首页   按字顺浏览 期刊浏览 卷期浏览 Double-Pass Measurement of Retinal Image Quality in the Chicken Eye
Double-Pass Measurement of Retinal Image Quality in the Chicken Eye

 

作者: NANCY,   COLETTA SUSANA,   MARCOS CHRISTINE,   WILDSOET and DAVID,  

 

期刊: Optometry and Vision Science  (OVID Available online 2003)
卷期: Volume 80, issue 1  

页码: 50-57

 

ISSN:1040-5488

 

年代: 2003

 

出版商: OVID

 

关键词: chicken;optical quality;aberrations;modulation transfer function;refractive error;myopia;animal model

 

数据来源: OVID

 

摘要:

Purpose.The chicken,Gallus gallus domesticus, is used as an animal model to study the development of refractive error. Although vision is important in determining the eye’s refractive state, relatively little is known about the retinal image quality of the chicken eye. An objective double-pass technique was used to measure the optical quality of the eyes of White Leghorn chickens.Methods.Measurements were made on 21 eyes of six untreated birds and eight experimental birds that were members of a study of refractive development. Ages ranged from 3 to 6 weeks, and refractions ranged from −1.29 to +0.58 D in the untreated eyes and −4.58 to +10.17 D in the experimental eyes. The measurements were made under general anesthesia combined with either cycloplegia or ciliary nerve section. Proper optical alignment of the eye was achieved with the aid of a TV monitor, CCD camera, and an infrared source. A 543-nm laser point source was focused on the retina, and the double-pass aerial image was collected by a high-resolution CCD camera. Refractive errors were corrected with trial lenses, using a bracketing method to optimize the retinal images. Both the full width at half-maximum of the double-pass aerial image and the single-pass modulation transfer function were used as objective estimates of the optical quality.Results.The mean full width at half-maximum value in eyes of the untreated birds was 1.60 min arc for a 4.50-mm mean pupil diameter. Optical quality tended to be worse in the experimental myopic eyes.Conclusions.The optical quality of the chicken eye measured under monochromatic conditions meets or may even exceed the neural limits of spatial acuity based on anatomical estimates of ganglion cell spacing. The data also suggest that optical quality is worse in myopic eyes, which is consistent with studies of human eyes.

 

点击下载:  PDF (653KB)



返 回