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Laser treatment for diabetic retinopathy

Patient information A-Z

Eye problems are common in diabetes and can, in some cases, seriously affect vision. Laser treatment is very effective in preventing loss of vision. Best results are achieved if laser treatment is applied before any vision is lost.

Laser treatment rarely restores vision. A small number of patients lose vision despite timely laser treatment.

There are two types of sight threatening diabetic retinopathy:

  • Diabetic macular oedema
  • Proliferative diabetic retinopathy

Diabetic macular oedema

Diabetes causes blood vessels near the centre of the retina (macula) to leak fluid. The retina becomes water logged (oedematous). This causes gradual loss of vision. Laser treatment causes the retina to dry out, thus preventing loss of central vision.

Possible side effects of macular laser treatment:

  • Small ‘blind spots’ near the centre of vision.
  • Reduction in colour vision.
  • Rarely, some permanent loss of central vision.

Proliferative diabetic retinopathy

Diabetes causes small retinal blood vessels to block and the retina is starved of blood. Abnormal blood vessels then grow on the retina. This can lead to permanent loss of vision from bleeding into the eye, retinal scarring and retinal detachment. Laser treatment is usually highly effective in preventing this loss of vision if done before visual loss occurs.

Possible side effects of treatment for proliferative diabetic retinopathy:

  • Poor night vision and reduced colour vision.
  • Reduction in peripheral vision. In some cases this can be severe enough to prevent you holding a driving licence (80% of patients retain driving vision).
  • Permanent loss of central vision from a laser burn inadvertently hitting the centre of the retina. This is very rare.


  • The treatment is performed while the patient is sitting at an instrument that is used to examine the eyes.
  • Drops are put in to dilate the pupil and anaesthetise the eye.
  • A contact lens is placed on the eye to focus the laser beam and minimise eye movement.
  • Very brief intense bursts of light are shone into the eye.
  • Some patients find laser treatment uncomfortable. In some cases, a local anaesthetic injection renders the procedure pain-free. Several treatment sessions are required.
  • After laser treatment, the vision will be blurred. This normally clears in a few hours, but may last a few days if extensive treatment is required.
  • Please do not drive until your vision has recovered.
  • Occasionally, there is some pain after the treatment. Common pain relief tablets will help.


Patients are reviewed from two to six months after treatment. Several sessions of laser treatment are frequently required. Most patients retain good vision following laser treatment, but regular review is advisable as severe retinopathy can occasionally recur. This is unlikely with good control of blood sugar and blood pressure.

General advice

Good control of blood sugar and blood pressure is very important in preventing loss of vision from diabetic retinopathy.

Emergency contact telephone number

If you have severe pain after laser treatment please contact:

Monday to Friday 08:30 to 16:00: Emergency Eye Clinic on01223 217778. Leave a message with your name, date of birth, hospital number, and a brief description of your concern and one of the nurses will call you back.
Out of hours: attend the Emergency Department.

Additional ophthalmology contact telephone numbers

Medical retina specialist nurse (for advice): 01223 256672
Clinic 14 reception desk (appointment queries): 01223 216401

More information can be found on these websites:

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Same sex bays and bathrooms are offered in all wards except critical care and theatre recovery areas where the use of high-tech equipment and/or specialist one to one care is required.

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

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Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151