SURGICAL PEARLS

Beyond the Data

Researchers report findings on largest study of ECP performed in conjunction with cataract surgery.

BY STANLEY J. BERKE, MD, FACS

In the largest study on endoscopic cyclophotocoagulation (ECP) performed in conjunction with cataract surgery to date, researchers found that combined ECP and cataract surgery resulted in lower IOP and a greater reduction of the need for glaucoma medications than cataract surgery alone in patients with medically controlled open-angle glaucoma (OAG) and cataract. The study was conducted over a 3-year period. Here is an analysis of the clinical implications of this long-term data.

Clinical Findings

Patients with medically controlled OAG and visually significant cataracts were treated with ECP and cataract extraction or cataract extraction alone. The groups were matched in age and baseline IOP. Researchers then measured the change in IOP, number of glaucoma medications used, visual acuity and postoperative complications.

In the study group comprised of 80 patients, the number of glaucoma medications decreased from 1.5 ± 0.8 to 0.4 ± 0.7 at 1 year, 2 years and 3 years. Mean IOP decreased from 18.1 mm Hg ± 3.0 at baseline to 16.0 ± 2.8 mm Hg at 1 year, 16.0 ± 3.3 mm Hg at 2 years, and 15.4 ± 2.5 at 3 years. The control group of 80 eyes did not experience a significant decrease in IOP or medications at 1 year, 2 years nor 3 years. The visual acuity and rate of complications were similar in both groups.¹

The findings of this study are like no other due to the matched control arm of patients who underwent cataract extraction alone, the large number of patients and the length of follow-up. The study shows that adding ECP to phacoemulsification is effective in decreasing IOP as well as the number of glaucoma medications. Cataract surgery alone resulted in medication reduction in a small number of patients within 6 months that was not sustained beyond 1 year. Also, both groups experienced an initial downward trend in IOP that peaked at the end of the first postoperative year. However, the eyes that underwent ECP and cataract surgery maintained lower IOP during the following 2 to 3 years, while the eyes that underwent cataract surgery alone regressed to a level that was higher than the initial IOP. Adding ECP did not increase the risk for serious complications compared with cataract surgery alone.

Figure 1. Endo Optiks E2 laser and endoscopy system.

These findings confirm that ECP is a safe and effective adjunct to cataract surgery. The results are encouraging because they demonstrate that by addressing glaucoma and cataract simultaneously, we not only have the potential to lower IOP but also may be able to reduce the need for glaucoma medications, which reduces the costs, treatment burden and side effects for patients.

Clinical Relevance

As a surgeon who has been performing ECP since 1998, I feel the ideal patient for a combined ECP and cataract surgery procedure has visually significant cataract and medically controlled glaucoma. ECP combined with cataract surgery provides a third choice beyond the previously existing options, which were cataract surgery combined with a surgical trabeculectomy or cataract surgery alone. Surgical trabeculectomy, in these patients, is considered excessive because trabeculectomy warrants an extensive and involved postoperative course and an increased potential for complications in the early and late postoperative period. Alternatively, cataract surgery alone doesn’t help glaucoma in the long term. Therefore, a “cataract plus” procedure, which entails performing cataract surgery with modern phacoemulsification techniques using the E2 and E4 laser endoscopy systems (Endo Optiks, Inc.) to perform ECP, has been ideal.

In 1998, after analyzing the first 25 cases I performed with a phacoemulsification/ECP procedure with a follow-up of 6 months, I found that combining ECP with cataract surgery resulted in IOPs with an average of 2 to 3 points lower than the preoperative IOP as well as a significant reduction in medication in the range of approximately 50% to 60%. This approach is beneficial to the patient’s quality of life, because he doesn’t have to take as many medications or endure the side effects or expense of medications.

A Comparison

ECP is the first and most proven microinvasive glaucoma surgery (MIGS). Typically, MIGS procedures are performed with the same indications as someone who has cataract and glaucoma, and they’re performed through the phaco incision so there are no additional conjunctival or scleral incisions. The procedures are fairly simple and easy when performed as an add-on procedure to phacoemulsification, and they offer a benefit in terms of lowering IOP and reducing medications. However, after exploring other MIGS procedures, to include stent implantation (iStent, Glaukos) or trabeculotomy ab interno (Trabectome, NeoMedix), I found that performing those procedures at the end of cataract surgery involves rotating the patient’s head 45° degrees away from the surgeon, rotating the surgical microscope 45° degrees toward the surgeon to create an extreme tilt, placing a gonioprism lens on the cornea, visualizing and treating the trabecular meshwork directly, or implanting a stent in the Schlemm’s canal. Even though I’m an experienced surgeon, I found those steps difficult to perform while maintaining visibility and positioning the implants accurately. I prefer ECP because it’s simple and more predictable, with fewer complications and a short learning curve.

Long-Term Study Data

There is some confusion in regard to the effects of cataract surgery alone on IOP. Phacoemulsification alone can lower IOP in some patients, but that tends to be short lived as the reduction may last for 6 months to 1 year, which I call the “honeymoon” period. After that time period, the IOP tends to slowly increase, and by the end of 2 years, not only is the IOP back to baseline but the amount of medication required also returns to baseline. Conversely, patients who undergo ECP combined with phacoemulsification have a long-term decrease in IOP and a long-term reduction in the need for medications.

Figure 2. Illustration of ECP following cataract surgery.

In 2009, Brooks Poley, MD, reported that patients who have a high IOP are more likely to experience an increased reduction in IOP when they undergo cataract surgery alone.² However, it’s important to note that the patients Dr. Poley treated didn’t have glaucoma nor were they being treated for glaucoma, and patients with IOPs under 20 mmHg didn’t experience a pressure-lowering effect. Dr. Poley’s findings weren’t based on patients with concomitant cataract and glaucoma. Although his findings are relevant, some surgeons have misinterpreted the data to mean that cataract surgery alone will benefit their glaucoma patients in the long term. Our recent findings dispel any misinterpretations. They reveal that cataract and glaucoma, two of the most common conditions causing visual impairment in our patient population, can be treated effectively with ECP combined with cataract surgery, yielding long-term, positive outcomes. ■

References