The retina is the inner nerve layer of the eye that is responsible for detecting visual stimuli that pass through the cornea and lens. Visual information that is focused on the retina is passed through the optic nerve to the brain where the information is processed and interpreted, thereby allowing the person to see the object. The central part of the retina is called the macula, which is responsible for central vision that is critical for sharp and defined vision.
Retinal detachment is a serious eye condition where the retina is separated from the outer layers of the eye. The nerve layer loses its function and this results in loss of vision. Retinal detachments need to be treated early to prevent permanent loss of vision.
Causes of Retinal Tear/Detachment
Retinal detachments may arise from various causes. The most common cause is a retinal tear or hole in the retina. The retinal tears may arise as result of vitreous degeneration and shrinkage which pulls on the retinal layer, leading to a hole. Fluid passes through these holes which results in progressive separation of the retina leading to retinal detachment.
People who are short-sighted are more prone to retinal tears and detachments, especially those who are extremely short-sighted. These eyes may have thinning or degeneration of the retina which make them more prone to retinal tears. Patients with a family history of retinal detachment are also more prone to retinal detachment.
Other causes of retinal detachment include certain retinal diseases, such as diabetic retinopathy. These eyes may develop abnormal new vessels and fibrous strands that tug on the retina and detach it. Other causes include inflammation of the eye.
Symptoms of Retinal Tear/Detachment
The person may notice a sudden increase in the number of floaters or flashes of light. There may be an appearance of a shadow or blurring of vision in a particular part of the visual field. As the retinal detachment progresses, the shadow or blurry area may progress like a curtain to involve a larger area.
In many situations, however, the retinal detachment may go unnoticed until a significant portion is involved or if it starts to encroach the central area of the retina, known as the macula. When the macula is involved, the patient will lose central vision and the visual loss will be severe. Patients may also experience a sudden loss of vision if there is internal eye bleeding associated with the retinal tear.
The patient should seek an eye consultation promptly should these symptoms appear, and a thorough examination of the eye and retina will be carried out by an ophthalmologist.
Treatment for Retinal Tear/Detachment
If the retina is torn and no detachment has occurred, then laser treatment may be performed to seal the break so as to prevent the retina from detaching.
If the retina is already detached, then this would need to be surgically reattached. Surgical repair may either be a sclera buckle operation, where a silicone band or tyre is used to indent the sclera and release the tractional forces on the retina, or a vitrectomy where an instrument is inserted into the inner cavity of the eye to remove the vitreous gel that is tugging on the retina. These may be combined with laser treatment or freezing of the retina to seal the edges of the hole and to prevent further detachment. Air or gas may also be injected into the eye to create an additional tamponade effect so that the retina remains attached. In most instances retinal detachments may be reattached successfully if treated early.