AUTOMATING CUSTOMized LAsik
Compared with earlier models, the Ladar 6000 excimer laser is easier to use and speeds procedural time and patient flow. A primary advantage of the system is that it automatically places the limbal ring at the Ladarwave and thus quickens the capture-match-treat registration process. Because the system provides side-by-side viewing of the wavefront image, it ensures that the customized ablation profile is aligned exactly to the same position on the eye from which the wavefront was taken. Software prompts guide surgeons through each step of the procedure.
The registration process unique to Ladarvision ensures that the system compensates for cyclotorsion as the patient moves from an upright to a supine position. Although the capture-match-treat process has been a part of the Ladarvision system since its debut, recently other laser manufacturers have recognized its necessity in delivering an accurate wavefront-guided treatment. Now, however, Alcon's system has automated registration that will speed up procedure time and promote consistency.
The advanced illumination of the system increases visibility throughout the procedure and allows for optimal surgeon-controlled lighting conditions for each phase of the treatment (Figure 1). This advanced illumination system makes it easier to locate landmarks on the eye, including the limbus and scleral vessels (Figure 2). This capability speeds and eases the registration process, which is imperative for true registration and accurate wavefront-guided procedures.
Planned future advances in the system's registration include registering on scleral vessels, a technique that will eliminate the need to mark the eye and will allow surgeons to take wavefront measurements on a day prior to surgery (Figure 3). These advances will tremendously speed both clinical flow and throughput on the day of surgery.SPEED
Many of the software and hardware features in the laser are designed to quicken the entire process of providing truly customized procedures. In addition, the laser supports high rates of ablation.
As a new laser, with 90% new parts and components, it includes an entirely new state-of-the-art laser cavity that is much more efficient. The Ladar 6000 excimer laser also enhances patients' and practitioners' intraoperative comfort. An ergonomically designed bed provides more headroom for the patient and more working space for the surgeon (Figure 4).
The laser and workstation have been redesigned for greater overall ease of use. A retractable arm, flat-screen monitor, and neatly encased computer and recording system offer a clean look. The adjustable workstation provides more workspace and flexible ergonomics for surgeons' different work styles.
The new laser is more robust and requires less maintenance than the previous model. Gas bottle changes are now only required once a week rather than daily as with other systems, and the gas bottle now requires replacement only once every 6 to 8 months for a high-volume practice—far less frequently than with the Ladarvision 4000 or other lasers.INDICATIONS
With its release, the new laser will be able to treat the full range of indications approved for the Ladarvision 4000. The system recently obtained expanded indications to treat virtually all myopes. Surgeons may provide Customcornea with the existing system to correct myopia of up to -8.00D, with or without astigmatism of up to -4.00D—the broadest customized myopic treatment range for any wavefront-guided system. The expanded labeling addresses refractive errors beyond the formal approval range, up to the maximum treated in the FDA trial (-9.75 and -5.00D), although a warning flag will appear when the planned treatment exceeds the approved range. Tissue-related considerations remain important in these higher corrections.CLINICAL TRIAL
The clinical trial for the expanded indications included 295 eyes, of which 232 had myopic astigmatism and 63 had spherical myopia. Preoperatively, the mean spherical equivalent was -4.10D (-0.88 to -10.63D). Mean sphere was -3.75D and went as high as -9.75D. Mean cylinder was -1.07D but ranged as high as -5.00D.
Six months postoperatively, 95% of the eyes saw 20/25 or better uncorrected, and 89% were 20/20 uncorrected. Ninety-nine percent of eyes had a BCVA of 20/20 or better, and 42% had a BCVA of 20/12.5 or better, compared with only 18% preoperatively. Five times as many eyes gained versus lost high-contrast BCVA, and no eye lost more than two lines of BCVA.
More than twice as many Customcornea eyes showed a gain in mesopic contrast sensitivity (21%) compared with a loss (8%) (Figure 5). In a comparison of Customcornea eyes with a matched population of 138 eyes that underwent a conventional Ladarvision treatment, the two groups had similar levels of preoperative higher-order aberrations. Six months postoperatively, the mean amount of certain higher-order aberrations increased significantly less for Customcornea compared with the conventionally treated eyes. The mean change in RMS values for all higher-order aberrations was 11% in the Customcornea eyes, for example, compared with 65% in the conventional group. The difference in induced aberrations was significant for spherical aberration. Following the customized treatments, mean spherical aberration increased by only 4% with the Customcornea eyes and 135% with conventional treatment. Surgeons hope not just to reduce the induction of aberrations but also to decrease the total aberrations present in the eye from preoperative levels. More than twice as many Customcornea (44%) eyes showed a net reduction in higher-order aberrations from preoperative levels when compared to the conventionally treated (17%) eyes. Also, almost half the Customcornea eyes (49%) experienced a decrease from preoperative levels of spherical aberration, compared with only 12% of the conventional eyes.CONCLUSION
The bottom line is that compared with the Ladarvision 4000, the Ladar 6000 excimer laser is better technology that is easier to use, and it will immediately be able to treat the full range of patients that can be treated on the Ladarvision 4000 today. All of the improvements to its design aim to save time, improve patient flow, and enhance procedural accuracy. The automatic registration process introduces an even greater level of precision to the already excellent outcomes surgeons are achieving with the Ladarvision 4000 excimer laser system.Stephen F. Brint, MD, is in private practice at Brint Custom Vision and is Associate Clinical Professor of Ophthalmology at Tulane University School of Medicine, both in New Orleans. He is a paid consultant for Alcon Laboratories, Inc. Dr. Brint may be reached at (504) 888-2020; firstname.lastname@example.org.
Eric D. Donnenfeld, MD, is a partner at Ophthalmic Consultants of Long Island in New York. He is a paid consultant for Alcon Laboratories, Inc., but states that he holds no financial interest in the products mentioned herein. Dr. Donnenfeld may be reached at (516) 766-2519; email@example.com.
Roger F. Steinert, MD, is Professor and Vice Chair at the University of California in Irvine. He is a paid consultant for Alcon Laboratories, Inc., but states that he holds no financial interest in the products mentioned herein. Dr. Steinert may be reached at (949) 824-8089; firstname.lastname@example.org.
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