Role of Antivegf in Proliferative Diabetic Retinopathy

✅ Medically reviewed by Dr Sharon Heng

Oftentimes, I get patients who are drivers, and have unfortunately developed bleeding in the eye from diabetic retinopathy.  What are the treatments out there for proliferative diabetic retinopathy or new vessels in the retina as a result of diabetes?

What is Diabetic Retinopathy ?

Diabetic retinopathy is a complication of diabetes. This is due to chronic high blood sugar levels causing damage to the retina (the layer at the back of the eye). 

The global prevalence of diabetic retinopathy amongst patients with diabetes is approximately 22.7% from pooled studies published. (Global Prevalence of Diabetic Retinopathy and Projection of Burden through 2045, Teo et al). 

Any individual with diabetes, type I or 2 is at risk of developing diabetic retinopathy.

You're at a greater risk if you:

• had diabetes for a long time

• poor control of glucose levels

• have high blood pressure

• have high cholesterol levels 

• are pregnant

• are of Asian or Afro-Caribbean background

How Does High Sugar Affect the Eye?

The retina is supplied by many important blood vessels. They provide nutrition and remove waste materials from the retina.  When blood glucose levels or sugar levels are high and consistently high, it may cause serious damage to these important blood vessels.

When blood vessels are damaged, they can swell and then leak, causing macular oedema or they can close up, and stop blood flowing through. New abnormal blood vessels may then grow and eventually cause bleeding, causing visual loss.

High blood pressure and high cholesterol has also been shown in numerous studies over decades of increasing the risk and progression of diabetic retinopathy. This is because they can enhance or worsen the blockage in the retina vessels, causing worsening leakage or possibly progression of retinopathy.

How is Severity of Diabetic Retinopathy Graded?

Diabetic retinopathy usually happens in stages – this is why screening is so important and being able to capture and start treatment early will be crucial in preventing sight loss. Diabetic Retinopathy may be graded as follows:

• Background or mild non proliferative diabetic retinopathy – tiny bulges develop in the blood vessels, which may bleed slightly but do not usually affect your vision. This is usually monitored on a 6 monthly or annual basis. 

• Pre-proliferative or moderate / severe nonproliferative diabetic retinopathy – more severe and widespread changes affect the blood vessels, including more significant bleeding into the eye. This is monitored more closely as there is higher risk of progression into proliferative stages of which treatment will be required.

• Proliferative retinopathy – new blood vessels are noted on the retina - this may result in bleeding, vision loss, sometimes permanent.

• Diabetic Macular Oedema – this is leakage and swelling in the center of the eye which may cause visual loss.

What Happens When New Vessels Develop

Prevention is always better than cure. Diabetic Retinopathy is one of the main preventable sight loss diseases. With multimodal imaging today, we can screen and monitor for signs of progression and start early treatment. In some cases, where new vessels are noted, laser or antivegf therapy may be started to reduce risk of progression.

Unfortunately in certain cases, patients may present with vitreous haemorrhage or tractional retina detachment which is the most severe stage of the disease. These present as visual loss, floaters, and urgent treatment is required to save sight.

What are the Treatment Options for Proliferative Diabetic Retinopathy?

Laser

Laser photocoagulation or also known as panretina photocoagulation (PRP) is the primary or mainstay/gold standard treatment for proliferative diabetic retinopathy (PDR). Laser is applied to the periphery retina to shrink or regress the growth of new blood vessels. PRP is applied over several sessions and may sometimes be required as a top up over time if further new vessels develop.

It is known to be effective and long-lasting but side effects include peripheral visual field loss which may cause impaired night time, colour vision, and blurred vision. Sometimes, PRP may worsen or cause macular oedema, which is fluid in the center of the eye. There is a small risk of central scotomata if the laser burn is accidentally placed in the macula which itself is a very rare complication.

Antivegf

Anti-vascular endothelial growth factor (anti-VEGF) drugs are used to treat various eye conditions such as age related macular degeneration and macular oedema due to diabetes or retina vein occlusion. Several studies have shown the advantage of the use of antivegf as a treatment for proliferative diabetic retinopathy. 

In cases with vitreous haemorrhage, antivegf treatment may assist in faster resorption of haemorrhage. However, antivegf only lasts limited period of time, and further studies are currently warranted to determine the impact of time on effectiveness of antivegf therapy in PDR. 

Meta analysis of evaluation of multiple studies did not find evidence that effectiveness of antivegf waned over first two years of starting treatment but there was no significant benefit in visual acuity gains as compared to laser therapy.

Anti-VEGF treatments are eye injections, the treatment is injected into the eye, under local anaesthetic, at regular intervals. The  rare but potentially serious adverse effects include: ocular hypertension, retinal detachment, endophthalmitis and other intraocular inflammation, and cataracts. Patients undergoing antivegf therapy would require close and frequent monitoring.

Personalising Your Treatment

Ms Heng is a strong advocate for personalised medical therapy, utilising multimodal imaging, science, and biomarkers to determine the most effective and optimal treatment modality for patients, with consideration for their lifestyle, career, and individual needs.

During your consultation, Ms Heng will discuss your individual circumstances and disease burden and severity to recommend the treatment modality and plan for you.

Diabetic Retinopathy Screening

Diabetes is one of the main causes of preventable sight loss. When diabetic retinopathy is diagnosed in the early stages, and where possible, early treatment, sight loss can be prevented. So it’s important  if you have been diagnosed with diabetes or impaired fasting glucose, to start diabetic screening.

Contact

Ms Sharon Heng

Consultant Ophthalmic Surgeon

info@retina-eye.co.uk

+44 (0)7886 677351