As a person ages, the thick vitreous gel becomes less a gel and more like a fluid. Small pockets of fluid form within the gel of the viteous. As the eyeball moves, the liquified vitreous moves around inside the vitreous cavity. Because of this movement of fluid, the vitreous begins to pull on the retina. With time, the vitreous can pull free and separtate from the retina and optic nerve in the back (or posteror) part of the eye. This is called a "posterior vitreous detachment" (PVD). this kind of detachment happens eventually in most people and only infrequently causes a problem.

when a person develops a posterior vitreous detachment, flashes of light or large spots in the vision may occur. The flashes of light are caused by the tugging of the vitreous where it is attached to the retina. As the vitreous pulls on the retina, the brain interprets this pulling as flashes of light. As it liquifies and pulls away from the retina, the vitreous becomes somewhat condensed and stringy and forms strands. The patient can see these strands and strings; tey appear as spots, small circles, or irregular fine threads in the vision. They seem to float and are therefore called "floaters".

vitreous changes are most commonly caused by aging, but they can also be caused by previous inflammation in the eye, nearsightedness, trauma, or other causes. If a patient has floaters, he or she should be examined to be sure there are no other serious retinal problems (such as a retinal tear or a retinal detachment). If there are no problems, the patient can feel reassured, and will learn to ignore the floaters. There is no treatment for floaters.

There may be areas where the vitreous is very strongly attached to the retina. If the vitreous pulls away from the retina in an area where the retina is weak, the retina may tear. One condition that weakens the retina is called lattice degeneration. When lattice degeeration is present, it indicates that the retina is thin and may be more susceptible to a tear of the retina than in an area without lattice degeneration. Imagine a piece of scotch tape off the tissue paper, you will tear the paper. A tear of the retina works very much the same way. If the vitreous is firmly attached, as it pulls away, it can tear the retina. If the retina tears across a retinal blood vessel, there will be bleeding into the vitreous. This is called a vitreous hemorrhage.

When there is a little bleeding, red blood cells floating and moving in the vitreous create the sensation of walking through a swarm of flies. If even more bleeding occurs in the vitreous, it looks like a spiderwe or a swirling mass of black or red lines. If there is a great deal of bleeding intothe vitreous cavity, vision may be reduced significantly, or even become very dark. When a retinal tear occurs, it is a potentially serious problem. if a vitreous hemorrhage also occurs, it is even more serious.

The retina can tear immediately following a posterior vitreous detachment (PVD), or weeks later. If no tear has developed within eight weeks after a PVD, the retina probably will not tear.

Any patient who experiences sudden or new floaters, or flashing immediately. These symptoms may indicate that a retinal tear has occurred. A retinal tear may result in a retinal detachment. Since retinal tears and retinal detachments begin in the peripheral retina, your doctor may suggest that you test your peripheral vision to be sure there are no changes.

Testing Peripheral Vision

1. Cover your left eye with the palm of your hand and look at your right eye in a mirror.
2. While you are looking at your eye in the mirror, and without moving your eye up or down or from side to side, be sure that you can see all four corners and sides of the mirror.
3. Now, cover your other eye and perform the same test.

You have just completed testing the peripheral vision of each eye. If you notice any peripheral vision loss, or any visual changes, distortion, or blur that was not present the day before, notify your eye doctor immediately.

If a tear of the retina has occurred, laser treatment or cryotherapy, or both, may be used toseal the retinal tear in order to prevent a retinal detachment from occurring. the laser is a beam of light that turns to heat when it hits the retina. The laser light is directed through a special contact lens. Cryotherapy (also called "cryo") is a means of freezing the part of the retina that needs to be treated. This is done with a cryoprobe which is placed on the outside of the eye. Both laser treatment and cryotherapy seal the retina to the back wall of the eye by forming a scar. This scar, which takes approximately 10 days to heal, forms a bond which seals the retina around the retinal tear and prevents a detachment.

Sometimes a very small retinal detachment develops around a retinal tear. Although surgery can be done for a small retinal detachment, frequently it is so small that either laser or cryotherapy alone can be used to wall the detachment off. The treatment prevents the detachment from getting bigger. The retinal detachment, however, may break through the laser or cryotherapy scar, so the patient must always be aware of the possibility of develoing a retinal detachment, which would be experienced as a loss of peripheral vision. Your doctor may suggest that you test your peripheral vision daily.

