What Are the Long-Term Complications of Diabetes?

People with diabetes mellitus may experience serious, long-term complications that develop gradually. The longer the duration of diabetes, which is poorly controlled, the higher the risk of these complications which begins within months of the onset of diabetes, although most tend to develop after a few years and gradually worsen.

Possible long-term complications of diabetes mellitus include damage to the eyes, foot ulcer, and nerve damage (neuropathy).

EYE DAMAGE (DIABETIC EYE DISEASES)

Diabetic eye disease is a group of eye problems that can affect people with diabetes. These conditions include diabetic retinopathy, diabetic macular edema (which usually develops along with diabetic retinopathy), cataracts, and glaucoma.

Damage to the eyes can lead to poor vision or even blindness. But early diagnosis and treatment can go a long way toward protecting one’s eyesight.

Diabetic Retinopathy

Diabetic retinopathy is caused when high blood sugar damages the blood vessels in the retina (a light-sensitive layer of cells in the back of the eyes). Damaged blood vessels can swell and leak, causing blurry vision or stopping blood flow. Sometimes, new blood vessels can grow abnormally and these can cause further vision problems, affecting both eyes.

Who is at Risk of Developing Diabetic Retinopathy?

Anyone with any kind of diabetes can get diabetic retinopathy - including people with type 1, type 2, and gestational diabetes (a type of diabetes that can develop during pregnancy). The risk increases the longer one has diabetes. Over time, more than half of people with diabetes will develop diabetic retinopathy, but the risk of developing diabetic retinopathy can be reduced by controlling one’s diabetes. Women with diabetes who become pregnant - or women who develop gestational diabetes - are at high risk for getting diabetic retinopathy.

What are the Symptoms of Diabetic Retinopathy?

A diabetic person can have diabetic retinopathy and not know it. This is because it often has no symptoms in its early stages. As diabetic retinopathy gets worse, one will notice symptoms such as:

• Seeing an increasing number of floaters in front of the visual field
• Having blurry vision
• Having a vision that changes sometimes from blurry to clear and back (fluctuation)
• Seeing blank or dark areas in your field of vision
• Having poor night vision
• Noticing colors appear faded or washed out
• Losing vision

How Is Diabetic Retinopathy Diagnosed and Treated?

Diagnosis

• Dilated Eye Examination: Eye doctors can check for diabetic retinopathy as part of a dilated eye exam. The exam is simple and painless - the doctor will give put some eye drops to dilate (widen) the pupil and then check the eyes for diabetic retinopathy and other eye problems.
• Fluorescein Angiography: After the eyes are dilated, a dye is injected into a vein in the arm. The pictures are taken as the dye circulates through the eye’s blood vessels. The images can pinpoint blood vessels that are closed, broken, or leaking.
• Optical Coherence Tomography (OCT): With this test, pictures provide cross-sectional images of the retina that show the thickness of the retina. This will help determine how much fluid, if any, has leaked into retinal tissue. Later, OCT exams can be used to monitor how the treatment is working.

For diabetic patients, it is very important to get regular eye exams. If one does develop diabetic retinopathy, early treatment can stop the damage and prevent blindness.

Treatment

In the early stages of diabetic retinopathy, eye doctors will probably just keep track of how the eyes are doing. Some people with diabetic retinopathy may need a comprehensive dilated eye exam as often as every 2 to 4 months.  In later stages, it is important to start treatment right away, especially if there are vision changes. Treatments such as:

• Injections: Medicines called anti-VEGF drugs can slow down or reverse diabetic retinopathy. Corticosteroids can also help.
• Laser Treatment:To reduce swelling in your retina, eye doctors can use lasers to make the blood vessels shrink and stop leaking. It is also called laser photocoagulation. It is done for patients who have growth of new blood vessels in the retina.
• Eye Surgery (Vitrectomy): If the retina is bleeding a lot or there are lots of scars in the eye, the doctor may recommend a type of surgery called a vitrectomy. This is the removal of vitreous gel and blood from leaking vessels in the back of the eye. This allows light rays to focus properly on the retina again. Scar tissue also might be removed from the retina.

How Can Diabetic Retinopathy Be Prevented?

