Combining cataract surgery with endoscopic cyclophotocoagulation has been a practice of mine for many years in patients with early glaucoma who want to discontinue the use of medications.
In anticipation of the release of the iStent trabecular micro-bypass stent (Glaukos), my colleagues and I surmised that combining cataract surgery, endoscopic cyclophotocoagulation (ECP, Endo Optiks) and iStent implantation — the ICE procedure — would be a winning combination because ECP decreases aqueous production and the iStent increases aqueous outflow. Historically, combining an aqueous suppressant with a prostaglandin that increases uveal scleral outflow has proven to be a successful combination yielding positive outcomes. Being able to provide two surgical procedures that are minimally invasive, do not involve sutures, do not introduce astigmatism and can be performed through the same wound as the cataract incision offers unique advantages to patients with early to moderate glaucoma who are controlled on medications or patients who have borderline IOP.
How I perform ICE
I begin ICE by performing temporal clear corneal cataract surgery, my usual method. Once the IOL has been implanted, I proceed with ECP. I remove viscoelastic from the capsular bag, and I place viscoelastic into the ciliary sulcus, enough to properly visualize the entire ciliary process. Next, I perform 360° of ECP. After I complete ECP, I remove the viscoelastic from the ciliary sulcus and place Miochol-E (Bausch + Lomb) to bring down the pupil and allow for visualization of the angle to implant the iStent. Then I place more viscoelastic in the anterior chamber to visualize the entire nasal angle. I turn the head 45° away from me and tilt the microscope toward me so that I can fully view the angle. I place viscoelastic on the cornea and use a surgical gonioprism to see the angle. I implant the iStent through the cataract wound. Once the iStent is in place, I remove the viscoelastic once more and the case is essentially complete, leaving the final step of ensuring the wounds are sealed nicely.
Interestingly, the iStent portion of the procedure could safely be performed at any point during this procedure, including before phacoemulsification or just after and before ECP. Some prefer earlier implantation of the iStent to improve visualization of the nasal angle before the other procedures cause any edema in the cornea.
ICE could easily be performed under topical anesthesia; however, for patients who do not tolerate the discomfort of ECP, I may consider a retrobulbar block. Because I am able to effectively communicate with my anesthesiologist, she can give sedation during the ECP portion of the procedure so that the patient is comfortable even under topical anesthesia. If the patient had topical anesthesia during ICE, I instruct the patient to start placing drops in the eye immediately after the procedure. I recommend a fluoroquinolone every 2 hours while awake the day of the surgery and four times a day for the week thereafter. I use Durezol (difluprednate ophthalmic emulsion 0.05%, Alcon Laboratories) every 2 hours while awake the day of surgery. Then I rapidly taper the Durezol to four times a day for 1 week and then down to twice a day for 2 weeks. After that, I taper the patient depending on how he or she responds.
Unlike typical cataract surgery or iStent implantation alone, I am more aggressive with steroids in ICE to obtain the best results from ECP. Because I am mindful of IOP spikes from a steroid response, I recommend seeing patients at 1 week postoperatively and again at 3 to 4 weeks postoperatively to monitor them. If IOP is not stable at the 3- to 4-week visit, I will discontinue steroids and keep the patient on an NSAID four times a day.
Pearls for ICE
I have been experimenting with using an endoscope to visualize the iStent during ICE. Endo Optiks has been developing a high-resolution probe that is shorter and straighter than the usual probe to help visualize the angle. Using the endoscope takes practice, especially if a surgeon is accustomed to viewing the angle with a surgical gonioprism. I typically open up the paracentesis to 1.5 mm to 2 mm, and I make sure the monitor is close enough to view the angle. The advantage of using the endoscope to visualize the angle is that I do not have to tilt the patient’s head or the microscope because my visualization is not through the gonioprism. Visualizing the angle to place the iStent obviates the need for head movement and microscope readjustment, making use of the endoscope a distinct advantage. The other advantage of using the endoscope is if the patient is under topical anesthesia and experiencing rapid eye movement, iStent implantation is difficult. Placing the endoscope in the eye through a second port stabilizes the eye to allow for easier implantation.
Because I do not have to tilt the patient’s head or the microscope, the endoscope avoids unneeded maneuvering time and allows for more efficient surgery.
By combining surgical procedures for ICE, I have a dual mechanism of action. I am treating two sides of the equation: inflow and outflow. With ECP alone or iStent implantation alone, I am treating only one side of the equation. These procedures are additive in that I can get more patients off of their medications than I could with the individual techniques on their own. I have performed several hundred ICE procedures to date, and my findings have been that the effects are greater than the effects of separating the procedures.
- For more information:
- Steven R. Sarkisian Jr., MD, can be reached at Dean McGee Eye Institute, 608 Stanton L. Young Blvd., Oklahoma City, OK 73104; email: firstname.lastname@example.org.
Disclosure: Sarkisian reports he is an investigator in the MIGS study group and the iStent inject study sponsored by Glaukos and on the advisory board for Endo Optiks.