Both laser surgery and cryotherapy are done on an outpatient basis. Patients may return to full activity, without restrictions, in a short period of time. Vision may be blurred for several days following laser or cryotherapy. If cryotherapy is used to treat the retinal tear, the eye may be red for several weeks.

Why is a etinal tear considered a serious problem? When a tear of the retina occurs, the liquid in the vitreous cavity may pass through the tear and get under the retina. The liquid collects under the retina and lifts it up off the back wall of the eye. Little by little, the liquid from the vitreous passes through the reinal tear and settles under the retina, separating it from the back wall of the eye. This separation of the retina is called a retinal detachment. Vision is lost wherever the retina becomes detached. Because most tears are located in the peripheral (or side of the) retina, the retinal detachment first results in loss of side, or peripheral, vision. A patient may notice a dark shadow, or a veil, coming from one side, above, or below. In most cases, after a retinal detachment starts, the entire retina will eventually detach and all useful vision in that eye will be lost.

Who gets retinal detachments? Each year in the United States approximately one out of 10,000 people develops a retinal detachment. Certain people have a greater chance of getting a retinal detachment that others: those with a highdegree of nearsightedness, a family history of retinal detachment, or those who once had a retinal detachment in the other eye. Patients who have thinning or the retina (termed "lattice degeneration") or other degenerative changes of the retina are also at increased risk. Patients who have had cataract surgery have about a 1% to 2% chance of developing a retinal detachment. A person in any of these high risk groups should have a thorough retinal examination regularly and should be seen immediately if they experience sudden flashing of lights, new floaters, or loss of peripheal vision.

If the retina has become detached and the detachment is too large for laser treatment or cryotherapy alone, surgery is necessary to "reattach" the retina. Without some type of retinal reattachment surgery, vision will almost always be completely lost. There are two types of surgery for retinal detachment; one is called scleral buckling surgery and the other is called pneumatic retinopexy.

The traditional surgery for retinal detachmetn is scleral buckling surgery. THis surgery is generally performed in the operating roon under general aneshesia but, in some cases, may be performed under local anesthesia. The surgeon first treats the retinal tear with cryotherapy. A cryoprobe is placed on the outside part of the ye (the sclear) as the surgeon looks into the eye. The surgeon then places the cyroprobe in the position ant the reinal tear is treated. A piece of silicone plastic or sponge is then sen onto the outside wall of the eye (sclera) ove the site of the retinal tear. This pushes the sclera in toward the reinal tear and holds the retina against the sclear until scarring form the cryotherapy seals the tear.

This surgery is called scleral buckling because the sclear is buckled (pushed) in by the silicone. The silicon buckle is left on the eye permanently. Another type of scleral buckling surgery for retinal detahment can be done with a small rubber balloon which is left on the eye only a few days and then removed.

The silicone may also be placed all around the outside circumference of the eye. Theis is called an encircling scleral buckle or band. The purpose of the encircling scleral buckle is to lessen the pulling of the vitreous on the retina. During the surgery, the surgeon may drain the fluid from beneath the retina by making a tinay slit in the sclera, and then making a small puncture into the spamce under the retina. The fluid under the retina then drains out through the slit in the sclera.

Occassionally, the surgeon may place a gas bubble into the vitreous cavity. When the surgery is over, the patient is positioned so that the gas bubble rises and pushes the retinal tear against the scleral buckle to help keep the tear closed.

In most cases, there is a better than 80% chance of successfully reattaching the reina wiht one operation. But successful reattachment does not necessarily mean restored vision. The return of good vision after the surgery depends on whether, and for how long, the macula was detached prior to surgery. If the macula was detached, vision rarely returns to normal. Still, if the retina is successfully reattached, vision usually improves. The best vision may not occur for many months after the surgery. In some cases, even if the macula was still attached befor ethe surgery, and even if the surgery results in successful reattachment of the retina, some vision may be lost. If the first retinal detachment operation fails, a second operation is usually possible.

