To reduce the amount of fluid in the eye and subsequently lower intraocular pressure (IOP), a cyclophotocoagulation can be performed.* This type of laser surgery is done through the disruption of ciliary processes, which produce fluid, or aqueous humour (AH), which lubricates the tissue at the front of the eye.

Historically, cyclophotocoagulation was used as second-line therapy after trabeculectomy and tube shunt surgeries because of the destruction of ciliary processes. More recently, however, it has been used earlier on in treating glaucoma, since it leads to less inflammation and is more targeted than other treatments.

Who is cyclophotocoagulation right for?

All forms of glaucoma can be treated with cyclophotocoagulation, but some forms have special considerations. For example, people with uveitic glaucoma may not be ideal candidates because of the risk of worsening inflammation.

In contrast, people diagnosed with plateau iris syndrome may benefit from laser treatment because of its ability to shrink ciliary processes and potentially open up the angle of the eye (where the iris and cornea meet and where AH drains).

From there, your doctor will decide what type of cyclophotocoagulation is best for you based on the type of glaucoma you have.

What are the different types of cyclophotocoagulation?

Transscleral diode cyclophotocoagulation

The standard treatment is known as transscleral diode cyclophotocoagulation involves the placement of an 810-nanometer (nm) diode laser probe on the surface of the eye on the sclera with “spots” of laser treatment being applied. Because of the absence of incisions being made into the eye, there is no risk of infection. The eye treatment will usually be performed under localized anesthesia in the operating room although it can be performed in a clinic setting too.

Micropulse transscleral cyclophotocoagulation

A newer laser treatment known as micropulse transscleral cyclophotocoagulation has become available and is being more widely used. Similar to the above surgery, an 810-nm diode laser probe is placed on the surface of the eye on the sclera, however, the laser energy produces little pulses, or “micropulses,” resulting in less inflammation and potentially less impact to other eye tissues.

Endocyclophotocoagulation

In endocyclophotocoagulation, an 810-nm laser probe is used, and through an incision into the eye, the laser probe has a camera that allows the surgeon to see the ciliary processes. Surgeons can directly target the ciliary processes through this treatment. It is considered to be a minimally invasive glaucoma surgery (MIG) procedure by some surgeons and may be combined with cataract surgery.

What are the potential risks?

Since the ciliary processes can regenerate, sometimes cyclophotocoagulation must be repeated. In some cases, the results of the treatment can be incomplete, even intentionally, to reduce the risk of hypotony (when IOP gets too low). In knowing this risk, some surgeons will partially treat the ciliary processes and complete the procedure over several sessions.

Other common risks of cyclophotocoagulation include:

• Inflammation, which can cause the front of the eye to show signs of inflammation, or less commonly, the retina to swell (macular edema)
• Bleeding, especially in patients with neovascular glaucoma

Less common side effects include:

• Vision loss
• Hypotony
• Sympathetic ophthalmia, in which the treated eye becomes inflamed (very rare)

Cyclophotocoagulation is a treatment suitable for various types of glaucoma, whose goal is to lower eye pressure by 20% to 30%. Speak with your doctor about if cyclophotocoagulation is right for you and what type would be best.

*Oui, Y. (2020, Nov. 5). Glaucoma Surgery Series: Cyclophotocoagulation. BrightFocus Foundation. https://www.brightfocus.org/glaucoma/article/glaucoma-surgery-series-cyclophotocoagulation

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