Retina conditions: diabetic eye disease, floaters and macular problems

What the retina does

The retina lines the inside of the back of the eye and converts light into nerve signals. At its centre is the macula, a small area responsible for reading, recognising faces and fine detail. Because the retina is nerve tissue, damage to it is often permanent, so timely treatment matters.

Most retinal disease is painless. Changes in vision are the main clue, and some conditions produce no symptoms at all until they are advanced, which is why screening is used for people with diabetes and high blood pressure.

Common reasons people are referred

• Diabetes or high blood pressure, for screening or treatment of retinal changes
• New flashes of light, new floaters, or a shadow or curtain across the vision
• Gradual blurring or distortion of central vision when reading
• A sudden painless drop in vision in one eye
• A family history of macular degeneration or retinal detachment

How the retina is examined

Examination usually begins with vision testing, then dilating drops so the whole retina can be viewed at the slit lamp with a lens. Dilation blurs near vision and makes eyes light sensitive for a few hours, so it helps to bring sunglasses and to avoid driving yourself home.

At Standard Eye Specialist Hospital retinal assessment includes digital fundus imaging and optical coherence tomography, which produces a cross section of the macula and shows fluid or thickening that cannot be seen by eye alone.

Frequently asked questions

Is retinal damage reversible?

Sometimes. Swelling of the macula and bleeding can often be reduced with treatment, and vision may improve. Where retinal nerve tissue or the macula has scarred, that part of the damage does not reverse, so early treatment gives the best chance of keeping sight.

Do eye injections hurt?

The eye is numbed with anaesthetic drops first. Most people feel pressure and a brief stinging rather than pain, and the injection itself takes a few seconds.

How often should someone with diabetes have their eyes checked?

At least once a year, and more often if retinal changes are already present or diabetes control has been difficult. Your ophthalmologist will set the interval after examining your retina.