The retina lines the back of your eye like wallpaper. When the vitreous gel moves within the eye, it can pull on the retina causing a flashing light sensation. Rarely, it can cause a small tear in the retina. Unfortunately, the retina sits on its' blood supply (choroid) and is only attached to the choroid at the very back of the eye (optic nerve) and the very front (ora serrata). If a small tear occurs in the retina, the fluid inside the eye can go under the retina, and the retina can detach from the choroid like wallpaper falling off a wall.
A retinal detachment is when the retina is separated from its' blood supply in the choroid. The choroid is a very well vascularized layer under the retina, that nurtures the retina, supplying it with oxygen and nutrients. When the retina is separated from the choroid, it does not function normally. This causes symptoms of a shadow or blind spot that enlarges over time. There are three types of retinal detachments:
- Rhegmatogenous: The most common type of retinal detachment occurs when a tear develops in the retina, allowing fluid inside the eye to go under the retina. These retinal detachments usually develop quickly and present after an acute vitreous detachment or retinal tear with symptoms of new flashes and increased floaters, followed by a curtain obscuring part or all of the vision. Rhegmatogenous retinal detachments are treated surgically and are usually considered an emergency requiring immediate repair.
- Serous: Serous retinal detachments occur secondary to a medical problem such as a tumor or inflammation in the eye. In a serous retinal detachment, there is no break in the retina and the retina is floating on top of fluid being excreted. The treatment for a serous retinal detachment is to fix the underlying medical problem.
- Tractional: A tractional retinal detachment occurs when scar tissue grows above or below the retina. This scar tissue contracts and elevates the retina since the eye is a round ball. The most common causes of tractional retinal detachments are vasoproliferative disorders (diabetic retinopathy, retinal vein occlusion, sickle cell retinopathy, etc.) or proliferative vitreoretinopathy (PVR) from previous surgery or trauma. Tractional retinal detachments are the most difficult to repair and are always treated surgically.
If you believe you may have a retinal detachment, you should see a retinal surgeon immediately as the visual prognosis depends on how quickly it is repaired.