Purchase this article with an account.
L. Lundstrom, J. Gustafsson, P. Unsbo; Assessment of objective and subjective eccentric refraction . Invest. Ophthalmol. Vis. Sci. 2004;45(13):2757.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: It has been shown that correction of peripheral refractive errors can improve the remaining vision of subjects with large central visual field loss. However, traditional methods for foveal refraction often give uncertain results in the eccentric angles of none foveal vision due to the large aberrations and the reduced retinal function. The aim of this study is to compare and evaluate different methods for eccentric refraction. Methods: The eccentric refraction in the right eye of 50 subjects, with normal healthy eyes, was measured off–axis in 30º nasally. Four methods were tested: Subjective optimization of the contrast sensitivity with trial–case lenses, photorefraction with the PowerRefractor instrument, wavefront measurements with a specially designed Hartmann–Shack sensor and software to optimize the Strehl ratio and, finally, retinoscopy, performed by an experienced low–vision optometrist. Results: All four methods are highly correlated (p<0.001) in measuring the mean sphere, while the astigmatism is slightly less correlated. There is a statistically significant difference (p<0.001) in the mean sphere between retinoscopy and the other methods. The eccentric measurement with the PowerRefractor sometimes fails due to the oblique angle which makes the visible area of the pupil too small. Conclusions: In general, the eccentric refraction can be measured with all four methods. However, retinoscopy shows a difference compared to the others, the PowerRefractor cannot measure all subjects and the subjective method is very time consuming. In conclusion, the wavefront measurement with the Hartmann–Shack sensor seems to be the most useful method. The Hartmann–Shack sensor also has the advantage of providing the total peripheral wavefront aberrations of the eye.
This PDF is available to Subscribers Only