Please use this identifier to cite or link to this item:
Title: Integration of defocus by dual power Fresnel lenses inhibits myopia in the mammalian eye
Authors: McFadden, SA
Tse, DY
Bowrey, HE
Leotta, AJ
Lam, CS 
Wildsoet, CF
To, CH 
Keywords: Myopia
Fresnel lens
Spectacle lens compensation
Guinea pig
Issue Date: 2014
Publisher: Association for Research in Vision and Ophthalmology
Source: Investigative ophthalmology and visual science, 2014, v. 55, no. 2, p. 908-917 How to cite?
Journal: Investigative ophthalmology and visual science 
Abstract: Purpose.: Eye growth compensates in opposite directions to single vision (SV) negative and positive lenses. We evaluated the response of the guinea pig eye to Fresnel-type lenses incorporating two different powers.
Methods.: A total of 114 guinea pigs (10 groups with 9–14 in each) wore a lens over one eye and interocular differences in refractive error and ocular dimensions were measured in each of three experiments. First, the effects of three Fresnel designs with various diopter (D) combinations (−5D/0D; +5D/0D or −5D/+5D dual power) were compared to three SV lenses (−5D, +5D, or 0D). Second, the ratio of −5D and +5D power in a Fresnel lens was varied (50:50 compared with 60:40). Third, myopia was induced by 4 days of exposure to a SV −5D lens, which was then exchanged for a Fresnel lens (−5D/+5D) or one of two SV lenses (+5D or −5D) and ocular parameters tracked for a further 3 weeks.
Results.: Dual power lenses induced an intermediate response between that to the two constituent powers (lenses +5D, +5D/0D, 0D, −5D/+5D, −5D/0D and −5D induced +2.1 D, +0.7 D, +0.1 D, −0.3 D, −1.6 D and −5.1 D in mean intraocular differences in refractive error, respectively), and changing the ratio of powers induced responses equal to their weighted average. In already myopic animals, continued treatment with SV negative lenses increased their myopia (from −3.3 D to −4.2 D), while switching to SV positive lenses or −5D/+5D Fresnel lenses reduced their myopia (by 2.9 D and 2.3 D, respectively).
Conclusions.: The mammalian eye integrates competing defocus to guide its refractive development and eye growth. Fresnel lenses, incorporating positive or plano power with negative power, can slow ocular growth, suggesting that such designs may control myopia progression in humans.
ISSN: 0146-0404
EISSN: 1552-5783
DOI: 10.1167/iovs.13-11724
Appears in Collections:Journal/Magazine Article

View full-text via PolyU eLinks SFX Query
Show full item record


Last Week
Last month
Citations as of Feb 19, 2019


Last Week
Last month
Citations as of Feb 16, 2019

Page view(s)

Last Week
Last month
Citations as of Feb 18, 2019

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.