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Endophotocoagulation
Summary
In summary, ECP should not be considered the same as transscleral forms of cycloablation, which are ‘blind’ procedures that can cause much collateral tissue damage and which can result in overtreatment or undertreatment of the tips of the ciliary processes.
ECP may not be indicated for some cataract patients with very mild or very advanced glaucoma. However, it is a simple and easy addition to the armamentarium used to treat glaucoma patients with moderate disease on two or more medications.
Key Points
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ECP is a useful tool in the treatment armamentarium for surgical glaucoma.
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ECP is a reasonable substitute or adjunct to medical therapy.
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ECP appears to be one of the safer therapies for glaucoma.
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ECP can be a very cost-effective treatment of glaucoma.
Tips for Performing ECP
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Treat at least 200° for every case. Treating 270–360° is preferable, and can be accomplished with a second clear corneal incision or with a curved endolaser probe. Do not worry about hypotony: it does not happen.
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Treat the entire ciliary process from top to bottom, as well as the space between processes (the ‘valleys’ between the ‘hills’).
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Treating eyes with pseudoexfoliation (PXF) is more difficult, since the ciliary processes are smaller, abherrent, and covered with white PXF material. It may be necessary to increase the power, or to move the tip of the endolaser probe closer to the target tissue.
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Spend a few extra moments removing all viscoelastic from inside the eye, including in front of and behind the iris, as well as from behind the IOL.
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Monitor patients for postoperative pressure spike within the first 24 hours postoperatively, and possibly even 3 hours postoperatively. Treat all patients with a topical glaucoma medication and oral Diamox 500 mg sequel immediately postoperatively.
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If IOP is lower, taper off glaucoma medications. It may take 4–6 weeks to see the full effect of the procedure.
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Some phaco/ECP patients appear exactly the same as phaco-alone patients, and can be treated with the standard regimen of topical steroid and nonsteroidal anti-inflammatory agent q.i.d. for 2–3 weeks. Other phaco/ECP patients may exhibit increased inflammation, and are treated more intensively with anti-inflammatory agents for a longer period of time.
Introduction
Endoscopic cyclophotocoagulation (ECP) is a safe and effective method to lower intraocular pressure (IOP). This is confirmed by several new, large, long-term studies summarized by the author. Since the ciliary processes are visualized directly and treated precisely with diode laser energy, the problems of pain, inflammation, hypotony, and visual loss associated with transscleral forms of cycloablation do not occur. The endolaser probe has an 18-gauge diameter and can be used through the limbus or pars plana to treat virtually any type of glaucoma, regardless of etiology. ECP is particularly easy and well suited to lower IOP and reduces the need for glaucoma medications by combining it with phacoemulsification in cases of cataract and medically controlled glaucoma. Surgical techniques and clinical ‘pearls’ are provided by the author. A video of the Combined Phaco and ECP procedure is available online 
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Historical Perspective
Transscleral cycloablation has been performed for many years by penetrating diathermy and cryotherapy, and more recently by Nd : YAG and diode. Traditionally, cycloablative procedures have been relegated as a last resort for eyes that have failed multiple glaucoma procedures such as trabeculectomies and glaucoma drainage devices, or for eyes that are blind and painful or have very poor visual potential. This was appropriate, since transscleral cycloablative procedures are unpredictable. They are ‘blind’ procedures because the tissue being treated is not visualized, which means that overtreatment or undertreatment is higher. They are associated with many postoperative complications, such as pain, inflammation, visual loss, and phthisis.
In contrast, endoscopic cyclophotocoagulation (ECP) is a much kinder and gentler procedure than transscleral cycloablation, since the tips of the ciliary processes are visualized directly and treated precisely to achieve the desired tissue effect. ECP does not cause undesirable collateral tissue damage and therefore does not cause the complications associated with transscleral cycloablation described above. ECP can be done in eyes with excellent visual potential; the two procedures should not be ‘lumped’ together.
Since ECP can be performed with topical/intracameral anesthesia, it is well suited for patients who are monocular or are anticoagulated. Transscleral diode cyclophotocoagulation is usually best performed under retrobulbar or peribulbar anesthesia.
Ocular endoscopy was first suggested by Thorpe in 1934. However, there were no other reports until Norris and Cleasby described an endoscope for ophthalmology in 1978. In 1986, Patel was the first to report endolaser treatment of the ciliary body for uncontrolled glaucoma, but this was done with scleral depression through an operating microscope, not with an endoscope. Uram developed an intraocular laser endoscope with vitreoretinal and anterior segment applications and reported his results treating neovascular glaucoma using this technique in 1992.
Techniques
To benefit from minimally invasive endoscopic surgery, the practitioner must have an understanding of the components that are employed. There are two basic sets of instrumentation: the laser endoscope itself, and the equipment console.
The laser endoscope has three fiber groupings: the image guide, the light guide, and the laser guide. There is an 18-gauge endoprobe ( Fig. 123-1A and B ) with a 110° field of view and a depth of focus from 1 mm to 30 mm. The advantages of this larger-diameter laser endoscope are the greater clarity provided by the image bundle and the panoramic field of view that it creates. This feature is especially helpful for the novice endoscopist in that the wide field of view permits simpler orientation to the anatomy.
The laser endoscope is connected to the console ( Fig. 123-1C ) that contains all of the instrumentation used for endoscopy, such as a video camera, light source, video monitor, and video recorder. A semiconductor diode laser tuned to the 810 nm wavelength is utilized. The surgeon places the console next to the surgical table and controls the progress of surgery by viewing the video monitor, rather than imaging through the operating microscope.
The ciliary processes may be accessed from either a limbal or a pars plana approach. The status of the lens and vitreous is a primary consideration when planning ECP. Mechanism of glaucoma, level of IOP, previous surgical interventions, visual acuity, and visual field status are less important.
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