Vitreous Surgery
Occasionally, a retinal detachment is so complicated and severe that it cannot be treated with either standard scleral buckling surgery or pneumatic retinopexy. In such cases, vitreous surgery to reattach the retina may be necessary.
Vitreous surgery is performed in an operating room usually under local anesthesia. The vitreous is removed and, therefore, this procedure is called vitrectomy. The surgeon uses a fiber optic light to illuminate the inside of the eye and other instruments inside the eye, such as forceps, 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 gas that completely fills the eye. Over time, the fluid (or gas) is absorbed by the eye and 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.
Dr. Moises A. Chica, MD, and Dr. Calvin E. Mein, MD, offer vitreous surgery, also known as vitrectomy, and other vitreoretinal care services at Retinal Consultants of San Antonio, serving San Antonio, Kerrville, New Braunfels, Castle Hills, Converse, Schertz, Hollywood Park, Kirby, Somerset, Castroville, Alamo Heights and the surrounding area.
Protocols
Vitrectomy is required for retinal reattachment in a variety of conditions. For example, scar tissue may grow on the vitreous or the surface of the retina and pull on the retina and detach it. Occasionally, something in the vitreous, such as blood, 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 membrane (macular pucker), intraocular infection (endophthalmitis), trauma, intraocular foreign body, and macular hole. Today vitrectomy is often used to repair retinal detachment in eyes that have already had cataract surgery.
The Procedure
In a vitrectomy, instruments are passed through the sclera into 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.
Recent advancements in technology have led to smaller instrumentation for vitrectomy surgery. Standard size for vitrectomy was 20-gauge until recently when much smaller 25-gauge instrumentation became available. No suturing is required in most cases. Healing is quicker, pain is less, and the overall experience of vitrectomy surgery is much more comfortable for the patient. Dr. Mein and Dr. Chica now do over 90% of cases with 25-gauge instruments.
Vitrectomy can be combined with the placement of a scleral buckle. Usually, air, gas, or silicone oil is place in the vitreous cavity. These materials hold the retina in place against the back wall of the eye while the laser scars are forming. 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.
Positioning after vitrectomy surgery with gas bubble present in the eye
Eventually, the gas is absorbed and replaced by fluid produced by the eye. If silicone oil has been used, it frequently must be removed at a later time with another surgical procedure.
Vitreous surgery usually lasts one to two hours but, with very severe and difficult problems, may take longer.
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 promptly.
Ultrasonography for Vitreous Hemorrhage and Retinal Detachment
When a retinal tear occurs, retinal blood vessels may also be torn. When this happens, blood enters 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 and retinal detachment is difficult to treat because the hemorrhage prevents the surgeon from seeing the retina and finding the tears. 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. The combination of retinal detachment and vitreous hemorrhage puts the eye at high risk for developing proliferative vitreoretinopathy.
