Effect of higher order aberrations on contrast sensitivity function in myopic eyes

Feizi, Sepehr; Karimian, Farid

doi:10.1007/s10384-009-0677-4

Cited by 11 publications

(6 citation statements)

References 40 publications

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“…Still, studies have successfully correlated specific visual complaints such as halos, glare, and contrast sensitivity with higher-order aberrations. 12 Further investigation of visual outcomes between the two laser platforms should be investigated before determining superiority in terms of visual image and quality postoperatively. Additional factors such as cost, availability, patient characteristics, and surgeon preference should be taken into consideration when determining the most appropriate laser to use for refractive surgery.…”

Section: Discussionmentioning

confidence: 99%

Retrospective Analysis of the Post-Operative Changes in Higher-Order Aberrations: A Comparison of the WaveLight EX500 to the VISX S4 Laser in Refractive Surgery

et al. 2017

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Introduction: In an attempt to maximize treatment outcomes, refractive surgery techniques are being directed toward customized ablations to correct not only lower-order aberrations but also higher-order aberrations specific to the individual eye. Measurement of the entirety of ocular aberrations is the most definitive means to establish the true effect of refractive surgery on image quality and visual performance. Whether or not there is a statistically significant difference in induced higher-order corneal aberrations between the VISX Star S4 (Abbott Medical Optics, Santa Ana, California) and the WaveLight EX500 (Alcon, Fort Worth, Texas) lasers was examined. Methods: A retrospective analysis was performed to investigate the difference in root-mean-square (RMS) value of the higher-order corneal aberrations postoperatively between two currently available laser platforms, the VISX Star S4 and the WaveLight EX500 lasers. The RMS is a compilation of higher-order corneal aberrations. Data from 240 total eyes of active duty military or Department of Defense beneficiaries who completed photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK) refractive surgery at the Wilford Hall Ambulatory Surgical Center Joint Warfighter Refractive Surgery Center were examined. Using SPSS statistics software (IBM Corp., Armonk, New York), the mean changes in RMS values between the two lasers and refractive surgery procedures were determined. A Student t test was performed to compare the RMS of the higher-order aberrations of the subjects' corneas from the lasers being studied. A regression analysis was performed to adjust for preoperative spherical equivalent. The study and a waiver of informed consent have been approved by the Clinical Research Division of the 59th Medical Wing Institutional Review Board (Protocol Number: 20150093H). Results: The mean change in RMS value for PRK using the VISX laser was 0.00122, with a standard deviation of 0.02583. The mean change in RMS value for PRK using the WaveLight EX500 laser was 0.004323, with a standard deviation of 0.02916. The mean change in RMS value for LASIK using the VISX laser was 0.00841, with a standard deviation of 0.03011. The mean change in RMS value for LASIK using the WaveLight EX500 laser was 0.0174, with a standard deviation of 0.02417. When comparing the two lasers for PRK and LASIK procedures, the p values were 0.431 and 0.295, respectively. Conclusion: The results of this study suggest no statistically significant difference concerning induced higher-order aberrations between the two laser platforms for either LASIK or PRK. Overall, the VISX laser did have consistently lower induced higher-order aberrations postoperatively, but this did not reach statistical significance. It is likely the statistical significance of this study was hindered by the power, given the relatively small sample size. Additional limitations of the study include its design, being a retrospective analysis, and the generalizability of the study, as the Department of Defens...

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Section: Discussionmentioning

confidence: 99%

Retrospective Analysis of the Post-Operative Changes in Higher-Order Aberrations: A Comparison of the WaveLight EX500 to the VISX S4 Laser in Refractive Surgery

et al. 2017

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“… [20] Feizi et al demonstrated that the AULSCF was significantly associated with total HOAs and fourth-order aberrations, but not third-order aberrations, in myopic eyes. [21] Fujikado et al found a significant association between the AULCSF and HOAs in eyes with cataract. [17] Although we cannot fully explain the discrepancy between the current and previous findings, the sample size, the methodology of the measurements, the distribution of subject age, the presence of age-related cataract, and other subject backgrounds of the study population, may contribute to this discrepancy.…”

