Peripheral refraction in pseudophakic eyes measured by infrared scanning photoretinoscopy

Purpose Peripheral refraction and retinal shape may influence refractive development. Peripheral refraction has been shown to have a high degree of variability and can take considerable time to perform. SD OCT and peripheral axial length measures may be more reliable, assuming that the retinal position is more important than the peripheral optics of the lens/cornea. Methods 79 subjects right eyes were imaged for this study (age range: 22 to 34 yr, refractive error: −10 to +5.00.) Thirty deg SD OCT (Spectralis, Heidleberg) images were collected in a radial pattern along with peripheral refraction with an autorefractor (Shin-Nippon Auto-refractor) and peripheral axial length measurements with partial coherence interferometry (PCI) (IOLmaster, Zeiss). Statistics were performed using repeat measures ANOVA in SPSS (IBM), Bland-Altman analyses, and regression. All measures were converted to diopters to allow direct comparison. Results SD OCT showed a retinal shape with an increased curvature for myopes compared to emmetropes/hyperopes. This retinal shape change became significant around 5 deg. The SD OCT analysis for retinal shape provides a resolution of 0.026 dipopters, which is about ten times more accurate than using autorefraction or clinical refractive techniques. Bland-Altman analyses suggest that retinal shape measured by SD OCT and the PCI method were more consistent with one another than either was with AR. Conclusions With more accurate measures of retinal shape using SD OCT, consistent differences between emmetrope/hyperopes and myopes were found nearer to the fovea than previously reported. Retinal shape may be influenced by central refractive error, and not merely peripheral optics. Partial coherence interferometry and SD OCT appear to be more accurate than autorefraction, which may be influenced other factors such as fixation and accommodation. Autorefraction does measure the optics directly, which may be a strength of that method.

show abstract

“…Others have shown relative myopia in the vertical meridian regardless of central refractive error. 13,25 …”

mentioning

confidence: 99%

Eye Shape Using Partial Coherence Interferometry, Autorefraction, and SD-OCT

Clark

Elsner²,

Konynenbelt³

2015

Optometry and Vision Science

View full text Add to dashboard Cite

show abstract

“…There is some evidence [21,22] indicating that current IOLs do not provide peripheral image quality as good as that of the natural crystalline lens. Being designed specifically around surgical technique and aiming to restore emmetropia on the optical axis, IOLs are associated with increased astigmatism and higher order aberrations at the periphery of the visual field of the pseudophakic eye.…”

Section: Introductionmentioning

confidence: 99%

Peripheral image quality in pseudophakic eyes

Togka

Livir-Rallatos

Christaras

et al. 2020

Biomed. Opt. Express

View full text Add to dashboard Cite

The purpose of this work was to evaluate peripheral image quality in the pseudophakic eye using computational, physical, and psychophysical methods. We designed and constructed a physical model of the pseudophakic human eye with realistic dimensions using a corneal phantom and a board-only camera that was pivoted around an axis that matched the anatomical center of a human retina, assuming a radius of curvature of 12 mm, while it was submersed in a 23.4 mm long water filled chamber to emulate human ocular axial length. We used this optical setup to perform direct recording of the point spread function (PSF) and the associated retinal images for a commercial intraocular lens (IOL). Additionally, psychophysical tests were carried out to investigate the impact of the off-axis astigmatism in peripheral visual performance, where spectacle-induced astigmatism simulated the pseudophakic conditions in healthy subjects. Our findings using the physical eye model confirm the existence of large amounts of astigmatism in the periphery of the pseudophakic eye. The psychophysical tests revealed a significant reduction of detection sensitivity in the peripheral visual field. The latter suggests that off-axis astigmatism in patients implanted with IOLs may have performance and safety implications for activities requiring efficient peripheral vision.

show abstract

“…revious clinical studies and computational modeling have shown that the retinal image in the peripheral visual field differs in pseudophakic eyes than in phakic eyes. [1][2][3][4][5][6][7][8] Recent studies found that the peripheral retinal image quality is degraded in pseudophakic patients and peripheral image degradation can affect visual function. 1,9 Reduced contrast and image quality in the periphery of the visual field could also affect diagnostic and imaging procedures in pseudophakic eyes, such as wide-field retinal imaging or visual field testing.…”

mentioning

confidence: 99%

Peripheral defocus of monofocal intraocular lenses

Natarajan,

Maceo Heilman,

et al. 2024

J Cataract Refract Surg

View full text Add to dashboard Cite

Purpose: To quantify the angular-dependence of monofocal intraocular lens (IOL) power. Setting: Ophthalmic Biophysics Laboratory, Kallam Anji Reddy campus, L V Prasad Eye Institute, Hyderabad, India. Design: Laboratory study. Methods: Experiments were performed on IOLs from two different manufacturers (APPALENS 207, Appasamy Associates and SN60WF, Alcon Laboratories). IOL powers ranged from 17 to 25 D. The IOLs were mounted in a fluid-filled chamber and the on-axis and off-axis powers were measured using a laser ray tracing system over the central 3 mm zone with delivery angles ranging from -30° to +30° in 5° increments. The position of the best focus was calculated for each IOL at each angle. The angular dependence of IOL power was compared with theoretical predictions. Results: Peripheral defocus increased significantly with increasing incidence angle and power. The peripheral defocus at ±30° increased from 5.8 D to 8.5 D when the power increased from 17.5 D to 24.5 D for APPALENS 207 and from 4.9 D to 7.4 D when the power increased from 17 D to 25 D for SN60WF. The mean difference between the measured and theoretical tangential power at ±30° was 0.50 ± 0.16 D for the APPALENS 207 and -0.40 ± 0.10 D for the SN60WF, independent of IOL power. Conclusions: IOLs introduce a significant amount of peripheral defocus which varies significantly with IOL power and design. Given that peripheral defocus is related to lens power, replacement of the natural lens (approximately 24 D) with an IOL will produce a significant difference in peripheral defocus profile after surgery.

show abstract

Peripheral refraction in pseudophakic eyes measured by infrared scanning photoretinoscopy

Abstract: No author has a financial or proprietary interest in any material or method mentioned.

Cited by 12 publications

References 29 publications

Eye Shape Using Partial Coherence Interferometry, Autorefraction, and SD-OCT

Eye Shape Using Partial Coherence Interferometry, Autorefraction, and SD-OCT

Peripheral image quality in pseudophakic eyes

Peripheral defocus of monofocal intraocular lenses

Contact Info

Product

Resources

About