The retina is the inner nerve layer of the eye that is important for sight. The central part of the retina is called the macula, which is responsible for sharp and defined central vision.
Retinal tear and detachment
Retinal tears are breaks in the retina that may arise as result of vitreous degeneration and shrinkage which pulls on the retinal layer. Fluid passes through these holes which results in separation of the retina leading to retinal detachment.
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.
Retinal detachments may arise from various causes. The most common cause is a retinal tear or hole in the retina. People who are more prone to retinal tears and detachment include those that are very short-sighted, eyes with thinning or degeneration of the retina, and those with a family history of retinal detachment.
Retinal detachment may also be caused by retinal disease like severe diabetic retinopathy or internal inflammation of the eye.
The person may notice a sudden increase in the number of floaters or flashes of light. Theremay 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.
If the retina is torn and no detachment has occurred, 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.