Optical quality of the eye degraded by time-varying wavefront aberrations with tear film dynamics.
OBJECTIVE
Wavefront aberrations (WFAs) of the eye vary with time because of the tear film dynamics. We investigated, using a simulation method, the variation of optical quality with time-varying wavefront measurements of 13 eyes with different refractions.


METHODS
WFAs of 13 normal eyes of 13 subjects were measured every second for 10 s. First, we simulated WFAs with conventional corneal laser refractive surgery by subtracting the second-order aberrations of the least aberrated measurement from measured consecutive WFAs. Second, we simulated customized refractive surgery by subtracting the second- to sixth-order aberrations of the least aberrated measurement from measured consecutive WFAs. We calculated Strehl ratios and retinal images from these corrected consecutive WFAs.


RESULTS
In one eye, the root mean square (RMS) values of WFAs with a second-order correction were sometimes smaller than those of WFAs with a second- to sixth-order correction, when these were compared at the same time point after a blink. However, in the other 12 eyes, the RMS values with second- to sixth-order corrections were smaller than those with only a second-order correction. In eight eyes, the Strehl ratios with second- to sixth-order corrections were larger than those with second-order corrections. In the remaining five eyes, Strehl ratios with second- to sixth-order corrections were sometimes smaller than those with second-order corrections.


CONCLUSIONS
In a simulation, the correction of time-invariant higher order aberrations usually reduced RMS values, but it did not always result in higher Strehl ratios than those obtained with only second-order corrections.
Hirohara
Yoko
Y
Department of Applied Visual Science, Osaka University Graduate School of Medicine, Osaka, Japan.
Mihashi
Toshifumi
T
Koh
Shizuka
S
Ninomiya
Sayuri
S
Maeda
Naoyuki
N
Fujikado
Takashi
T
D000328:Adult; D001767:Blinking; D003198:Computer Simulation; D005500:Follow-Up Studies; D006801:Humans; D012016:Reference Values; D012029:Refraction, Ocular / Q000502:physiology*; D012160:Retina / Q000502:physiology*; D013499:Surface Properties; D013666:Tears / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*