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Assessment of objective and subjective eccentric refraction

Lundström, Linda; Gustafsson, Jörgen LU ; Svensson, Ingrid and Unsbo, Peter (2005) In Optometry and Vision Science 82(4). p.298-306
Abstract
Purpose. When performing perimetry, refracting subjects with central visual field loss, and in emmetropization studies, it is important to accurately measure peripheral refractive errors. Traditional methods for foveal refraction often give uncertain results in eccentric angles as a result of the large aberrations and the reduced retinal function. The aim of this study is therefore to compare and evaluate four methods for eccentric refraction.



Methods. Four eccentric methods were tested on 50 healthy subjects: one novel subjective procedure, optimizing the detection contrast sensitivity with different trial lenses, and three objective ones: photorefraction with a PowerRefractor, wavefront measurements with a... (More)
Purpose. When performing perimetry, refracting subjects with central visual field loss, and in emmetropization studies, it is important to accurately measure peripheral refractive errors. Traditional methods for foveal refraction often give uncertain results in eccentric angles as a result of the large aberrations and the reduced retinal function. The aim of this study is therefore to compare and evaluate four methods for eccentric refraction.



Methods. Four eccentric methods were tested on 50 healthy subjects: one novel subjective procedure, optimizing the detection contrast sensitivity with different trial lenses, and three objective ones: photorefraction with a PowerRefractor, wavefront measurements with a Hartmann-Shack sensor, and retinoscopy. The peripheral refractive error in the horizontal nasal visual field of the right eye was measured in 20 degrees and 30 degrees.



Results. In general, the eccentric refraction methods compared reasonably well. However, the following differences were noted. Retinoscopy showed a significant difference from the other methods in the axis of astigmatism. In 300 eccentric angle, it was not possible to measure 15 of the subjects with the PowerRefractor and the instrument also tended to underestimate high myopia (<-6 D). The Hartmann-Shack sensor showed a myopic shift of approximately 0.5 D in both eccentricities. The subjective method had a relatively larger spread.



Conclusions. This study indicates that it is possible to assess the eccentric refraction with all methods. However, the Hartmann-Shack technique was found to be the most useful method. The agreement between the objective methods and the subjective eccentric refraction shows that detection contrast sensitivity in the periphery is affected by relatively small amounts of defocus. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
peripheral vision, detection, eccentric refraction, contrast sensitivity, photorefraction, wavefront aberrations, certec, retinoscopy, refractive errors
in
Optometry and Vision Science
volume
82
issue
4
pages
298 - 306
publisher
Lippincott Williams & Wilkins
external identifiers
  • wos:000228572400012
  • pmid:15829857
  • scopus:17444369423
ISSN
1538-9235
language
English
LU publication?
yes
id
e905a8a7-7efe-4539-81a6-ee8ea4109066 (old id 245729)
alternative location
http://www.optvissci.com/pt/re/ovs/abstract.00006324-200504000-00015.htm;jsessionid=GzdB96XyjpT2CG7922V4Vv22ph8b6TXyh2gmtv2ht46RmnWLLFyR!2112021004!181195629!8091!-1
date added to LUP
2007-08-03 14:15:48
date last changed
2017-10-01 03:45:21
@article{e905a8a7-7efe-4539-81a6-ee8ea4109066,
  abstract     = {Purpose. When performing perimetry, refracting subjects with central visual field loss, and in emmetropization studies, it is important to accurately measure peripheral refractive errors. Traditional methods for foveal refraction often give uncertain results in eccentric angles as a result of the large aberrations and the reduced retinal function. The aim of this study is therefore to compare and evaluate four methods for eccentric refraction. <br/><br>
<br/><br>
Methods. Four eccentric methods were tested on 50 healthy subjects: one novel subjective procedure, optimizing the detection contrast sensitivity with different trial lenses, and three objective ones: photorefraction with a PowerRefractor, wavefront measurements with a Hartmann-Shack sensor, and retinoscopy. The peripheral refractive error in the horizontal nasal visual field of the right eye was measured in 20 degrees and 30 degrees. <br/><br>
<br/><br>
Results. In general, the eccentric refraction methods compared reasonably well. However, the following differences were noted. Retinoscopy showed a significant difference from the other methods in the axis of astigmatism. In 300 eccentric angle, it was not possible to measure 15 of the subjects with the PowerRefractor and the instrument also tended to underestimate high myopia (&lt;-6 D). The Hartmann-Shack sensor showed a myopic shift of approximately 0.5 D in both eccentricities. The subjective method had a relatively larger spread. <br/><br>
<br/><br>
Conclusions. This study indicates that it is possible to assess the eccentric refraction with all methods. However, the Hartmann-Shack technique was found to be the most useful method. The agreement between the objective methods and the subjective eccentric refraction shows that detection contrast sensitivity in the periphery is affected by relatively small amounts of defocus.},
  author       = {Lundström, Linda and Gustafsson, Jörgen and Svensson, Ingrid and Unsbo, Peter},
  issn         = {1538-9235},
  keyword      = {peripheral vision,detection,eccentric refraction,contrast sensitivity,photorefraction,wavefront aberrations,certec,retinoscopy,refractive errors},
  language     = {eng},
  number       = {4},
  pages        = {298--306},
  publisher    = {Lippincott Williams & Wilkins},
  series       = {Optometry and Vision Science},
  title        = {Assessment of objective and subjective eccentric refraction},
  volume       = {82},
  year         = {2005},
}