EYLEA approved for Retinal Vein Occlusions


EYLEA approved for Retinal Vein Occlusions

The latest anti-VEGF in the market now is Aflibercept (known as Eylea) and has been approved for the treatment for wet age related macular degeneration(wAMD) for almost a year now. Eylea has the potential to reduce the number of injections required as according to the landmark trials (VIEW 1 and 2), the recommended frequency of injections is bi-monthly as compared to Lucentis which is monthly.

It is a very natural progression to translate the use of Eylea from treating wAMD to other retinal diseases with VEGF as the "culprit" in the pathophysiology. Examples of such other disease would be retinal vascular occlusions and diabetic retinopathy.

What are retinal vascular occlusions?

The retinal vasculature as like anywhere else in the body, consists of arteries and veins. In the retina, the end branches of arteries and veins form capillary networks.

And also like vasculature in other organ systems, the retinal vessels can get occluded.

Retinal artery occlusions

This can be equivalent to having a "stroke" in the eye. Individuals with hypertension, diabetes, high cholesterol and heart disease are at increased risk of developing these type of occlusions.

In a central retinal artery occlusion, there is severe loss of vision which can occur suddenly and is painless. There is a blockage in the main artery supplying the retina and the lack of oxygenation results in rapid loss of function and permanent damage.

Unfortunately, there is no good treatment for this condition. The risk factors mentioned earlier have to be managed well; anti-platelet therapy, intraocular pressure lowering, ocular massage are some of the strategies used. There are no specific medications or surgery which can be used and the prognosis following a central retinal artery is not very good at all.

Visual loss from branch retinal artery occlusion is less severe. Mostly, there is partial loss of vision and affected individuals can still retain functional vision. Not unlike central retinal artery occlusion however, there is no specific treatment for this condition and management of the risk factors remains the prime focus. If a patient who has no risk factors or is particularly young (under 35 years) and develops a retinal artery occlusion, it is important to investigate thoroughly for a cause and blood tests, ultrasound scans, etc. may be necessary.

Retinal Vein Occlusions

These occur when there is an obstruction of the retinal vein and subsequent build up of pressure within the "blocked system" results in the leakage of blood and other contents and vein occlusions are characteristically shown to have "blood everywhere" as compared to artery occlusions.

As in artery occlusions, blockage of the central vein results in more severe consequences. The will be sudden painless loss of vision and could be quite severe as compared to a branch vein occlusion which causes paritial visual loss.

Again there is no direct treatment for vein occlusions and the management of risk factors as mentioned earlier is of vital importance. However, the difference is in the management of complications from vein occlusion which includes macular oedema, ischemia and new vessel formation as well as a severe form of glaucoma known as neovascular glaucoma.

This is where anti-VEGF injections have made a big difference in preventing blindness from vein occlusions. Since Lucentis first came to the scene for wAMD, it has also been used widely for the treatment of macular oedema for vein occlusions. Now with this "new kid on the block" that is Eylea, there is further improvement to our treatment options. Following the clinical trials of COPERNICUS and GALILEO, the FDA has approved Eylea for the treatment of macular oedema following central retinal vein occlusions. Eylea has been shown to improve vision in approximately 60% of patients who received injections as opposed to only 30% in those who did not receive injections.

This is good news for the retinal community as it adds to our growing armamentarium of treatment options for potentially blinding diseases. Next in line will be Eylea for diabetic retinopathy. More on this in due course.