Postperative period: following surgery, the eye will be red and slightly sore for a month or two. Patients often feel a scratchy sensation produced by the stiches used to close the lining around the eye. Severe pain in uncommon; if it occurs, the surgeon should be told immediately. The eye will water for several weeks, and the patient may find it more cmfortable to wear a patch on the operated eye. Usually, serveral medicines given as eye drops must be taken after the surgery. These should be continued until the surgeon asks the patient to stop These drops are used to prevent infection and to help make the eye feel more comfortable. In most cses, the patient may leave the hospital within a day or two of the surgery, or even the day of the surgery. Each surgeon handles treatment differently, and each case is unique.

Following the surgery, vision will be blurry; it may take a many weeks for the vision to improve. During this period the main concern is that the retina remains attached. Many surgeons ask their patients to restrict their physical activity for several weeks.

Complications of scleral buckling: even though the surgery for retinal detachment is generally successful, certain complications can occur. Any one of these complications can result in failure of the operation, loss of some or all vision, and, in rare situations, even loss of the eye.

Retinal detachment surgery done by scleral buckling can affect the eye muscles that move the eye and keep the eye straight. This can result in double vision, which on rare occasions is permanent. Retinal formation, glaucoma, rtianl redutachment, proliferative vitreoretinapathy, vitreous hemorrhage, frooping of th upperlid, and infection. Although any one of these can result in th need for more surgery, or in the total loss of vision, these compkications are very infrequent. Retinal redetachment is the most commonly occuring problem. If this occurs, your surgeon will discuss the chance that reoperation will successfully reattach the retina.

Another type of surgery that can be done for retianl detachment is called "pneumatic retinopexy." Pneumatic retinopexy is performed on an outpatient basis. Local anesthesia, rather than general anesthesia, is used.

Cryotherapy of laser treatment is performed to seal the retinal tear. Instead of placing a scleral buckle on the outside of the eye, the surgeon, using a needle, injects a gas bubble inside the vitreous cavity of the eye. The patient is instructed to keep his head in a specific position so that the gas bubble pushes the detached retina against the back wall of the eye to seal the retinal tear. The patient is asked to remain in this position for various periods of time until the retinal tear is sealed against the back wall of the eye. Your surgeon will tell you how long special positioning in necessary. Antibiotic eye drops may be used during the days following the procedure.

The gas bubble in the various cavity of the eye expands for several days and takes two to six weeks to disappear. During this time, airplane travel or travel to a high altitude must be avoided because high altitudes can result in an expansion of gas and an increase in pressure that can damage the eye. Your surgeon will tell you when it is safe to travel. It is also important for a patient with a gas bubble not to lie face up, as the air bubble may come to rest against the lens of the eye and cause a cataract or high pressure in the eye.

The chance of successfully reattaching the retina with pneumatic retinopexy is less than with the scleral buckling surgery. Also, pneumatic retinopexy cannot be used, or is not effective, for every retinal detachment. Your surgeon will discuss with you whether pneumatic retinopexy is feasible and the chances for successfully reattaching the retina. With pneumatic retinopexy, hospitalization, general anesthesia, and the cutting done for the scleral buckling surgery are all avoided. Complications of pneumatic retinopexy include cataract formation, glaucoma, gas getting under the retina, excessive scar tissue formation, and infection. Any one of these complications can lead to a total loss of vision, but each is rare. The most common complication is recurrence of the retinal detachment. If the retina becomes detached again, scleral buckling surgery or vitrectomy can usually be performed to reattach it.

Occasionally, a retinal detachment is so complicated and severe that it cannot be treated with either standard scleral buckling surgery or pneumantic retinopexy. In such cases, vitreous surgery to reattach the retina may be necessary. Vitreous surgery is performed on the hospital, often under general anesthesia. The vitreous is removed and, therefore, this procedure is called "vitrectomy." The surgeon uses a fiberoptic light to illuminate the inside of the eye and other instruments inside the eye, such as foreceps, and scissors, to do the surgery. The vitreous is replaced during the operation with either clear fluid that is compatible with the eye, or with air that completely fills the eye. Over time, this fluid (or air) is absorbed by the eye and is replaced by the eye's own fluid; the eye does not replace the vitreous itself. The lack of vitreous does not affect the functioning of the eye.

