Treatment of Diabetic Retinopathy
Treatment depends on the ophthalmologist’s observations made while examining the patient’s eyes. It may include:
Controlling blood sugar levels. Sometimes, just by improving a patient’s metabolic control, their vision can improve.
Laser. This reduces the number of abnormal blood vessels and those which are producing oedema.
Intraocular injections. Different medicines are injected into the eye, or into the vitreous body (they are also known as intravitreal injections), to reduce the amount of fluid in the macula.
Vitrectomy. Surgical intervention that eliminates any blood inside the eye. It is also the technique used to repair a retinal detachment.
Therapeutic education. Therapeutic education is vital for encouraging control over diabetes and reducing its complications. Lifestyle modification programmes, which involve the health team, patient and their family, achieve improved weight control, help patients quit toxic habits (e.g., smoking) and encourage them to accept their diabetes. Patients who are well-informed about their diabetes, self-care skills and medication management participate more actively and therefore obtain better results.
Medical nutrition therapy. Diet is a basic pillar of diabetes treatment. It must be nutritionally healthy and each meal must include a controlled amount of carbohydrate-containing foods (milk, floury foods and fruit). The diet must be tailored to each patient’s bodyweight, drug treatment (insulin or tablets), physical activity, eating habits and blood sugar profile.
Physical activity. Physical activity is another cornerstone of treatment, especially in the case of type 2 diabetes. Patients should complete a minimum of 150 minutes of physical activity per week, spread over 3 or 5 days. It is essential that patients adjust their diet and drug therapy according to the duration and intensity of their activity. (Link con diabetes / actividad física).
Contraindications for physical exercise:
- Patients with moderate non-proliferative retinopathy should avoid very vigorous exercises that increase blood pressure, such as weightlifting.
- In the case of unstable diabetic retinopathy, patients must also avoid activities that raise blood pressure, such as jumping, and those involving sudden head movements.
- Patients with vitreous haemorrhage are advised to avoid all types of physical activity.
Oral antidiabetic medicines reduce blood glucose levels and can therefore help improve diabetic retinopathy. However, drugs with a direct influence on diabetic retinopathy are administered into the eye via injections. There are currently two types of intraocular drugs available:
Anti-VEGF drugs. These block the action of a molecule that is heavily involved in diabetic macular oedema. They are liquid medicines and must be injected several times a year because they are usually only effective for a couple of months.
Corticosteroids. These reduce the ocular inflammation that accompanies diabetic macular oedema. They are solid medicines (implants) that continue working inside the eye for several months, so fewer injections are required.
A surgical intervention (pars plana vitrectomy) is usually required to treat advanced stages of diabetic retinopathy, such as proliferative retinopathy.
There are three main situations that require an operation: very dense or recurrent vitreous haemorrhage, tractional retinal detachment and treatment-resistant macular oedema.
The operation consists of inserting some tiny instruments (e.g., suction devices, forceps or lasers) inside the vitreous body of the eye while illuminating the retina and maintaining the internal eye pressure constant. It is a very delicate procedure, but it has evolved a lot in recent years and can often be completed without the need for stitches.
Vitreous haemorrhages that do not heal fully or which reoccur may require a vitrectomy to remove the blood and treat the damaged vessels causing the bleeding. If severe cases of vitreous haemorrhage go untreated for long periods, the eye’s pressure may increase and even cause pain, a condition known as neovascular glaucoma.
Tractional retinal detachment occurs when the inner retina wrinkles up due to the pulling action of membranes and filaments, thus causing vision loss and the appearance of wavy lines. Vitrectomy tends to help this problem, but vision may be permanently affected depending on the extent of damage to the inner retina.
Cases of macular oedema that do not respond to drug therapies may require surgery to clean the membranes growing on the macula. However, the patient does not always recover their full vision.
Intravitreal injection has become a popular technique for treating several conditions affecting the retina. Every day, retina specialists apply the procedure to several of their patients. The specialist must provide a detailed explanation of the risks, benefits and alternatives for this treatment.
- There are very few risks, but there is always the possibility of infection which can develop into a serious condition, although it occurs rarely as it affects less than 1 in every 1,000 patients.
- The benefits of these injections depend on the eye disease being treated, but they basically include improved vision or a reduced chance of deterioration.
- Alternative treatments can include simply waiting to see if the condition improves with better control over blood sugar levels, surgery (vitrectomy) or laser treatment, depending on the eye disease. However, intravitreal injections are undoubtedly the best option if the specialist recommends them and the alternatives are often clinically worse from the outset.
Lastly, it is important to bear in mind some advice concerning the injections. The treatment will be carried out in a consultation room or a small operating theatre, depending on the centre, and there is no need for fasting or to stop taking any other medications. Patients do not usually need to complete any prior preparation, but they may sometimes need to administer eye drops for a few days after the injections, based on the specialist’s recommendations. Patients often observe floaters for a few days after the injections (these may be due to a small air bubble or the eye drops). However, if you notice pain and have red eyes, you should visit an emergency ophthalmologist for a check-up.
While laser treatment for diabetic retinopathy has not changed too much in recent years, the treatment of diabetic macular oedema has witnessed great advances. Laser treatment is now accompanied by various options including intravitreal drug therapy.
These new treatments have yielded more significant and satisfactory results in terms of improving patients’ vision. For example, current therapies with anti-VEGF drugs and corticosteroids have totally revolutionised the treatment of diabetic macular oedema, but there is still a subgroup of patients with treatment-resistant oedema.
Therefore, new treatment strategies are being studied, above all, to discover therapies that require less injections. Researchers are looking into new anti-VEGF molecules, for instance, which stay active inside the eye for longer, while new corticosteroid implants which remain active for up to 3 years have recently become available for cases of chronic diabetic macular oedema.
Thanks to technical breakthroughs, complications associated with treatments for diabetic retinopathy are now much less significant than they were a few years ago.
Laser photocoagulation can be complicated by the development of haemorrhages and scarring in the retina if too much energy is applied to the eye fundus and, depending on the situation, this can produce some dark spots in the patient’s vision. Patients may also notice a decline in their nocturnal vision and colour vision.
The severest complication associated with intravitreal drug therapy is an infection inside the eye, or endophthalmitis, which in some cases can lead to complete vision loss. Although the frequency varies, it is always very low as less than 1 in every 1,000 people who receive this treatment develop an infection. Other complications are haemorrhages inside the eye and even retinal detachment, but again they are both rare events. Finally, the administration of corticosteroids introduces a greater risk of developing cataracts and increasing the intraocular pressure.
Complications associated with surgery are the same as those for intravitreal injections (e.g., intraocular infection, haemorrhage and retinal detachment).