Regular eye exams, good control of blood sugar and blood pressure, and early intervention for vision problems can help prevent severe vision loss. If one has diabetes, the risk of getting diabetic retinopathy can be reduced by doing the following:

• Managing Diabetes: Make healthy eating and physical activity part of one’s daily routine. Try to get at least 150 minutes of moderate aerobic activity, such as walking, each week. Take oral diabetes medications or insulin as directed.
• Monitor blood sugar level.One might need to check and record the blood sugar level several times a day - or more frequently.
• Do a Glycosylated Hemoglobin Test:The glycosylated hemoglobin test, or hemoglobin A1C test, reflects the average blood sugar level for the two- to three-month period before the test. For most people with diabetes, the A1C goal is to be under 6%.
• Keeping Blood Pressure and Cholesterol Under Control:Eating healthy foods, exercising regularly, and losing excess weight can help. Sometimes medication is needed, too.
• Quit Smoking.Smoking increases the risk of various diabetes complications, including diabetic retinopathy.
• Pay Attention to Vision Changes:Visit a doctor right away if one’s vision suddenly changes or becomes blurry, spotty, or hazy.

Diabetic Macular Oedema

The part of the retina that helps a person see is referred to as the macula. Diabetes can lead to swelling in the macula, which is called diabetic macular edema. Over time, this disease can destroy the sharp vision in this part of the eye, leading to partial vision loss or blindness. Macular edema usually develops in people who already have other signs of diabetic retinopathy.

Cataracts

A cataract is the clouding of the normally clear lens in the eye. Though everyone’s lenses tend to get cloudy as they get older, people with diabetes are more likely to have cataracts, and at a younger age. Most cataracts develop slowly and don't disturb your eyesight early on. But with time, cataracts will eventually interfere with your vision.

It is usually caused by high blood sugar deposits building up in the lenses and making them cloudy most especially in diabetic persons. Other risk factors include high blood pressure, obesity, too much sun exposure over time, previous eye injury or inflammation and surgery, and smoking.

Who is at Risk of Developing Cataracts?

Anyone is at risk of developing cataracts as one gets older. But at higher risk, if one is diabetic; smokes; drinks too much alcohol; is having a family history of cataracts; had an eye injury, has eye surgery; or spends a lot of time in the sun.

Any Symptoms of Cataracts?

One might not have any symptoms at first when cataracts are mild. At first, the cloudiness in one’s vision caused by a cataract may affect only a small part of the eye's lens and one may be unaware of any vision loss. As the cataract grows larger, it clouds more of your lens and distorts the light passing through the lens.

This may lead to more-noticeable symptoms. One can also notice that:

• Clouded, blurred, or dim vision
• Increasing difficulty with vision at night
• Sensitivity to light and glare
• Need for brighter light for reading and other activities
• Seeing "halos" around lights
• Frequent changes in eyeglass or contact lens prescription
• Fading or yellowing of colors
• Double vision in a single eye

How Are Cataracts Diagnosed and Treated?

To determine whether a patient has cataracts or not, a doctor may need to review the patient’s medical history and symptoms and perform an eye examination. There may be a need to conduct several tests, including:

• Visual Acuity Test:This is the use of an eye chart to measure how well a person can read a series of letters. The eyes are tested one at a time, while the other eye is covered. Using a chart or a viewing device with progressively smaller letters, an eye doctor can determine if the person has 20/20 vision or showing signs of impairment.
• Slit-Lamp Examination:A slit lamp helps to see the structures at the front of the eye under magnification. The microscope is called a slit lamp because it uses an intense line of light, a slit, to illuminate the cornea, iris, lens, and the space between the iris and cornea. The slit allows the doctor to view these structures in small sections, which makes it easier to detect any tiny abnormalities.
• Retinal Exam:To prepare for a retinal exam, an eye doctor puts eye drops into the eyes to open the pupils wide (dilate). This makes it easier to examine the back of the eyes (retina). Using a slit lamp or a special device called an ophthalmoscope, the eye doctor can examine the lens for signs of a cataract.
• Applanation Tonometry:This test measures the fluid pressure in the eye.

