As one gets older, the vitreous, the clear gel-like substance that fills the inside of the eye, tends to shrink slightly and take on a more watery consistency. Sometimes as the vitreous shrinks it exerts enough force on the retina to make it tear in one or more places.
Retinal tears increase the chance of developing a retinal detachment. Fluid vitreous passes through the tear, lifting the retina off the back of the eye like wallpaper peeling off a wall.
Retinopexy (laser) or cryotherapy (freezing) are often used to seal retinal tears and a prevent detachment. If the retina is detached, it must be reattached before sealing the retinal tear. These treatments can be performed in the eye doctor's office.
This procedure is done at the slit lamp that the doctor uses to examine your eyes. By placing a special lens on your eye, the ophthalmologist uses a laser to surround the tear and avoid any fluid from getting behind the retina and causing a detachment.
Sometimes, the location of the the tear will make it difficult to use the laser to seal it. In this case, the doctor will use cryopexy, to freeze the area surrounding the tear from the outside of the eye and causing it to scar. Cryopexy may cause inflammation inside the eye, which is treated with eye drops.