Bowrey Hannah, Zeng Guang, Tse Dennis, Leotta Amelia, Wu Yi, To Chi-Ho, Wildsoet Christine, McFadden Sally
Hunter Medical Research Institute and School of Psychology, University of Newcastle, Newcastle, Australia 2Save Sight Institute and Department of Clinical Ophthalmology, University of Sydney, Sydney, Australia.
Hunter Medical Research Institute and School of Psychology, University of Newcastle, Newcastle, Australia.
Invest Ophthalmol Vis Sci. 2017 May 1;58(5):2705-2714. doi: 10.1167/iovs.16-20240.
It has been proposed that the peripheral retina, responding to local optical defocus, contributes to myopia and associated altered eye growth in humans. To test this hypothesis, we measured the changes in central (on-axis) and peripheral ocular dimensions in guinea pigs wearing a concentric bifocal spectacle lens design with power restricted to the periphery.
Five groups of guinea pigs (n = 83) wore either a unifocal (UF) spectacle lens (-4, 0, or +4 Diopters [D]), or a peripheral defocus (PF) spectacle lens that had a plano center (diameter of 5 mm) with either -4 or +4 D in the surround (-4/0 or +4/0 D). The overall optical diameter of all lenses was 12 mm. Lenses were worn over one eye from 8 to 18 days of age for negative and plano lenses, or from 8 to 22 days of age for positive lenses. Refractive error was measured centrally and 30° off-axis in the temporal and nasal retina. The shape of the eye was analyzed from images of sectioned eyes.
Lenses of -4 D UF induced myopia, reflecting enhanced ocular elongation, which was centered on the optic nerve head and included the surrounding peripapillary zone (PPZ, 18° in diameter). Some ocular expansion, including within the PPZ, also was recorded with -4/0 and +4/0 D PF lenses while the +4 D UF lens inhibited rather than enhanced elongation, centrally and peripherally.
Peripheral defocus-induced ocular expansion encompasses the PPZ, irrespective of the sign of the inducing defocus. Understanding the underlying mechanism potentially has important implications for designing multifocal lenses for controlling myopia in humans and also potentially for understanding the link between myopia and glaucoma.
有人提出，周边视网膜对局部光学离焦作出反应，这在人类近视及相关的眼球生长改变中起作用。为了验证这一假设，我们测量了佩戴同心双焦点眼镜镜片设计（其度数仅限于周边）的豚鼠的中央（光轴上）和周边眼部尺寸的变化。
五组豚鼠（n = 83）佩戴单焦点（UF）眼镜镜片（-4、0或+4屈光度[D]），或周边离焦（PF）眼镜镜片，该镜片中央为平光（直径5 mm），周边为-4或+4 D（-4/0或+4/0 D）。所有镜片的总光学直径为12 mm。对于负度数和平光镜片，从8至18日龄开始在一只眼睛上佩戴镜片；对于正度数镜片，则从8至22日龄开始佩戴。在中央以及颞侧和鼻侧视网膜离光轴30°处测量屈光不正。从剖切眼球的图像分析眼睛的形状。
-4 D UF镜片诱发近视，反映出眼球伸长增强，其以视神经乳头为中心，包括周围的视乳头周围区（PPZ，直径18°）。-4/0和+4/0 D PF镜片也记录到了一些眼球扩张，包括PPZ内的扩张，而+4 D UF镜片在中央和周边抑制而非增强伸长。
周边离焦诱发的眼球扩张包括PPZ，与诱发离焦的正负无关。了解其潜在机制可能对设计用于控制人类近视的多焦点镜片具有重要意义，也可能有助于理解近视与青光眼之间的联系。
