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Rita Nieu, Alexandra Benavente-Perez, Ann Nour, Xiaoying Zhu, Harrison Feng, Philip B Kruger, David Troilo; Measurements of Spherical Aberration through Contact Lenses in an Animal Model of Myopia Development. Invest. Ophthalmol. Vis. Sci. 2017;58(8):2735.
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© ARVO (1962-2015); The Authors (2016-present)
Spherical Aberration (SA) may be a factor in the visual regulation of eye growth. We measured SA in the eyes of awake marmosets before, after, and while wearing contact lenses of different power to determine the effective speherical aberration during lens wear. We also examined changes in SA with age and induced refractive errors.
Spherical aberration (SA) and refractive error were measured under cyclopegia (1% cyclopentolate) in 11 awake marmosets wearing contact lenses for emmetropization studies (N=8, treated with -5D; N=1 -10D; N=2 +5D) from approximately 7 to 35 weeks of age using the COAS Aberrometer and Nidek autorefractometer. Axial length (AL) was measured under anesthesia (alfaxan, 1.5mg/kg, im) using an A-scan ultrasound.
The range of SA measured for all marmosets over all ages was -0.15 to -0.07 (mean±SD -0.09±0.06µm). SA measures were repeatable; the mean difference in repeated measures without lenses was -0.005±0.04µm (95% CI:±0.07µm), through lenses was -0.008±0.07µm (95% CI:±0.13µm), overall was -0.006±0.05µm (95% CI:±0.09µm). SA became relatively less negative with age (R2=0.39, p<0.05), approaching zero as the eye emmetropized (rate of SA change: 0.09±0.01µm/100d). Contact lenses shifted the effective SA towards relatively more positive values when measured through the plano (+0.01±0.04µm), +5D contact lenses (+0.06±0.03µm) and -10D contact lenses (+0.02±0.10 µm), while the -5D contact lens induced more negative changes (-0.02±0.04µm). Following extended lens treatment, the SA in animals that had developed myopia (change in Rx and AL: -2.06±1.68D, 0.69mm±0.18mm) shifted towards more negative values (change in SA: -0.05±0.005µm) than animals that became hyperopic (change in Rx, AL: +1.58±0.45D, 0.44±0.02mm, change in SA: +0.02±0.02).
SA can be measured in awake marmosets using the COAS aberrometer in a safe and repeatable manner, including while wearing contact lenses. Contact lenses of different powers can induce changes in SA that are measurable and can help us understand the role of SA in the visual control of eye growth.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
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