DIABETIC RETINOPATHY

QUICKFACTS

• Early Symptoms: None
• Later Symptoms: Blurry vision, seeing floaters, blindness
• Treatment: Improve diabetic control, laser treatment, injections, surgery
• It is a leading cause of blindness in people: between 20 to 60 years of age

What is Diabetic Retinopathy?

High blood sugar levels cause damage to blood vessels in the retina:

• These blood vessels can swell and leak.
• Or they can block up, stopping blood from passing through.
• Poor blood flow can cause abnormal new blood vessels grow on the retina.
• These abnormal blood vessels can
  – bleed into the eyeball
  – cause very high eyeball pressure
  – pull on the retina causing it to detach
• All of these changes can lead to loss of vision.

What are the stages of Diabetic Retinopathy?

There are two main stages of diabetic retinopathy.

1. NPDR (non-proliferative diabetic retinopathy)

This is the early stage of diabetic retinopathy.

• Many people with diabetes have it but will not know about it because it does not cause vision problems until very late.
• Screening is therefore important to pick it up early.
• Depending on the severity, a yearly exam is needed at least.

Leakage in the retina causing: blot and dot bleeding and leakage of fat. Vision may still be very good at this stage.

2. PDR (Proliferative Diabetic Retinopathy)

PDR is the more advanced stage of diabetic retinopathy.

• The retina starts growing new blood vessels: a process called neovascularisation
• These fragile new vessels often bleed within the eye called: vitreous haemorrhage
• If they only bleed a little, you might see a few floaters.
• If they bleed a lot, vision may be blocked.
• These new blood vessels can form fibrous scar tissue.
• Scar tissue can pull on the retina and cause detachment of the retina called: tractional retinal detachment.
• Some of these abnormal new vessels may grow in the front part of the eye causing very high eye pressure
• This is a very serious form of glaucoma called: neovascular glaucoma

Tractional Retinal Detachment

Abnormal blood vessels

Abnormal bleeding in eye

What are the symptoms of Diabetic Retinopathy?

You can have diabetic retinopathy and not know it. This is because it often has no symptoms in the early stages. As diabetic retinopathy gets worse, there may be symptoms such as:

• seeing an increasing number of floaters,
• blurry vision,
• vision that changes from blurry to clear,
• seeing dark areas in your field of vision,
• poor night vision, and
• noticing colours appear faded or washed out

DIABETIC MACULAR EDEMA (DME)

QUICKFACTS

• It is the leading cause of vision loss in adult-onset diabetes patients
• In the Singapore Epidemiology of Eye Diseases (SEED) study, 6% of diabetics had DME

What is macular edema?

• It is the build-up of fluid in the macula, an area in the center of the retina.
• The macula is the part of the retina responsible for sharp, straight-ahead vision.
• Fluid build-up causes the macula to swell and thicken, which distorts vision.

What are the symptoms of macular edema?

• Blurry or wavy vision near or in the center of your vision.
• Colours might also appear washed out or faded.
• If only one eye is affected, you may not notice your vision is blurry until the condition is more serious

Amsler grid can be used to test your central vision.

Covering one eye to test each eye.

Look at the black dot at reading distance.

If the lines appear wavy, you may have a macular problem (Image B).

What causes macular edema?

• In diabetes, high blood sugar affects the small blood vessels or microcirculation
• The retinal blood vessels are some of the smallest blood vessels are often affected first in diabetes.
• Abnormal leakage and accumulation of fluid in the macula occurs from these damaged blood retinal vessels.

What is the treatment?

• Take control of the Diabetes
  –  Controlling your blood sugar and blood pressure can help prevent progression of diabetic retinopathy.

Medication

Anti-VEGF medication:

• helps to block the action of chemicals that cause abnormal blood vessel growth and bleeding.
• This drug is introduced directly into the eye through injections
• Minimising side-effects to the body.

• Steroid medication
  • is an option to reduce macular swelling.
  • This is also introduced through injections to the eye.

• Laser treatment
  • This is a clinic-based procedure which can be done as an outpatient.
  • Laser can used to help seal off leaking blood vessels causing swelling in the macular: this is called focal laser.

– Laser can used to help seal off leaking blood vessels causing swelling in the macular: this is called focal laser.

• Vitrectomy
  • In advanced PDR, where there is vitreous haemorrhage (bleeding) or tractional retinal detachment you may benefit from a vitrectomy.
  • This is an operation involving the removal of the vitreous gel and blood and release of fibrous bands causing traction and pulling on the retina.