A detached retina happens when the retina peels away or detaches from its underlying layer of support tissue at the back of the eye. The retina is a thin layer of light-sensitive nerve cells at the back of the eye. We need a healthy retina to be able to see clearly.
At first, detachment might only affect a small part of the retina, but, without treatment, the whole retina may peel off, and vision will be lost from that eye.
A detached retina, or retinal detachment, usually only occurs in one eye. It is a medical emergency.
A person with a detached retina may experience a number of symptoms.
- Photopsia, or sudden, brief flashes of light outside the central part of their vision, or peripheral vision. The flashes are more likely to occur when the eye moves.
- A significant increase in the number of floaters, the bits of debris in the eye that make us see things floating in front of us, usually like little strings of transparent bubbles or rods that follow our field of vision as our eyes turn. They may see what looks like a ring of hairs or floaters on the peripheral side of the vision.
- A heavy feeling in the eye
- A shadow that starts to appear in the peripheral vision and gradually spreads towards the center of the field of vision
- A sensation that a transparent curtain is coming down over the field of vision
- Straight lines start to appear curved
It is not usually painful.
The retina is the layer of tissue that lines the inside of the eye. It is light sensitive and its function is to send visual signals to the brain, through the optic nerve.
When we see, light goes through the optical system of the eye and hits the retina, like in a nondigital camera.
When the light hits the retina, this produces an image that is translated into neural impulses and sent to the brain through the optic nerve.
In other words, an image focuses on the retina, nerve cells process the information, and they send it by electrical impulses through the optic nerve to the brain.
If the retina is damaged, this can affect a person's ability to see.
Retinal detachment happens when this layer is pulled from its normal position. Sometimes, there are small tears in the retina. These, too, can cause the retina to become detached.
There are three types of detached retina:
Rhegmatogenous retinal detachment is a break, tear, or hole in the retina. This hole allows liquid to pass from the vitreous space into the subretinal space between the sensory retina and the retinal pigment epithelium. The pigment epithelium is the pigmented cell layer just outside the neurosensory retina.
Secondary retinal detachment is also known as exudative retinal detachment or serous retinal detachment. It happens when inflammation, vascular abnormalities, or injury cause fluid to build up under the retina. There is no hole, break, or tear.
Tractional retinal detachment is when an injury, inflammation, or neovascularization causes the fibrovascular tissue to pull the sensory retina from the retinal pigment epithelium.
Surgery will be necessary to find all the retinal breaks and seal them and to relieve present and future vitreoretinal traction, or pulling. Without surgery, there is a high risk of total vision loss.
Options for surgery include:
- Laser surgery, or photocoagulation: A laser beam is directed through a contact lens or ophthalmoscope. The laser burns around the retinal tear, resulting in scarring tissue that then fuses the tissue back together.
- Cryotherapy: Cryosurgery, cryopexy, or freezing, involves applying extreme cold to destroy abnormal or diseased tissue. The procedure produces a delicate scar that helps connect the retina to the wall of the eye.
- Scleral buckling: In the area where the retina has detached, very thin bands of silicone rubber or sponge are sewn onto the sclera, the outside white of the eye. The tissue around the area may be frozen or lasers may be used to scar the tissue.
- Vitrectomy: The vitreous gel is removed from the eye and a gas bubble or silicon oil bubble is used to hold the retina in place. The wound is stitched. Silicon oil needs to be removed 2 to 8 months after the procedure.
- Pneumatic retinopexy: This can be used if the detachment is uncomplicated. The surgeon freezes the tear area, using cryopexy, before injecting a bubble into the vitreous cavity of the eye. This pushes the retina back against the tear and the detached area, preventing further flow of fluid behind the retina. After some days, the pressure eventually makes the retina reattach itself to the wall of the back of the eye.
A person who has a gas bubble placed in the eye may be advised to hold the head in a particular way for some time, and they will not be allowed to fly. If an oil bubble is used, flying is allowed.
Researchers have been looking into the use of silicone oil to treat proliferative vitreoretinopathy (PVR), a complication of retinal detachment surgery that can lead to further detachment of the retina.
The National Eye Institute estimate that around 90 percent of treatments for retinal detachment are successful, although some people will need further treatment.
Sometimes, it is not possible to reattach the retina, and the person's vision will continue to deteriorate.
The patient's vision should return a few weeks after treatment. If the macula is involved in the detachment, the person's sight may never be as clear as it was before. The macula is the part of the eye that enables us to see what is straight in front of us.
The cost of surgery for retinal detachment depends on the type of procedure. Research published in 2014 suggests that "treatment and prevention of RD are extremely cost effective compared with other treatment of other retinal disease, regardless of treatment modality."
The study, published in the journal Ophthalomology, balanced the cost of treatment against the benefits of good eyesight and quality of life.
Attending regular eyesight tests can help to reduce the risk of retinal detachment, as eye conditions such as this can sometimes be detected in the early stages.
Treatment options for a detached retina are all kinds of surgery, as described above.
If a doctor suspects retinal detachment, they will normally refer the patient to an eye specialist, or ophthalmologist, for a precise diagnosis.
Factors that may increase the risk of developing retinal detachment include:
- genetics, for example, if a close family relative has had retinal detachment
- middle and older age
- extreme nearsightedness
- previous cataract surgery, especially if it was complicated
- previous retinal detachment
- eye conditions, such as uveitis, degenerative myopia, lattice degeneration, and retinoschisis
- trauma, for example, a blow to the eye
- diabetes, especially if the diabetes is poorly controlled
Anyone with these risk factors should be aware of the possibility of a detached retina.