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With an estimated 79.6 million people expected to be affected by glaucoma by 2020,1 responsibility for the treatment of glaucoma is expanding from specialists to comprehensive and anterior segment ophthalmologists as well. Endocyclophotocoagulation (ECP) is an easy-to-learn, minimally invasive surgical option. It has been around for some time, and it has been shown to significantly lower intraocular pressure (IOP), whether combined with cataract surgery or as a standalone procedure.2-5
ECP is performed using the E2 Laser and Endoscopy System (Endo Optiks/Beaver-Visitec International), which integrates an endoscope, a light source, and an endolaser all in a single 20-gauge probe. With this tool, the surgeon can precisely apply 810-nm wavelength laser energy to shrink ciliary processes without destroying surrounding tissue.
With a history now stretching back almost 25 years,6 ECP might be called the first minimally invasive glaucoma surgery (MIGS) procedure. ECP can be used on glaucoma patients at various stages of the disease. Despite its flexibility and its demonstrated efficacy, this treatment modality is still vastly underutilized, most likely due to a lack of awareness among practitioners. Many surgeons may be hesitant to adopt the technology, as they have not had exposure to the unit itself. However, there is a minimal learning curve, and the device is extremely user-friendly.
There are many mechanisms that contribute to the pathophysiology of glaucoma, but the best option to control the disease through use of a modifiable risk factor is to lower IOP. ECP enhances and supplements the treatment effects patients receive from their topical antiglaucoma therapies.
Most surgical glaucoma therapies lower IOP by improving outflow mechanisms. ECP is the only surgical approach that reduces aqueous inflow. This allows ECP to be combined with surgery options that affect outflow. I often perform ECP in conjunction with implantation of the iStent Trabecular Micro-Bypass (Glaukos) in what has been termed the ICE procedure (iStent plus cataract surgery plus ECP). Combining these two MIGS procedures with cataract surgery greatly enhances the IOP-lowering response.
I do not perform ECP with the intent of reducing medication regimens for my patients; rather, I believe the greatest value for patients comes from maintaining their IOPs as low as possible. Performing ECP can potentially prevent having to increase a patient’s medication regimen if it can enhance the stability of the glaucoma and halt progression of the disease. This adjunctive procedure may make the difference between maintaining a glaucoma patient on topical therapy rather than having to move to a more invasive incisional glaucoma surgery such as a trabeculectomy or tube shunt.
I perform ECP on every cataract surgery patient who is being treated for glaucoma, with the exception of those who have a contraindication for the procedure such as a known history of significant uveitis or macular edema. I also exclude those of African or Hispanic descent, as I have found individuals in these populations to have inordinate inflammatory responses to the procedure. I have performed ECP in a handful of patients as a standalone procedure not in conjunction with cataract surgery; however, these patients were pseudophakic with a posterior chamber IOL implant. Phakic patients are not good candidates, as there is a chance of damage to the zonules or capsular bag occurring at the time of ECP.
In my hands, ECP has been an immensely safe procedure, yielding an average IOP lowering of 3 to 5 mm Hg when done in conjunction with iStent implantation or 2 to 3 mm Hg as a standalone procedure. Keep in mind, these patients often have IOPs of approximately 16 mm Hg before the procedure or procedures, despite their regimen of IOP-lowering medications. Our goal is not to get these patients off their medications. Rather it is to achieve an endpoint of lower IOP and to stabilize their glaucoma without adding medications or resorting to more invasive surgeries. In this respect, ECP is tremendously successful.
Other authors have reported mean reductions in IOP of 7.1 mm Hg to 18.62 mm Hg in refractory glaucoma with the use of ECP or phacoemulsification plus ECP.2,3
In my own experience, no patient has had an increase in IOP as a result of ECP, nor have there been any instances of hypotony or other types of dangerous IOP situations. The only adverse events I have noted are recalcitrant or difficult-to-control postoperative uveitis or iritis. These occurrences have been almost exclusively in patients of African or Hispanic descent, which is why I stopped performing ECP in these populations.
