Spotlight on Technology & Technique
Spotlight ON TECHNOLOGY & TECHNIQUE
LensAR’s New Look at Imaging
This femto-phaco unit ushers in a new era of 3-D OCT technology.
By Bill Kekevian, Associate Editor
In August, two surgeons on opposite coasts performed the first laser cataract procedures using the LensAR Laser System in the United States. LensAR Inc. had been approved for anterior capsulotomy and laser phacofragmentation, but in June, the company received 510(k) FDA clearance for cataract surgery.
The LensAr system sets itself apart from the field by employing a proprietary three-dimensional imaging, measurement and guidance system in place of typical optical coherence tomography (OCT). Kerry K. Assil, MD, one of the doctors who performed the initial surgeries, calls this “the world’s most sophisticated laser for cataract surgery.”
Changes Your Practice
“Having a laser like this changes your treatment model,” Dr. Assil says. “There is inherent appeal in the mind of the patient.” Although traditional cataract surgery is safe, the laser surgery can be safer and more accurate and that’s attractive to patients.
The fact this device provides consistent and precise performance, particularly for elements of the procedure a surgeon cannot perform, may be attractive to doctors.
“I can perform corneal entry incisions and limbal relaxing incisions on my own. I can even perform a round capsulotomy, though not as precisely as can the laser,” Dr. Assil says. “I can’t, however, pre-chop or pre-soften the nucleus prior to initiating phacoemulsification. This laser system does exactly that and safely. It chops up the nucleus as I wish and that makes the procedure a little easier and safer.” He adds that, besides enhancing the precision of the procedure via highly accurate IOL centration, this laser also improves safety via nuclear prefragmentation and reduced ultrasound time and energy.
At his practice in Los Angles, where he is the official LASIK and cataract surgeon for the Lakers of the National Basketball Association, Dr. Assil reports performing about 190 cataract surgeries over the first three months using the LensAR, including the very first one in the United States, and notes he hasn’t experienced a single capsular tag or tear nor any radial cuts in the capsule.
The procedure time should be short. While a traditional cataract surgery can take 5 to 6 minutes and a premium cataract (including LRI and aberrometry), 15-20 minutes, Dr. Assil says his typical docking time is less than 2 minutes. The first step is affixing the suction ring to the eye, which is then filled with fluid and docked to a device mounted onto the unit.
Once in place, the LensAR uses a rotating camera to scan from the front of the cornea to the back of the lens to create a profile of the eye and a three-dimensional reconstruction of the entire anterior segment, automatically imaging and analyzing all grades of cataract. The camera produces high-contrast, low-noise images.
The laser system uses a fluid-filled patient interface to avoid compressing the cornea and creating folds. This immersion system also prevents imaging distortions. By avoiding corneal applanation, less suction is needed, resulting in a reduced rise in IOP and no subconjuctival bleeding. In addition, the amount of ultrasound phacoemulsification energy required to remove lenses is considerably less than conventional cataract removal. In grade 1 cataracts, one study showed, no phacoemulsification energy was needed; the lens was removed purely with aspiration.1
New Approach to Imaging
According to Dr. Assil, the OCT unit in the LensAR required extended development time so it would image over a long focal lens. He says the company came to recognize that to treat the nucleus properly, the device needed to be able to image over a long depth of field and through opacities. “It’s something they had to invent,“ Dr. Assil says of LensAR. The technique employs Scheimpflug imaging technology to find anatomical landmarks for laser pattern mapping.
The unit is also somewhat portable. It fits through a 36-inchwide door and can be wheeled from room to room without the need for recalibration, according to the company. OM
1. Edwards KH, Frey RW, Tackman RN, et al. Clinical outcomes following laser cataract surgery. Invest Ophthalmol Vis Sci. 2010;51:E-Abstract 5394
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