Author: Michael J. Siegel, MD, FACS June 1, 2023
Endoscopic cyclophotocoagulation (ECP), a procedure that glaucoma specialists combine with cataract surgery to partially shrink 270° to 300° of the ciliary processes and lower intraocular pressure (IOP), bears some persistent myths related to postoperative inflammation. This is because when ECP was introduced, some surgeons were familiar with older procedures like transscleral cryotherapy and transscleral diode therapy, both of which are “blind” procedures used for more aggressive ciliary process treatment in eyes with poor potential. Following cryotherapy or diode therapy, the eyes tended to struggle with persistent and aggressive inflammation and, at times, pain. Because ECP allows us to visualize the ciliary processes directly, we can treat conservatively with controlled energy. However, when surgeons initially started using ECP, many treated the ciliary process with a similar approach to the older procedures — destroying (or “popping”) the ciliary processes in advanced cases, leading to significant postoperative inflammation, fibrin formation, pain, and poor visual outcomes.
Surgeons quickly realized that less was more, and less aggressive laser treatment (ie, shrinkage, not popping) was possible with direct visualization of the ciliary processes. Unfortunately for many, the historical bias of the initial impression of ECP has proven difficult to shake. Here are 3 lingering myths and the realities, as well as my own experience.
MYTH 1: It’s difficult or impossible to perform ECP gently.
In those older procedures where surgeons do not directly visualize ciliary processes, gentle treatment would have been difficult. Also, although surgeons have learned different, less invasive ways to approach transscleral diode, it is still “blind” and less titratable. With ECP (Endo Optiks, BVI Medical), under direct visualization, gentle treatment of the ciliary processes is possible. In our practice, following intraocular lens placement, we inject cohesive ophthalmic viscosurgical device to create ample space in the ciliary sulcus. Next, the 19-gauge curved ECP probe is inserted through the clear corneal incision previously made for cataract surgery and into the ciliary sulcus. Ideally, we visualize 4 to 5 of the ciliary processes. Under direct visualization, we apply 150 mW to 250 mW laser energy to the tips of the ciliary processes, leading to shrinking and whitening — an effect continuously observed throughout the procedure, to ensure we are not overtreating. Surgeons can titrate treatment by adjusting the power, moving closer or farther away, or adjusting the time spent on treating an area. We move along the ciliary processes until we’ve treated 270° to 300°.
MYTH 2: ECP causes significant postoperative inflammation.
The gentle and titratable nature of the ECP procedure generally produces minimal postoperative inflammation additional to cataract surgery. We generally recommend intracameral or sub-Tenon dexamethasone at the end of the procedure. Postoperative inflammation is similar to a cataract alone; the one caveat is that these patients require longer taper of postoperative steroids compared to cataract surgery alone. They are slightly more prone to rebound iritis if the steroids are tapered too aggressively. Our protocol is to administer 0.1 mL of nonpreserved generic dexamethasone intracamerally during surgery; postoperatively, patients use 1% prednisolone acetate 4 times daily for 1 month before slowly tapering off over 2 to 4 weeks. With this regimen, in our experience, the inflammation for phaco-ECP patients is similar to that of cataract-only patients.
MYTH 3: There’s not enough data on the long-term efficacy of ECP.
Long-term data about ECP have existed for some time. Francis et al published a prospective study in 2014 showing that 36 months after surgery, 73.3% of patients with mild to moderate glaucoma who had phaco-ECP surgery had an IOP >5 mmHg and <21 mmHg, at least 20% lower than baseline, with no loss of light perception and without new medications or surgery. Only 11.9% of patients with phaco alone achieved this result.
Similarly, my colleagues and I published data comparing 261 eyes with phaco-ECP to 52 eyes with phaco alone in patients with mild to moderate glaucoma and found that 36 months after surgery, 72.3% of the phaco-ECP patients still had a stable IOP and were using at least 1 fewer medication than they used before surgery, compared to just 23.6% of patients who had cataract surgery alone.2 In the phaco-ECP group, 62.4% maintained an IOP at least 20% lower than baseline, compared to 22.4% in the phaco group. We followed these patients and later presented our 6-year findings. The mean IOP reduction in the phaco-ECP group was 19.2% at 72 months, 70% of patients still had a stable or lower IOP, and patients were still using 1 fewer medication.
More recently, Feinberg et al published 6-year data showing that IOP reduction in phaco-ECP is potentially greater than in combinations of cataract surgery with other MIGS devices. Although many patients did require selective laser trabeculoplasty or medications again by the 6-year time frame (and were considered “failures” per the success criteria), functionally only 14.3% went on to need more invasive glaucoma filtration surgery.
Endoscopic cyclophotocoagulation is an elegant addition to cataract surgery that leaves no device in the eye, has low risk of hyphema compared to other MIGS options, has little impact on short-term visual outcomes (patients basically “look like” a straight phaco the next day), and has minimal influence on postoperative inflammation and recovery with proper steroid use. While I also perform a variety of other MIGS procedures, ECP has still been my mainstay option for glaucoma patients with well-controlled, mild to moderate disease who also need cataract surgery.
Future Applications
A new technique being evaluated is the synergistic combination of ECP with angle-based procedures such as angle-based stents, viscocanalostomy, or goniotomy. More studies are slowly being published, but anecdotally, the combination of inflow procedures that reduce aqueous with outflow procedures like ECP shows significant promise. It has saved many of my advanced and unstable glaucoma patients from more invasive traditional filtration surgery. I am hopeful we’ll continue to see more utilization of ECP as reality replaces myth for surgeons focused on expanding their minimally invasive options for patients with glaucoma. GP
References
- Francis BA, Berke SJ, Dustin L, Noecker R. Endoscopic cyclophotocoagulation combined with phacoemulsification versus phacoemulsification alone in medically controlled glaucoma. J Cataract Refract Surg. 2014;40(8):1313-1321. doi:10.1016/j.jcrs.2014.06.021
- Siegel MJ, Boling WS, Faridi OS, et al. Combined endoscopic cyclophotocoagulation and phacoemulsification versus phacoemulsification alone in the treatment of mild to moderate glaucoma. Clin Exp Ophthalmol. 2015;43(6):531-539. doi:10.1111/ceo.12510
- Khandan S, et al. Long-term follow-up of combined phacoemulsification and endoscopic cyclophotocoagulation in the treatment of mild to moderate glaucoma. Poster presented at: American Glaucoma Society 2017 annual meeting; March 2-5, 2017; Coronado, California. Accessed April 13, 2023. http://endooptiks.com/assets/poster-ags-siegel-phaco-ecp.pdf
- Feinberg L, Swampillai AJ, Byles D, Smith M. Six year outcomes of combined phacoemulsification surgery and endoscopic cyclophotocoagulation in refractory glaucoma. Graefes Arch Clin Exp Ophthalmol. 2022;10.1007/s00417-022-05906-0. doi:10.1007/s00417-022-05906-0