Purchase this article with an account.
J.C. He, I. Gendelman, J. Gwiazda; The Change in Corneal and Whole Eye Aberration After Reading and Its Association With IOP for Myopes and Emmetropes . Invest. Ophthalmol. Vis. Sci. 2005;46(13):5599.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To investigate the change in aberrations in both the anterior corneal surface and the whole eye for myopes and emmetropes, and the relationship between aberration changes and baseline IOP. Methods: Twenty–six subjects, aged 21–35 years (mean, 25.3) and having no ocular pathologies, participated in the study. 16 were myopes, (mean spherical equivalent –3.75D, range –9.48D to –1.15D) and 10 were emmetropes, (mean spherical equivalent +0.32D, range –0.50D to +0.84D). Corneal and whole eye aberrations were measured using the Humphrey Corneal Topographer System Model 995 and a psychophysical wavefront sensor, respectively, prior to and after 60 min of reading. A Riechert Ocular Response Analyser (ORA) was used to measure IOP. The experiment was conducted in the morning, and subjects were directed not to perform any near work before testing and to refrain from wearing contact lenses for at least 24 hours. Results: Immediately after one hour of reading, myopes had more Zernike aberration changes in both the cornea and the whole eye than emmetropes, with the largest change in main–axis astigmatism (Z5). For both the corneal and the whole eye Z5 aberrations, myopes showed changes toward more with–the–rule (WTR) astigmatism while emmetropes showed changes toward less WTR astigmatism. The change in Z5 in the whole eye was significantly correlated with the change in the cornea for both myopes (r=0.74, p<0.01) and emmetropes (r=0.66, p<0.05). For myopes, but not emmetropes, baseline IOP was significantly correlated with the changes of Z5 in both the cornea (r=0.66, p<0.01) and the whole eye (r=0.50, p<0.05), with lower IOP associated with increased WTR astigmatism. Conclusions: The results suggest that the change in corneal main axis astigmatism plays an important role in contributing to this aberration change in the whole eye after a long period of reading. The results also suggest that the eyes with lower IOP may be unable to resist eyelid pressure during reading.
This PDF is available to Subscribers Only