Data Supports Safety and Efficacy of Phaco/ECP

Long-term data is emerging on this procedure including a large study of ECP in glaucoma patients undergoing cataract surgery.

Stanley J. Berke, MD, FACS, Lynbrook, N.Y.
6/13/2006

Endoscopic cy­clo­pho­to­co­ag­u­la­tion has been available to ophthalmologists for a number of years. In cases of refractory glaucoma, ECP rep­resents an ad­vance over older trans­scleral cy­clo­pho­to­co­ag­u­la­tion for cy­clo­destruction of the ciliary pro­cesses. By providing direct visualization not available in TCP, ECP en­ables treatment with less damage to adjacent tissue.

The desired tissue effect in endoscopic cyclophotocoagulation is to whiten and shrink the ciliary processes.


Another use of ECP that's been an option for some time is phacoemulsification combined with ECP for cat­aract patients with medically controlled glaucoma. The benefit of this combined procedure is both lowering of intraocular pressure and decreasing the number of medications needed to maintain adequate IOP control. While many cat­aract surgeons have successfully used phaco/­ECP in this setting, many more have been awaiting long­er-term studies and data to support its clinical efficacy, safety and benefit.

In this article, I will share data from studies in which I and some colleagues have participated that I be­lieve may lead to a significant shift in the way we think about cat­aract sur­gery in patients with medically controlled glaucoma.

 

ECP/Phaco Study

My colleagues and I conducted a study to delineate the natural history of phaco in the setting of medically controlled glaucoma, and to determine if adding ECP to phaco results in significantly lower long-term IOP, fewer glaucoma meds, or both when compared to phaco alone. In addition, the study sought to determine if adding ECP to phaco increases risk compared to phaco alone, and to calculate the cost benefits, if any, re­sulting from long-term de­crease in glaucoma medications.

We recently com­pleted data analysis on the pro­spective, randomized four-year study of 707 total eyes with medically controlled glaucoma that were undergoing cataract surgery; 626 were randomized to ECP/phaco and 81 were randomized to phaco alone. The surgery was performed by five surgeons within the same group. Data on visual acuity, intraocular pres­sure, medications and complications were collected. The mean follow up was 3.2 years, (range from 0.5 to 5.8 years), extending from January 2000 to December 2004. All patients received a foldable, three-piece silicone IOL.

The parameters of the typical cat­aract surgery are unchanged in combined phaco/ECP. The anesthesia used can be topical, intracameral or peribulbar block. The incision used can be scleral tunnel or clear corneal. The eye is inflated with viscoelastic and the endolaser probe is inserted through the phaco wound; the ciliary process is visualized and treated di­rect­­ly. The laser endoscope is a 20-ga. probe, and the action is at the tip. It incorporates a very bright, variable xenon light source, a diode laser and a fiber-optic video image. This is connected to a control box.

The ECP treatment zone can ex­tend from 180 degrees to 360 de­grees. In our study all of the patients were treated from 200 degrees to 270 de­grees. The desired tissue effect is to whiten and shrink the ciliary processes.

Postop medications are also straight­­forward: In our study, the post­op regimens were the same for the phaco/ ­ECP group as for the phaco alone. All patients received Zymar, Acular and Pred Forte q.i.d.

All patients were initially maintained on their preop glaucoma medications, and if IOP reduction was believed to be adequate based on the patient's optic nerve and visual field, one glaucoma medication at a time was eliminated.



The Results

The outcomes we looked at were change in IOP and stability over the follow-up period, and change in number of glaucoma medications compared to preop. (See Tables 1 and 2 for the results).

In the 626 combined phaco/ECP eyes, the preop IOP was 19.08 mmHg and at the end of the study pe­riod of 3.2 years on average, the post­op IOP was 15.73; this was highly statistically significant with a p value of 10-72.

The number of preop medications in the phaco/ECP group was 1.53; this was dramatically reduced at the end of the study period to 0.65, and again this was highly statistically significant with a p value of 10-85.

The phaco alone group included 81 eyes. The preop IOP was 18.16 mmHg; and at the end of the study pe­riod, it was 18.93. The number of preop medications in the phaco alone group was 1.2 and it remained 1.2 at the end of the study.

In the phaco/ECP group, in 68 percent there was a decrease in medications, in 27 percent there was no change in medications, and in 5 percent there was an increase in medications. This compares to the phaco alone group, wherein only 11 percent of eyes experienced a decrease in med­ications. In 77 percent there was no change in medications, and in 12 percent there was an increase in medications.

Another important result is the percentage of patients who were on two or more glaucoma medications in the two groups. In the phaco/ECP group, preoperatively there were 44 percent; postoperatively, this fell to 18 percent and was highly statistically significant. In the phaco alone group, 32 percent of eyes were on two or more medications preop, and at the end of the post­op period, 38 percent were on two or more medications.

A vital consideration is the percentage of subjects with a reduction in IOP at the end of follow up. We know that cataract surgery alone may reduce IOP in some glaucoma pa­tients. One of the key parameters, therefore, in considering a combined procedure is how it compares over time with cataract surgery alone.

