Endoscopic cyclophotocoagulation may benefit patients with uncontrolled glaucoma

Reduced IOP and medications yield high cumulative success rates.

Brian Alan Francis

Patients with uncontrolled glaucoma who underwent prior aqueous tube shunt surgery had lower IOP and were taking less medication following endoscopic cyclophotocoagulation, researchers found.

“There is no accepted procedure to be done after a failed tube shunt procedure, other than another tube shunt,” lead study author Brian Alan Francis, MD, MS, told Ocular Surgery News. “Some people have advocated transscleral cyclophotocoagulation, but endoscopic cyclophotocoagulation is a much more targeted approach and better to use in patients with good visual potential.”

Endoscopic cyclophotocoagulation (ECP) is performed under direct observation using a device from Endo Optiks that combines a diode endolaser, aiming beam, light source and endoscope and is designed to “deliver the minimum necessary amount of energy to achieve the desired result,” according to the authors.

Researchers analyzed ECP because the tube shunt procedure was once considered the last available option for glaucoma patients whose IOP could not be controlled with other treatments. The prospective, nonrandomized, interventional clinical trial was published in the Journal of Glaucoma.

Study parameters

Researchers evaluated 25 eyes of 25 glaucoma patients, with a mean age of 59 years. All subjects had either open-angle or angle-closure glaucoma and had undergone aqueous tube shunt surgery at least 6 months earlier.

IOP in all subjects was either greater than 21 mm Hg and not controlled by at least two topical glaucoma medications or less than or equal to 21 mm Hg in patients who were intolerant to medication or were on an oral carbonic anhydrase inhibitor.

Exclusion criteria were neovascular glaucoma, visual acuity of light perception or worse, prior transscleral cyclophotocoagulation or ECP, and nonfunctional aqueous shunt without fluid drainage to the plate.

Dr. Francis, who performed all the ECP procedures, used a laser set at 250 mW to 350 mW to photocoagulate the ciliary processes that were visible up to 360° as well as the spaces in between processes. Because most ECP is done during cataract surgery, Dr. Francis said that surgeons are often limited to a 270° treatment area using only the cataract incision. However, a wider treatment area can be achieved by creating a paracentesis that can be enlarged after the cataract is removed in order to use the probe in both incisions.

Study outcomes

The authors defined success as either an IOP reduction of at least 3 mm Hg or discontinuing the medication in patients who were medication-intolerant. Follow-up was conducted every 3 to 6 months for 2 years, but 1 year was considered the primary endpoint of the study.

Mean IOP decreased from 24 mm Hg at baseline to 15.4 mm Hg at 1 year. Mean number of medications also decreased from 3.2 medications before ECP to 1.5 medications at 1 year.

The cumulative success rate remained at 88% at 2 years’ follow-up, even though the authors observed a trend of gradual increase in both IOP and number of glaucoma medications needed between the first and second year. However, according to Dr. Francis, the positive results from most surgical procedures are not permanent.

“The effects of any surgery wear off over time in a certain percentage of patients, and I think the trend in our study of increasing medications or increasing IOP would be present no matter what surgery you were looking at,” he said.

Complications related to ECP included decrease in vision, corneal graft failure and cystoid macular edema. The authors noted, however, that topical steroids and nonsteroidal anti-inflammatory drops resolved the corneal edema and cystoid macular edema, and vision returned to baseline.

To avoid complications in patients with uncontrolled glaucoma, Dr. Francis said, a thorough anti-inflammatory regimen is necessary to balance an equally aggressive treatment. He recommended intravenous steroids and/or intracameral, preservative-free steroids during surgery — or oral steroids postoperatively — in addition to topical steroids and nonsteroidal agents.

According to the authors, there is no way to know whether ECP is a significant risk factor for corneal graft failure, because the eyes included in the study had already undergone multiple surgeries. Dr. Francis said that he and his colleagues have begun collecting data on cornea transplant patients undergoing either aqueous shunt or ECP for glaucoma treatment.

“There is an increased risk of corneal graft failure with tube shunt,” he said. “We just don’t know yet whether ECP, because of inflammation, is at higher risk for graft failure.” – by Courtney Preston

Reference:

• Francis BA, Kawji AS, Vo NT, et al. Endoscopic cyclophotocoagulation (ECP) in the management of uncontrolled glaucoma with prior aqueous tube shunt [published online ahead of print Nov. 2, 2010]. J Glaucoma. doi: 10.1097/IJG.0b013e3181f46337.

• Brian Alan Francis, MD, MS, can be reached at the University of Southern California, 1450 San Pablo Street, #4804, Los Angeles, CA 90033; e-mail: bfrancis@usc.edu.
• Disclosure: Dr. Francis is a paid consultant for Endo Optiks.

This paper describes the management of a very challenging patient population that is most likely pertinent to the glaucoma specialist. All patients in this study had already been implanted with an aqueous drainage device or “tube shunt,” yet the IOP remained uncontrolled in all patients despite an average of 3.2 medications. There are very few viable therapeutic options for such patients. One option often employed is placement of a second tube shunt. However, the risk of such management includes corneal decompensation, strabismus and tube erosion. Endoscopic cyclophotocoagulation would seem to be a very reasonable alternative treatment option. The results of this prospective, non-randomized, single-surgeon series are encouraging. Patients achieved meaningful and impressive pressure reduction. Moreover, the number of medications required to control IOP was significantly reduced. Not surprisingly, complications such as worsening corneal edema and graft failure were encountered in this refractory patient population. Yet this should not discourage pursuit of this management strategy. High-risk eyes such as those enrolled in this series (28% of eyes had either prior corneal transplant or ICE syndrome) are at high risk for corneal edema with virtually any management. The authors have contributed important information that will help clinicians manage this difficult clinical problem.

– Thomas W. Samuelson, MD
OSN Glaucoma Section Editor
Disclosure: Dr. Samuelson is a paid consultant for and/or receives financial support from Alcon, AcuMEMS, Allergan, Abbott Medical Optics, AqueSys, Endo Optiks, Glaukos, iScience, Ivantis, Optonol, Pfizer, QLT and Santen.