One of the triad symptoms of Congenital Rubella Syndrome is sight loss. Not only can a Rubella baby be born with sight loss, it’s also possible for eyesight to deteriorate later in life.
One of the most common forms of sight loss is Congenital Cataracts. This is a clouding of the natural lens in the eye. The lens is situated behind the iris and the pupil. Much like a camera lens, the lens in the eye is responsible for ensuring a sharp and focussed image.
Cataracts can be any size and it can form in any part of the lens. Depending on the size and where it forms, depends on whether or not it is necessary for it to be removed. A small cataract, or one which only forms around the edge of the lens, rarely affects vision. A larger, more central cataract can affect vision and therefore also impact the child’s development. Removal is then recommended. This requires the natural lens to be taken out. It is then replaced with an artificial lens.
Depending on the time in which Rubella virus was contracted during pregnancy and how the virus affects the unborn foetus, depends on whether or not removing a Congenital Cataract restores full vision. It is common for the virus to damage the retina, leaving a lot of scar tissue behind and impairing vision. This is known as Chorioretinitis. If this is present, the surgeon may make a decision not to replace the lens as to prevent further damage to the eye. The amount of sight loss will vary depending on the amount of damage to the retina.
It is also possible for Rubella virus to cause damage to the optic nerve. This nerve is responsible for relaying visual signals from the eye to the brain. If there is damage, signals may be distorted. They may even be unable to travel. This can result in distorted vision, or no vision. This again varies depending on the damage caused.
Another common issue which affects sight loss, and the last that we will discuss in this article, is Congenital Nystagmus. This is an involuntary movement of the eye. Either horizontally (from side-to-side), vertically (up and down) or a combination of both. In patients with CRS, it is either caused by lack of muscle strength, neurological impairment or a combination of both. The severity of the Nystagmus determines how vision is affected. Very small movements tend to go un-noticed by the patient and don’t have any effect on vision at all. Severe and frequent movements can cause blurred vision.
Any type of vision loss, whether slight, or even total blindness, does not need to limit the things a CRS patient wishes to achieve in life. In a lot of cases, corrective glasses can be provided to restore or improve vision. Thus improving the way an individual develops and functions. When corrective glasses don’t help, there are many other technologies that do. These can range from a simple braille book, to a complex smart phone. Contact your local Low Vision Service to find out more information. Or feel free to ask questions in the comments below.
CRS Life 