Laser retinal procedures can be performed for a number of different conditions. These include retinal tears, retinal detachments, diabetic retinopathy, macular degeneration, central serous chorioretinopathy, retinal vein occlusions and an assortment of more uncommon conditions such as vascular tumors. Most laser procedures are performed on the retina by using a thermal laser, meaning that the laser procedure produces heat which causes changes in the tissues treated. The exception to this is photodynamic therapy which uses a laser that activates medication, which is injected intravenously, without causing any heat damage to the tissue.
Types of Laser Treatments (click on your condition)
Laser Treatment for Diabetic Retinopathy
Focal Laser Treatment
This is used on occasion for diabetic macular edema. Diabetic macular edema occurs when the damage to the retinal vessels by high blood sugar causes leakage of fluid into the surrounding tissue with swelling of the retina. For a more complete discussion see “Diabetic retinopathy” under “Diseases”. This treatment is used much less commonly than it was in the past due to the fact that medical treatment with injectable medication is, in general, more effective and safer. However, there are still situations in which focal laser treatment can be very effective and safe.
The purpose of the treatment is to cauterize the leaking blood vessels and stimulate the retina to reabsorb the excess fluid. This is done by specifically targeting the damaged blood vessels and sometimes by performing a "grid" pattern of laser spots in the swollen area of retina.
This treatment is performed in the office. A drop of topical anesthetic is used to numb the eye and then a large contact lens is placed on the eye to focus the laser beam on the retina and to prevent the patient from blinking during the treatment. The treatment itself consists of brief, bright flashes of light. There is usually little or no pain and the treatment usually takes only a few minutes to perform. There are very few after effects other than a brief period of visual recovery following the treatment. The eye may or may not be patched for 24 hours, but no medication or eye drops are needed following the treatment. It usually takes between 6 and 12 weeks for the eye to completely heal before the results of the treatment can be evaluated.
This treatment is performed for proliferative diabetic retinopathy, in which abnormal blood vessels grow into the eye which can cause bleeding and a retinal detachment if untreated. For a more complete discussion please see "Diabetic retinopathy" under "Diseases". This laser treatment is still commonly performed for this condition, but there is now also an alternative method of therapy using injectable medication. Sometimes these two treatments are used in combination.
In this treatment a grid pattern of laser spots is performed in the peripheral retina, outside of the macula (or central retina). The purposes not to cauterize the abnormal blood vessels directly, but to reduce the production of hormones in the eye which causing abnormal blood vessels to grow. This usually results in their regression.
This treatment is usually conducted in 1 to 3 treatment sessions in the office. It can be done through a contact lens after numbimg the eye with a drop of anesthetic, or by using indirect laser treatment in which the laser treatment is administered through the surgeon's head scope while the patient is lying back. Both treatment methods are equally effective. The treatment usually takes between 3 and 5 min. There can be some occasional mild discomfort during the treatment, but most patients tolerate the procedure well. If the treatment is not tolerated well by the patient, a deeper anesthetic can be used to "block" the eye, which eliminates all sensation to the eye, but does require an additional injection.
To some degree, panretinal photocoagulation has been replaced with intravitreal injections, in which medication is injected directly into the eye. There are advantages and drawbacks to both treatment methods, so a discussion with your doctor is recommended to determine which method, or combination of methods, would be the best choice for you.
Laser Treatment for Retinal Tears & Detachment
Laser treatment is frequently used for retinal tears, which can lead to a retinal detachments which can also require surgery. Occasionally, laser treatment can also be used for a limited retinal detachment to prevent progression. The purpose of the treatment is to create a barrier of scar tissue surrounding the retinal tear or detachment to prevent fluid inside the eye from getting between the retina and the outer wall of the eye, causing a progressive retinal detachment, which can eventually completely blind the eye.
The treatment is performed in the office and can be performed either with a contact lens or with the indirect laser head scope which is mounted on the surgeon's head. The laser is used to create a pattern of small burn spots surrounding the area to be treated. Each one of these spots requires only a fraction of the second to perform. This will then cause a small area of inflammation in the tissue which releases fibrin, which is a type of natural tissue glue. This causes adherence between the retina and the outer wall of the eye which then gradually evolves into a scar. This usually results in an adequate barrier to prevent fluid from entering the space between the retina and the outer wall of the eye.
