Silicone oil can be used to fix retinal detachments. Using the same principles of intraocular gas to repair a retinal detachment, oil can be thought of as a non-absorbable intraocular gas. It is a useful “tool” for difficult or recurrent retinal detachments. Both gas and oil may, or may not, be used in retinal detachment surgery (e.g. vitrectomy and scleral buckle).
A recurrent retinal detachment is basically a retinal detachment that can’t be fixed. An operation is performed, often involving intraocular gas, the gas gets reabsorbed and the retina…detaches again. Every time the retina redetaches, more vision is lost.
“Rhegmatogenous” retinal detachments are all caused by a retinal tear or retinal hole. By definition, “rhegma,” or a retinal tear, must be present to cause the retinal detachment. The retinal tear allows communication with the space underneath the retina. These are the most common type of retinal detachments.
Fluid is able to migrate from the center of the eye, through the tear to the space underneath the retina, thus, causing the retinal detachment.
Intraocular gas and silicone oil work by “plugging the hole” and stop migration of fluid from the center of the eye to the sub-retinal space. As long as the oil is pushing against the retinal hole causing the retinal detachment, the detachment will go away. The oil acts like a cork.
Silicone oil is usually used after other attempts have failed.
Initial attempts at fixing retinal detachments associated with tears usually involve the injection of gas. The gas is temporary, and will absorb within days to weeks after the operation depending upon the type of gas used. It does not require an additional operation to remove the gas.
The best reason to use oil is due to the fact that it does not absorb. This “permanancy” increases the liklihood of the retina staying attached. It breaks up the vicious cycle of repeated retinal detachment surgery. The whole process of having multiple retinal detachment surgeries can be mentally, physically and financially draining.
Now, I use oil earlier in my treatment algorithm. It allows the retina to become attached, prevents redetachment and therefore saves vision!
The oil is safe and not known to cause any problems elsewhere in the body. Some doctors feel that the oil can damage the eye directly, but this is controversial. Many people feel the silicone oil can damage certain tissues of the eye such as the cornea and optic nerve.
I believe the oil to be safe to the eye. There are no studies by the way, but if doctors wait too long to employ the oil, the same tissues get damaged from recurrent detachment anyway, that is, I think the actual cause of the “damage” is the mere fact of repeated retinal detachments.
What Does This Mean?
Silicone oil is a safe alternative and a good way to fix complicated retinal detachments. For the time the oil is in place, however, the vision is usually poor, but the oil may increase the visual prognosis in the long term.
Most doctors don’t use silicone oil early enough. They wait too long. By then, too much vision may be lost from repeated retinal detachments.
I have found it to be more useful as I have “matured.” As a younger doc, I was reluctant to turn to silicone oil. I hadn’t learned that sometimes the disease wins. My feeling is that docs should be using it earlier and not waiting until the 3rd or 4th redetachment. It can be a wonderful tool and can buy you time as it interrupts the cycle of reoperation after reoperation.
I recently injected silicone oil into my patient with recurrent detachments in his only eye. He is presently completely attached and is stable. We no longer worry (for a long as the oil stays in the eye) about him redetaching. While he may not be seeing well, we have stabilized him.
Silicone oil gives you stability and piece of mind.