Step 1 – Learn the basics about the eye and tractional retinal detachments
Step 2 – Learn about the surgery and what to expect
Step 3 – Learn about the other options
Step 4 – Learn about the potential risks of the procedure
Step 5 – Learn to maximize your results
The eye can be thought of as similar to a camera, with two main parts, a lens and a film. In addition, there is a gel called the vitreous that is located in front of the retina and is very firmly adherent to it. The film layer is called the retina and lines the back wall of the eye. The cells responsible for converting light to an electrical signal and producing vision are located in the outer layer of the retina. This layer receives blood flow from the outer wall of the eye. A retinal detachment is a separation of the outer layer of the retina from the wall of the eye.
Abnormal new blood vessels grow from the retina surface into the vitreous. They proliferate within the back face of the vitreous. Over time, the abnormal blood vessels start to regress (go away) and transform into scar tissue. The scar tissue contracts, causing a pulling force on the retina. The pulling force may distort the area of central vision, cause edema (swelling) within or under the macula, or create a retinal tear.
Pars plana vitrectomy is a surgical procedure which is performed in the operating room. It may be performed under twilight (monitored anesthesia care) or general anesthesia.
The retina specialist places 3 small ports that are less than 1mm in size through the white of the eye and into the vitreous cavity. Fluid is infused into the vitreous cavity while the surgeon uses a vitrectomy probe to carefully removes the vitreous. The surgeon meticulously visualizes and separates the network of scar tissue into smaller segments. The smaller segments are separated from the vitreous (gel) and carefully removed. Laser is applied carefully throughout the retina to decrease the risk of new blood vessels developing. The scar tissue is typically very adherent to the retina, and retinal tears may form when removing the tissue. Retinal tears are lasered and the eye may then be filled up with either absorbable gas or silicone oil. No gas or oil is required if there are no retinal tears.
The eye is then patched and a shield is placed on the eye. The patient may be asked to maintain a specific position for approximately 7 days if there is a retinal tear. The surgery is not typically very painful. Tylenol is all that is usually needed for pain.
More about gas and silicone oil.
The purpose is to allow the gas or oil to move into a position that it covers the retinal tears, and prevents fluid from collecting underneath it while the retinal laser takes effect.
There are two different types of self-absorbing gas: SF6 and C3F8. SF6 typically lasts approximately 2 weeks and C3F8 approximately 6-8 weeks. Patients will notice a clear area at the top of their visual field which represents the area of retina not covered by the gas bubble. This area will become larger over time until the gas bubble no longer covers the area of central vision. At this point, the central vision will slowly become clearer. This process will occur until the gas bubble resolves completely. The central vision is typically decreased or distorted if it was affected by the retinal detachment. This typically improves slowly over a period of several months.
It is not possible to see through the gas bubble. The gas bubble will resolve over a period of several weeks. The central vision will become clearer (if pre-operatively involved by the retinal detachment) over several weeks to months. If the central vision is not involved, the primary visual improvement will be an improvement in the peripheral vision whch was previously affected by the retinal detachment.
Patients may not travel to high altitudes or fly when they have a gas bubble in the eye. The gas bubble expands rapidly in high altitudes causing high eye pressure and blindness.
Silicone oil is a great choice for patients who need a longer acting agent to prevent retinal re-detachment. It is not self-absorbing and may be removed safely at a later date. It is difficult to see through silicone oil and the vision is typically limited with the silicone oil in the vitreous cavity. The vision typically improves with removal of the silicone oil, but may be limited due to underlying damage from the pre-existing diabetic changes.
Surgery is typically recommended once the tractional retinal detachment is threatening or involving the area of the retina responsible for central vision. Waiting longer than suggested by the retinal specialist may result in a permanent visual decline.
Panretinal photocoagulation (laser) will help the abnormal new blood vessels begin to regress (go away), but this will not cause the scar tissue to resolve.
Intravitreal Avastin is an in-office eye injection which may be administered with minimal discomfort. It is very effective in causing abnormal blood vessels to go away, but does not cause scar tissue to resolve. It is often used prior to surgery to decrease the risk of bleeding.
The retina specialists who recommends the treatment will discuss the risks, benefits, and alternatives to the procedure. It is up to the judgement of the physician to weigh the benefit of the procedure to the potential risks. It is only once the decision is made that the benefits outweigh the potential risks is the procedure offered to the patient.
Pars plana vitrectomy is reported to result in a visual improvement in 2 more lines in approximately 50% of patients. The vision is frequently limited not due to the surgery, but by underlying poor blood flow related to diabetes.
The most significant risk of pars plana vitrectomy is failure of the procedure to repair the tractional retinal detachment or redetachment. In this case, another surgery, such as an additional pars plans vitrectomy (possibly with silicone oil) is typically required.
Symptoms of retinal re-detachment include the sudden onset of many new floaters, new onset flashing lights, or noting a progressive decrease in the peripheral vision (like a curtain coming down at a play). This is urgent and the treating physician should be made aware the same day.
There is a small risk of infection following the procedure. If this is going to occur, it typically occurs 3-5 days following the procedure. Symptoms include redness around the eye that gets worse not better, extreme light sensitivity, and worsening pain. This is a medical emergency and requires immediate treatment by a retina specialist.
Patients who still have their nature lens will experience progression of their cataract following vitrectomy surgery. Approximately 90% of patients who are 50 years or older will require cataract surgery within 2 years.
All surgeries are associated with a number of other uncommon, but possible problems. Potential complications of pars plana vitrectomy include cataract formation, high eye pressure, bleeding within the eye, development of new retinal tears, proliferative vitreoretinopathy, and need for further procedures.
It is important to use eye drops as prescribed by your retina specialist. Patients may continue to use prescription eye drops (such as for glaucoma), unless otherwise told not to by their physician.
The peripheral vision should gradually become clearer. If the peripheral vision becomes dark and starts to become larger, this is a sign of a retinal detachment or vitreous hemorrhage. This requires prompt evaluation by your retina specialist.
Tylenol is all that is typically needed for pain. It is recommended to all your retina specialist if you are having more severe pain, as this could be a sign of high pressure or infection.
The eye should continue feeling better following surgery. Infection is characterized by a combination of severe eye pain, profound light sensitivity, and a decrease in vision. If infection is to occur, it most commonly occurs between 3-5 days following surgery. This must be treated emergently.
It is critical to the success of the procedure to maintain the positioning requested for 50 minutes per hour, 24 hours per day (including during sleep). Most physicians will recommend 1 week of positioning.
Traveling to high altitudes results in rapid expansion of the gas bubble and subsequent blindness. Patient may not travel to high altitudes until the gas bubble resolves.
It is not possible to see through the gas bubble. The gas bubble will resolve over a period of several weeks. The central vision will become clearer (if pre-operatively involved by the retinal detachment) over several weeks to months. If the central vision is not involved, the primary visual improvement will be an improvement in the peripheral vision whch was previously affected by the retinal detachment.
Administration of nitric oxide for anesthesia may cause rapid expansion of the gas bubble and blindness. Patients should make their anesthesiologist aware they have a gas bubble in the eye if they are undergoing surgery.
This information is being provided to you for educational purposes only. Accessing or using this information does not constitute the practice of medicine nor does it establish a physician-patient relationship. This information does not replace a consultation with your eye care specialist. This information should be used at your own risk. The authors and Eye Know More do not assume any responsibility for harm incurred by the viewers. All information on the website is copyrighted and is the property of Eye Know More. Unauthorized redistribution of Eye Know More’s proprietary information constitutes a copyright violation.
