Change in visual acuity is well correlated with change in image-quality metrics for both normal and keratoconic wavefront errors

Ravikumar, Ayeswarya; Marsack, Jason D; Bedell, Harold E.; Shi, Yue; Applegate, Raymond A.

doi:10.1167/13.13.28

Cited by 39 publications

(49 citation statements)

References 60 publications

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“…The three metrics reported here have previously been found to be well correlated with visual performance in keratoconus. 40 …”

Section: Resultsmentioning

confidence: 99%

“…30-31 The literature now contains several descriptions of optical quality metrics that examine the interaction of individual terms and the impact on visual performance. 32-40 Three metrics: light in the bucket, visual Strehl ratio and neural sharpness, have been shown to be well-correlated with changes in optical performance in keratoconus. 40 All three are based on retinal image quality and two of the three incorporate neural weighting functions.…”

mentioning

confidence: 99%

“…32-40 Three metrics: light in the bucket, visual Strehl ratio and neural sharpness, have been shown to be well-correlated with changes in optical performance in keratoconus. 40 All three are based on retinal image quality and two of the three incorporate neural weighting functions. Their mathematical formulation (briefly presented here) was previously detailed by Thibos et al 33 …”

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confidence: 99%

“…40 Results are compared to similar values for the well-corrected normal population. Importantly, this report also details the clinical process utilized in dispensing wfgSCLs as envisioned by the investigators; this description is included for the interest of the contact lens practitioner that may be interested in fitting these lenses in the future.…”

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confidence: 99%

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Wavefront-Guided Scleral Lens Correction in Keratoconus

Marsack¹,

Ravikumar²,

Nguyen

et al. 2014

Optometry and Vision Science

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Purpose To examine the performance of state-of-the-art wavefront-guided scleral contact lenses (wfgSCLs) on a sample of keratoconic eyes, with emphasis on performance quantified with visual quality metrics; and to provide a detailed discussion of the process used to design, manufacture and evaluate wfgSCLs. Methods Fourteen eyes of 7 subjects with keratoconus were enrolled and a wfgSCL was designed for each eye. High-contrast visual acuity and visual quality metrics were used to assess the on-eye performance of the lenses. Results The wfgSCL provided statistically lower levels of both lower-order RMS (p < 0.001) and higher-order RMS (p < 0.02) than an intermediate spherical equivalent scleral contact lens. The wfgSCL provided lower levels of lower-order RMS than a normal group of well-corrected observers (p < < 0.001). However, the wfgSCL does not provide less higher-order RMS than the normal group (p = 0.41). Of the 14 eyes studied, 10 successfully reached the exit criteria, achieving residual higher-order root mean square wavefront error (HORMS) less than or within 1 SD of the levels experienced by normal, age-matched subjects. In addition, measures of visual image quality (logVSX, logNS and logLIB) for the 10 eyes were well distributed within the range of values seen in normal eyes. However, visual performance as measured by high contrast acuity did not reach normal, age-matched levels, which is in agreement with prior results associated with the acute application of wavefront correction to KC eyes. Conclusions Wavefront-guided scleral contact lenses are capable of optically compensating for the deleterious effects of higher-order aberration concomitant with the disease, and can provide visual image quality equivalent to that seen in normal eyes. Longer duration studies are needed to assess whether the visual system of the highly aberrated eye wearing a wfgSCL is capable of producing visual performance levels typical of the normal population.

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“…The three metrics reported here have previously been found to be well correlated with visual performance in keratoconus. 40 …”

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Wavefront-Guided Scleral Lens Correction in Keratoconus

Marsack¹,

Ravikumar²,

Nguyen

et al. 2014

Optometry and Vision Science

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show abstract

“…The choice to evaluate the impact in terms of visual image quality was based on evidence in the literature that root mean square (RMS) wavefront error is relatively poorly correlated with visual acuity 12 and that measured change in visual quality metrics (in particular visual Strehl ratio and neural sharpness) are highly correlated to a measured change in visual performance as measured by acuity in the presence of keratoconus (KC) aberrations. 17,18 …”

Section: Introductionmentioning

confidence: 99%

A Comparison of Three Methods to Increase Scleral Contact Lens On-Eye Stability

Ticak

Marsack²,

Koenig³

et al. 2015

Eye &Amp; Contact Lens: Science &Amp; Clinical Practice

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Purpose To: 1) quantify on-eye rotational and translational stability of three scleral contact lens stabilization methods and 2) model the variation in visual acuity when these movements occur in a wavefront-guided correction for highly aberrated eyes. Methods Three lens stabilization methods were integrated into the posterior periphery of a scleral contact lens designed at the Visual Optics Institute. For comparison, a lens with no stabilization method (rotationally symmetric posterior periphery) was designed. The lenses were manufactured and lens movements were quantified on eight eyes as the average standard deviation of the observed translations and rotations over 60 minutes of wear. In addition, the predicted changes in acuity for 5 eyes with keratoconus wearing a simulated wavefront-guided correction (full correction through the fifth order) were modeled using the measured movements. Results For each lens design, no significant differences in the translation and rotation were found between left and right eyes, and lenses behaved similarly on all subjects. All three designs with peripheral stability modifications exhibited no statistically significant differences in translation and rotation distributions of lens movement and were statistically more stable than the spherical lens in rotation. When the measured movements were used to simulate variation in visual performance, the three lenses with integrated stability methods showed a predicted average loss in acuity from the perfectly aligned condition of approximately 0.06 logMAR (3 letters), compared to the loss of over 0.14 logMAR (7 letters) for the lens with the spherical periphery. Conclusions All three stabilization methods provided superior stability, as compared to the spherical lens design. Simulations of the optical and visual performance suggest that all three stabilization designs can provide desirable results when utilized in the delivery of a wavefront-guided correction for a highly aberrated eye.

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Computational analysis of retinal image quality with different contact lens designs in keratoconus

Devi¹,

Kumar²

2023

Contact Lens and Anterior Eye

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Change in visual acuity is well correlated with change in image-quality metrics for both normal and keratoconic wavefront errors

Cited by 39 publications

References 60 publications

Wavefront-Guided Scleral Lens Correction in Keratoconus

Wavefront-Guided Scleral Lens Correction in Keratoconus

A Comparison of Three Methods to Increase Scleral Contact Lens On-Eye Stability

Computational analysis of retinal image quality with different contact lens designs in keratoconus

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