The length of the treatment usually depends on the number and size of the retinal holes or detachment being treated. In general, the treatment lasts a few minutes.
The patch may or may not reapplied to the eye after treatment, usually for less than 24 hours. No additional treatment is required.
It usually takes several days to a couple of weeks for the laser scars to form an effective barrier around the area treated, so we recommend a reduced activity level, avoiding strenuous, high impact or jarring activities, for at least 2 weeks following the treatment.
Laser Treatment for Wet Macular Degeneration
Both thermal, or hot laser, and photodynamic therapy, sometimes called cold laser, have been used in the past for wet macular degeneration. Currently they are used very rarely, if at all, but most retina specialist. This is because medical treatment with intravitreal injections of medication into the eye have been shown to be much more effective and with fewer side effects for most patients.
Hot laser treatment (which is also called focal laser) has been used in the past to cauterize abnormal blood vessels growing under the retina in wet macular degeneration. The problem is that the recurrence rate of these vessels is very high after treatment, and the hot laser leaves a scar in the retina which results in a permanent blind spot. This can be very debilitating if the blind spot is close to the center of vision. On rare occasions hot laser treatment is used if the abnormal blood vessels are very far away from the center of the macula.
Hot laser treatment is performed through a contact lens in the office and usually requires only a few minutes. It is usually painless.
Photodynamic therapy (PDT) or "cold laser"
We use PDT on some cases of wet macular degeneration that are resistant to all other modes of treatment. It is also useful and some variants of wet macular degeneration such as polypoidal choroidopathy.
PDT is performed by injecting a medication called verteporfin (Visudyne) intravenously. The medication circulates throughout the body but is only activated in areas that are exposed either to a specific type of laser, which does not burn the retina, or to sunlight. After injecting the dye the eye is anesthetized with a drop of numbing medication and a contact lens is placed on the eye to help focus the laser and prevent blinking during the procedure. The retina is then exposed to the laser for 83 seconds and the contact lens is then removed from the eye. Sometimes, the eye is patched for 24 hours. No additional medications are required following the treatment.
Sometimes this treatment is also combined with an intravitreal injection of steroid medication and, a week later, with Avastin to improve the effectiveness of the treatment.
Following the treatment the patient's skin is sensitized to sunlight for 5 days, so we ask patient's to bring a wide brimmed hat, a long sleeved shirt and long pants to avoid exposure to sunlight on the way home. The patient is then instructed to stay inside for 5 days following the treatment. Exposure to indoor light or sunlight coming through the window briefly is not dangerous. Exposure to direct sunlight can cause a severe burn which can even require a skin graft.
PDT can be very effective and some cases, but in most cases it is not the first choice of treatment. A discussion with your doctor is recommended in considering the various modes of therapy for your condition.
Central Serous Chorioretinopathy
This is a condition that usually affects men younger than 55 and results from a “leak” of fluid under the retina causing a blister of fluid in the center of the retina (the macula). This can cause the center of vision to be distorted, blurred or images can look smaller than in the other eye. The condition does not always require treatment because it will frequently resolve on it’s own, untreated. But if the symptoms persist for several months or recur, either PDT or focal laser (as described above) can be used depending on the area of the leakage.
Retinal Vein Occlusions
Partial or complete blockage of a retinal vein results in bleeding and swelling within the retina. This is usually treated with intravitreal injections of medications into the eye. However on occasion complications can occur that require laser treatment.
This occurs when the retina vein blockage is so severe that the retina is starved of oxygen (ischemia). As a result the retina creates hormones that cause abnormal blood vessels to grow on the iris (the colored part of the eye around the pupil) which block up the ports that drain the fluid from the eye. The eye is constantly making fluid to keep the eye inflated and blockage of these ports causes the pressure in the eye to increase to dangerous levels. This can result in a blind and painful eye without treatment. Treatment can involve intravitreal injections of medication into the eye, panretinal photocoagulation laser (as described above under diabetic retinopathy) and sometimes surgery.
Swelling of the central retina is also a common complication of retinal vein occlusions. This is most commonly treated with intravitreal eye injections, but on rare occasions “grid” laser treatment (described above under “focal laser treatment”) can be tried if injections are ineffective.
Most of these treatments, in addition to their risks and benefits, are described in more detail in the video section of our website.