VOL: 102, ISSUE: 05, PAGE NO: 25What is it?
What is it?
- Retinal detachment occurs when the sensory and pigment layers of the retina separate and the retina is pulled away from its normal position in the back of the eye. This is due to trauma, inflammation or, in the majority of cases, changes to the vitreous chamber associated with the ageing process. A detached retina is very serious and almost always causes blindness unless it is treated. It occurs most often in middle-aged and older people. It is relatively rare, affecting one in 10,000 people.
There are three causes:
- Rhegmatogenous: the most common cause of retinal detachment. A tear results in fluid seeping under the retina, causing it to separate from the retinal pigment epithelium, the pigmented cell layer that nourishes the retina;
- Tractional: the second most common cause. Scar tissue on the surface of the retina contracts and causes it to separate from the retinal pigment epithelium. This type can affect people who have diabetes;
- Exudative: this is often caused by retinal diseases, including inflammatory disorders and trauma to the eye. Fluid leaks into the area under the retina, separating it from the back of the eye.
- Bright flashes of light, especially in the peripheral vision;
- Translucent specks (floaters) in the eye;
- Blurred vision;
- Shadow or blindness in the visual field of one eye.
A detached retina is a medical emergency and a patient with any of these symptoms must be urgently referred. Because the retina has no sensory nerves, the condition is painless.
- Diagnosis is based on symptoms and a thorough examination of the retina with an ophthalmoscope, through which abnormalities can be seen.
- The first concern is to determine whether the macula (responsible for the central vision) is attached. The type of surgery needed and the likelihood of retaining functional vision after the operation depend on whether or not the macula is still attached.
- Ultrasound imaging can help to assess the condition of the retina from several different angles.
- The eye may also be examined with a slit lamp microscope. This allows examination of different parts of the eye under magnification. After instilling drops to dilate the pupil, the slit lamp is used to detect retinal tears and detachment.
- A visual acuity test can assess loss of vision.
- Retinal detachment often requires surgery to return the retina to its correct position. There are several procedures, all of which use laser surgery or cryotherapy to seal retinal tears.
- Pneumatic retinopexy involves the injection of a gas bubble into the vitreous space. This pushes the retina back against the wall of the eye, thereby closing the tear. Laser or cryotherapy is used to secure the retina to the eye wall around the tear. The gas bubble will gradually disappear after the operation, being replaced with fluid.
- A scleral buckle is placed around the eye to recorrect any force pulling the retina out of place. The fluid from under the detached retina may also be drained, allowing the retina to return to its normal position.
- Vitrectomy removes any vitreous gel that may be tugging on the retina. Sometimes a vitrectomy may be combined with a scleral buckle.