Vitrectomy is required for retinal reattachment in a variety of conditions. For example, scar tissue may grow on the vitreous or surgace of the retina and pull on the retina and detach it. Occasionally, something is in the vitreous, such as blood, that prevents the passage of light through the eye to the retina. The most common conditions requiring vitrectomy are vitreous hemorrhage with retinal detachment, proliferative vitreoretinopathy, giant retinal tears, diabetic retinopathy with vitreous hemorrhage and/or traction retinal detachment, epiretinal membranes (macular pucker), intraocular infection (endophthalmitis), trauma, and intraocular foreign body.

In a vitrectomy, instruments are passed through the sclera inot the vitreous cavity. A variety of instruments can be used to remove the vitreous gel and any scar tissue that may be growing on the surface of the retina. A laser probe can be inserted into the eye so that laser treatment can be done during surgery.

Vitrectomy can be combined with the placement of a scleral buckle. Occasionally, air, gas, or silicone oil is placed in the vitreous cavity. These materials hold the retina in place against the back of the wall of the eye while the laser scars are taking hold. After this surgery, it may be important for the patient to maintain a certain position of the head, which is often a face-down (prone) position. Eventually, the air or gas is absorbed by the body and replaced by fluid produced by the eye. If silicone oil has been used, it usually must be removed at a later time with another surgical procedure. Vitreous surgery usually lasts one to two hours. Following surgery, the patient may experience some discomfort and a scratchy sensation in the eye, but significant pain is unusual. If it occurs, the surgeon should be told immediately.

When a retina tear occurs, retinal blood vessels may also be torn. When this happens, blood spills into the vitreous cavity; this is called a vitreous hemorrhage. Because there is a tear in the retina, a retinal detachment may also occur. The combination of a vitreous hemorrhage prevents the surgeon from seeing the retina and finding the hole. In such a case, a special technique called ultrasonography is necessary to help make the diagnosis of retinal detachment beneath the hemorrhage.

Ultrasonography is a harmless and painless test. It is like the sonar on a submarine. Sound waves are sent into the eye. They travel through the hemorrhage and bounce off of the retina. The returning sound waves make an image on a monitor and allow the doctor to see whether the retina is attached or detached.

If a patient has a combined vitreous hemorrhage and retinal detachment, a vitrectomy must be performed to remove the blood so that the surgeon can see the retina. Also, a scleral buckle is placed around the eye. Because of the combination of retinal detachment and vitreous hemorrhage, the eye is at high risk for developing proliferative vitreoretinopathy.

Scleral buckling surgery fails approximately 5% to 10% of the time because excessive scar tissue grows on the surface of the retina. This scar tissue is very bad for the eye. It pulls on the retina, causing it to redetach. Retinal redetachment usually occurs four to eight weeks after the initial surgery. The scar tissue also puckers the retina into stiff folds, like wrinkled aluminum foil. The vitreous also pulls on the retina, detaching it from the back of the wall of the eye. This condition is called proliferative vitreoretinopathy (PVR). The only way to unfold and reattach the retina is to cut away the vitreous and remove the scar tissue with vitrectomy surgery and then reattach the retina. The lens of the eye almost always has to be removed during the surgery. If an intraocular lens implant is in the eye, it can usually be left alone.

Removing the vitreous and especially the scar tissue from the surface of the retina is a delicate process that requires the surgeon to lift and peel strands of scar tissue away from the retina. The surgery may take many hours in severe cases. After the vitreous and the scar tissue are removed, an encircling scleral buckle is placed around the eye. The eye is then filled with air so that the retina is pushed against the back wall of the eye and against the scleral buckle. Once the retina is placed, a laser is used to seal the retinal tears, and to form a strong attachment between the retina and the back wall of the eye. At this point, the surgeon will replace the air with a long-acting gas. The gas remains in the eye for many weeks before it is naturally absorbed. The vision is always very poor when air or gas is in the eye. The gas keeps the retina pushed up against the eye wall long enough for the laser burns to heal and take hold. In some cases, the same effect is achieved with clear silicone oil that is placed into the eye. If oil is placed into the eye, it is usually removed at a later time. Following surgery, it may sometimes be necessary for the patient's head to be positioned in such a way as to help the gas seal the retinal tears. In some cases, extra injections of gas may be required after the surgery

The chance of successful retinal reattachment with vitrectomy for PVR is about three out of four. The chance of regaining good enough vision just to get around is about 50%. Reading vision rarely returns. It should be clearly understood that the purpose of PVR surgery is to give the patient an eye that would have some vision and could serve as a "spare tire," if the other eye ever loses vision entirely.

