Anti VEGF Agents

introduction

What is VEGF?

Vascular endothelial Growth factor (VEGF) is a protein produced in the human body which is responsible for production of new vessels and maintaining them. Under abnormal conditions like diabetic retinopathy, blood vessels obstruction and age related macular degeneration it causes formation of abnormal vessels which bleed, leak and ultimately lead to scar formation and vision loss

What are anti VEGF Agents

Anti Vascular endothelial Growth factor (anti VEGF) agents a group of medications which block the activity of VEGF and thus mitigate the abnormal effects of VEGF

What are the anti VEGF Agents available for treatment

  • Bevacizumab
  • Ranibizumab
  • Aflibercept
  • Brolucizumab


How are these anti VEGF agents different from one another

 

Bevacizumab

Ranibizumab

Aflibercept

Brolucizumab

Molecule

Monoclonal antibody

Antibody fragment

Fusion protein

Single chain antibody

Molecular weight

149 kDa

48kDa

97-115 kDa

26 kDa

Clinical dose

1.25 mg

0.5 mg

2 mg

6 mg

FDA approval

Not approved

Approved

Approved

Approved

Intravitreal anti VEGF activity

4 weeks

4 weeks

Upto 12 weeks

Upto 12 weeks

 

 

How have anti VEGF treatment influenced the management of various eye conditions

Anti VEGF agents when administered under appropriate conditions act at molecular level countering the action of VEGF and thereby reducing the morbidity.

Many diseases which were considered untreatable earlier like age related macular degeneration are rendered treatable, enabling patients maintain quality vision and subsequent improvement in quality of life

Ocular manifestation of systemic diseases with diabetes hypertension are also now treated with anti VEGF agents, with quality vision being restored and maintained.

 

What are the common conditions treated with anti VEGF agents and their benefits

 

Disease

Pathology

Benefits

Wet age related macular degeneration

Abnormal vessels at the back of the eye leak fluid and blood, leads to drop in vision

Abnormal vessels regress with resorption of fluids with subsequent improvement of vision

Diabetic macular edema

Leakage of fluid due at the back of the eye leading to swelling and vision drop

Prevent leakage and reduce swelling

Proliferative diabetic retinopathy

Abnormal vessels on the retina which bleed

Regression of abnormal vessels

Retinal vein occlusion

Swelling of retina due to obstruction of retinal blood vessels

Resolution of swelling with improvement of vision

 

  • How do I choose the type of anti VEGF agent

    The doctor examining you will prescribe the appropriate agents as per the disease process and systemic illness. Active bleeding or fluid leak at the back of the eye called macula warrants urgent treatment. The doctor will perform appropriate scans to confirm, quantify and monitor the progress of the disease. Vision is measured and is one of the yardsticks for monitoring response to treatment

     

    How is the anti-VEGF agent administered

    • After clinical examination and relevant scans and making a diagnosis, the doctor will discuss the available options with the patient
    • The anti-VEGF agent is administered into the eye by means of a fine needle under sterile conditions in an operation theater.
    • The eyes are numbed with topical anaesthetic agent
    • Cleaning of eyes and surrounding structures with an antiseptic solution is done
    • Protective sheet called eye drape is applied around the eye
    • Eyelids are opened with a clip called an eyelid speculum
    • The doctor injects the drug through the white part of the eye through a fine needle
    • After injection, gentle massage is done at the site of injection
    • The eye clip is removed, and antibiotic drops are instilled in the eye

    Antibiotic drops are prescribed for usage after injection in the eye.

     

    What are the anti-VEGF agents available for treatment?

    • Bevacizumab
    • Ranibizumab
    • Aflibercept
    • Brolucizumab

 

Written by: Dr. Mohanraj – Consultant Ophthalmologist, Coimbatore

FAQ

1. What are some most common drawbacks of Anti-VEGF injections?

The chances of complications arising after the Anti-VEGF injections are extremely rare. Though most commonly, the problem arises from getting the injection in the eye, not the medicine. Some of the most common drawbacks are as follows- 

  1. Mild pain or ache in the eye can last two or three days 
  2. Floaters- will take a week minimum to get clear
  3. Sclera may appear bloodshot or bruised
  4. Eyes may feel rough, irritated, or puffy

These are common drawbacks of Anti-VEGF injections. However, if, in time, they don’t go away, then you should connect with your doctor and get a check-up done. 

Bevacizumab injection is given to treat eye disease to block the abnormal growth of blood vessels in the back of the eye. The abnormal growth can block the vision and cause blood leaks in the eye resulting in vision loss. 

The medicine takes approximately one month to show effect and improves vision. Though this depends upon your doctor and if they deem you fit for the eye injection. Patients with central retinal vein occlusion, myopic choroidal neovascularization, diabetic retinopathy, and other eye conditions are given bevacizumab injections. 

The procedure is conducted inside the room and under the supervision of an experienced ophthalmologist. The surgeon might ask you to read a chart to check your vision. They will give eye drops to numb your eye, making the process painless. 

Upon this, your eye will be cleaned with an ointment to prevent infection. Once done, the surgeon will place a tool to hold your eye open, or it will be hard to inject based on a human’s reflex mechanism. 

Then the bevacizumab injection will be inserted in the sclera of your eye (the white part of the eye). The needle is extremely thin so as not to damage the eye or the vessels. The procedure will be painless, considering the numbing eye drops have been applied. 

Once the procedure is over, the antiseptic and anaesthetics are washed from the eye and an eye patch is applied. Though an eye patch might not be mandatory, in a few cases, it is advised. 

You are advised to consult with your ophthalmologist about what to do and what not to do. Please do not put any eye makeup on, refrain from straining your eye, and do not rub it unnecessarily, or the process might not occur because of eye irritation. 

Though both are the most commonly used VEGF agents and have similar active molecule parts, bevacizumab and ranibizumab are different. The Avastin Bevacizumab is the anti-VEGF, whereas ranibizumab is an antibody fragment. 

In the systemic circulation, the bevacizumab has an extended half-life compared to ranibizumab. But the latter one is said to have better retina penetration and higher affinity than the Avastin Bevacizumab. 

Note that ranibizumab is a monoclonal antibody that slows the abnormal eye blood vessel growth and decreases the leak from these vessels. It falls in the category of vascular endothelial growth factor antibody. It stops vision loss and penetrates the retina to stop the growth. 

The aflibercept injection helps in treating the age-related wet macular degeneration that causes the vision loss, or loss in seeing straight, causing discomfort in reading, driving, watching tv or other activities. The solution is injected into the eye sclera with a very thin needle. Once the proper dosage is injected, your eye will be cleaned. After the medicine takes effect, the vision loss will be restored, and you can read without discomfort. 

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