Retinal conditions can affect the retina (including the macula) and the vitreous – some of the main conditions are mentioned below.
Retinal vein occlusion: This occurs when the veins in the retina are blocked and the build-up of pressure causes smaller downstream blood vessels to leak. The blockage can occur in a branch vein with vision loss restricted to part of the visual field (branch vein retinal occlusion) or a central vein with the entire visual field affected (central vein retinal occlusion).
Retinal detachment: A retinal detachment is a serious condition in which the retina lining the back of the eye separates from the wall of the eye. If not treated, it can lead to permanent blindness. Surgery under local anaesthesia is needed to reattach the retina.
Retinal tears: A retinal tear is not usually as serious as a retinal detachment, but it can develop into a retinal detachment if untreated. Retinal laser treatment is an effective treatment for retinal tears.
Macular hole: A macular hole is a small tear in the macula that usually forms gradually. The first sign is usually distortion of central vision. A vitrectomy may be recommended.
Retinitis pigmentosa: This is the name for a range of genetic diseases that damage the retinal rod and/or cone cells (photoreceptors), causing vision loss. Unfortunately, there is no known treatment. An ophthalmologist can give you advice on what to expect and how to manage the disease.
Epiretinal membrane: Also known as macular pucker, epiretinal membrane occurs when a thin sheet of scar-like tissue grows on the surface of the macula and interferes with central vision. Your doctor will monitor progression using an OCT scan and fluorescein angiogram. Vitrectomy may be recommended.
These will vary depending on the exact condition, for example:
The examination usually begins with an ophthalmoscope to look inside the eye and directly visualise the back of the eye. This is followed by more detailed examination that requires your pupils to be dilated using eye drops. It’s important to note that your eyes will remain dilated for approximately 4 to 6 hours and your vision will be blurry, meaning that you won’t be able to drive home – please make other arrangements.
After dilating your pupils, your ophthalmologist will use a special condensing lens and a bright light, usually mounted on their forehead, to evaluate the retina, the optic nerve and tiny blood vessels. A retinal tear or retinal detachment can often be detected during this type of examination.
Other tests may be necessary to assess the severity of your condition, diagnose other retinal conditions and guide treatment.
State-of-the-art equipment is used to produce high-resolution photographs of your retina, optic nerve and blood vessels. The photographs help your ophthalmologist detect changes in these areas, as well as in the macula (in the centre of the retina). Your retinal photographs will be kept in your medical records and used as a comparison if more are taken at a later stage.
A fluorescein angiography (sometimes called retinal photography or eye angiography) uses a fluorescent dye to show any blockages or leaks in the tiny blood vessels supplying the retina. The dye is usually injected into a vein in your arm and flows through the blood system to the vessels at the back of the eye. Your ophthalmologist can detect any blockages or leaks and will use a special camera to take photographs. Your vision will be blurred for up to 12 hours after the test.
OCT is a non-invasive test that captures detailed images of the retina. This scan allows your doctor to identify areas of retinal thinning, thickening or swelling caused by fluid build-up and leaking blood vessels. The OCT scans your eyes without making direct contact. The procedure takes less than 10 minutes.
This is a simple test you can do at home to alert you to any vision changes that may indicate the presence of macular degeneration or epiretinal membrane. The Amsler Grid contains a series of horizontal and vertical lines with a dot in the middle. If the lines appear wavy or lines are missing, have your eyes checked immediately.
A vitrectomy involves removing the vitreous gel (the clear, jelly-like fluid inside your eye) using keyhole surgery so that stitches are not needed. It is performed in the day surgery – the procedure itself takes around 30 to 45 minutes.
Once the vitreous is removed, it is replaced with a bubble of gas or with sterile saline. Silicone oil may be used if the retina has been detached for a long time or retinal scarring is present.
Laser or freezing treatment is used to seal the retinal holes.
Because gas and oil bubbles float upwards, you will need to keep your head in a certain position for a number of day after the surgery to place the bubble in the correct position, while the retina is healing. The silicone may remain in the eye for months, or it can be removed after the retina has healed.
A protective eye patch is necessary for about 24 hours afterwards, followed by eye drops and ointment. Generally, patients can resume their regular activities after a day or so, although this can vary from person to person. A vitrectomy may be needed to treat:
These injections are also called intravitreal injections. They are administered in the clinic or day surgery, after your eye is numbed with a local anaesthetic to stop any pain. Ongoing treatment is necessary for many of the disorders.