In general terms, the VISX® (Santa Clara, CA) WaveScan™ aberrometer assesses high-order aberrations that occur when light passes through the eye. In contrast, adaptive optics technology compensates for these aberrations in real time, simulating aberration-free vision for the patient while he or she looks into the device.

The new adaptive optics machine developed by 20/10 PERFECT VISION, uses red wave-light and thousands of mirrors, which distort in a pattern inversely proportional to the eye's distortions as determined by the WaveScan.™ Each mirror, or facet, is 40 µm. A 6-mm pupil requires approximately 40,000 facets, although the device has many more facets for measuring larger pupils. This mirror system, which has a patented microchip, is capable of measuring aberrations such as a strong coma.

The diagnostic mirror pattern that the adaptive optics machine creates can be checked by the patient before surgery to provide objective and subjective proof that the proposed changes will result in improved acuity.

The mirrors rise to portray their sections of the eye and its defects (Figure 2). The system can compensate for any height defect, however, at the time of publication, specific technical details could not be discussed because they involve patented technology.

As determined by the VISX® WaveScan,™ the acuity maps and Bille aberration maps for a typical patient illustrate the problems that current wavefront scanners have. The aberration maps show only higher-order defects, with the right eye having a spherical defect and a large pupil, and the left eye having a “hill-and-valley” defect with a small pupil.

Although the data can be used to ablate a PMMA disk as part of the PreVue Lens™ system, the goal is to connect it to the WaveScan™, also developed by 20/10, so that it provides the preview compensation with the push of a button. There are plans for the improved WaveScan™ to become part of the VISX® excimer laser setup, and for the new device to be capable of being linked to the VISX® STAR lasers. The new accessory maps individual errors after the pupil. Whereas current wavefront scanners only find optical error in the anterior of the eye, this device can find every error.

Today's wavefront technology measures vision as if it was flat, and does not account for the effect of a curved retina. But the 20/10 device creates a two-dimensional wavefront print that does account for internal distortions. Current wavefront machines can be described as measuring our vision as a flat picture, although we see like the reflection of a mirror.

The machine will serve two important goals in a physician's office: to give the physician a subjective check that the correction will work and to provide the patient with confidence about the proposed surgery's outcome. The device works well with almost any eye, except opacified eyes where the diagnostic light rays pass poorly. At this time, 20/10 Perfect Vision is readying patient studies of the prototype device. VISX® has licensed the 20/10 device.

Frieder H. Loesel, PhD, serves as Chief Executive Officer of 20/10 Perfect Vision in Heidelberg, Germany. He may be reached at +49-6221-75933-20; loesel@2010pv.com
Portions of this material appeared in Dr. Loesel's presentation, ?Diagnostic Wavefront Compensation With Adaptive Optics,? presented at the AAO meeting in New Orleans, Louisiana.