What is a Retinal Detachment?
The retina is the light-sensitive layer of tissue that lines the inside of the eye and sends visual messages through the optic nerve to the brain. The vitreous inside the eye (see image) can pull on the retina and cause a tear. Once there is a tear, fluid can travel from inside the eye to under the retina. When the retina detaches, it is lifted or pulled from its normal position. This is usually accompanied by a shadow in the side vision. If the retinal detachment involves the center of the retina, central vision declines and sometimes becomes distorted. If not promptly treated, retinal detachment can cause permanent vision loss. There are several approaches to a retinal detachment which include the following possibilities (some of which can be combined depending on the situation).
- Laser Demarcation
- Pneumatic Retinopexy
- Scleral Buckle
- Pars Plana Vitrectomy
- Vitrectomy with scleral buckle
- Membrane peel for proliferative vitreoretinopathy
- Retinectomy for proliferative vitreoretinopathy
- Silicone Oil vs Gas
What is laser demarcation?
One way to treat a retinal detachment is to demarcate it with laser. Some retinal detachments are very small and minimally affect the vision. If there is a small retinal detachment and it is minimally affecting vision, treating it with laser can prevent it from growing into a larger retinal detachment. The advantage of laser for retinal detachment is that the laser is very low risk. It does not involve any incision or injection or surgery on the eye. There are two main disadvantages to laser demarcation. The first is that it doesn't really fix the detached retina, it just barriers off the detached retina. So if the retinal detachment is causing a shadow in the side vision, that will not get better after laser demarcation. The second disadvantage of laser demarcation is that if it doesn't work, if the retinal detachment breaks through the laser barrier, then the subsequent retinal detachment can be a little more difficult to fix. The areas that were treated with laser before the detachment extended can be weak and require further therapy. In addition, sometimes parts of the laser stick while others do not, making the retina difficult to smooth out. Most surgeons reserve laser demarcation for very small retinal detachments that are minimally symptomatic or asymptomatic.
What is a Pneumatic Retinopexy?
There are several ways to reattach a retinal detachment. Each technique involves reattaching the retina and then inducing a localized adhesion to keep the retina attached. The least invasive and least risky way to fix a retinal detachment is with a pneumatic retinopexy. A pneumatic retinopexy is an office procedure. In an eye with a retinal detachment caused by a break that is superior (in the upper part of the retina) like the eye pictured on the right, a gas bubble can be injected into the eye to push the break closed and push the retina back into position.
In addition to the gas bubble, a form of retinal adhesion is needed: either with cryotherapy--which is done on the same day as the gas bubble injection and works like glue, or laser--which is done once the retina is attached and works a like a staple.
Why is Positioning Required?
Since a gas bubble in the eye does not know where it is supposed to go, it is very very important that patients who are treated with pneumatic retinopexy position their head properly during the days and weeks following treatment. A bubble in the eye rises to the top of the eye. So patients with breaks at 12:00, for example, would need to sit upright looking straight ahead to keep the bubble on the break. Patients with breaks at 3:00 would need to lay on their side. Pneumatic retinopexy, in properly selected cases, has about a 90% success rate of reattaching the retina. It is almost impossible to reattach a retina with a break at 6:00 with a pneumatic retinopexy, because in order to place the bubble on the break, the patient needs to hang upside down. Believe it or not, this procedure has been done in very motivated patients with some success.
A patient with a gas bubble in his eye cannot fly until the gas bubble re-absorbs. Most airplanes are pressurized to about 1/2 atmosphere, so a bubble in an airplane will double in size. In the case of gas filled eye, this causes an abrupt rise in intraocular pressure that can be blinding if the pressure in the eye is high enough to cut off the circulation to the eye.
What is a scleral buckle?
The very first widely adopted method to repair a retinal detachment was with a scleral buckle. Today, scleral buckling is reserved for a few specific types of retinal detachment. A scleral buckle works by indenting the outside of the eye over the retinal break that is causing the retinal detachment. By indenting the eye, it allows the break to seal down onto the underlying tissue and the retinal detachment will flatten. In select cases, a scleral buckle is about 90 percent successful at reattaching a retina. The biggest advantage of the scleral buckle is that it is an entirely external procedure and carries no risk of cataract. So if there is a young patient with a retinal detachment, and the detachment is caused by breaks below the midline that cannot be treated with a gas bubble (pneumatic retinopexy - see above) then a scleral buckle can work beautifully. There are disadvantages to a scleral buckle which is why it is only used in limited situations. First, the surgery requires suturing the buckle to the eye which sometimes can cause severe intraocular bleeding. Second, the scleral buckle changes the shape of the eye which requires a change in prescription glasses. In addition, sometimes scleral buckles are uncomfortable and they may adversely affect the circulation to the eye in some cases. Finally, in studies comparing visual recovery in pneumatic retinopexy vs. scleral buckle, it seemed like the vision is sometimes better following pneumatic retinopexy.
What is a vitrectomy?
