What is a retinal detachment?
The inside of the eye is full with a gel-like substance called the vitreous. The vitreous has a gel-like consistency when we are young and is firmly attached to the front of the eye on the inside (called the vitreous base). The retina is the tissue that lines the inside of the eye cavity like wallpaper. The vitreous is loosely adherent to the retina. As we age, the vitreous gradually becomes thinner and more liquefied. It eventually collapses inwards and separates from the retina. This separation of the vitreous from the retina is called a posterior vitreous detachment (PVD). PVD’s are typically harmless and may cause an increase in floaters. In some cases, the traction on the retina may create a retinal tear. Retinal tears frequently lead to retinal detachment as fluid from the vitreous seeps underneath the retina. This fluid causes the retina to separate from the outer layers of the eye. A retinal detachment is a serious problem and can result in permanent visual loss. Fortunately, most retinal detachments are treatable with surgery.
What are symptoms of a retinal detachment?
The initial symptoms of a retinal detachment may be quite mild. A sudden onset of flashing lights and multiple new floaters (like “cobwebs” or specs that float about in your field) of vision may occur. Flashes and floaters are often the symptoms of a retinal tear. After a retinal tear has occurred the retina may begin to detach. As the retina starts to detach, changes in the peripheral vision (outside vision) in the affected eye begin to occur. Loss of peripheral vision from the top or bottom may advance towards the centre of the vision like a black curtain, often in a half-moon shape. This can progress to total vision loss. Sometimes, the symptoms of a retinal detachment may go unnoticed until central vision is affected. Occasionally, a peripheral retinal detachment may be present without producing any symptoms at all.
Who is at risk for a retinal detachment?
A retinal detachment can occur at any age,but it is more common in people over the age of 40.You should discuss your risk of retinal detachment with your ophthalmologist.
Risk factors for retinal detachment include:
• Myopia (nearsightedness)
• Previous retinal detachment in the fellow eye
• Family history of retinal detachment
• Cataract surgery
• Eye trauma
• Predisposing genetic conditions
• Other predisposing eye diseases or disorders
How are retinal detachments repaired?
A retinal detachment can only be repaired with a surgical procedure. Your retinal specialist will discuss your surgery with new. There are three main types of surgical procedures for retinal detachment repair
This procedure is used to treat retinal a detachment with very specific characteristics. A temporary gas bubble is injected into the vitreous cavity of the eye. The surface tension of the gas bubble acts to seal off the retinal tear or hole. Your eye can then pump out the fluid that has accumulated under the retina. The success of this procedure requires strict positioning of your head after the gas injection to ensure the bubble seals of the retinal break. The retinal tears directly treated with cryopexy or retinal laser to prevent the detachment from the returning once the bubble is absorbed by your eye.
In this procedure, a silicone band is placed around the outside of the eye behind the insertion of the four major muscles that move the eye. This indents the eye wall to move it closer to the retina. This acts to release the pulling of the vitreous gel on the retina to allow closure of the retinal breaks. Fluid is then removed from the front of the eye to decrease pressure inside the eye. Finally, a temporary gas bubble is injected into the eye. The surface tension of the gas bubble acts to seal off the retinal tear or hole.
Pars plana vitrectomy
This is the most common form of retinal detachment surgery. Three small incisions are made through the sclera (the white of the eye). A microscope and a special vieweing system are used to operate directly in the eye. A special instrument, called a vitrector, is used to remove the vitreous gel. This eliminates any traction on the retina. The fluid under the retina is then drained and laser is applied around the retinal break to permanently seal it off. A slow absorbing gas is then injected into the eye to completely full the vitreous cavity. The surface tension of the gas acts to seal off the retinal breaks while the laser spots are maturing. You may be asked to position your head in a specific way after surgery to position the gas bubble on the retinal breaks. The gas bubble will slowly be absorbed by your eye at different rates depending on the type of gas used. Sometimes silicone oil is placed within the vitreous cavity instead of gas. In this case, a second surgery is usually required to remove the oil. Sometimes a combination of both skilled buccal and vitrectomy surgeries will be performed.
What is intraocular gas and silicone oil?
Gas placed within the eye will be gradually reabsorbed by the eye over a 2 to 8 week period following surgery. As the bubble is reabsorbed, the vitreous cavity refills with the fluid that is naturally produced by the eye. Vision will be markedly reduced immediately after surgery since you cannot see well through a bubble. As the bubble is reabsorbed you will gradually see more and more. You should not expect to experience significant improvement in vision until at least six weeks after surgery. Final visual outcome may not be obtained for up to 2 years following the retinal detachment repair. You may not fly in an aeroplane or travel to high elevations until the bubble is completely gone. Some types of general anaesthetic agents must be avoided (nitrous oxide) while there is a gas bubble in the eye.
Silicone oil does not reabsorb on its own, instead it must be removed with an additional surgical procedure. There are no travel restrictions with silicone oil.
The single operation success for retinal detachment repair in an acute (no signs of chronicity) retinal detachment is 85%. The reason for this is due to the scar tissue the eye produces when it heals. Visual outcome is not always predictable and the final visual result will only be known several months following surgery.