Treatment

Surgery is the only way to get rid of a cataract, but you may not need surgery immediately until the cataracts are mature. After surgery (when the lens is removed), special eyeglasses are used. Modern surgery can put corrective lenses after removing the opaque lens in the eyes.

How Can Cataracts Be Prevented?

Certain conditions can be helpful in the prevention of cataracts, they include:

• Regular Eye Examination – This can help to detect cataracts and other eye diseases early
• Managing Health Issues – For patients with diabetes or other medical conditions, following their treatment plan can help reduce the risk of cataracts
• Choosing a healthy diet that includes fruits and vegetables can help increase the vitamins and nutrients in the body. Fruits and vegetables have many antioxidants that help maintain the eyes’ health.
• Quit smoking
• Reduce alcohol intake because excessive alcohol can increase the risk of cataracts
• Wearing sunglasses to prevent excessive ultraviolet light from the sun

Glaucoma

Glaucoma is a group of eye diseases that causes blindness and vision loss by damaging a nerve in the back of the eye called the optic nerve. This damage caused is often related to high pressure in the eye, but glaucoma can happen even with normal eye pressure.

Glaucoma can happen to any person within any age group, but common among adults. It is one of the leading causes of blindness among people over the age of 60. This eye disease in most cases usually has no early symptoms but its effect is so gradual that one may not notice any change in vision until the condition is in its later stages.

Glaucoma in Children

A child may be born with glaucoma or develop it in the first few years of life. Blocked drainage, injury, or an underlying medical condition may cause optic nerve damage.

Who is at Risk of Developing Glaucoma?

Anyone can get glaucoma, but some people are at higher risk if they: 

• Are above the age of 60 years
• Are Black and over age 40 years
• Have a family history of glaucoma
• Have high internal eye pressure, also known as intraocular pressure
• Have extreme nearsightedness or farsightedness (myopia or hypermetropia)
• Have had an eye injury or certain types of eye surgery

What are the Symptoms of Glaucoma?

At first, glaucoma doesn’t usually have any symptoms. This is most people with glaucoma do not know they have an eye disease. Over time, the person may slowly lose his/her vision, starting with patchy blind spots in one side vision (peripheral vision) that is closest to the nose. Then at later stages, difficulty seeing things in the central vision begins to occur. To diagnose it early, routine eye examinations like intraocular pressure should occur yearly after 40 years.

Other symptoms include severe headache, severe eye pain, blurred vision, nausea or vomiting, eye redness, and halos or colored rings around lights.

How Is Glaucoma Diagnosed and Treated?

A comprehensive eye examination is needed to diagnose the presence of glaucoma using tonometry to measure raised intraocular pressure found during the eye examination. Also, several other tests may be performed including:

• A dilated eye examination to test for optic nerve damage
• Imaging tests
• Visual field test to check for areas of vision loss
• A gonioscopy test used to inspect the drainage angle
• Using pachymetry examination to measure the corneal thickness

Treatment

Early treatment and regular checkups can help slow or prevent vision loss, especially if the disease is diagnosed in its early stages. Such early treatment includes eye drops, oral medications, and surgery. Surgery is required in the late stages to reverse intraocular pressure.

How can Glaucoma be Prevented?

Glaucoma diagnosis and early management can help to prevent vision loss or slow its progress. The steps used include:

• Regular comprehensive eye exams to help detect glaucoma in its early stages, before significant damage occurs. It is recommended that a comprehensive eye exam be every 5 to 10 years if one is under 40 years old; every 2 to 4 years if one is between 40 to 54 years old; every 1 to 3 years if one is between 55 to 64 years old; and every 1 to 2 years if one is older than 65.
• Understand one’s family eye medical history especially as glaucoma tends to be genetic and a person could be at risk of glaucoma.
• For persons who are at risk of glaucoma, they will need more frequent screening.
• Wear eye protection. Serious eye injuries can lead to glaucoma. Wear eye protection when using power tools or playing sports.
• Take prescribed eye drops regularly. Glaucoma eye drops can significantly reduce the risk of high eye pressure progressing to glaucoma. Use eye drops as prescribed by the doctor even if there are no symptoms.