Retinal Tears & Detachments
Inside the eye, the middle and back sections are filled with a clear, gel-like substance called the vitreous, which is connected to the retina—the thin, light-sensitive layer of tissue lining the back of the eye. While the vitreous is primarily made up of water, it has certain areas where it clings more firmly to the retina.
As everyone ages, the vitreous condenses, becomes more liquid in some regions, and usually separates from the surface of the retina. This vitreous separation is called a “posterior vitreous detachment”. Posterior vitreous detachment tends to occur at an earlier age in patients with high near-sightedness (myopia) and often occurs within several months of cataract surgery.
Symptoms of a posterior vitreous detachment include the sudden onset of floaters and sometimes flashes of light caused by parts of the vitreous that are still attached and pulling on areas of the retina. Sometimes this tension by the vitreous causes a tear in the retina. Symptoms of a retinal tear are usually similar to posterior vitreous detachment, although the floaters and flashes may be more pronounced.
If the vitreous mechanically injures a blood vessel, bleeding into the vitreous can result in a “vitreous hemorrhage” and can block light and sometimes lead to significant blurring of vision.
If a retinal tear is not diagnosed and treated, it can progress to a retinal detachment. This happens when fluid from the interior of the eye migrates under the retina through the tear and causes a separation of the retina from its underlying skin layer. Symptoms of a retinal detachment usually involve a dark shadow or curtain in the peripheral vision.
Retinal holes do not always happen from a posterior vitreous detachment and can also occur from thinning or “atrophy”. This is particularly common in high near-sightedness but can also occur in normal eyes. These thin areas are called “lattice degeneration” and can sometimes lead to a retinal hole or detachment even in the absence of a posterior vitreous detachment. In this case, symptoms of a retinal detachment can occur without preceding floaters or flashes.
Treatment of Retinal Tears & Detachments
Laser Treatment
Most retinal tears can be treated with special surgical laser equipment. Laser treatment involves shining a beam of light through the pupil and creating small burns to the region of retina around the tear. This stimulates the skin under the retina to create an adhesion that seals the area around the tear and prevents progression to a retinal detachment.
This is often called laser retinopexy. Laser treatment can be slightly uncomfortable while being performed but usually lasts only a few minutes. However, there should be no pain during or following the procedure.
Occasionally, small areas of retinal detachment can be treated with laser alone to “wall off” the area of separation from progressing to larger areas. Laser treatment does not remove floaters or stop flashes from occurring. Flashes usually subside after several days following a retinal tear, and floaters gradually become less noticeable over several weeks or months.
Before Retina Tear Treatment
After Retina Tear Treatment
Scleral Buckle
A scleral buckle involves stitching a silicone band around the outside of the eye, under the eye muscles and hidden from view.
This treatment works by indenting the eye wall and reducing the height of the detached retina. This also reduces the inward forces of vitreous pulling on the retinal tear. Laser or cryotherapy is then applied to the affected areas. Additional procedures can also be used.
A scleral buckle may cause a slight increase in near-sightedness and works particularly well for limited retinal detachments in young patients that have not had cataract surgery.
Cryotherapy
This procedure works by freezing and destroying abnormal tissue or causing a mild inflammatory response that promotes scarring. This scarring acts as a “glue,” helping to reattach the retina or seal retinal tears to prevent fluid from passing through and causing a detachment.
The freezing process is quick and localized, ensuring minimal impact on surrounding healthy tissues.
Vitrectomy
A vitrectomy involves mechanically repairing the retinal detachment from inside the eye. During this procedure, small incisions are placed through the conjunctiva and sclera in a region called the “pars plana”. While a saline infusion maintains eye pressure and shape, two additional instruments are used to remove the vitreous that is the cause of the underlying problem. The fluid under the retina is then aspirated while air is infused, and the retina is re-attached. Following this, laser treatment is used to seal the retinal tears, and the air is replaced with either gas or silicone oil.
Many additional tools and techniques can be used to treat a wide range of eye problems with vitrectomy. Vitrectomy is sometimes performed in addition to or following a scleral buckle based on the preference of the retinal specialist and the individual patient’s situation.
Before and After Retinal Detachment Repair with Vitrectomy and Gas Bubble
Pneumatic Retinopexy
Once a retinal tear has progressed to a retinal detachment, something more than laser treatment is recommended. If the retinal tear is in the upper interior portion of the eye, a gas bubble can be injected to seal it off. The surface of the gas bubble prevents more fluid from migrating under the retina, and allows the skin to reabsorb the retinal detachment. Since bubbles float, it makes sense that this form of treatment usually works best for tears and detachments located in the upper portion of the retina, or in locations that simple head positioning can let the bubble contact the retinal tear. This treatment is used together with cryotherapy or laser treatment, performed either on the day of the gas bubble injection or several days later, after the retinal detachment has resolved.
It is very important to remember that one cannot travel by air or have anesthesia in with nitrous oxide while a gas bubble is present. Occasionally, additional procedures or surgery will be required several days following the initial gas bubble injection if the procedure fails to resolve the problem or a new tear develops.
Proliferative Vitreoretinopathy
Proliferative Vitreoretinopathy (PVR) is a serious condition that can develop after a retinal detachment or retinal tear. It occurs when scar tissue forms on the retina or its surface membranes, causing the retina to stiffen, wrinkle, or pull away from the back of the eye again, even after it has been repaired. PVR is a leading cause of failed retinal detachment surgeries. Occasionally, PVR is present prior to surgery and is more common in retinal detachments that have existed for several weeks or longer.
Sometimes multiple surgeries are required to fix a retinal detachment. In this scenario, silicone oil is used in place of a gas bubble to provide long term waterproofing to the surface of the retina. Silicone oil is a clear liquid that stays in the eye long term and may eventually be removed, if the retina remains completely attached. Silicone oil does not block vision, but it does change the way light bends and makes patients more farsighted (less nearsighted). Rarely, proliferative vitreoretinopathy progresses despite multiple retinal surgeries, and the final situation may be inoperable.