Lasers and Surgery

Abstract

Lasers and surgeries represent the main modalities for the treatment of most retina diseases. Lasers can be used in the treatment of diabetic retinopathy, macular degeneration and retinal detachments. More advanced retina diseases may require surgical intervention in the operating room. Most surgeries are done under local anaesthesia, so patients will be awake yet they will unlikely feel any pain during the operation. Some surgeons might use lasers as adjuncts prior or during the surgery. Most common surgical procedures are used to treat retina detachments, bleeding secondary to diabetic retinopathy and macular holes. The most common surgical procedures are vitrectomy, membrane peels, pneumatic retinopexy and scleral buckles.

by Zaid Mammo

Full Article

LASER stands for (Light Amplification by Stimulated Emission of Radiation), is a high-energy beam of light that can be used to treat a number of retina diseases. Using a special microscope and lenses, lasers can be focused on specific areas of unhealthy retina tissue in the clinic. Lasers can be used to stop leaking blood vessels or destroy abnormal vessels in diabetic retinopathy or wet macular degeneration. In addition, lasers can be used to seal retinal tears to prevent fluid build-up and the development of retina detachments.

Laser treatments are usually done in the clinic and last approximately 15-30 minutes.  These treatments are almost always pain-free, although some patients may have slight discomfort during the procedure.

After receiving laser treatments, a minority of patients may complain of blurriness or increasing spots in the field of vision. These symptoms will most likely subside with time. Few patients experience an ache inside the eye, you may rest and consider taking an over-the-counter medication such as Tylenol or Advil might help. If you notice that your vision is gradually decreasing with increasing pain in the eye, you should call back your eye doctor office.

Surgeries:

More advanced retina diseases may require surgical intervention in the operating room. Most surgeries are done under local anaesthesia, so patients will be awake yet they will unlikely feel any pain during the operation. Some surgeons might use laser in the operating room prior to surgery. Most common surgical procedures are used to treat retina detachments, bleeding secondary to diabetic retinopathy and macular holes. The most common surgical procedures are vitrectomy, membrane peels, pneumatic retinopexy and scleral buckles.

To maximize your chances of complete recovery, you will be given specific instructions to follow in the period following your surgery. This might involve patching the eye, activity-restrictions and maintaining certain positions during the day and night. It is of great importance to follow your surgeons’ instructions as they are vital for the healing of the retina and maximizing your visual potential.

Full recovery is expected after at least few weeks, during this time, patients may still complain of blurry vision and spots/floaters in the field of vision. These symptoms would usually subside with time. If you notice that your vision is gradually decreasing with increasing pain and redness in the eye, you should call back your eye doctor office.

Vitrectomy

The vitreous humor is a clear gel-like material that fills and gives the eye its shape. Many retina-related problems involve the vitreous humor. A vitrectomy is a procedure that involves the removal of the vitreous humor. It is usually the first step of routine retina surgeries, further steps may be required based on the nature of the surgery. A special microscope and lenses are used to visualise the back of the eye during the procedure. Two to three entry points are made through the white part of the eye. This will facilitate the passage of the necessary lighting and equipment necessary to remove the vitreous humor

  1. Vitreous hemorrhage:

    In a number of conditions, the clear vitreous humour may become opaque due to the presence of blood. Blood is usually attributed to the bleeding of new frail vessels in diabetic retinopathy or the rupture of vessels during posterior vitreous detachments. Vitreous hemorrhages may resolve on their own while many still obscure vision. The surgical management of vitreous hemorrhage usually involves a vitrectomy and allow free passage of light. In diabetic retinopathy, laser treatment may follow a vitrectomy to prevent future vitreous hemorrhages.

  2. Giant Retinal Tears and advanced retinal detachments

    With age, the vitreous changes shape and can also cause retina tears and possible retinal detachments. Conventional treatments with lasers would not be sufficient in these cases and a vitrectomy would be indicated. To help the healing process, the vitreous humor is replaced with other material is necessary during certain procedures. For example, a repaired retinal detachment may require a heavy material such as silicone oil to seal the retina. This will reduce the chances of recurrence after surgery, allowing the retina to heal and re-attach as desired.

