Off-axis refraction and aberrations following conventional laser in situ keratomileusis

Ma, Liwei; Atchison, David A.; Charman, W. N.

doi:10.1016/j.jcrs.2004.05.059

Cited by 42 publications

(33 citation statements)

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“…The changes in peripheral spherical refraction equivalent in spherical aberration and in peripheral coma after LASIK can be largely explained by these differences. 24,41 Similar effects have been found in myopic orthokeratology. 43,48 One orthokeratology study 43 showed the influence of treatment zone, with the eye with the smaller zone having a reversal in coma slope out to approximately G15 degrees only.…”

Section: Discussionsupporting

confidence: 68%

“…The image quality worsens considerably as the pupil becomes larger than the ablation zone. Ma et al 41 found greater peripheral myopic shifts and greater astigmatism along the horizontal meridian in eyes treated with conventional LASIK than in untreated myopic eyes. Peripheral HOAs were measured in 2 LASIK patients; the rates of change in spherical aberration were greater than in the control group, and the rates of change in horizontal coma were of the opposite sign in the central G25 degrees of the visual field than in the control group.…”

mentioning

confidence: 97%

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Influence of spherical intraocular lens implantation and conventional laser in situ keratomileusis on peripheral ocular aberrations

Mathur¹,

Atchison²

2010

Journal of Cataract and Refractive Surgery

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Section: Discussionsupporting

confidence: 68%

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confidence: 97%

Influence of spherical intraocular lens implantation and conventional laser in situ keratomileusis on peripheral ocular aberrations

Mathur¹,

Atchison²

2010

Journal of Cataract and Refractive Surgery

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“…There is little published data in this area and a previous study found a myopic shift in M into the nasal field in four of six hyperopic subjects with an increase in J 0 in the periphery. 18 The order of retinoscopy in each subject was not randomized, but we do not feel that this introduced any significant order effect. We also did not measure pupil size and were unable to correlate pupil size with the error induced.…”

Section: Rempt Et Almentioning

confidence: 99%

The impact of off the visual axis retinoscopy on objective central refractive measurement in adult clinical practice: a prospective, randomized clinical study

Tay

Mengher

et al. 2011

Eye

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Purpose The objective of this study was to examine the effect of the off axis retinoscopy on objective central refractive measurement in adult clinical practice. Methods In all, 40 subjects underwent undilated retinoscopy in a randomly selected eye both on and off the visual axis by a single masked examiner. Off axis retinoscopy was defined as retinoscopy performed with the testing eye of the examiner aligned with the contralateral (non-test) eye of the subject resulting in an off axis deviation in the nasal horizontal visual field. Retinoscopy was performed in negative cylinder only and spherocylindrical measurements were converted to power vectors for analysis. Paired t-test was used to assess differences in M, J 0 and J 45 power vectors including differences between mean aided and unaided LogMar acuities. Results In all, 14 subjects were myopic (SErÀ0.5 D), 13 subjects were emmetropic (SE between À0.49 and 1.0 D) and 13 subjects were hyperopic (SE 41.0 D). Mean angle of deviation was 5.581 in the nasal horizontal visual field. J 0 showed a significant negative shift in those with myopia (Po0.001) and emmetropia (P ¼ 0.049) following off axis retinoscopy. No significant differences in M, J 0 and J 45 were found in the hyperopes. Mean aided LogMar acuities after on and off axis retinoscopy were both significantly better than mean unaided LogMar VA (Po0.001 in both cases). Conclusion Small degrees of off axis retinoscopy encountered in everyday clinical practice can induce errors in objective central refractive measurement.