It takes the vision a long time to completely recover after a vitrectomy. It is important to know that in some cases the scar tissue may re-form after the surgery and cause redetachment of the retina.

Just as vitreous pulling creates small retinal tears, it can also cause very large retinal tears. If the retinal tear is very great (one quarter of the retina or more), it is called a "giant retinal tear." Occasionally, the tear is so large that the retina folds over on itself, like a piece of paper folded in half. A giant retinal tear is a very serious problem.

Vitreous surgery, scleral buckling, and laser treatmetnt may be used to treat giant retinal tears. The lens of the eye is usually removed to make this surgery successful. The goal of the surgery is to unfold the retina, put it back in place, and seal it into its proper position. Silicone oil or fluids that are heavier than water (called perfluorocarbons) may be used to unfold a giant retinal tear and reattach the retina.

Many patients will see well after surgery for a giant retinal tear, but some will not. Most will recover enough vision to get around. Despite modern techniques to reposition the folded retina and hold it into place, many eyes develop scar tissue (proliferative vitreoretinopathy) after the surgery and the retina again becomes detached. Your surgeon will discuss with you chances for regaining some vision with this surgery, as well as the possible complications.

In proliferative diabetic retinopathy (PDR), abnormal blood vessels and scar tissue grow on the surface of the retina and also attach firmly to the back surface of the vitreous. The vitreous then pulls on the scar tissue and can cause the blood vessels to bleed into the vitreous cavity (called vitreous hemorrhage). This can cause immediate and severe visual loss. Often, the hemorrhage will clear by itself. If it doesn't clear, a vitrectomy can be performed to remove the blood-filled vitreous.

When the vitreous pulls on the scar tissue, it can detach the retina. This is called a "traction retinal detachment." When the detachment involves the macula, central vision is lost. Also, scar tissue may wrinkle the retina and cause visual loss.

The patient can regain some vision only if the scar tissue is removed from the surface of the retina and the retina is reattached. This is accomplished by vitrectomy. The surgeon removes the vitreous and scar tissue from the surface of the retina so that they stop pulling on the retina, thereby releasing the traction. Removal of the scar tissue also reduces or eliminates wrinkling of the retina.

The surgeon may also use laser inside the eye to prevent later development of abnormal new blood vessels on the iris, called "rubeosis." Preventing rubeosis is important since rubeosis may cause bleeding and blinding glaucoma. Laser is also used to seal off any tears of the retina. If there are tears of the retina, a large air bubble may be placed in the eye to press the retina completely against the back wall of the eye while the laser treatment takes hold. In time, the air bubble will disappear and be replaced by the eye's own fluid.

Scar tissue can grow on the surface of the retina, directly over the macular. This scar tissue can contract, and cause the retina to wrinkle. The scar tissue on the surface of the retina is called an "epiretinal membrane" or "macular pucker." An epiretinal membrane can cause visual loss, as well as distorted or double vision.

Epiretinal membranes may be caused by a variety of eye problems. They may follow retinal detachment surgery or laser treatment r cryotherapy for retinal tears. They may be associated with retinal blood vessel problems. In most cases, the epiretinal membrane occurs in an otherwise healthy eye as a result of a posterior vitreous detachment.

The only treatment for visual loss caused by an epiretinal membrane is surgery to remove the membrane. If the vision is only mildly reduced, it is best not to do surgery. If the visual loss or distortion is significant, however, a vitrectomy may be performed under general anesthesia. The membrane is picked up with a fine instrument and gently peeled off the surface of the retina.

Vision usually improves slowly after surgery, with most of the improvement coming within the first three months, though it may continue to improve for many months. In some cases, the vision may not improve at all. The chance that vision will improve following surgery is about 75%. On average, patients regain approximately half of the vision that was lost because of the epiretinal membrane.

The complications of the surgery include retinal tears and detachment, cataract formation, infection, and regrowth of the membrane. These complications may result in mild to total loss of vision, though vision-losing complications are rare.

When and infection occurs inside the eye, it is called "endophthalmitis." This is a very serious problem and often results in loss of all vision or even the eye. Endophthalmitis usually occurs after intraocular surgery (surgery done inside the eye) or penetrating trauma. Endophthalmitis may be treated with antibiotics which are injectioned into the eye.

