Although not very common (1 in 10,000), retinal detachment is a potentially blinding condition.
How Do Retinal Detachments Develop?
Most retinal detachments begin when a posterior vitreous detachment causes a retinal tear. Fluid from the inside of the eye then passes through the tear and strips the retina off the inside of the eye, a little like freshly pasted wallpaper can sometimes peel off the wall. The retina is then floppy inside the eye and does not work properly because the photoreceptors (light-sensitive cells) are stripped away from the retinal pigment epithelium (RPE) and underlying choroid, on which they rely for oxygen and nourishment.
Retinal detachments almost always begin at the periphery of the retina, where the patient may not notice any visual problems other than flashes and floaters. These are usually due to a posterior vitreous detachment and progress quite rapidly.
Retinal detachments can also occur due to a slow movement of fluid from within the vitreous into the space under the retina through round holes present in areas of peripheral retinal degeneration. This is the type of retinal detachment common in young short-sighted people and often is not associated with symptoms of flashes or floaters.
The next thing that many patients notice is either a dark shadow at the edge of their vision that slowly grows and gets closer to the centre of vision. This can come form any direction and then, if left untreated, may well move across the centre of vision and have a devastating effect.
The build-up of fluid under the retina, stripping the retina off the RPE, causes the growing shadow. In some people this can happen very quickly over a matter of hours or even overnight.
How Are Retinal Detachments Treated?
Surgery is by far the best treatment for retinal detachment and this is generally performed in one of two ways: vitrectomy with cryo (or laser) and gas (or oil) and cryo-buckle surgery. Dr Chauhan will advise you of the best choice for you, as there is often a definite advantage of one over the other, but occasionally patient preference can come into play when both are equally likely to succeed.
How Urgent Is The Surgery?
When the fovea (centre of the macula) is still attached to the RPE, i.e. in its correct position, the retinal detachment is known as a macula-on retinal detachment. Whilst this is good news, it is generally only a matter of time before the central vision is affected so urgent attention is required. An operation will be required, but not necessarily immediately; a number of other factors will help decide on the timing of the operation, but it would ideally be done before the fovea is detached. If this is achieved successfully then central vision is very likely to remain normal or thereabouts.
If the detachment has progressed so that the fovea is detached too, it is known as a macula-off retinal detachment. This situation it is still urgent, but surgery may be delayed a little longer. This is because, once the fovea is detached, the vision never returns to normal. Many circumstances will determine when surgery needs to be done.