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“…18 Several factors with the potential to affect peripheral refraction were also analyzed; namely age, 2,19 refractive error, 4,20 eccentric horizontal and vertical retinal locations, 21 different fixation distance 22 and the impact of anterior cornea reshaping with orthokeratology 16 or LASIK. 23 Several of the cited studies were intended to analyze peripheral refraction using a number of instruments, 24 either under cycloplegia 24 or without cycloplegic agents. 21 Peripheral refraction has also been studied with the goal of obtaining a theoretical model of the ophthalmic lenses that could correct the peripheral refractive error.…”

Section: Introductionmentioning

confidence: 99%

Influence of Fogging Lenses and Cycloplegia on Peripheral Refraction

Queirós

Jorge

González-Meijóme

2009

Journal of Optometry

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PURPOSE:To compare objective peripheral refraction measured with an open-field autorefractor without cycloplegia with the values obtained with fogging lenses or with cycloplegia to inhibit accommodation. METHODS: For one hundred and sixty young adults aged 18 to 28 (mean 21.5 ± 2.3 years) their refraction was measured with the Grand Seiko (GS) autorefractor at the center and at four peripheral locations in the nasal and temporal directions under three different conditions: 1) without cycloplegia (GS); 2) without cycloplegia, but using a +2.00D fogging lens (GS_2D) and 3) with cycloplegia (GS_cycl). RESULTS: Mean spherical equivalent refraction (M) was significantly more negative with the GS method in the hyperopic group for central and peripheral refraction, and only at the center and at 10º nasal eccentricity for the emmetropic group (P<0.05, KruskalWallis). Paired comparison showed that differences of M values across techniques were larger for the GS-vs.-GS_2D comparison in myopes and emmetropes, and for the GS-vs.-GS_cycl one in hyperopes (P<0.001, Wilcoxon Signed Ranks Test). The gap between M values for all paired comparisons remained almost constant across all eccentric positions under analysis. CONCLUSIONS: Fogging lenses used with open-field autorefraction up to 20º in the nasal and temporal fields seem to provide similar accommodative relaxation to that provided by a cycloplegic. This is particularly important when refracting emmetropes and hyperopes. Moreover, this behavior seems to be independent of the eccentricity at which measurements are taken. RESUMEN OBJETIVO:Comparar las medidas objetivas de refracción periférica realizadas sin cicloplégico con los valores obtenidos con "lentes de miopización" o con cicloplegia, ambas técnicas utilizadas para inhibir la acomodación. MÉTODOS: Se midió la refracción a 160 adultos jóvenes, con edades comprendidas entre 18 y 28 años (media=21,5± 2,3 años), con un autorrefractómetro Grand Seiko (GS), tanto en el centro del campo visual como en 4 regiones de la periferia situadas nasal y temporalmente, y todo ello en 3 condiciones diferentes: 1) sin cicloplegia (GS); 2) sin cicloplegia , pero utilizando una lente translúcida de +2.00 D (GS_2D) y 3) con cicloplegia (GS_cycl). RESULTADOS: La media del equivalente esférico de la refracción (M) resultó ser significativamente más negativa en la condición GS en el grupo de los hipermétropes en lo que respecta a refracción central y periférica, mientras que en el grupo de los emétropes sólo ocurrió esto en el centro y a una excentricidad de 10º nasal (P<0,05, Kruskal-Wallis). La comparación por pares de muestras relacionadas reveló que la mayor diferencia de M entre distintas condiciones se obtuvo al comparar GS y GS_2D en el grupo de los miopes y en el de los emétropes, y al comparar GS y GS_cycl en el de los hipermétropes (P<0,001, contraste de Wilcoxon de rangos con signo). La discrepancia entre valores de M para las distintas comparaciones por pares se mantiene prácticamente constante para todas las excentrici...

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Off-axis refraction and aberrations following conventional laser in situ keratomileusis

Cited by 42 publications

References 43 publications

Influence of spherical intraocular lens implantation and conventional laser in situ keratomileusis on peripheral ocular aberrations

Influence of spherical intraocular lens implantation and conventional laser in situ keratomileusis on peripheral ocular aberrations

The impact of off the visual axis retinoscopy on objective central refractive measurement in adult clinical practice: a prospective, randomized clinical study

Influence of Fogging Lenses and Cycloplegia on Peripheral Refraction

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