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A. Suzaki, Y. Hirohara, T. Mihashi, N. Maeda, T. Fujikado; Dynamic Changes of Higher–Order Aberration After Blink in Eyes With Hard Contact Lens . Invest. Ophthalmol. Vis. Sci. 2006;47(13):2396.
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© ARVO (1962-2015); The Authors (2016-present)
Hard contact lenses (HCL) are designed to move on the cornea after blink to keep the corneal metabolic condition by exchanging the tear film. Because of this, visual quality in the eye with HCL depends not only the stabilized position but also the movement pattern of CL on the cornea. Previously, we have reported the static higher–order aberration (HOA) in the eye with HCL using Hartmann–shack (H–S) wavefront (WF) sensor (Hirohara, et al, ARVO, 2003). In this report, we developed a new WF sensor system in which the ocular HOA and the position of HCL were measured simultaneously, and evaluated the dynamic changes of visual quality after blink in HCL wearer.
Three eyes of 3 normal subjects were examined. Spherical HCLs with a power of –4 diopter (D) and –10 D were used. Ocular HOA was measured continuously for 1500ms after blink with an interval of 350ms using H–S WF sensor (Topcon Corp., Tokyo, Japan). An infrared light source was attached to the placid ring equipped with WF sensor and the contour of the HCL was identified from Meyer images. Ocular HOA was calculated up to 6th Zernike order for 4 mm pupil (RMS error, µm).
The dynamic changes of the ocular HOA and the position of HCL were measured simultaneously and reproducibly after blink. The total ocular HOA was high (Median, 1.50 µm) just after blink, decreased remarkably at 350 ms (0.79 µm), and stabilized at 1050 ms (0.16 µm) when –10D lens was weared. The HOA was high when the optical zone of HCL did not cover the 4mm pupil. The HOA just after blink was higher with –10D lens compared with –4D lens.
A dynamic measurement of HOA in eyes with HCL may be useful to evaluate the visual quality not only in the stabilized position but also in the transient position of HCL after blink.
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