If you have diabetes, you probably already know that it can cause problems in many different parts of your body. The eye is no exception.

People with diabetes are at risk for a variety of eye diseases. The American Academy of Ophthalmology (AAO) groups diabetes-related eye problems under the umbrella term “diabetic eye disease.” Conditions that qualify as diabetic eye disease include:

• Glaucoma
• Diabetic retinopathy
• Diabetic macular edema
• Cataracts

This article will discuss each of these diabetic eye diseases. We will also talk about another, lesser-known eye problem that is linked to diabetes known as retinal vein occlusion.

1. Glaucoma

Glaucoma is the second most common cause of blindness among adults in the United States. This disease is the result of a multistep process that involves:

• Fluid buildup in the eye
• High eye pressure
• Optic nerve damage

The front of your eye is always making a fluid called aqueous humor, which provides nutrients to the eye and maintains the eyeball’s inflated shape. Old aqueous humor needs to drain out to make room for new fluid. When this fluid doesn’t drain out properly, it builds up and increases the pressure in your eye.

High eye pressure can kill the fibers that make up the optic nerve. This is the nerve in the back of the eye that is directly connected to the brain. When light falls on the retina (lining on the back wall of the eyeball), it sends signals via optic nerve to the part of the brain that’s responsible for eyesight.

Damaged fibers can’t communicate with the brain very well. This results in blind spots that you don’t even notice at first. Vision loss increases as more fibers of the nerve are damaged and may lead to complete blindness.

Once you develop vision problems from glaucoma, they’re permanent and irreversible. However, if it’s detected early, prompt treatments can prevent it from worsening and preserve what vision you have. If you have diabetes, frequent complete eye exams are very important to detect the glaucoma in early stages.

Diabetes and Glaucoma Risk

People with diabetes have a higher risk of developing this glaucoma. However, there are many different types of this eye disease. Diabetes increases the risk of these three types:

• Primary open-angle glaucoma — This is the most common type among people with diabetes. Large-scale research studies have found that primary open-angle glaucoma is specifically associated with type 2 diabetes.
• Steroid-induced glaucoma — This develops in people who take steroid eye drops or injections for other eye problems.
• Neovascular glaucoma — In this type of glaucoma, blood vessels grow abnormally, blocking the drainage of the aqueous humor. It develops in people who already have diabetic retinopathy.

Glaucoma Diagnosis

Glaucoma is asymptomatic in the early stages, so you won’t know initially that something is wrong. An eye doctor can detect it with a glaucoma eye exam, however. A regular eye exam that only tests eye pressure isn’t enough to find glaucoma. During the complete eye exam for glaucoma, your eye doctor will also:

• Check your eye drainage.
• Test your peripheral (side) vision.
• Take pictures of your optic nerve.

2. Diabetic Retinopathy

As noted, the retina is an area in the back of the eye made of specialized cells that capture light and turn it into signals. These signals help the brain to understand what we’re seeing.

“Retinopathy” means “disease of the retina.” In retinopathy, the tiny blood vessels that carry oxygen and nutrients to the retina are damaged.

How Diabetes Leads to Retinopathy

High blood glucose (sugar) levels can damage the retina’s blood vessels. Having high blood sugar levels regularly for a long time has detrimental effects all over your body. Glucose buildup in the blood vessels can cause them to leak, swell, or close off.

Types of Diabetic Retinopathy

There are two stages of diabetic retinopathy — nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR).

NPDR is early-stage retinopathy and is common in people with diabetes. In NPDR, leaky blood vessels caused by high blood sugar may eventually close off. People with NPDR may notice blurred vision, but mild symptoms don't always require treatment.

PDR is the late stage of diabetic retinopathy and is a serious condition. In this stage, the retina starts forming new, abnormal blood vessels. These new blood vessels can bleed into an area in the middle of the eye called the vitreous humor. People with PDR may notice floaters (shadowy specks moving in the eye) or complete vision block due to this bleeding. The abnormal blood vessels can also form scar tissue which may pull on the retina causing it to detach. If left untreated, this condition can eventually cause vision loss.

Treatment for Diabetic Retinopathy

There are several treatments for NPDR and PDR, including:

• Steroid injections (shots or implants) — These treatments help to reduce swelling.
• Anti-VEGF shots — VEGF stands for “vascular endothelial growth factor,” a protein that promotes the creation of new blood vessels. Anti-VEGF treatment works to stop new, abnormal blood vessels from forming.
• Laser treatments — Laser treatments can close leaky blood vessels, shrink blood vessels, and prevent new blood vessels from growing. Some people may require multiple rounds of laser treatment for their diabetic retinopathy.
• Eye surgery — To treat PDR, an ophthalmologist may perform an eye surgery called vitrectomy. Vitrectomy can remove scar tissue and blood from the vitreous humor and scar tissue from the retina.

3. Diabetic Macular Edema

Diabetic macular edema is a potential complication of diabetic retinopathy that affects a part of the eye called the macula. It’s the area located in the center of the retina that’s responsible for helping you see fine details in front of you (your central vision). Damage to the macula makes recognizing faces and reading difficult.

Fluid from leaky blood vessels caused by diabetic retinopathy can pour into the macula. “Edema” is the medical term for “swelling due to fluid buildup,” meaning that this condition causes swelling in the macula.

People with diabetes need regular eye exams to check for macular edema. Diabetic macular edema is the No. 1 cause of blindness among people with diabetic retinopathy. It’s important to work with your doctor and stick to a treatment plan to prevent vision loss and blindness.

4. Cataracts

A cataract is a clouded area in the lens of the eye. The lens is a clear and transparent area behind the colored part of your eye. It’s responsible for helping your eye to focus and see things. Cataracts usually develop slowly as people age (called age-related cataracts). However, people with diabetes can rapidly develop cataracts at younger ages.

High blood sugar levels can cause changes in the lens and create clouding. People with cataracts may notice blurred vision initially. Cataracts may also give bright colors a dull or yellow hue. When they affect the whole lens, they can lead to blindness.

Eyeglasses can treat vision problems caused by cataracts. However, if you feel the vision problems are interfering with your life, you can ask your eye doctor about cataract surgery. During cataract surgery, the cloudy lens is removed and an artificial lens is put in.

5. Retinal Vein Occlusion

According to the AAO, diabetes also puts you at a higher risk for retinal vein occlusion (RVO). This is when the veins that carry blood away from the retina become blocked off.

Symptoms of RVO include blurry vision and the inability to see out of one eye, either suddenly or over the course of a few days. It’s important to contact your eye doctor if you develop these symptoms — untreated RVO can lead to vision loss.

Follow Up With Your Eye Doctor

The AAO recommends people with type 1 diabetes have eye exams within five years of their diabetes symptoms first appearing. Anyone who is diagnosed with type 2 diabetes should schedule an eye appointment right away.

Your eye doctor can help you set up your follow-up exams after your initial visit depending on the health of your eye. During visits to the eye doctor, always tell them about any eye or vision changes, and make sure to go to any eye specialists that you’re referred to. Most eye problems due to diabetes can be treated if found early, which can prevent you from losing your vision.

Talk With Others Who Understand

On DiabetesTeam — the online social network for people with diabetes and their loved ones — more than 137,000 members come together to ask questions, give advice, and share their stories with others who understand life with diabetes.

Have you had diabetes-related eye problems? Have you been treated for any of the conditions mentioned in this article? Share your experience in the comments below.