Questions about injections

The current recommended treatments for wet age-related macular degeneration (AMD), diabetic macular oedema (DMO), and retinal vein occlusion (RVO) require injections into the eye (intravitreal injections). Before the injection, the eye is numbed with local anaesthetic and povidone iodine (brand name Betadine) is used to clean the eye and the eyelids.

Pain during your eye injection

Although a true allergic reaction to iodine is rare, some people find that it causes irritation to their eye or skin. If you experience discomfort or pain after injections, tell your specialist or nurse. They may use a different local anaesthetic, saline or lubricant drops.

If none of these changes help, they may talk to you about using a different antiseptic called chlorhexidine, which doesn’t contain iodine. Chlorhexidine kills a smaller range of microbes than Betadine and there’s less evidence about how effective it is at preventing infection, so your specialist should make sure you fully understand the possible risks. A drop of Betadine will still be used in the exact point the injection will be given. Saline will be used to wash the eye after the injection.

The effect of the local anaesthetic normally lasts for about half an hour. The injection should therefore be painless. There may be a bit of discomfort when the anaesthetic wears off, but this is usually mild.

Pain in the hours following an eye injection

The eye can develop significant discomfort or severe pain about one hour or more after the injection. This may be due to corneal abrasion: a scratch on the cornea (the clear glassy part of the eye).

The injection can also cause the eye to become very dry. This can result in the eyelid sticking to the epithelium layer and damaging it. Dry eye gel can be used to prevent this from happening after future injections, but please check with your eye care professional before using any product.

Excessive rubbing of the eye soon after an injection may make an abrasion more likely - especially as you won't be able to feel it while the eye is still frozen.

If you have any severe eye pain after an injection, patients are advised to call the clinic or return to Eye Casualty immediately. Treatment is required to reduce the pain and allow the scratch to heal properly, which may take up to 48 hours. The clinic also needs to know so they can stop it happening again.

Pain in the days following an eye injection

Pain which develops in the eye between 24 hours or more and one week after the injection requires immediate action. Pain, redness and a reduction in vision indicate an infection inside the eye called endophthalmitis which requires urgent treatment. Contact your macular clinic straight away.

Taking care of your eyes after an injection

The following activities should be avoided for at least a week:

• swimming – even with goggles
• the use of makeup
• gardening – unless you wear safety goggles
• physical sports which could increase eye pressure.

You are able to fly immediately after an injection but if complications occur you will not be able to get swift access to your hospital eye unit. Most problems occur within 24 hours so allow a day or two before flying.

Last review date: 05 2022
Next review date: 12 2023