The retina is a thin clear layer of brain tissue one-fifth of a millimeter thick. The retina coats the inner wall of the eye and is much like the “film” in the camera; light hits the retina and the retina sends a signal to the brain, via the optic nerve.
If we think about how amazing our vision is in the sense of the detail, color, and motion we can see, we realize that the retina is quite an tissue to capture and convey such a rich visual signal. To perform that job, the retina needs a tremendous amount of oxygen. The retina has its own blood vessels but those blood vessels only supply one-third of the retina’s oxygen requirements. The other two-thirds of the retina’s needed oxygen comes from a layer of tissue directly underneath the retina, called the RPE-choroid complex. RPE stands for retinal pigment epithelium. The RPE-choroid supplies two-thirds of the retina’s oxygen and also provides nutrients to the retina and removes the retina’s metabolic byproducts.
The macula is the “center” of the retina which accounts for our sharpest vision–our 20/20 central vision that allows us to read books and road signs, watch TV, play baseball or tennis, etc. The remainder of the retina gives us “peripheral” vision.
There are 3 main types of retinal detachment. The most common type is a “rhegmatogenous retinal detachment.” Rhegmatogenous means “hole in the retina.” Where there is a hole or tear in the retina, fluid from the vitreous or gel portion of the eye moves through the hole and detaches the retina from the RPE-choroid. When the retina is no longer attached to the RPE-choroid, the retina starts to lose visual function. This loss of visual function can be partially or even completely non-reversible, depending on how much time passes before the retina is surgically re-attached. That is why it is best to perform surgery to re-attach to the retina promptly, within a few days.
Why do holes or tears develop in the retina? With age, the vitreous or gel portion of the eye may shift and pull on the retina, creating a tear. With age our vitreous gel shifts. Thus age is a risk factor for retinal detachment. Also, any significant eye surgery–cataract surgery, glaucoma surgery, even LASIK–may cause a shift in the gel and subsequent tear in the retina. Trauma to the eye may cause a tear in the retina. People who are near sighted (myopic) may have a retina that is more prone to holes and tears and may be at increased risk of retinal detachment at any age.
To repair a rhegmatogenous detachment surgically, various combinations of techniques may be used, depending on the situation. We may inject a gas bubble into the eye in the office to help re-attach the retina (“pneumatic retinopexy”). We may then “tack down” the retina to prevent a re-detachment using either laser or localized freezing treatment (“cryotherapy”) on the eye. Often, however, surgery in the operating room is needed. We may perform a “scleral buckle” where we tie a silicone band around the eye to indent the wall of the eye a special way to help re-attach the retina. We may go inside the eye with special instruments and remove the vitreous gel portion of the eye (“vitrectomy” surgery). We may use both a scleral buckle and vitrectomy technique together in one surgery. With both vitrectomy and scleral buckle techniques we often use air and/or gas bubbles injected into the eye as well as laser and/or cryotherapy to help tack down the retina.
The retina can achieve successful permanent reattachment with a single surgery 80 to 85% of the time. That means that one out of seven patients with rhegmatogenous retinal detachments ends up needing multiple surgeries. With multiple surgeries 95 to 98% of patients achieve permanent reattachment. About 1 to 2 percent of patients may never achieve permanent retinal reattachment despite multiple surgeries. There is always a risk of permanent vision loss, and even a small risk of loss of the eye. Therefore, retinal detachment is a serious problem when it occurs. Thankfully most patients do quite well.
Click here to read a Daily Oklahoman article on rhegmatogenous retinal detachment.
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The second type of retinal detachment is a “tractional” retinal detachment.” This type of detachment is less common than a rhegmatogenous detachment. In a tractional detachment, there is no hole or tear in the retina. Fibrous scar tissue builds up on the surface of the retina, usually from diabetes
, and pulls and detaches the retina. Trauma may also cause this fibrous scar tissue to build up and pull on the retina. To repair a tractional detachment, vitrectomy surgery is performed. The goal of surgery is to go into the eye and remove the scar tissue to allow the retina to re-attach.
The third type of retinal detachment is fairly rare and is seen in patients with special forms of uveitis. This detachment is known as a “serous,” “exudative,” or “inflammatory” retinal detachment and is seen in patients with special forms of uveitis
. Inflammation in the RPE-choroid causes that tissue to release fluid (“exudation”) and that fluid builds up underneath the retina and detaches the retina. The treatment for this type of retinal detachment is medical, not surgical, in the vast majority of cases. We use steroids and other special medicines to treat the inflammation. Once the inflammation calms, the fluid underneath the retina is reabsorbed by the eye and the retina re-attaches.
More information on retinal detachment from the National Eye Institute of the National Institutes of Health.
More information on retinal detachment from Eye Care America/American Academy of Ophthalmology
Medline Plus: retinal detachment