Vision Improvement by Correcting Higher-order Aberrations With Phase Plates in Normal Eyes

<p>ABSTRACT</p><p>PURPOSE: To psychophysical^ demonstrate vision improvement when correcting higher-order aberrations with phase plates in normal eyes.</p><p>METHODS: The wavefront aberrations of three nonsurgical normal eyes were measured with a Shack-Hartmann wavefront sensor. With these measured aberrations, phase plates were fabricated using a lathing technique. Theoretical improvement in retinal image quality was estimated by calculating the optical modulation transfer functions under the white light condition. Visual acuity measurements were also conducted to demonstrate improvement in visual performance after correcting higher-order aberrations with the phase plate. In this visual acuity measurement, a tumbling "E" with high (100%) and low (10%) contrast was used.</p><p>RESULTS: The phase plate reduced the higherorder root mean square (RMS) wavefront error from 0.39 ? 0.09 to 0.15 ? 0.02 µm (mean ? standard deviation from three eyes) for a 6 -mm pupil. With the phase plate, retinal image quality based on the volume of modulation transfer function under 60 cycles per degree (c/deg) was improved by a factor of 1.8 ? 0.4 over that of the eyes with spherocylindrical correction only. Average improvement in visual acuity achieved by correcting the higherorder aberration was 0.23 lines with high-contrast letters and 1.12 lines with low-contrast letters. All subjects reported subjective improvement in image quality of the letter with the phase plate.</p><p>CONCLUSION: The phase plate effectively corrected the higher-order aberrations in normal eyes. As a result, both retinal image quality and visual acuity especially with the low -contrast letters were improved. This study demonstrated the feasibility of correcting higher-order aberrations and improving vision with customized optics. [J Refract Surg 2004;20:S523-S527]</p>