Spotlight ON TECHNOLOGY & TECHNIQUE

Achieve Accurate Biometry With the Lenstar LS 900

By Leslie Goldberg, Associate Editor

Accurate biometry is essential for the calculation of precise refractive power of IOLs in cataract surgery. The newly-approved Lenstar (Haag- Streit AG, Switzerland) can measure central corneal thickness, anterior chamber depth, lens thickness and axial length, in addition to keratometric readings, corneal diameter, pupil size, eccentricity of the visual optical line and retinal thickness.

Physician Feedback

"The Lenstar is both reliable and precise in its measurements," says Mike P. Holzer, MD, associate professor and director of refractive surgery at the University of Heidelberg.

Dr. Holzer, who has been using the Lenstar for almost three years, says that one of its greatest benefits will be the ability to measure the anterior chamber depth of pseudophakic patients. "The Lenstar uses a laser beam to measure axial length, anterior chamber depth, corneal thickness and lens thickness," says Dr. Holzer. "The advantage of using a laser beam is you can measure several structures of the eye simultaneously. Patients rest their chin on the chinrest and need to fixate just once."

Mark Packer, MD, FACS, in private practice in Eugene, Ore., has been impressed with the European findings. "Data from Europe is showing the Lenstar is extremely accurate in terms of measuring axial length," he says. Dr. Packer says that other advantages of the Lenstar are that it provides lens thickness measurement and uses noncontact technology. He also states that the Lenstar works well when measuring patients with dense cataracts.

"In addition to highly accurate biometrics, the Lenstar collects all of its data simultaneously so each item is measured at the same reference time and physical reference point," says Michael E. Snyder, MD, in private practice at the Cincinnati Eye Institute. "I believe that this will improve the spherical and cylindrical accuracy of our IOL calculation even with the current generation of formulae."

Dr. Snyder says this kind of improved accuracy in results is particularly critical when implanting premium IOLs. He adds that the measurement of corneal thickness provides the ability to assess overor underestimation of IOP by tonometry in cataract consult patients.

"Similarly, the central macular thickness measurement provides a useful surrogate screening test for subtle macular pathology that may be difficult to see through a dense cataractous lens," says Dr. Snyder. "While this point measurement does not replace the need for optical coherence or spectral domain tomography testing when pathology is identified, it can certainly alert clinicians to obtain such testing when they may otherwise not have adequate means to become suspicious enough to order these additional tests."

Dr. Snyder says the end result is a more complete picture of the patient's comorbid diseases, if any, pre-operatively, better counseling for the patient on the selection of the most appropriate IOL for that patient and overall improvement in patient outcomes.

Additional Features

The Lenstar is the first optical biometer with the precision of optical lowcoherence reflectometry, which is similar to the technology used in OCT devices. It utilizes a dual-scanning system in which the reflection from a reference beam is used to calculate distances within the eye. This technology provides true A-Scan measurements without contacting the eye. With an external personal computer, the Lenstar can be networked and directly communicate with EMR systems. OM

To learn more about the Lenstar, visit www.mylenstar.com or call (800) 787-5426.