Articles

Cyclophotocoagulation

Author(s):

Michael Giovingo

Shyam Patel

Si Chen

Amar Mannina

Thomas D. Patrianakos

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Abstract:

Purpose: To discuss cyclophotocoagulation as a treatment for glaucoma and review recent innovations in the technology.

Summary: Cyclophotocoagulation is a procedure that lowers intraocular pressure by thermally damaging the nonpigmented ciliary epithelium, which is responsible for producing aqueous humor. Historically, it was viewed as a last line therapy for end-stage disease due to difficulty titrating results, post-procedure inflammation, and risk of phthisis bulbi. Traditional cyclophotocoagulation still has a significant role in glaucoma treatment as newer techniques have improved the side effect profile. Technologic advances, including endoscopic application and micropulse application of the laser, have also broadened the scope of cyclophotocoagulation. Endocyclophotocoagulation allows for direct application of the thermal energy to the ciliary body, which decreases collateral damage and subsequent postoperative inflammation. Micropulse technology is still applied in a trans-scleral approach, but also is minimally inflammatory. Recent studies also indicate that micropulse cyclophotocoagulation may have multiple mechanisms of action which allow for a more physiologic treatment. Overall, cyclophotocoagulation has been a mainstay in glaucoma treatment. Newer treatment parameters and technologies have allowed for improved outcomes, better side effect profiles, and new mechanisms of action.

New Concepts in Glaucoma Surgery Series: Volume 1, pp. 211-230 #15
Edited by: John R. Samples and Iqbal Ike K. Ahmed
© Kugler Publications, Amsterdam, The Netherlands

Video:

Video 1

Video Description: With the patient under adequate sedation and a lid speculum in place, the G-Probe is positioned with its anterior edge at the limbus. Laser pulses are placed using the foot pedal, which is depressed for the entire desired time. The surgeon moves on to the next desired laser spot adjacent to the previous and fires the laser again. The procedure is continued on the superior and inferior halves of the eye with equidistant laser pulses. The 3 o’clock and 9 o’clock positions are avoided so that the long ciliary nerves are not damaged.

Video 2

Video Description: The illuminate version of the G-Probe is used in a very similar fashion to the standard G-Probe. The fiber optic light is constantly illuminated during the application of laser so as to guide the treatment to be over the ciliary body. The surgeon starts at the standard position with the leading edge of the probe at the limbus, but looks for transillumination of the ciliary body. If transillumination is seen, the laser pulses are placed as usual. If it is not, the surgeon moves the probe posteriorly until transillumination occurs and then laser pulses are placed as usual. This new version of the G-Probe allows for confirmation of proper placement.

Video 3

Video Description: Once the endoscope is placed through the main wound, the ciliary body is visualized on the monitor. When the aiming beam is properly positioned over the ciliary body, the laser is discharged in continuous fashion. The surgeon confirms adequate treatment when the ciliary contracts and becomes discolored. Video courtesy of Lucy Shen MD.

Video Caption: Video 4

Video Description: The micropulse trans-scleral cyclodiode is applied to the eye once adequate anesthesia is achieved and the eye is opened using a speculum. The laser is delivered in a continuous fashion one hemisphere or quadrant at a time. The probe is held perpendicular to the scleral surface with the leading edge 1-2 mm posterior to the limbus. Delivery of the laser is done in a sweeping fashion, moving across each hemisphere in 10 seconds or each quadrant in 5 seconds. The surgeon sweeps back and forth until the desired treatment time is achieved. As with the G-Probe, most clinicians avoid the 3 o’clock and 9 o’clock positions to avoid damage to the long ciliary nerves.

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