Cyclophotocoagulation techniques produce similar effective outcomes, study shows

Transscleral cyclophotocoagulation significantly reduced IOP but was more prone to complications than endoscopic cyclophotocoagulation.

ORLANDO, Fla. — Two cyclophotodestructive procedures yielded similar outcomes and safety profiles but were associated with increased IOP 6 months after treatment, according to a study presented here.

At the American Academy of Ophthalmology meeting, Robert M. Beardsley, MD, compared transscleral cyclophotocoagulation (TCP) with endoscopic cyclophotocoagulation (ECP) for glaucoma.

ECP is considered safe despite being more invasive than TCP, Dr. Beardsley said.

“It is a previously well-defined procedure [with a] relatively high success rate and relatively low complications,” he said. “Despite being intraocular, it is felt to be safer than transscleral cyclophotocoagulation.”

TCP is generally easy to perform but may involve an increased risk of hypotony and phthisis.

“This is an office procedure that is fairly well tolerated and simple to perform,” Dr. Beardsley said. “Traditionally used in more advanced stages of disease with higher intraocular pressure, it does have the potential increased risk of hypotony and phthisis, especially in neovascular glaucoma. And there is some question as to the destruction of the overlying ciliary vessels.”

Patients, study design

The 10-year retrospective study included 42 eyes that underwent ECP and 44 eyes that had TCP. Mean patient age was 58 years in the ECP group and 71 years in the TCP group.

Mean preoperative best corrected visual acuity was 1.36 in the ECP group and 1.84 in the TCP group; one eye in the ECP group and 22 eyes in the TCP group had no light perception.

Preoperative IOP was 26.6 mm Hg in the ECP group and 45.3 mm Hg in the TCP group. Mean number of medications was 3.25 in the ECP group and 2.98 in the TCP group.

ECP was performed with an Endo Optiks E2 810-nm endoprobe (Endo Optiks) through a clear corneal incision with viscoelastic elevation of the iris.

TCP was performed with an 810-nm Iris OcuLight with a G-probe (Iridex).

Mean follow-up was 19 months in the ECP group and 17.6 months in the TCP group.

Data were recorded at 1, 3, 6 and 12 months, as well as at the most recent office visit.

Investigators also studied two subgroups: patients with neovascular glaucoma and patients with baseline BCVA better than counting fingers. The neovascular glaucoma subgroup comprised seven eyes from the ECP group and 18 eyes from the TCP group. The subgroup with BCVA better than counting fingers comprised 18 eyes from the ECP group and seven eyes from the TCP group.

Results, conclusions

Study results at 1 year showed that BCVA improved by two or more lines in seven eyes in the ECP group (17.1%) and no eyes in the TCP group. BCVA decreased more than two lines in eight eyes in the ECP group (19.5%) and three eyes in the TCP group (13.6%).

Mean IOP 1 year after treatment was 20.4 mm Hg in the ECP group and 22.2 mm Hg in the TCP group.

One eye in the ECP group (2.4%) and five eyes in the TCP group (22.7%) progressed to no light perception.

Mean number of IOP medications at 1 year was 2.28 in the ECP group and 1.95 in the TCP group.

The re-treatment rate was 16.7% in the ECP group and 18.1% in the TCP group.

Acute complications less than 1 month after treatment were rare in both groups. After 1 month, nine eyes in the TCP group progressed to phthisis, Dr. Beardsley said.

Seven eyes in the ECP group (16.7%) and eight eyes in the TCP group (18.1%) required re-treatment at 1 year.

In the neovascular glaucoma subgroup, IOP was reduced from 32.1 mm Hg to 29.3 mm Hg in the ECP group. No ECP eyes progressed to phthisis, hypotony or no light perception.

Among the TCP eyes in the neovascular glaucoma subgroup, IOP was reduced from 47.8 mm Hg to 14.6 mm Hg. However, 38.8% of these eyes progressed to phthisis, 11.1% progressed to hypotony and 50% progressed to no light perception, Dr. Beardsley said.

In the subgroup with BCVA less than counting fingers, TCP appeared safer in eyes with better vision. ECP resulted in greater loss of vision and progression to no light perception.

Limitations of the study included its retrospective design and possible patient selection bias. A prospective, randomized trial is needed to further gauge IOP reduction and long-term complications, Dr. Beardsley said. – by Matt Hasson and Patricia Nale

• Robert M. Beardsley, MD, can be reached at Jules Stein Eye Institute, 100 Stein Plaza, Los Angeles, CA 90095; 310-825-4617; fax: 310-206-8015; email: beardsley@jsei.ucla.edu.
• Disclosure: Dr. Beardsley has no relevant financial disclosures.