Myopic choroidal neovascularisation is a serious eye condition that can lead to blindness if left untreated.
What is myopia?
Myopia is the medical term for short- or near-sightedness.
If your vision is normal, your eyeball will be almost perfectly round. Light rays enter your eye and come to a sharp focusing point on your retina, the light-sensitive tissue at the back of your eye, and this enables you to see clearly.
If you have myopia, your eyeball is slightly too long, and so the light rays enter your eye but focus in front of your retina, which makes distant objects appear blurred or out of focus, while close objects appear clear. Myopia can usually be corrected by wearing glasses or contact lenses.
In some people with myopia, the eyeball is very elongated, which leads to stretching and thinning of the white of the eye (the sclera), the retina, and the blood vessels between the retina and the sclera (the choroid). This is called pathological myopia and is a degenerative condition, which means that it becomes worse over time. Approximately 1 in 50 people with myopia will develop pathological myopia.1
What is myopic choroidal neovascularisation?
Pathological myopia can lead to a condition known as myopic choroidal neovascularisation (myopic CNV). This is the formation of new, abnormal blood vessels in the choroid, which can leak fluid and cause swelling (edema) within the eye.
If you have myopic CNV you may experience blurred vision (metamorphopsia), distorted vision and/or blind or grey spots in the centre of your vision (scotoma).
Myopic CNV is a serious condition that, if left untreated, can lead to a loss of vision. In fact, most people with myopic CNV will become legally blind within approximately 10 years if they do not receive treatment. Approximately 1 in 10 people with pathological myopia will have myopic CNV.2
Severe myopia is particularly common in Asia. For example, in Japan, pathologic myopia is the second most common cause of blindness.
What causes myopic choroidal neovascularisation?
Vascular endothelial growth factor (VEGF) is a naturally occurring protein that is involved in the formation of new blood vessels (angiogenesis) to support the growth of tissues and organs in the body. VEGF plays a key role in the development of myopic CNV.
How is myopic choroidal neovascularisation treated?
If you have myopic CNV you may be treated with a high-energy laser (photocoagulation) or with the combination of a drug, called a photosensitizer, and a special type of light (photodynamic therapy). Both of these treatments are designed to destroy the abnormal blood vessels in the eye that are leaking fluid.
Recently, a new class of medicines that directly targets VEGF has become available (anti-VEGF therapies). These work by blocking the action of VEGF and suppressing the growth of new blood vessels in the choroid.
We have developed an anti-VEGF therapy that improves the vision of patients with myopic CNV. The substance works by blocking the growth of new blood vessels and decreasing the ability of fluid to pass through blood vessels. The substance is also approved and effective in people with other eye diseases.
Advice for patients
Each body reacts differently to medicines. Therefore it is impossible to tell which medicine works best for you. Please consult your physician.