get Help

Organizations

American Academy of Ophthalmology: EyeSmart (U.S.)
www.geteyesmart.org

American Diabetes Association (ADA)
www.diabetes.org

Library of Congress: National Library Service for the Blind and Physically Handicapped (U.S.)
www.loc.gov/nls/index.html

References

Citations

  1. American Diabetes Association (2018). Standards of medical care in diabetes—2018. Diabetes Care, 41(Suppl 1): S1–S159. http://care.diabetesjournals.org/content/41/Supplement_1. Accessed December 8, 2017.

Other Works Consulted

  • American Academy of Ophthalmology (2014). Diabetic retinopathy summary benchmark—2014 (Preferred Practice Pattern guidelines). http://one.aao.org/summary-benchmark-detail/diabetic-retinopathy-summary-benchmark--october-20. Accessed December 15, 2014.
  • American Diabetes Association (2018). Standards of medical care in diabetes—2018. Diabetes Care, 41(Suppl 1): S1–S159. http://care.diabetesjournals.org/content/41/Supplement_1. Accessed December 8, 2017.
  • American Optometric Association (2014). Evidence-based clinical practice guideline: Eye care of the patient with diabetes mellitus. http://www.aoa.org/optometrists/tools-and-resources/clinical-care-publications/clinical-practice-guidelines?sso=y. Accessed December 15, 2014.
  • Brownlee M, et al. (2011). Complications of diabetes mellitus. In S Melmed et al., eds., Williams Textbook of Endocrinology, 12th ed., pp. 1462–1551. Philadelphia: Saunders.
  • Fletcher EC, et al. (2011). Retina. In P Riordan-Eva, JP Whitcher, eds., Vaughan and Asbury's General Ophthalmology, 18th ed., pp. 190–221. New York: McGraw-Hill.
  • Mohamed QA, et al. (2011). Diabetic retinopathy (treatment), search date June 2010. BMJ Clinical Evidence. Available online: http://www.clinicalevidence.com.
  • Solomon SD, et al. (2017). Diabetic retinopathy: A position statement by the American Diabetes Association. Diabetes Care, 40(3): 412–418. DOI: 10.2337/dc16-2641. Accessed February 23, 2017.

Credits

ByHealthwise StaffPrimary Medical Reviewer Adam Husney, MD - Family Medicine Kathleen Romito, MD - Family Medicine Specialist Medical Reviewer Douglas Rett, OD, FAAO -

Current as ofFebruary 26, 2018