Is diabetic retinopathy treatable? Is it preventable?
Retinopathy is a common complication of diabetes. It is estimated that 20 years after diagnosis, 60-90 percent of people with type 1 and type 2 diabetes have at least some degree of retinopathy in their eyes2. Therefore, long standing diabetes is a major risk factor for retinopathy. However, vision loss from diabetic retinopathy is largely avoidable with early detection and timely treatment, meaning the condition can be both prevented and stopped in its tracks.
A person’s risk of developing DR increases if their diabetes is poorly controlled and they have significantly elevated blood sugar levels. Co-existing conditions such as high blood pressure and high cholesterol are also major risk factors. Therefore, keeping blood sugar levels under control, eating healthily, and exercising regularly can help delay or prevent DR.
What are the symptoms of diabetic retinopathy?
Some people with DR may experience symptoms such as blurring, floaters (small dots or strings appearing in vision), dark areas in their vision, and fluctuations in the quality of their vision1. However, in others, the initial changes in the retinal vessels may occur ‘silently’ — without any symptoms. That’s why it’s important to attend a screening exam at least once a year.
Several treatment options are available if changes in the blood vessels of the retina are detected. It is not unusual for doctors to recommend starting treatment before someone notices any changes in their vision.
Do I need diabetic retinopathy treatment?
Diabetic retinopathy screening results are classified as:
- No retinopathy
- Stages 1-4
- Presence/absence of diabetic macular oedema
In people with stage 1 — mild non-proliferative (no abnormal blood vessel growth) diabetic retinopathy — and stage 2 — moderate non-proliferative diabetic retinopathy — no specific treatment is required.
At these stages of the disease, vision is not affected, although there is a greater risk that it will be. However, strict control of blood sugar levels can delay or prevent progression to more advanced stages of the condition. People with stage 1 and 2 retinopathies may also be advised to undergo more frequent monitoring via screening exams.
In stages 3 (severe non-proliferative diabetic retinopathy) and 4 (proliferative diabetic retinopathy), specific treatment is required as, at these stages, vision can directly be affected. Treatments can prevent the problem from getting worse. To find out more about them, you can learn more in our dedicated article on the different stages of diabetic retinopathy.
Laser treatment for diabetic retinopathy
Stage 3 diabetic retinopathy is associated with proliferation (rapid growth) of new blood vessels in the retina. These new blood vessels are considered ‘abnormal’, which may cause bleeding in the eye and lead to increased vision problems.
Laser treatment can stabilise these changes and prevent further deterioration in vision, although eyesight is unlikely to improve. There are primarily two types of laser treatments for diabetic eye disease:
- Focal laser photocoagulation — the laser is applied in a grid-like pattern to a specific affected area
- Pan retinal photocoagulation — the laser is applied to the edges of the retina without touching the central area
How is laser treatment performed?
The treatment is performed under local anaesthesia, which works to numb the eyes. The procedure is not painful for most people, but the treatment of certain areas in the eye may produce a sharp pricking sensation. The pupils are first widened with eye drops, and then the eyelids are held open with special contact lenses. The laser is then aimed precisely at the retina. The entire process takes around 20-40 minutes and it is usually possible to go home the same day. However, more than one session may be required at an outpatient laser treatment centre.
Laser treatment side effects
Your vision will still be blurry for several hours after the procedure, so it’s important to have someone drive you home. You are also likely to have an increased sensitivity to light, so it’s a good idea to bring sunglasses for your journey home. An over-the-counter painkiller, such as paracetamol, is usually sufficient to take care of any mild discomfort or aching. It can take several months to find out if the treatment is helping.
Some of the possible complications of the procedure include floaters, blind spots in vision, reduced night vision, and having the laser pattern imprinted temporarily in the eye3. The laser photocoagulation procedure is largely safe and effective, and can reduce the risk of blindness by more than half in people with extensive amounts of new blood vessels on or near where the optic nerve meets the retina4.
Eye injections for diabetic maculopathy
Injections, given directly into the eyes, are called anti-VEGF (‘vascular endothelial growth factor’) agents. These inhibit the formation of abnormal blood vessels in the retina. This prevents diabetic eye disease from worsening and may even improve vision. Sometimes steroids are injected instead of anti-VEGF agents, but this comes with a risk of increased pressure inside the eyes.
How is the injection administered?
When the injection is administered, the skin in the area is first cleaned. Then, local anaesthetic drops are used to numb the eyes and small clips are used to keep the eyelids open. The injection is then given with a very fine needle. Initially, the treatment is typically given once a month, but as your vision begins to stabilise, the injections may be given less often or even stopped altogether.
Eye injection side effects
Possible side effects of the injection include floaters, bleeding, irritation, discomfort, and watery or itchy eyes3. Overall, however, these drugs are safe and effective: studies show that nearly 40 percent of eyes injected with ranibizumab exhibit an improvement in retinopathy5. The drugs can also slow the progression of the disease, and studies show that aflibercept is better at improving vision compared to laser treatment5.
- Mayo Clinic. (no date). Diabetic Retinopathy. [Online]. Available at: https://www.mayoclinic.org/diseases-conditions/diabetic-retinopathy/symptoms-causes/syc-20371611#targetText=Diabetic%20retinopathy%20(die-uh-,or%20only%20mild%20vision%20problems. [Accessed 21 August 2019].
- Garg, S, and Davis Richard M. (2009). Diabetic Retinopathy Screening Update. American Diabetes Association Clinical Diabetes. 2009 Oct; 27(4): 140-145. [Online]. Available at: https://clinical.diabetesjournals.org/content/27/4/140 [Accessed 21 August 2019]
- NHS Diabetic Retinopathy. (no date). Treatment. [Online]. Available at: https://www.nhs.uk/conditions/diabetic-retinopathy/treatment/# [Accessed 21 August 2019]
- No authors listed. Preliminary Report on The Effects of Photocoagulation Therapy. The Diabetic Retinopathy Study Group. Am J Ophthamol. 1976 Apr. [Online]. Available at: https://nei.nih.gov/news/pressreleases/drspressrelease [Accessed 21 August 2019].
- Zhao Y, Singh RP. The role of anti-vascular endothelial growth factor (anti-VEGF) in the management of proliferative diabetic retinopathy. Drugs Context. 2018;7:212532. Published 2018 Aug 13. [Online]. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6113746/ [Accessed 21 August 2019].
- Brănişteanu DC, Bilha A, Moraru A. Vitrectomy surgery of diabetic retinopathy complications. Rom J Ophthalmol. 2016;60(1):31–36. [Online]. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5712917/ [Accessed 21 August 2019].