The retina is a very thin tissue that lines the back of the eye, and is responsible for transforming light rays that enter the eye into the images we see. The large peripheral portions of the retina are responsible for side vision (peripheral vision), and the small central area known as the maculais responsible for clear central vision needed for reading or fine small work. As with the rest of the human body, the retina requires oxygen and nutrients and is supplied both through a network of small arteries, and is extremely sensitive to any changes in circulation.
A retinal detachment is when a part of the retina separates from the tissue at the back of the eye. A retinal detachment can be caused by a number of factors, most commonly a result of a tear or hole in the retina. These retinal holes and tears may occur when the gel that fills the posterior two-thirds of the eye(vitreous humour) pulls away from where it was attached to the retina (posterior vitreous detachment or PVD). Once there is a tear in the retina, the vitreous gel can pass through the tear and build up underneath the retinal membrane; this build up of fluid under the retina weakens the membrane, and is what detaches the retina from the back of the eye. The severity, or extent, of the retinal detachment depends on the amount of fluid collects under the retina, and as fluid builds up behind the retina, more of the retinal membrane can become detached.
Symptoms of a retinal detachment can include sudden:
- Flashes (flashing or cascading lights)
- Floaters (dark spots or stringy-strands)
- A shadow, curtain, or veil that covers part or all of the vision
Flashes of light occur when the vitreous gel tugs on the retinal membrane, and floaters are a result of small spots of vitreous gel that has clumped together. A shadow, curtain, or veil occurs as a result of the actual separation of the retina from the back of the eye. These symptoms warrant urgent consultation and examination by an ophthalmologist.It is important to note that some flashes and floaters can also occur with PVD, retinal holes and tears, and therefore, anyone experiencing these symptoms should be seen by an ophthalmologist to determine the specific cause.
Diagnosis of a retinal detachment is made by dilated eye examination by an ophthalmologist. Early diagnosis is crucial because visual improvement is much greater when the retina is repaired before the macula (central area of the retina) becomes detached. If the diagnosis of a retinal detachment is made, a surgical repair is required, and is performed by a retinal specialist.
There are a number of ways to surgically treat a retinal detachment, and some of the procedures performed at SAEC surgical include:
The retinal hole or tear is sealed with the use of laser or cryopexy (freezing). After this is complete, the surgeon injects a gas bubble into the posterior portion of the eye (vitreous cavity), and this gas bubble pushes the detached retina against the back part of the eye. This gas bubble slowly dissipates over a number of weeks. This surgery requires specific head positioning (such as head down) in order to keep the bubble in the position where it can maintain pressure on the retina against the back of the eye.
After the hole or tear in the retina has been sealed with either laser or use of a cryoprobe (freezing), a silicone buckle (band) is sewn to the outer wall of the eye and acts like a belt around the eye to keep the retina firmly pushed against the back of the eye. This band is not visible, and remains in place permanently. A gas or air bubble may also be placed into the vitreous cavity to keep the hole or tear in place against the scleral buckle until the healing process is complete. This procedure often requires specific head positioning for a number of weeks (such as head down) in order to keep the air or gas bubble in proper position.
Prior to surgery, you will receive your pre-operative instructions from your surgeon’s office, and these typically include not eating or drinking after midnight the night before your procedure. You will be asked to arrive at SAEC at a specified time, which will allow time for you to have your eye dilated for the procedure, and to meet the anaesthesiologist working with your surgeon that day. Your surgeon, anaesthesiologist, and yourself will determine the type of sedation that is necessary.For retinal surgery, most commonly an injection is used to freeze the eye. In the operating room, there will be two additional nurses there to assist you and your surgeon. Depending on the type of retinal repair you are having, your surgical procedure will typically take between 30 to 90 minutes. After your procedure, a nurse will go through your postoperative instructions with you, explain any required head positioning, and ensure that you have made arrangements to be transported home with your friend or family member. You can expect to have a patch and shield in place until your follow up appointment the following day.