If the endophthalmitis is severe, vitrectomy may be necessary to save the eye before all vision is lost. Vitrectomy is done to remove the infectious material inside the eye. At the same time, anitbiotics are injected into the eye. Your doctor will discuss with you the best method of treatment, although it must be understood that in any case of endophthalmitis, severe visual loss can occur.

Traumatic injuries to the eye can lead to severe retinal problems. A direct blow to the eye may cause vitreous hemorrhage and/or retinal detachment. Pieces of metal, or other materials, called "intraocular foreign bodies," may penetrate the sclera and cause retinal detachment, vitreous hemorrhage, or severe infection in the eye. Even if they don't cause immediate problems, certain metallic foreign bodies may be toxic and can eventually destroy the eye if they remain in place. If the eye is penetrated by a sharp object, scar tissue can form along the track of the object, as well as on the retinal surface. The scar tissue can pull on and detach the retina (traction retinal detachment).

In cases where trauma has caused retinal problems, vitrectomy may save vision. In some cases, the goal is to remove the intraocular foreign body or blood (vireous hemorrhage) and repair the damage to the retina wih laser or cryo. In other cases, virectomy removes scar tissue from the surface of the retina, or prevents traction retinal detachment from occurring.

The timing of the surgery, and the specific techniques used, will depend on the type of trauma that the eye has suffered. Your surgeon will counsel you about this and talk to you about your changes of saving the eye and vision. Your surgeon will also tell you about the complications of this surgery, the most important of which are loss of all vision and even the eye.

Occasionally, during cataract surgery, the natural lens of the eye (which is the cataract), or a portion of the lens, falls into the vitreous cavity. This may cause inflammation in the eye which can cause the normal pressure in the eye to rise to dangerous levels. The dislocated lens can be removed by vitrectomy surgery. Another problem that can occur durring or after cataract surgery is the dislocation of the plastic lent implant, the intraocular lens (IOL); the intraocular lens can fall into the vitreous cavity. This can also occur following trauma to the eye. Vitreous surgery can be done to place the plastic intraocular lens in its proper position. The vitreous is removed and then the lens is grasped with forceps and placed into position where it may be sutured in order to keep it stable.

Sometimes a retinal hole develops in the center of the macula. This is called a "macular hole" and is caused by vitreous traction. The vitreous overlying the macula may first contact and pull up the center of the macula. When this happens, the patient may notice slight distrotion or a reduction in vision. As the viteous continues to pull, the macula ma develop a tiny hole. With time, this hole may become larger. When a macular hole occurs, central or detail vision is lost.

When a patient develops a macular hole in one eye, there is about a 10% chance that a macular hole develops, vetrectomy surgery may improve the vision. The vitreous is removed and a gas is placed in the eye that helps the macular to remain in place and the hole to heal. Following the surgery, the patient is required to remain in a face-down position for seven to ten days.

Not all patients with a macular hole will see bette following the surgery. Your doctor will discuss with you the indications for and complications of the surgery. The complications are very much the same as for any vitreous surgery.

Subretinal neovascularization is a term used to describe the growth of abnormal blood vessels and scar tissue under the macula. These vessels grow for a variety of reasons, especially macular degeneration as well as certain types of inflammations. The vessels can leak fluid, bleed, and cause a scar, and all of these changes can cause loss of central or detail vision. Laser treatment may be possible for subretinal neovascularization.

When laser treatment is not helpful or cannot be done, vitrectomy surgery can be done to remove the subretinal neovascularization and scar tissue as well as blood from under the retina.

Special instruments are placed through a retinal hole under the retina to gasp, pull-on, and remove the subretinal neovascularization. In eyes with a great deal of blood under the retina, a drug may be placed under the retina to liquify the blood clot before it is removed. After this, a gas bubble is placed in the eye and retinal hole may then be treated with laser. The patient is then required to rmain in a facedown positioin following surgery so that the gas bubble in the eye can hold the retina in place while lase treatment creates a permanent seal.

It has not been determined whether submacular surgery is truly helpful to preserve vision. Your surgeon will discuss with you whenther this surgery may possibly be helpful for your particular problem.