1. How does diabetic retinopathy develop?
Diabetes is a silent killer that slowly damages tissues and organs throughout the body, and the eyes are no exception. According to studies, diabetic retinopathy is the leading cause of new legal blindness among working-age Americans, and about 21% of newly diagnosed diabetics already have manifestations of diabetic retinopathy, and some of them are even severely, near-blind diabetic retinopathy patients!
In a sense, the onset of diabetic retinopathy begins simultaneously with the onset of diabetes. The process of its development can be roughly divided into three stages: the first stage is the retinal lesion-free period, which occurs when diabetes first occurs, and the patient’s fundus tissue does not yet have any abnormal changes caused by diabetes; the second stage is the non-proliferative diabetic retinopathy period, which is caused by unsatisfactory control of the diabetic patient’s condition and the continuous development of the lesion, at which time the patient’s fundus begins to appear microangiomas, hemorrhages, exudates and other changes The third stage is proliferative diabetic retinopathy, which is formed when the disease is not effectively controlled in the second stage and is characterized by the development of severe blinding lesions such as retinal neovascularization, vitreous hemorrhage, and retinal detachment on top of the original lesions. In this process, patients with Stage I and early Stage II can delay the formation and development of fundus lesions if they can effectively control their diabetes and do not require special treatment by ophthalmology; whereas patients with late Stage II and Stage III can no longer control the progression of fundus lesions by simply controlling their diabetes and must undergo fundus laser treatment or fundus laser treatment based on vitreoretinal surgery. Laser treatment.
2. How to prevent diabetic retinopathy?
Theoretically, there is no way to prevent the occurrence of diabetic retinopathy, but blinding diabetic retinopathy can be prevented or mitigated.
The main measures include.
(1) Regular fundus examination to detect fundus lesions that require treatment in a timely manner
(2) Control risk factors: Intensive control of blood sugar can reduce the risk of retinopathy by 75% and the progression of retinopathy by 50%; intensive insulin therapy can reduce the risk of retinopathy progression by 5 times compared with conventional therapy; strict control of blood pressure can reduce the risk of diabetic mortality and retinopathy progression.
3.Why can fundus laser treat diabetic retinopathy?
Depending on the condition, the fundus laser modalities used for diabetic retinopathy can be divided into disseminated photocoagulation (also known as total retinal photocoagulation), localized photocoagulation and lattice photocoagulation. Disseminated photocoagulation is used to treat proliferative diabetic retinopathy by photocoagulating the peripheral fundus, while local and lattice photocoagulation can be used to treat diabetic macular edema.
We use disseminated photocoagulation as an example to illustrate why fundus lasers can treat diabetic retinopathy.
The process of diabetic retinopathy development is essentially a series of pathological processes caused by hyperglycemia resulting in thickening of the capillary basement membrane and loss of pericytes, which in turn produces severe retinal ischemia and hypoxia due to capillary occlusion, which in turn stimulates the release of cytokines that promote neovascularization in the surrounding retinal tissue, causing neovascularization in the retina, resulting in severe visual dysfunction.
Laser treatment for diabetic retinopathy involves irradiating the diseased retinal tissue with a laser of a certain wavelength. The laser energy is specifically absorbed by the pigments in the irradiated retinal tissue to produce heat, which has a destructive effect on the highly oxygen-consuming outer retinal tissue and reduces or eliminates the synthesis and release of cytokines that promote neovascularization, thus producing an inhibitory effect on retinal neovascularization. At the same time, the laser damage to the outer retina may also allow anti-neovascular factors in the choroid adjacent to the retina to enter the retina, further inhibiting the formation of retinal neovascularization.
Fundus laser is an invasive surgical procedure, but at the same time it is also the most effective and fundamental method available to interrupt the blinding process of diabetic retinopathy. The results of the Early Treatment Diabetic Retinopathy Study (ETDRS) in the United States showed that timely and appropriate laser treatment can reduce the risk of vision loss by 50% in patients with diabetic retinopathy.
