Retinal examination

The examination usually begins with an ophthalmoscope to look inside the eye and directly visualise the back of the eye. This 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 may not be able to drive home – please make other arrangements.

After dilating your pupils, your ophthalmologist may 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.

Digital retinal photography

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.

Fluorescein angiography

A fluorescein angiogram 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.

Optical coherence tomography (OCT)

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.

Amsler Grid

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.

Retinal laser treatment

The two most common diseases treated with laser are retinal tears and diabetic retinopathy. During retinal tear surgery, a laser is used to seal the retinal layers back together. Similarly, diabetic retinopathy can be treated using retinal laser surgery to stop leakage from small blood vessels that cause swelling, or to stop new blood vessels from growing.

Laser treatment aims to lower the risk of further vision loss – it is unlikely that lost vision will be recovered.

Vitrectomy is a type of retinal surgery that involves removing the vitreous gel (the clear, jelly-like fluid inside your eye). This procedure uses keyhole surgery so that stitches are not needed. It is performed in the day surgery – the procedure itself usually takes around 30 to 45 minutes.

Once the vitreous is removed, it is replaced with a bubble of gas or 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 tears.

Because gas and oil bubbles float upwards, you will need to keep your head in a certain position for a number of days 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:

• Epiretinal membrane (macular pucker)
• Vitreous haemorrhage
• Retinal detachment
• Macular hole
• Macular oedema
• Severe cases of floaters.

These injections are also called intravitreal injections. They are administered in the clinic or day surgery. The eye is numbed with a local anaesthetic to stop any pain. Ongoing treatment is often necessary for many of the disorders.

• Anti-VEGF injections: Vascular Endothelial Growth Factor (VEGF) is a protein secreted by oxygen-deprived cells. Low levels of VEGF are normal; however when there are high levels of this protein, abnormal blood vessels will grow. Anti-VEGF drugs block the protein and the corresponding abnormal blood vessel growth – they are given as eye injections. These drugs are used in the treatment of macular degeneration and diabetic retinopathy.
• Steroid injections: These work mainly by reducing inflammation caused by many retinal conditions, particularly those causing macular oedema (including diabetic retinopathy, central retinal vein occlusion and postoperative macular oedema).

• Pneumatic retinopexy: A gas bubble is injected into the eye and stops fluid from passing through the hole or tear in the retina, allowing it to reattach. Laser or freezing treatment is performed between 1 to 3 days after the gas injection to seal the retinal tear.
• Cryo–buckle surgery. A band of solid silicone rubber is stitched to the surface of the white of the eye (sclera) under the conjunctiva (transparent layer covering the sclera), where it can’t be seen. This material ‘buckles’ the sclera (wall) of the eye inwards against a small internal layer of tissue known as the retinal pigment epithelium (RPE), which in turn pushes the detached retina against the wall of eye. Freezing treatment (cryo) is used to scar the tissue around the retina, which creates a seal between the retina and the wall of the eye and closes up the tear or hole.
• Photodynamic therapy. Photodynamic therapy (PDT) is a treatment for wet age-related macular degeneration. A light-sensitive medicine is injected into the bloodstream, and a laser light shone into the eye, activating the medicine and causing it to create blood clots that block abnormal blood vessels.