When the retina detaches from its lower layer we speak of retinal detachment. Retinal detachment (ablatio retinae) occurs in about 1 in 10,000 people a year. It can occur at any age, but the risk is somewhat greater for the elderly. Nearsightedness or previous family-related occurrence of retinal detachment raise the risk. The risk also increases after cataract surgery. Without treatment, retinal detachment leads to visual impairment or blindness in one eye.
A retinal detachment is caused by the presence of one or more tears in the retina. These tears or holes are caused by the changes within the vitreous humor. Due to the shrinkage of the vitreous humor during life, cavities can be caused in the retina. Once a hole has formed, fluid can enter between the retina and the deeper layers of the eye. This is called a retinal detachment.
Often during middle and/or older age, people may suddenly see dark floating particles (floaters/mouches volantes) and/or lightning flashes. These phenomena may indicate changes in the vitreous humor. To determine if vitreous humor and retina are in order, an examination must be carried out by an ophthalmologist. Sometimes a retinal detachment will occur without the sighting of spots and flashes, but one will notice a decline in the visual field (seeing a “curtain” or “shadow”, or “looking over a wall”). Loss of vision is caused by the release of the center of the retina, or because the released part of the retina lies in front of its center.
Sudden loss of vision through retinal detachment occurs after a hemorrhage in the vitreous humor. It is important to know that this condition is not painful.
It cannot be observed externally whether a retinal detachment has occurred. With the abovementioned symptoms it is advisable to consult a GP/optometrist. This will ensure quick referral to an ophthalmologist, who will instill pupil dilating eye drops in order to inspect the retina properly. In the event of a vitreous hemorrhage, it can be determined if the retina is out of place or not, with the help of a specially designed ultrasound device. This examination is painless and not dangerous.
There are several possible treatments, depending on the situation and the judgment of the ophthalmologist.
1. Laser treatment
When the holes are not too large and the retina has not yet or hardly been released, the green laser can be used to make scars around the holes. These scars will attach the retina to the underlying layers, preventing the holes of getting larger. This also prevents moisture from getting underneath the retina. The treatment is performed on an outpatient basis in OMC Amstelland. If laser treatment is not possible, the patient will be referred to a retinal surgery center for surgical treatment (see below).
When moisture has come under the retina, the laser cannot produce scarring, because the fluid keeps the retina from sticking to the deeper layers. In this case, it is usually necessary to remove the vitreous humor, as it might actually be attached to the retina, thus pulling loose the underlying layers. Surgery in which the vitreous humor is removed is called a vitrectomy. The retina may have to be pressed firmly in place with the use of gas, silicon oil or other means. Sometimes the head must be kept in a certain position for a few days after surgery. As long as a gas mixture is present in the eye, flying and diving are not allowed.
Depending on the condition of the patient, the type of surgery and the preference of the surgeon, the surgery can be performed under general or local anesthesia.
This surgery is sometimes done in young patients. A tiny band (cerclage) is applied around the eye. Sometimes the eye will be punctured to release fluids. During or after surgery, the retinal hole is treated with a cold application (cryocoagulation) or with laser to achieve a thorough adhesion of the retina to the underlayer. Furthermore, the hole is closed off with a silicon fragment. At the end of the operation, sometimes some gas is left in the eye to keep the retina in place. This gas will dissolve gradually. During this period there should be no major fluctuations in pressure because the gas can expand: no flying or diving allowed. In specific cases, the introduction of gas combined with subsequent cryocoagulation or lasering of the retinal hole may be sufficient.
In 90% of the cases, it is possible to get the retina reattached after one or more surgeries. The extent to which the vision will recover depends on the location of the retinal detachment. When the central part of the retina (macula) has come loose, there is a risk of a permanent loss of visual acuity.
When the retina does not manage to get back in place, the eye will gradually grow blind.
After surgery, eye drops will have to be used for some time, and sometimes the strength of prescription glasses or contact lenses have to be adjusted.
Any questions? Please contact OMC Amstelland.
Source: NOG patient information | www.oogheelkunde.org