There are three types of
retinal detachment.
Rhegmatogenous retinal detachment is the most
common type of detachment. It is caused by tears or holes in the retina called
retinal breaks. A retinal break allows fluid from the middle of the eye to pass
through the tear and settle under the retina. As the fluid builds up under the
retina, it pushes the retina away from the layer beneath it. See an
illustration of a
detached retina
.
The most frequent cause of retinal tears is posterior vitreous
detachment (PVD), a condition in which the
vitreous gel separates from the retina. At points
where the gel is more strongly attached to the retina, the vitreous gel can
pull so hard that it tears the retina. Retinal tears occur most often on the
sides (periphery) of the retina because the vitreous gel is attached to the
retina most strongly in those areas. Often harmless, posterior vitreous
detachments usually result from normal changes in the vitreous gel that develop
as the eyes age.
Retinal breaks often do not lead to retinal detachment. However,
retinal tears that occur with new symptoms (such as
floaters,
flashes of light, or other visual disturbances) are
much more likely to progress to detachments. A retinal detachment also may be
more likely to occur if you have additional risk factors, such as being
nearsighted or having had recent cataract surgery.
Traction retinal detachment occurs when scar
tissue or other abnormal tissue grows on the surface of the retina, pulling the
retina away from the layer beneath it. This does not cause a specific tear or
break in the retina.
The leading cause of traction retinal detachment is
proliferative retinopathy, a condition most frequently
caused by diabetes.
Exudative retinal detachment occurs when blood
or fluid from the middle layer of tissue that forms the eyeball (choroid) flows
into the space under the retina and separates the retina from the layer beneath
it. The detachment does not involve tears in the retina or traction from the
vitreous.
Exudative retinal detachment is most often a complication of other
diseases or conditions. These can include severe
macular degeneration, eye tumors, inflammation in the
choroid or the retina, or severe high blood pressure.
Exudative retinal detachment may be referred to as serous,
hemorrhagic, or secondary retinal detachment.