4.When is fundus laser treatment necessary?
The primary goal of fundus laser treatment is to control the disease and reduce the risk of vision loss in patients with diabetic retinopathy, not to improve vision. Fundus laser is an invasive surgical treatment and is not indicated for all patients with diabetic retinopathy.
Conditions that do not require laser treatment: No retinopathy or mild non-proliferative diabetic retinopathy.
Conditions in which laser treatment is recommended.
1) Non-proliferative diabetic retinopathy in combination with clinically significant diabetic macular edema.
2) Severe non-proliferative diabetic retinopathy and proliferative diabetic retinopathy.
3) combined with iris neovascularization.
4) moderate non-proliferative diabetic retinopathy combined with cataract may be appropriately advanced for fundus laser treatment according to the condition.
5) Cases in which laser treatment is not appropriate and vitrectomy should be performed.
(1) with severe vitreous hemorrhage and preretinal hemorrhage
2) Progressive progressive diabetic retinopathy.
3) with retinal detachment of retinal pull or retinal detachment of foramen ovale.
6.Does fundus laser treatment cause vision loss?
There is often a saying among diabetic patients that laser treatment is not good, and the more laser treatment is used, the more vision loss there is. Even among some medical staff, there is also such a view.
Is this really true?
It is true that patients often experience some degree of vision loss in the early stages after laser treatment. This is a normal process after laser treatment, because: first, laser is a surgical treatment process, which will inevitably bring about surgical damage, a certain degree of visual function loss. However, this damage can be repaired after a certain period of time, and a certain degree of recovery can be achieved. Secondly, there is a possibility of aggravating the development of macular edema after total retinal photocoagulation. Third, there are a few patients with progressive proliferative diabetic retinopathy, where it is difficult to control the progression of the disease with laser alone, and the further development of their disease exacerbates the loss of vision.
The purpose of fundus laser can only be to control the disease and reduce the risk of vision loss, not to improve visual acuity. Foreign research data show that 27% of patients with improved vision, 66% of patients with unchanged vision and 7% of patients with deterioration after 9 months-3 years of laser treatment, while only 10% of patients without laser treatment had improved vision, 27% of patients with unchanged vision and 63% of patients with deterioration during the same period! The difference between treated and untreated patients is significant and even more striking.
Patients who need laser treatment and adopt a wait-and-see and hesitant attitude often miss the best time for laser treatment, leading to further progression of the disease and even blindness. At this point, even if vitreous is still available for retinal surgery, fundus laser remains a necessary option during or after surgery. In this case, the cost of treatment is great, and the results after treatment will not be better than those obtained by timely laser.
6.Does the disease still progress after laser treatment?
Some people think that if the diabetic retinopathy is controlled after laser treatment, they can rest easy in the future. Is this view correct?
The answer is no.
First, there are limitations to laser treatment. Although laser is effective for most patients, there are still a very small number of patients who have lost their vision after laser treatment.
Second, laser treatment is an important part of the treatment of diabetic retinopathy. However, diabetic retinopathy is a complication of diabetes, and diabetes is a disease that cannot be cured at this stage, but can be controlled. This dictates that controlling the risk factors associated with diabetes and diabetic retinopathy progression is also an important aspect that cannot be ignored.
There are many risk factors associated with the progression of diabetic retinopathy, including disease duration, blood glucose levels, lipids, and blood pressure. Research data show that intensive control of blood glucose can reduce the risk of diabetic retinopathy by 75% and the risk of diabetic retinopathy progression by 50%; strict control of blood pressure can not only reduce the risk of diabetic retinopathy progression by 34%, but also reduce diabetic mortality. Control of these risk factors, on the one hand, helps to control the disease and reduce the risk of further progression of retinopathy, on the other hand, also helps to promote the recovery of visual function after laser treatment.
In addition, regular fundus examinations should be performed after laser treatment according to medical advice in order to detect new lesions and provide timely and appropriate treatment.
It is recommended that all diabetic patients have a fundus examination or a fundus photography screening at least once a year.