  3. Macular Hole:

    A macular hole describes a break in the light-perception layers of the retina in the macula region. Given its location, this condition will interfere with patients’ central vision and requires surgical intervention. The etiology of macular holes is thought to relate to abnormal forces applied by scarred vitreous humor, due to age-related changes. These forces apply sideway traction and pull the retina layers away to form the hole. With time, these forces will continue to separate the retina and chances of visual recovery would worsen. Macular holes can be treated surgically by alleviating the tension on the retina. The surgical repair would require the removal of the vitreous (i.e. vitrectomy).To aid recovery, a special gas bubble is inserted in the eye which will float and help to seal the hole in the immediate period after surgery.

Membrane Peeling

Age-related changes to the vitreous and retina can cause the formation of what’s called an ‘epi-retinal membrane’. This membrane can overly the macula and interfere with vision. Vision worsening is usually gradual and typical symptoms include central vision distortions and blurriness. With time, the membrane may thicken, cause traction and subsequent swelling of the retina, leading to further worsening of vision.

Epiretinal membranes require surgical treatment to avoid further worsening of vision. The procedure is usually done in the operating room and under local anaesthesia. The procedure usually involved removal of the vitreous (vitrecomty) as well as removal or peeling of the membrane.

Visual recovery can be expected over the period of weeks to months after surgery. The vision will be expected to improve and then stabilize. Visual improvement can be expected but return to normal vision is not guaranteed.

Retina Tears and Detachment Surgery

Early diagnosis and treatment are urgent since long-standing retinal detachements would impair long-term visual potential. The surgical repair is usually successful in reattaching the retina, vision usually improves after then stabilizes. Success rates differ between patients, improvements in vision can be expected but the return of normal vision is not guaranteed. Some smaller retina tears can be treated with laser therapy or freezing (cryotherapy). More advanced tears and retinal detachments can be treated by either vitrectomy, pneumatic retinopexy and scleral buckling:

Scleral buckling

Scleral buckling has been the traditional treatment for retinal detachments for many years. The patient is usually awake during the procedure with anaesthesia applied locally to the eye. The retina tear or hole is sealed in the operating room using lasers or freezing (cryotherapy).  The resulting scar tissue would seal the retina and prevent fluid passage and retinal detachment formation. For further support, a scleral buckle is inserted along the outer surface of the eye. The buckle, usually made of silicone or plastic, is attached around the eye like a belt. The buckle indents the eye so the susceptible retina tear is pushed against the outer area as well as relieving any traction by the vitreous on the retina, further lowering the chance of a recurrent retinal detachment. The buckle is usually inserted under one of the outer layers of eye and so it is usually not visible after surgery. The detached retina is flattened by making a small slit on the outer surface of the eye and thus allowing the fluid to drain. A vitrectomy may be required in some instances of retinal detachments. A special gas or air bubble may be inserted to tamponade the susceptible areas and ensure optimal recovery. Patients may be asked to maintain their heads in certain positions after the surgery to ensure the air bubble can help in sealing the retina. The required  ‘heads down’  position might be required for 1-4 weeks for best results.

Pneumatic retinopexy

Pneumatic retinopexy is considered a new addition to the surgical treatments of retinal detachments. It is only useful to certain types of retinal detachments, some conditions will still require the more invasive scleral buckling procedure. Pneumatic retinopexy does not require an operating room and is usually done under local anaesthesia. First, the retina tear or hole is sealed using lasers or freezing (cryotherapy). The next step involves injecting a gas bubble into the vitreous humour. With the appropriate head position, the gas bubble can push against detached retina acting as a tamponade. The bubble is usually absorbed by the eye within four to six weeks. Adherence to the head positioning instructions is vital for the success of this treatment. Post-procedure evaluations is indicated over the following weeks, if retina reattachement is not adequate, a scleral buckle may be performed.

Zaid Mammo