What is the retina and how does it function?
The retina is a thin layer of tissue that lines the inside of the back of the eye. The retina is supplied with oxygen and nourishment by blood vessels. Light enters through the front of the eye (cornea, pupil and lens) and focuses on the retina. Simply speaking, the retina can be divided into two main areas: the macula, which is responsible for our sharp and detailed central vision and colour perception, and the mid and peripheral retina, which are responsible for our peripheral (side) vision and helps to detect movement and see in low light. The retina converts light into electrical signals that eventually travel to the brain.
What is a Retinal Detachment?
When your retina separates from the wall of your eye, it is known as a Retinal Detachment. Your retina needs to be attached inside your eye to stay healthy and work properly. If it remains detached and untreated, it can cause permanent sight loss. Most retinal detachments are as a result of a retinal tear or hole which has been caused by the vitreous jelly pulling on the retina. Once there is a tear or hole, fluid can build up behind the retina causing it to detach further.
In diabetic patients or after eye trauma, tractional detachment may occur. This is when scar tissue develops on the surface of the retina, pulling it away and detaching it. This can happen without a tear or hole.
What are the symptoms of a Retinal Detachment?
Retinal detachment itself is painless. But warning signs can appear before it occurs or has advanced, such as:
- Sudden appearance of or increase in floaters — tiny black spots that seem to drift through your field of vision
- Flashes of light in one or both eyes (photopsiae)
- A progressive curtain-like shadow over your field of vision
- Blurred vision
If experienced, patients need to undergo a full retinal examination through dilated pupils which includes a slit-lamp Biomicroscopy and Indirect Ophthalmoscopy with scleral indentation.
Who is more likely to get a Retinal Detachment?
Retinal Detachments caused by tears can happen in approximately 1 in 10,000 people per year and can occur at any age.
You may be at higher risk of developing a Retinal Detachment if you:
- Have a symptomatic Posterior Vitreous Detachment
- Are short-sighted
- Have had previous cataract surgery
- Have a history of Retinal Detachment in the other eye
- Have a family history of retinal detachment
- Have weak areas in your retina
What is the treatment for Retinal Detachment?
Retinal tears or holes, which occur before a retinal detachment, can sometimes be treated with laser therapy or cryotherapy (freezing) to prevent their evolution into a Retinal Detachment.
Once the retina has detached, there are three possible surgical treatment options to reattach the retina: vitrectomy, scleral buckling and pneumatic retinopexy.
Small peripheral Retinal Detachments with no symptoms can sometimes be “walled off” with laser treatment to prevent further expansion.
A Vitrectomy is an operation to remove the vitreous humour, the transparent jelly, from inside your eye. The vitreous is behind the iris (the coloured part of your eye) and the lens, and sits in the middle of the eyeball, in front of the retina.
Three micro-cannulas are inserted into the sclera (the white part of the eye) and instruments are passed through each. These include a tiny light source, a vitrector device which cuts or liquefies the vitreous depending on which technology Prof. Stanga thinks more appropriate for you, and an infusion port which replaces the fluid in the eye to maintain the pressure in the eye during the procedure. Laser or cryotherapy may be used during the procedure to treat any holes or tears which have caused the retinal detachment. Either a gas or oil bubble is injected into the eye during the procedure. Leakage from the usually self-sealing micro-cannula incisions may require self-absorbing stitches.
A scleral buckle is a piece of silicone that a Vitreoretinal Surgeon sutures to the outside of the wall at the back of the eye (the sclera or the white of the eye). This is then indented and it and move it closer to the retina, allowing the retina to settle against the wall of the eye.
A piece of silicone is sutured to the white of the eye and this pushes the back wall of the eye closer to the retina allowing it to reattach. First freezing is applied to the wall of the eye where the retinal tear is so that a scar develops which will seal the tear. The piece of silicone is covered with tissue (conjunctiva) and therefore is generally not visible. It is usually left in place permanently.
During pneumatic retinopexy, a bubble of gas is injected into the middle of the eye. Your head is positioned so that the bubble floats towards the tear in the detached area temporarily sealing it until the fluid under the retina reabsorbs and the retina reattaches. Freezing (cryopexy) or laser (photocoagulation) is used to permanently seal the retinal tear.
The bubble of gas remains in the eye for about 4 to 8 weeks to help flatten the retina to the back wall of the eye. The eye gradually absorbs the gas bubble.
Will I be anaesthetised?
Prof. Stanga will discuss with you whether you will have the operation under local anaesthetic (while you are awake) with or without intravenous sedation (to help you relax) or general anaesthetic (while you are asleep).
What are some of the risks of surgery?
- Formation of a cataract needing surgical extraction
- High pressure in the eye
- Excessive scarring leading to re-detachment
- Failure of surgery needing a re-operation
- Blindness in the operated eye
What to expect after your surgery
The first factor determining your rate of recovery and the final outcome is your pre-operative condition which required treatment. Prof. Stanga will advise you of your likely outcome. The other determining factor is how well you adhere to the postoperative instructions. Some patients will require more than one surgery.
You should expect:
- Blurred vision for several weeks after surgery.
- Swollen, sensitive and red eyes due to the nature of the
- To regularly administer your own eye drops once at home, this will help to reduce inflammation and prevent infection.
- If a gas or oil bubble has been inserted into your eye, you will be advised to adopt a certain posture in order for this to encourage healing and effectively apply pressure to the area. If gas is used, you will not be able to travel by aeroplane until the bubble of gas has fully reabsorbed (usually between 4-8 weeks depending on the type of gas used). This will be explained in greater detail by Prof. Stanga, and what is needed for your recovery.
You will be required to see Prof. Stanga on the first day after the surgery and at 1-2 weeks following your surgery for a check-up to examine your eyes and discuss your progress. Further appointments will be required and these will be organised after your consultation.