Vitrectomy (Trans Pars Plana Vitrectomy)
Vitrectomy is the surgical removal of vitreous gel from the middle and back of the inner eye. The vitreous gel fills the back 80% of the inner eye, otherwise known as the vitreous cavity, which is directly in front of the retina. Vitrectomy is typically performed in a surgery center or hospital. It as an outpatient procedure; usually you are not admitted to the hospital.
Vitrectomy is performed to treat a number of retinal diseases and disorders. In some cases the vitreous gel can fill with blood (typically due to vitreous hemorrhage) and fails t clear on its own; the vitreous gel will be removed. A vitrectomy can also be performed because there is scar tissue on the retina that needs to be removed. Removing the gel gives Dr. Jawad Qureshi access to the retinal surface to remove membranes or scar tissue or to fix a retinal detachment. Vitrectomy is also performed in the case of diabetic retinopathy, macular hole, macular pucker, retinal tears, traumatic eye injury and retained lens material following cataract surgery.
Vitrectomy is typically performed under local anesthesia, with sedation. This means that you will be awake during the procedure, but unable to see or feel anything. In some cases, general anesthesia is used.
During the surgery, Dr. Jawad Qureshi will make three microscopic 1mm or smaller incisions in the sclera (the white of the eyes) with a microscopic blade. Each incision serves as an access port for entry into the back of the eye. The first port is used to infuse fluid (saline solution) into the eye as the vitreous gel is being removed. This ensures that the eye stays pressurized and retains its shape. The second access port is typically used to insert a fiberoptic light to illuminate the inside of the eyeball and allow Dr. Qureshi to see where he is operating. The third port is typically used to insert and remove specialized instruments to operate on the retina and vitreous, including the vitrectomy probe used to remove the vitreous gel from the eye or vitreous cavity by cutting and then suctioning it out. The vitreous that is removed does not grow back, but over time is replaced by fluid that is normally produced by the eye. Vitreous gel was important during the development of the eye but is not necessary following birth for overall eye health.
Typical vitrectomy surgery uses I millimeter incisions in the eye as discussed above (20-gauge). Despite the small size of these incisions, sutures are still required in most cases. A newer technique allows for the use of 0.5 mm incisions (25-guage). The greatest advantage of this technique is that due to the size of the incisions, the incisions generally seal by themselves and do not require sutures.
Sutures can be irritating on the eye’s surface until they dissolve, which typically takes several weeks. Sutures can also temporarily change the shape of the eye and affect your ability to focus. Patients who undergo 25-gauge vitrectomy typically recover quicker (usually within days) while report minimal to no postoperative discomfort. Dr. Qureshi uses the “sutureless” vitrectomy surgical technique in all cases appropriate for this type of approach.
Depending upon the specific retinal disease or disorder being treated, after removing the vitreous gel, Dr. Qureshi may treat the retina with a laser (photocoagulation), repair holes or tears in the retina or macula, cut or remove scar tissue from the retina or flatten areas where the retina has become detached.
Many retinal diseases require laser photocoagulation treatment as a part of vitrectomy surgery. The laser is often used to treat vitreous hemorrhage (suspended blood in the vitreous gel) or abnormal blood vessels in diabetic retinopathy as well as seal tears in the retina that can lead to retinal detachment. A fiber-optic laser is inserted into the eye through one of the ports and laser therapy is delivered to the area of the eye being treated.
During the vitrectomy surgery, the eye is often filled with air, or a mixture of air and gas. The type of gas used depends on the circumstances. This “gas bubble” is used in macular hole surgery to close a macular hole, to prevent or repair retinal detachment or for other reasons. The primary reason the gas bubble is used is to seal holes or tears in the retina following surgery. The gas bubble essentially acts as a “cast” to aid the healing process, holding the retina in place till it is healed. This is why the patient will be instructed to assume a specific position following vitrectomy with gas infusion; the purpose is to float the gas bubble against the area of the retina that is torn or diseased while it heals. In most cases, this means lying on one side or looking straight down. Patients who undergo vitrectomy should avoid looking upward or lying on their back for any significant period of time, to minimize movement of the bubble, which can raise intraocular pressure, accelerate cataract formation, or damage the cornea. Finally, patients who have undergone vitrectomy must avoid flying with an air or gas bubble in the eye. The reduced atmospheric pressure during air travel causes the gas bubble to expand, which can raise the pressure in the eye to dangerous levels. Dr. Qureshi will tell you when it is safe to fly.
The eye reabsorbs the gas bubble over a period of time depending upon the concentration of air to gas. Air usually lasts about a week, while longer acting gases may take 2 months to be reabsorbed. The clear fluid your eye produces at all times, retaining the shape of your eye, replaces the gas.
If Dr. Qureshi suspects the retina will need longer support during the healing process, silicone oil will be used instead of a gas mixture. This typically occurs in the repair of complex retinal detachment cases with a lot of scar tissue. Scar tissue can be progressive in nature, meaning it will continue. Silicone oils is needed to protect the retina for an extended period of time to protect against more scar tissue being created. Scar tissue can pull on the retina and/or tears, leading to another retinal detachment and additional surgery. As stated above, the main advantage of silicone oil is that it provides support of the retina for a prolonged period of time. Other advantages include quicker visual recovery, less need for head-position restrictions following vitrectomy surgery and no restriction on air travel. The main disadvantage is that unlike a gas bubble that dissipates on its own, silicone oil must be removed with a second surgical procedure, similar to the initial vitrectomy.
Membrane peeling is a surgical technique that is commonly performed with vitrectomy. In membrane peeling surgery, Dr. Qureshi uses microscopic instruments to approach membranes and peel them off of the surface of the retina. Thin, delicate membranes (scar tissue) are often present on the surface of the retina; they pull on the retina causing distortion. These membranes, or scar tissue, are common in patients with diabetic retinopathy, macular hole, macular pucker and complex retinal detachment. The pulling on the retina-traction- is typically responsible for the hole formation, puckering or retinal detachment.
Although results vary depending on the individual condition treated, most patients see better following vitrectomy. Patients go home with a patch on the eye, which will be removed at the Retina Center of Texas office the next day. There may be several follow-up visits during the first month, and visits less frequently for a few months beyond. Eyedrops are used for a few weeks after the vitrectomy surgery. These typically include antibiotic drops to prevent infection, steroid drops to minimize inflammation and dilating drops to minimize scarring of the pupil and provide comfort. Sometimes drops to lower the pressure in the eye are necessary. Patients are usually able to return to normal activity within a few weeks. Most of the healing occurs during the first month; it may take a few months to achieve your best vision.