Laser has been used for 50 years as a definitive and effective treatment in the history of diabetic retinopathy. Clinical practice has proven that the efficacy of laser treatment is very positive.
1. How does the laser treat diabetic retinopathy? Some patients worry that laser treatment is destructive, so are there any side effects?
In order to know how laser treatment works, we must first understand how diabetic retinopathy is created. A patient’s long-term hyperglycemia leads to massive occlusion of capillaries in the retina and an extensive lack of blood supply to the retinal tissues, which leads to a series of serious lesions, which is called diabetic retinopathy. In other words, hyperglycemia slowly reduces the blood supply to the retina and prevents the retina from receiving sufficient nutrients, which means that there is an imbalance between the supply and demand of nutrients to the retina, and therefore, the retina becomes ischemic and hypoxic, resulting in lesions. To use a common metaphor, it is like the army’s rations are insufficient to supply the needs of so many soldiers, and in the long run, some soldiers are bound to be weakened by hunger, or even sick and die.
The principle of laser treatment is to use the photo-thermal effect of laser to make the protein in the cells of the retinal tissue irradiated by laser to coagulate and produce thermal coagulation, and the tissue is damaged to some extent. Using this destructive effect, the retina with severe ischemia is destroyed, and the supply-demand imbalance of retinal nutrients is improved from the perspective of reducing the nutrient demand of the retina.
Why is this destructive treatment still widely used in clinical practice? Why is it still efficacious? This is because we perform laser photocoagulation in a selective and targeted manner. We generally select the peripheral part, the area with severe capillary occlusion and retinal ischemia for the treatment. The peripheral retina has little effect on our vision, and the laser is not used for the central part of the retina, which obviously affects the vision. This is like, using laser to eliminate old, weak, sick and disabled soldiers who have no fighting ability, and supply the limited nutrition to the useful elite troops. Laser treatment is this kind of treatment principle – sacrificing the horse to protect the general.
Therefore, in order to reduce the risk of treatment, the laser is generally operated by a professional and experienced doctor in ophthalmology.
2.Do I need laser treatment for non-proliferative diabetic retinopathy, when my vision is not affected?
Severe, non-proliferative diabetic retinopathy is the best indication for laser treatment. The need for laser treatment is determined primarily by the degree and extent of retinal ischemia, not simply by the visual acuity. Patients with mild retinopathy and no effect on vision before laser will also have mild or no loss of vision after laser.
3.When is the best time to perform laser surgery? Is laser treatment still suitable for patients with diabetic retinopathy after stage V?
The best time for laser is for stage 3 to 4 lesions. for stage 5 and 6, laser is often ineffective and it is not possible to save the lesion with laser.
4. Is vision loss caused by non-proliferative diabetic retinopathy only when combined with macular edema? Is laser treatment possible? Can vision be improved?
Patients with non-proliferative diabetic retinopathy do experience vision loss only in combination with macular edema. With macular edema, laser is often effective if it is limited; with diffuse macular edema, patients have worse vision, however, the laser efficiency is very low, only 15%. So, what to do? Now, there are new drugs, anti-VEGF drugs, for intravitreal injection, which can effectively treat macular edema and improve the patient’s vision. However, the problem with this treatment is that the treatment is more expensive.
5.What preparation and examination are needed before laser treatment? Do I need to be hospitalized?
Laser does not require hospitalization. Laser is routinely performed on an outpatient basis.
Consultation Guidelines
1.What do first-time patients need to do before visiting the clinic? What is the procedure for visiting your department?
First, you will see a fundus specialist, have your pupils dilated, and decide whether to make an appointment for fundus angiography based on your fundus and systemic condition.
The second step is to perform an angiogram. Based on the results of the angiogram, a decision is made as to whether laser treatment is needed. Not all patients will need an angiogram.
The third step is outpatient laser treatment. To minimize treatment side effects, all laser treatments are performed by an experienced fundoplication specialist.
2.What information do I need to bring for a follow-up visit or for patients who have been examined at an outside hospital?
It is best to have the results of fundus angiography.