Abstract
Abstract: :
Purpose: To psychophysically demonstrate improvements in vision when correcting higher–order aberrations with customized optics in normal and abnormal eyes. Methods: The wavefront aberrations of six eyes, 3 normal and 3 abnormal (1 post–LASIK and 2 keratoconic) eyes, were measured with a Shack–Hartmann wavefront sensor. Phase plates were designed to correct for the measured wavefront aberrations and were fabricated using a lathing technique. Improvements in visual performance were measured psychophysically using high (100%) and low (10%) contrast tumbling E visual acuity (VA). VAs were compared when only second order aberrations (defocus and astigmatism) were corrected to when all aberrations were corrected with the phase plate. Results: Higher–order rms in the normal and abnormal groups was 0.39 ± 0.07 µm (mean ± standard deviation) and 2.1 ± 1.36 µm for a 6 mm pupil, respectively. In the normal eyes, the phase plate reduced the higher–order rms from 0.39 ± 0.07 to 0.15 ± 0.02 µm for a 6 mm pupil. For the abnormal eyes, the higher–order rms was reduced from 2.1 ± 1.36 to 0.55 ± 0.56 µm with the phase plate for a 6 mm pupil. With the phase plate, the average high contrast VAs were –0.24 ± 0.04 logMAR in normal eyes and –0.17 ± 0.14 logMAR in abnormal eyes. On average, normal eyes experienced a half line of improvement in high contrast VA and one line of improvement in low contrast VA. Abnormal eyes had a 2 line improvement in high contrast VA and a 3 line improvement in low contrast VA. In all eyes, larger visual benefits were achieved in low contrast VA than in high contrast VA. Conclusions: It has been successfully demonstrated that using customized optics to correct higher–order aberrations improves visual performance in normal and abnormal eyes. Higher order aberration corrections can provide substantially larger benefits over conventional corrections, especially in abnormal eyes. This study encourages the development of customized contact lenses as a practical tool for customized vision correction.
Keywords: refraction • keratoconus • contact lens