Diabetes causes blinding eye disease. This disease affects the retina and is called diabetic retinopathy. Performing green laser for diabetic retinopathy is one of the mainstays of treatment for this condition. This is also known as PRP laser for diabetic retinopathy.
Patients most commonly ask us “What is the cost of laser treatment for diabetic retinopathy ?”, and “What does laser surgery for diabetic retinopathy involve ?”. More on that later, but you could read more about diabetic eye diseases.
Retinal Lasers for diabetes are continuous-wave lasers because the laser beam is generated continuously. It is also known as double frequency Nd-Yag Laser and has a wavelength of 532nm. Another name for this laser is the Green Laser for diabetic retinopathy.
The Retina is most commonly treated using this Green Laser. The main uses of this retinal laser for diabetes are to perform PRP laser for diabetic retinopathy and to perform barrage laser for Lattice degeneration.
Let us quickly go through what happens in Diabetic Retinopathy. In diabetes, the small blood vessels of the retina start getting affected. They become leaky and cause blood spots and exudates to collect in the retina. Over time, small blood vessels start dying, reducing the oxygen supply to the retina. The retina thus becomes hypoxic or has low oxygen.
This causes the retina to secrete what is known as Angiogenic factors – Vascular Endothelial Growth Factor (VEGF) – and results in the formation of new vessels on the retinal surface. The retina basically tries to increase the oxygen that it gets. These new vessels, however, have a tendency to bleed, resulting in loss of vision. Over time they can contract and lead to scar formation. They also cause a pulling of the retina leading to retinal detachment. This type of detachment is called tractional retinal detachment.
Tractional retinal detachment if needing treatment can only be treated by surgery. Read more about diabetic eye surgery. All these events can be brought to a halt by treating the retina with laser eye surgery for diabetic retinopathy. The visual loss can thus be prevented.
The laser gets absorbed by the pigment in the retina (melanin) and causes a change in the retina known as photocoagulation. The effect of this is that it causes the death of the cells in the outer retina, and improves the oxygen supply to the inner retina. As a result of this, the production of VEGF is reduced.
As mentioned earlier, as Diabetic retinopathy progresses, there is increased production of VEGF. This leads to the formation of new vessels on the retinal surface, which can lead to bleeding and eventual retinal detachment.
Green laser for diabetic retinopathy is done in the peripheral retina and for the whole of the retina. Thus, this retinal laser treatment in diabetes is called Pan Retinal Photocoagulation. In short also known as PRP laser for diabetic retinopathy. The laser ends up killing the cells of the outer retina and thus this reduces the production of VEGF. This reduction results in regression of new blood vessels. This in turn helps prevent the disease from reaching advanced stages. Laser is a very effective way to prevent the blindness that occurs in end-stage diabetic eye disease.
Diabetes also affects the central part of the retina. This central part is known as the Macula. When there is macular involvement in diabetic eye disease it results in swelling known as Macula edema. This results in a drop in vision. While Macular edema, which involves the center is routinely treated with eye injections, the edema which spares the bang center can be treated using a laser. Central retinal green laser for diabetic retinopathy is done in the form of either Focal Laser or Macula Grid Laser. This provides a more long-term solution to control the swelling.
The laser is done as an OPD (out-patient) procedure. Prior to doing laser, the eyes need to be dilated with dilating drops. The doctor will then put drops to numb the eyes and make the procedure is more comfortable. The room lights will be dimmed. The laser could be done with you lying down or with you seated at the slit lamp, with a special lens held to your eye. During the procedure, you will see bright flashes of light, which are in fact the laser shots being delivered.
In PRP, a total of 1000-2000 burns are placed on the retina, depending on how advanced the disease is. These are given over 2-3 sessions, spaced at an interval of 5-7 days between each session. The laser treatment for 1 eye takes about 20-30 mins depending on how much laser needs to be done.
Unlike cataract surgery, a Laser can be done on both eyes simultaneously, one after the other. When we perform laser on one eye we can only do a maximum certain number of spots. Hitting too many laser shots can cause swelling in the retina. Thus, it actually makes sense to treat the other eye at the same sitting if required.
The Laser is not painful. The patient might experience mild discomfort during the procedure. However, in the hands of an experienced retina specialist, there are no other side effects. The patient can leave the clinic immediately after the procedure is done, and can resume normal activities thereafter. There is no need to bandage the eye. However, you cannot drive yourself home as your eyes will be dilated. The vision will be blurred for the rest of the day due to the effect of the dilating drops.
Some patients might experience a slight decrease in color vision, peripheral vision, or vision in dim light.
The laser treatment done in diabetic retinopathy is purely to stabilize the disease, and maintain the existing vision. Undergoing laser surgery WILL NOT improve your vision. However, it helps to prevent further visual loss, and prevent complications leading to eventual blindness.
If vision does improve, it could be because of a reduction in the macular edema but it important to understand that the purpose of doing the laser eye surgery for diabetic retinopathy is to stabilize the disease.
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