Long-term Safety Results
When discussing safety, some observers group ECP into the same category as transscleral cyclophotocoagulation and other high-energy, imprecise procedures. TCP tends to be a more destructive therapy allowing for the opportunity to over-treat, thus causing collateral damage and inflammation.

Surgeons using ECP for the first time generally are worried about over-treatment. For ECP, efficacy comes with aggressive treatment, commonly about 270 to 360 degrees in order to achieve clinically significant lowering of intraocular pressure. Sometimes physicians are not initially comfortable with this level of treatment due to experience with TCP.

To combat this incorrect comparison to TCP, nu­merous physicians experienced in ECP have formed an ECP Study Group and conducted a retrospective review of the safety of this procedure.

In a large group of patients with various subtypes of glaucoma, treated at multiple sites and with extended follow-up, ECP demonstrated an excellent safety profile with a low rate of short and long-term complications. Devastating complications were infrequent and mostly associated with neovascular glaucoma. Phakic eyes were prone to cataract formation, similar to other glaucoma surgical procedures. The safety of ECP compares favorably to the historical data associated with trabeculectomy and aqueous drainage devices.

In total, 5,824 patients were treated by the various surgeons of the ECP Study Group and followed for a mean of 5.2 years (range 1 year to 10.5 years). Early complications included:

 • IOP spike in 14.5 percent (844 eyes);

 • hyphema or vitreous hemorrhage in 3.8 percent (221 eyes);

 • serous choroidal effusion in 0.36 percent (21 eyes); and

 • intraocular lens displacement in 0.36 percent (21 eyes).

Long-term complications included:

 • cystoid macular edema with visual loss in 0.27 percent (16 eyes);

 • retinal detachment in 0.27 percent (16 eyes); and

 • massive choroidal hemorrhage in 0.09 percent (five eyes).

Hypotony or phthisis and progression to no-light-perception vision each occurred in 0.12 percent (seven eyes), and only in patients with neovascular glaucoma. Phakic patients had a rate of cataract formation of 27 percent (119/437) over time. Chronic inflammation, chronic pain and infectious endophthalmitis, were not observed.

The volume of patients included in this study is significant. The rates of complications are comparable to or better than other incisional glaucoma procedures. In addition, ECP efficacy results have been reported to be the same or better than incisional surgeries at controlling IOP.

Initial IOP spike is the most common complication. This relates to the fact that ECP does not lower IOP immediately, unlike other treatments which might drop IOP too quickly. Unlike outflow procedures, in which there is the potential for sudden drop in IOP, precipitous drops in IOP are uncommon with ECP. The difference in mechanism is probably the reason for the relative safety of ECP. IOP spike is generally a short-term complication and can be decreased even more with proper removal of viscoelastic from the zonules and ciliary sulcus.

Hyphema appears to result from trauma to the iris and ciliary body about 4 percent of time. This is generally caused by over-lasering of the iris or ciliary body. There may also be mechanical damage from the probe itself if not handled properly. This complication rate is on par with trabeculectomy or tube implant procedures.

Other less-common complications occur at rates that are the same or better than those associated with other incisional glaucoma procedures. Choroidal effusion tends to be lower with ECP than with other surgical procedures and the long-term CME rate is similar to that found in any incisional surgery.

Given the proven safety of ECP, surgeons do not have to reserve ECP for end-stage eyes. This procedure can be done in relatively healthy eyes as a first line of surgical therapy to decrease IOP.

—S. Berke, MD



In the phaco/ECP group there was a decrease in IOP in 79 percent of eyes, no change in 9 percent and an increase in 12 percent at the end of follow-up. In the phaco alone group, however, there was a decrease in IOP in 38 percent, no change in 2 percent and an increase in 60 percent.

The 20-ga. laser endoscope incorporates a very bright, variable xenon light source, a diode laser and a fiber-optic video image.




Complications, Cost Issues

No serious complications were re­ported in either group. The incidence of CME was equal in both groups at approximately 1 percent. (For additional information on a larger study of ECP complications, see sidebar, p. 68.)

The average annual cost of glaucoma medications for patients in the phaco/ECP group was $2,641 preop and $1,137 postop. This resulted in an average annual savings of $1,504 for each patient in the phaco/ECP group. The phaco alone group did not ex­perience any financial savings for glau­coma medications.



In summary, this long-term analysis of medically controlled glaucoma pa­tients undergoing cataract surgery demonstrates that phaco/ECP results in significantly lower IOP and significantly fewer medications compared to phaco alone, without any increase in early or late complications.

The statistical results of this study are sufficiently powerful to suggest a paradigm shift in our thinking about treatment of cataract patients with con­current glaucoma. It is evident from this study that phaco alone does not contribute to long-term IOP control, while adding ECP to phaco does. The high safety margin of ECP in this large cohort with extended follow up clearly indicates that this method of rendering decreased outflow is be­nign. Com­bining ECP with phaco should be considered in patients with cat­aracts and medically controlled glaucoma.

 

Dr. Berke is an associate clinical professor of ophthalmology and visual sciences at Albert Einstein College of Medicine, chief of the Glaucoma Ser­vice at Nassau University Medical Center, and in private practice at Oph­­thalmic Consultants of Long Island. Contact him at sberke@ocli.net.