Results for cataract surgery are better than they have ever been, and this can be shown in terms of refractive outcomes, patients’ satisfaction, and safety. With premium IOLs and femtosecond laser technology, an entire new category of refractive cataract surgery has emerged to reflect the union of disease management and premium outcomes. As various aspects of cataract surgery have progressed, demand has also risen for greater precision in aberrometry—the measurements on which every other decision during surgery is based. Fortunately, intraoperative biometry technologies have been emerging and continue to be developed.
ORA
Optiwave Refractive Analysis (ORA System; WaveTec Vision) has led this innovation, changing the way refractive cataract surgery is performed. The ORA System provides cataract surgeons with measurements for aphakic and pseudophakic refraction and projects a reticle into the ocular system of the microscope to aid the surgeon in identifying the axis for the placement of a toric IOL. In addition, the alignment of limbal relaxing incisions (LRIs) will help determine the correct IOL power, confirming that the surgeon has hit his or her desired refractive goal. According to the manufacturer, ORA is now relied on by more than 400 high-volume surgeons with approximately 110,000 procedures performed to date. It has also been a valuable tool in post-LASIK and post-RK patients.
WaveTec’s newest development is a system known as VerifEye, which streams refractive information to the ORA System. It provides high-quality measurements by verifying that the eye is stable and ready for measurement, greater consistency and accuracy with IOL power recommendations, and guidance for astigmatic measurements. VerifEye’s measurement goals hope to improve the already 85% success rate of being within 0.50 D of the intended refractive target and deliver the analysis in a just a few seconds, the company states.
Thanks to ORA with VerifEye, cataract surgeons are experiencing decreased enhancement rates and increased conversion rates.
VERION
As one the leaders of eye care advancements, Alcon Laboratories, Inc., prepares to unveil its answer to intraoperative biometry with the powerful Verion system. The new technology, derived from the former SMI surgery guidance technology (SensoMotoric Instruments GmbH) acquired by Alcon, provides holographic reference overlays seamlessly by merging digital preoperative technology into all of the company’s surgical products like the Luxor microscope, the new Centurion phacoemulsification units, and the LenSx femtosecond laser. The Verion system will have the flexibility to integrate with current established biometry systems like the IOLMaster (Carl Zeiss Meditec, Inc.) or the Lenstar (Haag-Streit AG).
In the office, the Verion will use this current information and take an image of the eye and capture reference points, such as vessels at the limbus and center of the pupil. All of these points of judication will be applied, and in the operating room, a live holographic overlay will be displayed over the eye to account for torsion and the slightest ocular movement. No longer will surgeons need to mark eyes to identify astigmatism. The hologram will be seen on the screen of the LenSx laser or at the microscope during phacoemulsification and can be used as precise guidance system to determine the true center of the pupil and choose reference points to orient a toric IOL or apply femtosecond LRIs for precise astigmatic correction. The hologram overlay is displayed through the eyepiece reticles with the Luxor microscope if surgeons purchase the microscope unit that comes with Alcon’s new Centurion phaco system. For surgeons not ready to upgrade microscopes or phaco units, there will also be a computer video system that can be attached to the microscope to provide the hologram overlay on a separate screen.
Another nice feature of the Verion is that it will allow surgeons to calculate the combined astigmatic correction when they choose to use the laser-guided LRIs with toric IOLs. With the ease of a slide of a bar on an analysis page, the system’s software calculator will allow surgeons to titrate the level of astigmatic correction using LRIs with different toric IOLs. Surgeons will be able to customize the astigmatic correction to an even tighter range than they currently can without the worry of flipping the axis.
TRUEGUIDE SOFTWARE AND TRUEVISION SURGICAL SYSTEM
Another interesting technology expected to be available soon is the TrueGuide software, which will integrate with the TrueVision 3D Surgical System (TrueVision 3D Surgical, Inc.). This device currently gives surgeons the ability to step away from the microscope during traditional microsurgery. By using a powerful 3D video system connected to the microscope and 3D glasses, surgery can now safely and comfortably be performed looking onto a precise video image on a large flat screen rather than under a microscope, according to the company. The system allows the surgeon to assume a more ergonomic position during surgery. TrueGuide complements this technology by providing holographic digital guidance during cataract and corneal surgery using state-of-the-art diagnostics and intelligent software applications with the TrueVision system.
Preoperative patient data and images are captured using the Cassini Color LED topography from i-Optics. Based on a patented color point-to-point measurement technology, colored LEDs are positioned in a unique relationship to four of its neighbors, which gives each LED an unmistakable identity and tighter topography than classic ring-based Placido topography.
TrueGuide software uses the digital topography information from the Cassini device as well as pixel-to-pixel image matching, which includes iris details, scleral vessels or pigmentation, and other physical ocular features. This robust technology then allows for the digital hologram to be overlaid in real time during routine procedures while tracking the eye during surgery. TrueGuide takes into account and compensates for cylcotorsion, as well as individual surgeon surgically-induced astigmatism and provides digital references for the true center of the of the visual system as well as guidance markers to manage astigmatism via toric IOLs or LRIs.
HOLOS INTRAOP
An exciting up-and-coming technology that is paving the way for the next generation of intraoperative biometry devices is Holos IntraOp (Clarity Medical Systems). Holos is a new, unique intraoperative aberrometry device that uses proprietary sequential scanning, invented by Clarity specifically for ophthalmology, that provides real-time intraoperative refractive data.
Current technologies capture images of the eye and then display refractive data or points of reference from a specific point in time. Holos’ technology bridges the gap from a still camera to a video camera, providing high-accuracy, real-time refractive wavefront measurements throughout the entire surgery. The Holos aberrometer attaches to a standard surgical microscope, and a separate screen displays a continuous live video of the patient’s refractive state. Without having to pause surgery, adjust lights, or change equipment, the surgeon is able to glance up to see how the refractive error is decreased. You literally can watch as the spherical error returns to plano as the IOL is placed in the eye as well as watch the astigmatism decrease when a toric lens is rotated into axis or as LRIs are made to titrate the residual cylinder.
The Holos device allows extremely precise and rapid refractive measurements in phakic, aphakic, and pseudophakic eyes. This elimination of dependence on preoperative measurements, which are subjective to technician error, furthers a surgeon’s ability to achieve emmetropia in every patient.
CONCLUSION
Going forward, no longer will it be enough for cataract surgeons to be satisfied with removing a cataract and putting in an implant. With these amazing new intraoperative systems will be able to recreate Lasik-like precision during cataract surgery and get our 93% success rate closer to 100%.
The manufacturers supplied the information in this article.
