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ECP with functional tube shunt reduces IOP in difficult cases
Study found limited complications in endoscopic cyclophotocoagulation for glaucoma patients with prior tube shunts and rising IOP.
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Endoscopic cyclophotocoagulation lowered IOP by about 30% and glaucoma medications by nearly 50% in patients with uncontrolled IOP and functioning tube shunt implants, a study found.
Brian A. Francis, MD, and colleagues examined endoscopic cyclophotocoagulation (ECP) in patients with prior tube shunt surgery. They conducted the study because they had noticed that the surgical options for treatment after tube shunt implantation were limited, Dr. Francis said.
Physicians typically place patients back on glaucoma medications if their IOP rises after tube shunts are implanted, he said. If the IOP is still not controlled, options include implanting additional tube shunts or performing ciliary body ablation. Dr. Francis and colleagues wanted to examine ECP’s role after IOP began rising.
“We found that [ECP] shows good intermediate success at a 12-month time period in IOP control of patients who have a functional tube shunt but pressures that are not controlled. We believe that some of this success is due to the combination of an inflow procedure with an existing outflow procedure,” Dr. Francis said at the American Glaucoma Society annual meeting.
“We feel that [ECP] has a role in glaucoma management after a tube shunt, and in our practice, we’re using it prior to a second tube shunt or a transscleral ciliary body ablation procedure,” he said.
Dr. Francis and colleagues did not find any serious complications, but they said there could be a possible increased risk of corneal graft rejection. Because of that, they have been more aggressive in treating at-risk patients postoperatively with steroids, he said.
Perimeters
The prospective, nonrandomized, interventional clinical study examined 25 eyes of 25 glaucoma patients. All patients had a functional tube shunt (Baerveldt 350 implant, Advanced Medical Optics). Patients were divided into two groups: One group had uncontrolled IOP with maximum medications, and the other group had controlled IOP but was intolerant to one or more medications or was on an oral carbonic anhydrase inhibitor.
Most patients in the study had primary open-angle glaucoma, Dr. Francis said. Some patients had secondary glaucoma, including five with corneal transplants, two with traumatic glaucoma and one with congenital glaucoma. Patients had to have a functional tube shunt with no blockage and a bleb over the plate and previous glaucoma surgery at least 4 months before the study.
Patients were excluded if they had vision of light perception or worse, prior transscleral or endoscopic ciliary body inflation procedures, or nonfunctional aqueous shunts that did not have fluid drainage to the plate. Dr. Francis and colleagues determined whether shunts were functional by using a slit lamp to see if a bleb over the plate area could be visualized and confirmed their determination by ultrasound.
The study’s main outcome measures were mean reduction in IOP at 12 months with a postop comparison of data points and the mean number of glaucoma medications, Dr. Francis said. The success criteria was measured as IOP reduction of 3 mm Hg or greater or a reduction in glaucoma medications.
“Failures were defined to be those with continued uncontrolled IOP, those with vision loss to no light perception and those with requirement for further glaucoma surgery,” he said. “Also those that had additional glaucoma medications required to control IOP, even if the pressure was controlled, if it required additional medications, they were considered a failure.”
Procedure and results
Dr. Francis said the procedure begins with the clear corneal incisions, one made temporally and one made nasally in order to ablate 360° of ciliary processes. The ciliary sulcus is expanded with a viscoelastic. Then, the probe is inserted between the iris and lens.
“Then each process is ablated individually with the shrinkage and whitening of the entire process as the treatment endpoint,” he said. “The attempt is made to ablate as close to 360º as possible.”
Results were promising, Dr. Francis said. Preoperatively, the mean pressure was 24 mm Hg. At 12 months postop, it was reduced to about 16 mm Hg, a drop of 30% from baseline. Glaucoma medications decreased about 50%, from a mean of 3.2 preop to a mean of 1.2 per patient 12 months out.
Complications
Dr. Francis and colleagues found that 16% of patients had a greater than two-line decrease in visual acuity postop. Three of those reductions were because of corneal problems and one was because of cystoid macular edema, he said, adding that one patient had an increase of two lines of visual acuity.
Complications in the procedure were few, Dr. Francis said. Five patients had corneal grafts, and two of those had corneal graft failure. No patients had hypotony, and there was no loss of light perception or progression to light perception. In addition, neither strabismus nor diplopia was found, as may occur in a second tube shunt, he said.
For more information:
- Brian A. Francis, MD, can be reached at the Doheny Eye Institute, 1450 San Pablo St., DEI4000, Los Angeles, CA 90033; 323-442-6454; e-mail: bfrancis@doheny.org. He has no direct financial interest in the products discussed in this article, nor is he a paid consultant for any companies mentioned.
- Advanced Medical Optics, maker of the Baerveldt 350 implant, can be reached at 1700 E. St. Andrew Place, Santa Ana, CA 92705; 714-247-8200; fax: 714-247-8672; Web site: www.amo-inc.com.
- Erin L. Boyle is an OSN Staff Writer who covers all aspects of ophthalmology.