Section: Discussionmentioning

confidence: 97%

“… [18] To date, there have been several studies assessing the effect of HOAs on the contrast sensitivity function in normal and diseased eyes. [17] – [21] Liang et al showed that human eye aberrations play a crucial role in degrading retinal image quality. [19] Oshika et al reported that the AULCSF was significantly correlated with coma-like aberrations, but not spherical-like aberrations.…”

Section: Discussionmentioning

confidence: 99%

Factors Influencing Contrast Sensitivity Function in Myopic Eyes

et al. 2014

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PurposeTo evaluate the factors affecting the area under the log contrast sensitivity function (AULCSF) in healthy myopic eyes.MethodsWe retrospectively examined 201 eyes of 201 consecutive subjects (age, 31.8±7.4 years (mean ± standard deviation)) with myopic refractive errors of −1.25 to −8.25 diopters (D). From the contrast sensitivity data, the area under the log contrast sensitivity function (AULCSF) was calculated. Stepwise multiple regression analysis was used to assess the factors affecting the AULCSF.ResultsThe mean AULSCF was 1.09±0.09 (0.89 to 1.55). Explanatory variables relevant to the AULCSF were, in order of influence, the objective scattering index (OSI) (p = 0.018, partial regression coefficient B = –0.032) and logMAR CDVA (p = 0.022, B = –0.209) (adjusted R2 = 0.231). No significant correlation was seen with other clinical factors such as gender, manifest refraction, pupil size, lens density, corneal HOAs, or ocular HOAs.ConclusionsAlthough the great majority of the variance remains unexplained, eyes with lower OSI and better CDVA are more predisposed to show higher contrast sensitivity function. These results indicate that not only CDVA but also intraocular forward scattering may play some role in predicting the contrast sensitivity function in myopic subjects.

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“…26 Williams et al 27 argue that CSF is improved when most WAs are reduced with a deformable mirror or adaptive optics (AO) system, compared to when only defocus and astigmatism (LOAs) are corrected. Feizi and Karimian 28 investigated the relationship between HOAs and CSF in 70 myopic eyes. The 'Area Under The Log Contrast Sensitivity Function' (AULCSF) was calculated for all 70 eyes, and the results of the study showed that the AULCSF was negatively correlated with the cycloplegic NES, the total RMS Zernike coefficients, as well as the RMS Zernike coefficients for SA.…”

Section: Contrast Sensitivity Functionmentioning

confidence: 99%

Higher order aberrations of the eye: Part two

Oberholzer¹,

Gillan²,

Rubin³

2016

African Vision and Eye Health

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This article is the second in a series of two articles, which provides a discussion of the factors that may possibly contribute to variable results when wavefront aberrations of the human eye are measured. Some of the factors discussed in this article are the influences that refractive errors (specifically myopia and astigmatism), pupil diameter, accommodation of the crystalline lens, age, mydiatric drops and the integrity of the tear film may have on these wavefront measurements. The first article in the series explained the general principles of higher order aberrations (HOAs), as well as HOAs of importance in the eye and the measuring apparatus used to measure HOAs of the eye.Keywords: wavefront aberrations; aberrometry

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Effect of higher order aberrations on contrast sensitivity function in myopic eyes

Abstract: Spherical and fourth-order aberrations significantly affect CSF in myopic eyes. However, the effect of myopia on CSF cannot be attributed only to HOAs. Other factors such as neural elements in the visual pathway should be taken into account.

Cited by 11 publications

References 40 publications

Retrospective Analysis of the Post-Operative Changes in Higher-Order Aberrations: A Comparison of the WaveLight EX500 to the VISX S4 Laser in Refractive Surgery

Retrospective Analysis of the Post-Operative Changes in Higher-Order Aberrations: A Comparison of the WaveLight EX500 to the VISX S4 Laser in Refractive Surgery

Factors Influencing Contrast Sensitivity Function in Myopic Eyes

Higher order aberrations of the eye: Part two

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