Trabeculoplasty

Trabeculoplasty is a laser surgery wherein a beam of light is focused on the eye to correct the drainage angle.

The drainage angle is that point of the eye where the iris (coloured part) meets the sclera (white part) of the eye. The fluid inside the inner eye drains out at the drainage angle. This fluid helps in lubricating the surface of the eye. Blockage in the drainage angle of the eye prevents the fluid from draining out, causing increased pressure inside the eye. This increased pressure can damage the nerve (optic nerve) that connects the eye to the brain, resulting in a condition called glaucoma.

Trabeculoplasty can be argon laser trabeculoplasty (ALT) or selective laser trabeculoplasty (SLT). Argon laser trabeculoplasty uses an argon or diode type continuous-wave laser. In contrast, SLT uses a neodymium-doped yttrium aluminium garnet laser. The power of the laser used in SLT is lower than that used in ALT. From the perspective of a person undergoing surgery, there is no actual difference between the use of the two lasers. Both the types reduce about 75% of the pressure inside the eye.

A doctor may recommend a trabeculoplasty if you have glaucoma that does not get better even after medical treatment. The surgery is also recommended to older adults who are unable to use medicines to treat glaucoma.

The conditions for which trabeculoplasty is indicated are:

• Steroid-induced glaucoma
• Primary open-angle glaucoma
• Secondary open-angle glaucoma
• Ocular hypertension
• Narrow-angle glaucoma

You may experience the following symptoms if you have glaucoma:

• Nausea
• Vomiting
• Headache
• Red eyes
• Blurred vision
• Severe eye pain
• Seeing rings around sources of light
• Tenderness around the eyes

A doctor may not recommend this surgery if you have any of the following conditions:

• Inflammatory, iridocorneal endothelial (ICE) syndrome (a condition marked by structural abnormalities of the corneal endothelium)
• Synechial closure (closure of the anterior chamber angle of eye)
• Certain types of glaucoma, namely,
  • Developmental glaucoma (abnormalities in the eye structure during development of eye)
  • Neovascular glaucoma (when the angle of eye is closed by new blood vessels)
  • Angle-recession glaucoma (caused due to eye trauma)

The following preparations are needed/done before a trabeculoplasty:

• Your doctor will take a history of your eye problems or problems related to your vision and conduct a gonioscopy to check the internal drainage system of your eye.
• He/she will measure intraocular (inside the eye) pressure and thickness of your cornea, and will also examine your optic nerve and visual field.
• Trabeculoplasty laser treatment does not involve any incisions; hence, you can normally drink and eat in the days leading to the surgery.
• You can continue taking all your prescribed glaucoma medicines and other medications as usual.
• You will need to sign a consent form, giving your approval for the procedure.
• Make sure you have a family member with you to take you home from the hospital after the surgery.

After you arrive at the hospital, the surgeon will examine your intraocular pressure and vision about two hours prior to the surgery. Pressure-lowering drops will be administered in your eye before the surgery. The laser treatment will most probably be performed in the doctor’s office and involves the following:

• You will be asked to sit in front of a special microscope with your chin placed in a chin rest and forehead relaxed against a headpiece.
• The surgeon will administer eye drops to numb the eye to be operated.
• He/she will then position a lens on your eye to minimise eye movements and keep you from blinking. In addition, it also helps to focus the laser into the eye.
• The surgeon will then target the laser to your eye and make small burns to repair the drainage angle.
• You may experience the bright flashes of light and a stinging sensation during the procedure.
• The procedure is usually completed in 10 to 15 minutes.

After the procedure, eye drops will be used to avoid any risk of immediate increase in eye pressure and you will come back to the waiting room. The surgeon will check your eye pressure an hour after surgery. You may experience blurry vision for a few hours after the laser treatment. You will be discharged on the same day as the procedure.

You can expect the following after the surgery:

• Avoid riding or driving any vehicle on the day of the surgery. 
• If you experience any discomfort after the surgery, you may be allowed to take the usual painkiller after consultation with the surgeon.
• You may experience gritty, itchy eyes throughout the day following the surgery.
• Continue using your old eye drops until you experience the complete effects of the laser surgery, which may take a few weeks.
• The surgeon may also prescribe anti-inflammatory drops for a few days following surgery. Use them as directed.
• You can start doing all your normal activities, including resuming work, from the next day of surgery.

When to see the doctor?

You should contact the surgeon immediately if you experience any of the following symptoms:

• Decreased vision
• Severe pain that does not subside
• Loss of vision
• Abnormal discharge from the eye

Although complications associated with trabeculoplasty are rare, it includes the following:

• Rise in eye pressure after surgery
• Decreased vision 
• Pain
• Cloudiness over the iris (temporary)
• Inflammation in the iris, for a brief period

If the eye pressure increases significantly after surgery, it could lead to permanent blindness.

If your pressure in the eye does not sufficiently decrease following surgery, the surgeon will recommend another laser surgery.

Trabeculoplasty does not correct the vision that was lost prior to the procedure. It stops or slows the progression of vision loss. Moreover, the effect of this surgery is not permanent, and it usually helps to control your eye pressure for three to five years.

Your surgeon will schedule appointments for the day after the surgery and a week thereafter to check your eye pressure. The frequency and number of follow-ups required after surgery will depend on your eye surgeon and the type of glaucoma.

Disclaimer: The above information is provided purely from an educational point of view and is in no way a substitute for medical advice by a qualified doctor.