12 Sep Why Vision is Poor with Silicone Oil
There are many reasons why you may not see well after silicone oil is used for your retinal detachment eye surgery. Remember, retinal detachments are potentially blinding conditions and silicone oil is often used for repeated detachments.
Did Your Macula Detach?
One major concern with every retinal detachment is whether or not the macula becomes detached. The macula is the most sensitive part of your retina. It provides central vision, reading ability, color vision, etc.
One goal of retinal detachment surgery, if possible, is to fix a retinal detachment before it spreads large enough to detach the macula.
If the macula detaches, you my lose permanent central vision and/or develop distortion regardless if the surgery is successful. Thus, if the macula detached at any time, there may be some permanent loss of vision.
Was Your Lens/Cataract Removed?
Silicone oil is rarely used during “primary” retinal detachment surgery, meaning we usually don’t use silicone oil unless the retina repeatedly detaches. So, too, is the necessity to remove the cataract, or your natural lens, during retinal detachment surgery.
If your lens was removed, this might impact your vision, too.
Index of Refraction
This is a fancy term referring to the ability of light to be focused in oil versus water. Light is focused differently depending upon the medium, or liquid in the eye. For instance, replacing the natural saline solution and the vitreous (i.e. during a vitrectomy) with oil would change the power of your glasses or contacts.
Too Much Oil
Oil and water focus light differently, therefore, your vision will change simply because the medium (water/vitreous exchanged for oil).
Filling an eye with silicone oil can be tricky. Eyes come in all sizes and therefore require different volumes of oil. We have to use our best judgement when filling the eye with oil.
The perfect amount of oil fills the entire back of the eye and stays behind the iris. In patients where there is no lens, too much oil can move forward through the pupil and decrease the clarity of the cornea.
Too Many Retinal Detachments
Many times eyes lose vision due to damage to the retina or cornea simply from repeated detachments and surgery. That is, while oil may be used to prevent complete loss of the eye (often the case), there has already been permanent damage to some of the ocular tissues and, thus, poor resulting vision.
What Does This Mean?
Retinal detachments are difficult to understand. Communication with your doctor is essential, though I realize we doctors vary in our ability communicate effectively.
Silicone oil is often used as a last resort to prevent further operations. As you can see from the list above, just by putting oil in the eye, the vision is reduced. This fact, coupled with the necessity for future surgery to remove the oil, prevents most of us from using oil during the initial surgery.
There is a difference between successful surgery, i.e. getting the retina fixed, and seeing well. They don’t always go hand in hand, especially in cases where there have been repeated retinal detachments….the most common use of oil.
In the end, ask your doctor why she thinks you are not seeing. If the answer you are receiving does not make sense to you, seek a second opinion. You have a right to understand.