SURGICAL PEARLS, POSTOP MANAGEMENT
When applying ECP, I always begin with a laser power setting of 0.3 mJ and then titrate up or down as necessary. The perfect response is a healthy-appearing whitening and shrinkage of the ciliary processes without popping. Popping is caused by the ciliary process “micro-exploding” similar to blowing a bubble with chewing gum. Also, I am careful not to overlook ciliary processes that are wedged behind those that are visible front and center. It is necessary to treat all the processes in order to get a full IOP-lowering response.
I have used both straight and curved probes. I prefer the straight probes as I find them easier to manipulate in the eye. With a straight probe, I can enter through my normal cataract incision and consistently treat around 270° of the ciliary processes. After I finish half of the 270° circuit, I reverse direction and treat the same processes again on the way back toward the midline, resulting in double treatment of the processes. This helps to ensure that treatment covers all the ciliary processes.
To combat postoperative inflammation, patients are given 4 mg of sub-Tenon dexamethasone, unless they have a history as a steroid responder. Every patient also uses the topical steroid Durezol (difluprednate ophthalmic emulsion, Alcon) four times a day until any inflammation has subsided. I have not seen inflammation resulting from ECP to significantly affect the positive results of cataract surgery.
In addition to performing ECP, the endoscope can be used to view peripheral pathology around the pars plana, and it can provide improved views—from angles impossible to view through the microscope—in pseudophakic and aphakic eyes during surgery. The endoscope can also be used to identify strands of vitreous that have prolapsed into the anterior chamber at the time of cataract surgery if capsular rupture has occurred.
One instance in which I found the endoscope to be particularly useful was in a patient with a cornea opacity that was obstructing my view. The patient presented with central cloudy corneal dystrophy of Francois.7 At the slit lamp, I had an excellent view obliquely of the cataract and the anterior segment anatomy. However, once I had the patient in the operating room, the dystrophy caused the collimated light beam from the microscope to be internally reflected from the cornea, creating a complete obscuration of my central view. I was able to use the ECP endoscope as a second instrument to help deconstruct the lens and guide me with placement of the IOL. This also saved the patient from undergoing an unnecessary corneal transplant.
ECP technology has taken some time to gain popularity, and some surgeons are still not aware of its potential benefits for glaucoma management. In my opinion, it is the first consistent and reliable MIGS procedure we have in our armamentarium. The procedure has a minimal learning curve, it is safe and reliable, and it works to the benefit of the patient. I strongly urge surgeons to, at minimum, take a wet lab course at any major meeting or consider bringing in a unit for a demonstration at their hospitals or ambulatory surgery centers. The potential benefits to their patients with glaucoma will become readily apparent. n
1. Quigley HA, Broman AT. The number of people with glaucoma worldwide in 2010 and 2020. Br J Ophthalmol. 2006;90(3):262-267.
2. Lindfield D, Ritchie RW, Griffiths MF. ‘Phaco-ECP’: combined endoscopic cyclophotocoagulation and cataract surgery to augment medical control of glaucoma. BMJ Open. 2012;2(3).
3. Murthy GJ, Murthy PR, Murthy KR, et al. A study of the efficacy of endoscopic cyclophotocoagulation for the treatment of refractory glaucomas. Indian J Ophthalmol. 2009;57:127-132.
4. Samuelson TW, Katz LJ, Wells JM, et al; US iStent Study Group. Randomized evaluation of the trabecular micro-bypass stent with phacoemulsification in patients with glaucoma and cataract. Ophthalmology. 2011;118(3):459-467.
5. Berke SJ, Sturm RT, Caronia RM, et al. Phacoemulsification combined with endoscopic cyclophotocoagulation (ECP) in the management of cataract and medically controlled glaucoma: A large, long term study. Paper presented at: American Glaucoma Society; March 2-5, 2006; Charleston, SC.
6. Uram M. Ophthalmic laser microendoscopy ciliary process ablation in the management of neovascular glaucoma. Ophthalmology. 1992;99:1823-1828.
7. Karp CL, Scott IU, Green WR, et al. Central cloudy corneal dystrophy of Francois. A clinicopathologic study. Arch Ophthalmol. 1997;115(8):1058-1062.
Steven M. Silverstein, MD, FACS
• President of Silverstein Eye Centers, Kansas City, Missouri
• Assistant clinical professor of ophthalmology at University of Missouri School of Medicine, Kansas City, Missouri
• (816) 358-3600; firstname.lastname@example.org
• Financial interest: none acknowledged