Optical aberrations of the human cornea as a function of age

Guirao, Antonio; Redondo, M.; Artal, Pablo

doi:10.1364/josaa.17.001697

Cited by 262 publications

(165 citation statements)

References 13 publications

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“…[12][13][14] This latter scenario was included in order to estimate the performance of the IOL once it is implanted in the aphakic eye. Figures 3 and 4 show the MTF curves and the PSF, respectively.…”

Section: Discussionmentioning

confidence: 99%

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In vitro optical performance of a new aberration-free intraocular lens

Madrid-Costa

Ruiz-Alcocer

Ferrer-Blasco

et al. 2014

Eye

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Purpose To assess the optical performance of the new EnVista intraocular lens (IOL). Materials and methods Four aspheric IOLs were evaluated; the new EnVista is one amoung them. This IOL, similarly to the Z-Flex HB and the Bi-Flex 1.8 667AB ones, has a neutral aspheric design, whereas the fourth IOL under test (AcrySof IQ IOL SN60WF) presents a negative spherical aberration (SA). The IOL's aberration patterns were measured in vitro, by setting them up on an optical bench. From these aberration-pattern data, the modulation transfer function (MTF), the average modulation values, and the points spread function (PSF) were calculated. Furthermore, in order to assess the potential optical quality that these IOLs would yield once they are implanted, an average cornealaberration pattern was juxtaposed to the in-vitro profiles and the same parameters were calculated again. Results For the IOL-only scenario (ie, without including the corneal factor), it was the EnVista IOL, which is aberration-free that showed the higher MTF, PSF values. This was followed by the other two aberrationfree IOL models. However, when the effect of an average corneal pattern was also taken into consideration, the AcrySof IQ IOL SN60WF always outperformed the other neutral-asphericity IOLs. Conclusions The in-vitro optical performance of the EnVista IOL was good, but it decreases substantially in a whole-eye scenario, when the wavefront profile of an average cornea is added. Other designs with different degrees of SA should be considered for this IOL in order to surpass these results.

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Section: Discussionmentioning

confidence: 99%

“…Previous studies have shown that corneal HOAs remain rather stable with age. [12][13][14] From those studies, an average corneal pattern could be obtained. To combine (add) this average corneal pattern with each IOL's pattern we used the abovementioned custom-made MATLAB-based application.…”

Section: Image Quality Parametersmentioning

confidence: 99%

In vitro optical performance of a new aberration-free intraocular lens

Madrid-Costa

Ruiz-Alcocer

Ferrer-Blasco

et al. 2014

Eye

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“…35,[37][38][39][40][41][42] With increasing age, a general shift in the axis of astigmatism is found from a predominance of WTR astigmatism (in adults younger than 40 years) to a predominance of ATR astigmatism (in adults older than 40 years). 35,[38][39][40]42,43 This shift in astigmatic axis in older age appears to be due to changes in corneal curvature. [38][39][40]42 In a cross-sectional study of corneal and total astigmatism, Anstice 38 found that internal astigmatism remained relatively stable over time and that changes in astigmatism throughout life were due primarily to changes in corneal curvature.…”

Section: Astigmatism In Adultsmentioning

confidence: 99%

A review of astigmatism and its possible genesis

Read

Collins

Carney

2007

Clinical and Experimental Optometry

229

205

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Astigmatism is a refractive condition encountered commonly in clinical practice. This review presents an overview of research that has been carried out examining various aspects of this refractive error. We examine the components of astigmatism and the research into the prevalence and natural course of astigmatic refractive errors throughout life. The prevalence of astigmatism in various ethnic groups and diseases and syndromes is also discussed. We highlight the extensive investigations that have been conducted into the possible aetiology of astigmatism, however, no single model or theory of the development of astigmatism has been proven conclusively. Theories of the development of astigmatism based on genetics, extraocular muscle tension, visual feedback and eyelid pressure are considered. Observations and evidence from the literature supporting and contradicting these hypotheses are presented. Recent advances in technology such as wavefront sensors and videokeratoscopes have led to an increased understanding of ocular astigmatism and with continued improvements in technology, our knowledge of astigmatism and its genesis should continue to grow.

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“…[1][2][3] However, spherical aberration of the crystalline lens increases with age, 4 whereas the corneal aberration changes little throughout life. 5,6 Therefore, the total ocular aberration increases with age, leading to deterioration of optical quality in older subjects. [7][8][9][10] When the crystalline lens is replaced by an intraocular lens (IOL) in cataract surgery, further changes may occur.…”

Section: Introductionmentioning

confidence: 99%

Correlation of higher-order wavefront aberrations with visual function in pseudophakic eyes

Hayashi

Yoshida

Hayashi

2007

Eye

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Aim To study the correlation between higher-order wavefront aberrations and visual function in eyes with a spherical monofocal intraocular lens (IOL), and to see if the aberrations differ between eyes that received different types of IOLs. Methods One hundred forty-eight eyes of 148 patients who underwent phacoemulsification and implantation of one of five types of acrylic IOL were enrolled. At 1 month after surgery, ocular aberrations were measured using a Hartmann-Shack aberrometer and corneal aberrations were measured using videokeratography. In addition, the aberration of internal optics was determined by subtracting the corneal aberration from the ocular aberration. These aberrations were correlated with visual acuity and with contrast visual acuity under both photopic and mesopic conditions. Results Ocular, corneal, and internal optic aberrations (total aberration, coma, and spherical aberration) were all correlated significantly with visual acuity, as well as with photopic and mesopic contrast visual acuity. The associations between internal optic aberrations and visual function tended to be stronger than were those of corneal aberrations. Furthermore, ocular aberrations differed significantly between eyes with the five different IOLs (Pp0.0078). Specifically, the internal optic spherical aberration was markedly significantly different between eyes (P ¼ 0.0142), and the corneal coma showed a marginally significant difference (P ¼ 0.0421). Conclusion Ocular, corneal, and internal optic higher-order wavefront aberrations are correlated significantly with visual function in eyes with a spherical monofocal IOL. The spherical aberration of the internal optics and coma of the cornea vary between eyes with different types of IOL.

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Optical aberrations of the human cornea as a function of age

Cited by 262 publications

References 13 publications

In vitro optical performance of a new aberration-free intraocular lens

In vitro optical performance of a new aberration-free intraocular lens

A review of astigmatism and its possible genesis

Correlation of higher-order wavefront aberrations with visual function in pseudophakic eyes

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