Vitrectomy Surgery allows the Retina Surgeon to work inside of the eye and repair damage caused by a variety of diseases. The vitreous is the jelly inside the eye and is removed during the vitrectomy. YOU DO NOT NEED YOUR VITREOUS. The vitreous is important when the eye forms as a fetus grows into a baby. For a primary retinal detachment or uncomplicated retinal detachment, vitrectomy can be used to re-attach the retina. The vitreous traction on the retina is responsible for the retinal tear(s) that caused the retinal detachment. Vitrectomy allows for release of the traction on the retinal tear. It is impossible to remove 100 percent of the vitreous because in some areas of the eye, the vitreous is firmly attached to the retina. Nevertheless, 90 percent of the vitreous can be removed. In addition to relieving traction on the retinal breaks and other areas of the retina, removal of the vitreous allows the surgeon to introduce instruments into the eye during retinal detachment surgery. It is possible to drain the subretinal fluid during vitrectomy. While draining the subretinal fluid, air is used to fill the eye which pushes the retina back into place. Thus, the retina can be reattached during the surgery. In addition, using a laser probe, laser retinopexy can be placed at the time of vitrecotmy surgery around the retinal break(s) and also around any other retina that looks weak or prone to retinal breaks. Some sureons add 360 degree peripheral retinal laser to tack down all of the peripheral retina. Vitrectomy surgery does not change the refractive error of the eye and therfore is sometimes appealing in patients who have had refractive surgery. One drawback to vitrectomy surgery is that is usually (almost always) causes a cataract. However, in a patient who had already had cataract surgery, vitrectomy surgery cannot cause a cataract and it is therefore an appealing procedure in someone who has already had cataract surgery.
Video Vitrectomy for Retinal Detachment
This 67 year old woman presented with acute shadow and vision loss in her left eye. She had previous retinal detachment repair in the right eye in 2005 by me. The left eye had a temporal retinal detachment with retinal holes and lattice degeneration at 12, 1, 4, and 6. I drained the subretinal fluid through the peripheral holes. I did NOT use perfluoron nor did I create a posterior retinotomy to reattach the retina. Her vision was back to baseline for her within about 2 months of the surgery.
What is a Buckle - vitrectomy?
There are advantages to combining a scleral buckle with a vitrectomy. The scleral buckle is placed around the eye, usually supporting the vitreous base. This is helpful because it is impossible to remove all the vitreous from the eye. The vitreous at the vitreous base will sometimes contract after a vitrectomy causing a recurrent retinal detachment. The scleral buckle helps support the vitreous base and likely reduces the risk of re-detachment in many situations. It also allows the retina to be attached with less laser. Without the scleral buckle, many surgeons laser the retina 360 degrees to decrease the risk of further detachments. There is some evidence that patients who have had a scleral buckle placed at their initial vitrectomy surgery do better if they require further surgery for retinal detachment than those who did not have a scleral buckle placed during the initial retinal detachment repair.
THE VIDEO BELOW SHOW SOME BLOOD.
The video below shows a 50 year old man had 4 days of vision loss. He had a total retinal detachment with multiple retinal breaks and lattice degeneration. He is a -12.00 myope with a dense cataract. The surgery shows retinal detachment repair with a scleral buckle (42 band and 70 sleeve) and a vitrectomy (23 gauge). Laser is used at the time of surgery and 25 percent sulfer hexafluoride gas is used as endotamponade. The surgery is done under general anesthesia. Marcaine (a long acting anesthetic) was irrigated around the eye for post-operative pain. The marcaine lasts about 8 hours. Subsequently the patient had moderate pain for about 2 days that was controlled with non-prescription pain medicines. After retinal detachment surgery, the patient positioned for a week, initially face down and then side to side.
Why would a retinal detachment recur?
There are two main reasons for recurrent retinal detachments. The first is new retinal tears. About 10 percent of people who have a retinal tear develop subsequent retinal tears, usually within the first 3 months of onset of the initial tear. Depending on the treatment, these new tears can cause a new retinal detachment. The second, more serious cause of recurrent retinal detachments is scar tissue that forms on, in, or under the retina following the initial repair: proliferative vitreoretinopathy (PVR). Proliferative vitreoretinopathy pulls on the retina and causes it to detach. Surgery for PVR detachments is often successful, but may require significant manipulation of the retina. If there are pre-retinal membranes they can be removed. If there are intra-retinal membranes or the retina is contracted, a retinectomy can be done to relax the retina and allow it to attach. Ultimately, about 99 percent of retinas can be attached. Unfortunately, the visual outcomes can be poor in eyes that have required multiple surgeries.
What is proliferative vitreoretinopathy (PVR)?
Proliferative vitreoretinopathy is the growth of unwanted scar tissue in an eye with retinal detachment. It usually occurs after retinal detachment repair. Sometimes PVR occurs in a primary retinal detachment associated with trauma or a retinal detachment that is very old (months) prior to repair. If the scar tissue is in front of the retina, it can be removed at the time of surgery to relax the retina so it will reattach (see below video). If the scar tissue is in the retina, then sometimes the retina needs to be relaxed with a peripheral retinectomy (see also the below video). Most retinal detachment failures are due to PVR. The below video shows a very complicated retinal detachment where the patient had many prior surgeries done locally and had developed severe PVR and also had subretinal silicone oil. Silicone oil is used to hold complex retinal detachments in place, like gas, until the laser adhesion has time to mature. Subretinal silicone oil is very bad for the retina because it cuts of the oxygen supply to the retina.
What is perfluoron?
Perfluoron is a special liquid used during surgery to a repair complex retinal detachment. Perfluoron is heavier than water and sinks when placed in a fluid filled eye during surgery. This makes it very useful for repairing retinal detachmnets with a giant retinal tear or where the retina needs to be relaxed surgically because of PVR. The below video shows surgery in an eye has a 3 clock hour retinal tear and nasal, relatively small, retinal detachment. Retinal tears that are 3 clock hours or bigger are considered "giant" retinal tears. The techniques to reattach these retinas are slightly different from those used in eyes without giant retinal tears. Perfluoron is used to flatten the retina initially. The Perfluoron is a heavier than water liquid. It rolls the retina back into its natural position and smooths out the area with the giant tear. Since this was a relatively small and very anterior (front of the eye) giant tear, I used air and gas to flatten the retina at the end of the surgery. In cases of larger giant retinal tears or more posterior giant retinal tears, silicone oil is often more appropriate.