FDA panel recommends Alcon’s CustomCornea with conditions

Results reported to the panel met or surpassed Food and Drug Administration guidelines, the panel said.

GAITHERSBURG, Md. — An advisory panel recommended Alcon’s CustomCornea wavefront-guided custom ablation system as “approvable with conditions” at a meeting here.

The Ophthalmic Devices Advisory Panel unanimously recommended that the Food and Drug Administration approve the system for the correction of myopia up to –7 D and astigmatism up to –0.5 D. The FDA is not bound to follow the panel’s recommendations, but it usually does.

The LADARVision 4000 Excimer Laser and the LADARWave Wavefront System comprise the CustomCornea system. Clinical trials using the system are continuing for the treatment of myopic astigmatism, hyperopia with and without astigmatism and other ocular irregularities.

According to the manufacturer, this is the first wavefront-guided LASIK system to receive recommendation for FDA approval.

George Pettit, MD, PhD, a chief scientist at Alcon, explained to the panel how wavefront technology and Alcon’s CustomCornea system work. He said the LADARVision system’s method of registration compensates for cyclotorsion and ensures an accurate match of the wavefront map and the ablation profile.

Study results: safety cohort

Daniel S. Durrie, MD, presented the LADARVision safety data to the advisory panel for Alcon. Dr. Durrie noted the safety cohort of 426 eyes included astigmatism cases that the company is not currently seeking approval to treat. The primary effectiveness cohort, presented by Omar Hakim, MD, included 139 eyes and excluded patients with more than – 0.5 D of astigmatism.

Patients included in both study cohorts were 60% white males. Most were contact lens wearers. Follow-up was completed out to 6 months.

Dr. Durrie said no eyes lost more than 2 lines of best corrected visual acuity (BCVA). Only 9.4% of patients lost 1 line or more of BCVA, and 37% of patients gained 1 line or more of BCVA.

At 6 months follow-up, all eyes had best corrected visual acuity of 20/32 or better.

Dr. Durrie said the incidence of complications reported at any visit during the trial was consistent with previous studies. Diffuse lamellar keratitis (DLK) was the most common complication, with a reported incidence of 3.5%.

Of all eyes in which complications were reported, all but two had a BCVA of 20/20 or better at the last reported follow-up, and all had a BCVA of 20/32 or better.

Adverse events that were related to the LASIK procedure included recalcitrant DLK with blepharitis (0.5%) and flap problems (0.2%). All eyes that experienced an adverse event had a BCVA of 20/16 at the last reported visit.

Effectiveness: spherical cohort

Dr. Hakim presented the effectiveness cohort of 139 eyes to the FDA panel. He said 83.5% of eyes had a mean refractive spherical equivalent within ± 0.5 D of emmetropia 1 month after surgery and 97.1% were within 1 D.

At 6 months follow-up, 74.8% of eyes remained within 0.5 D of emmetropia and 95.7% of eyes were within 1 D.

“These groups clearly exceed FDA guidelines,” Dr. Hakim said. FDA guidelines require that 75% of eyes be within 1 D.

“Even in higher levels of myopia excellent results were reported, with uncorrected visual acuity of 20/25 or better in 92% of the eyes between –5 and –5.99 D,” Dr. Hakim said.

Dr. Hakim said there was a small amount of undercorrection overall in the study. He added that these results will improve once Alcon has the ability to make nomogram adjustments during the trial. He said there was excellent stability over time, from 1 month postop on.

Postoperatively, 86.3% of eyes achieved 20/20 uncorrected visual acuity and 99.3% of eyes achieved 20/40 or better UCVA at 1 month after surgery. At 6 months, 79.9% of eyes remained at 20/20 or better UCVA and 98.6% of eyes remained at 20/40 or better UCVA.

Postoperatively, 59% of eyes had UCVA equal to or better than their preoperative BCVA. At 3 months the figure was 55.4% and at 6 months 52.5%.

Regarding subjective reports of ocular symptoms following surgery, at 6 months follow-up dry eye was the most frequent patient complaint at 2.2%. Burning and presence of a gritty feeling were also equally reported as significantly worse by 1.5% of patients. Most patients reported feeling “the same” as preoperatively for burning (79.4%), dryness (56.6%) and gritty feeling (72.8%).

At 3 months, 85.4% of patients said they were satisfied or extremely satisfied with their results, and at 6 months the figure was 79.4%.

Dr. Hakim said that the man- ifest refraction spherical equivalent (MRSE) in the satisfied patients was within –0.3 D of emmetropia, while the MRSE in unsatisfied patients was within –0.93 D.

“Reduction in this undercorrection should shift the cohort toward even higher patient satisfaction rates,” Dr. Hakim said.

Roughly 90% of patients rated their vision the same, better or significantly better at 3 months and more than 88% rated their vision as the same, better or significantly better at 6 months.

At 6 months, 94.1% of patients reported having no need for distance correction.

Panel concerns

Although safety and effectiveness data clearly exceeded the FDA grid requirements, concerns about the device’s labeling led the panel to make the conditional recommendation. Specifically, the panel was concerned about claims of effectiveness and patient education. Wording in the system’s labeling did not adequately explain the relationship between a patient’s level of higher-order aberrations and the patient’s quality of vision, according to the panel.

The custom ablation system does not reduce preoperative higher-order aberrations, the panel noted, but rather induces fewer aberrations postoperatively than conventional LASIK systems. (In the trial, LASIK with the CustomCornea system was compared to conventional, non-wavefront-guided LASIK with the LADARVision system.) The panel noted that conventional LASIK with the LADARVision laser induced an increase of approximately 77% in higher-order aberrations over preoperative levels, while wavefront-guided LASIK showed an approximate increase in higher-order aberrations of 20% over preoperative levels.

The panel further stated that the accuracy of the correction of myopia remains the primary determination of uncorrected image quality and vision.

Moreover, the panel required that the device’s patient labeling provide data on postoperative symptoms and patient satisfaction comparing conventional LADARVision LASIK eyes to wavefront-guided LASIK eyes.

Several revisions to the patient and physician information booklets regarding the system’s effectiveness and the study population were also suggested. The advisory panel noted that wavefront-guided LASIK demonstrated slightly superior optical quality over conventional LADARVision LASIK, which the panel defined as reduced higher-order aberrations. The panel also noted there were no data showing an improvement in functional performance — that is, activities of daily living such as reading and driving — or in patient satisfaction rates with wavefront-guided LASIK compared to conventional LADARVision LASIK.

However, the panel also recommended labeling changes to make clear that the CustomCornea system produced improvement in contrast sensitivity and best corrected visual acuity compared to conventional LADARVision treatment.

The panel also recommended that the physician booklet include existing dry eye as exclusion criterion.

The panel agreed that the company met or exceeded all FDA guidelines for safety and effectiveness, and the members unanimously voted to recommend the conditional approval of the system for the correction of myopia up to – 7 D with less than – 0.5 D of astigmatism.

For Your Information:

• Daniel Durrie, MD, can be reached at Hunkeler Eye Centers, 5520 College Blvd., Overland Park, KS 66211; (913) 491-3737; fax: (913) 491-9650; e-mail: ddurrie@novamed.com.
• Omar Hakim, MD, can be reached at TLC Toronto Laser Centre, 4101 Yonge Street, Suite 100, North York, ON, M2P 1N6, Canada; (416) 733-2020; fax: (416) 733-0316.

• Alcon, makers of CustomCornea wavefront-guided custom ablation system, can be reached at 6201 South Freeway, Fort Worth, TX 76134; (817) 293-0450; fax: (817) 568-6142.