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Yuan Y, Zhang Y, Sun T, Sun X, Zhao X, Chen Y. Topography-Guided FS-LASIK With PAE Algorithm and Sirius Tomography Data for Correction of Myopia and Myopic Astigmatism. J Refract Surg 2022; 38:235-242. [PMID: 35412929 DOI: 10.3928/1081597x-20220131-01] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To compare the clinical outcomes after topography-guided and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) planned with the Phorcides Analytic Engine (PAE) algorithm system and Sirius tomography data for correction of myopia and myopic astigmatism when the ocular residual astigmatism (ORA) was great or not. METHODS In this retrospective study, a total of 163 eyes with myopia and myopic astigmatism (99 patients) were included. Eyes with myopic astigmatism and high ORA of 0.75 diopters (D) or greater were assigned to the high ORA group and the others to the low ORA group. All surgeries were performed by topography-guided FS-LASIK planned with a PAE algorithm system. PAE took anterior and posterior corneal negative cylinder of the 5-mm zone from the Sirius combined topography and tomography. Refractive and visual outcomes, vector analysis, and corneal aberrations were compared between the two groups. RESULTS At 6 months postoperatively, the uncorrected distance visual acuity of 20/16 or better was measured in 59% of eyes in the high ORA group and 66% of eyes in the low ORA group (P = .307). Postoperative corrected distance visual acuity, manifest refractive spherical equivalent, refractive astigmatism, target induced astigmatism, surgically induced astigmatism, and difference vector were similar between the two groups (P > .05). The postoperative corneal astigmatism was significantly higher in the high ORA group (P = .008), and the high ORA group over-corrected astigmatism with the rule and showed a higher correction index (P = .003) compared with the low ORA group. CONCLUSIONS Topography-guided FS-LASIK with PAE algorithm and Sirius combined topography and tomography data for correction of myopia and myopic astigmatism achieved the predicted surgical outcomes and there was a tendency to have a similar clinical outcome for PAE when the ORA was great or not. However, the PAE with high ORA overcorrected astigmatism with-the-rule and showed a higher correction index compared with the low ORA group. [J Refract Surg. 2022;38(4):235-242.].
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Theoretical Effect of Coma and Spherical Aberrations Translation on Refractive Error and Higher Order Aberrations. PHOTONICS 2020. [DOI: 10.3390/photonics7040116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
(1) Background: The purpose of the study is to present a simple theoretical account of the effect of translation of coma and spherical aberrations (SA) on refractive error and higher order aberrations. (2) Methods: A computer software algorithm was implemented based on previously published methods. The effect of translation (0 to +1 mm) was analyzed for SA (0 to +2 µm) and coma (0 to +2 µm) for a circular pupil of 6 mm, without any rotation or scaling effect. The relationship amongst Zernike representations of various aberrations was analyzed under the influence of translation. (3) Results: The translation of +0.40 µm of SA (C[4,0]) by +0.25 mm with a pupil diameter of 6mm resulted in induction of tilt (C[1,1]), −0.03D defocus (C[2,0]), +0.03D astigmatism (C[2,2]) and +0.21 µm coma (C[3,1]). The translation of +0.4 µm of coma (C[3,1]) by +0.25 mm with a pupil diameter of 6 mm resulted in induction of tilt (C[1,1]), −0.13D defocus (C[2,0]) and +0.13D astigmatism (C[2,2]). A theoretical quantitative relationship between SA, coma, astigmatism and defocus is presented under the influence of translation. (4) Conclusion: The results can act as a guide for the clinician, in order to readily assess theoretical impact of wavefront map translation from pupil center to the visual axis. The resultant refractive coupling has to be taken into consideration especially when treating eyes with an abnormal corneal shape and/or large pupil center to corneal vertex chord.
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Wallerstein A, Gauvin M, Cohen M. Effect of Anterior Corneal Higher-Order Aberration Ablation Depth on Primary Topography-Guided LASIK Outcomes. J Refract Surg 2020; 35:754-762. [PMID: 31830291 DOI: 10.3928/1081597x-20191021-02] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 10/21/2019] [Indexed: 11/20/2022]
Abstract
PURPOSE To investigate the contribution of anterior corneal higher-order aberration ablation depth (HOA-AD) to topography-guided outcomes. METHODS This was a retrospective comparative analysis of 9,722 consecutive eyes undergoing laser in situ keratomileusis (LASIK) treated on the clinically measured refractive cylinder with Contoura software (Alcon Laboratories, Inc., Fort Worth, TX). Outcomes of the 3,246 eyes with the shallowest HOA-AD (first tercile: 5.4 ± 0.9 µm) were compared to the 3,362 eyes with the deepest HOA-AD (last tercile: 11.0 ± 1.7 µm). RESULTS The HOA-AD followed a left-skewed normal distribution (R2 = 0.98) with a mean ± standard deviation of 8.02 ± 3.00 µm, with 1.8% of eyes greater than 15 µm. The efficacy index of shallow versus deep HOA-AD eyes was identical (0.98 ± 0.07 vs 0.98 ± 0.09; P = .99), with a similar percentage having spherical equivalent within ±0.50 diopters (D) (95.2% vs 95.0%; P = .71) and within ±0.75 D (98.9% vs 98.7%; P = .46) of intended target. The safety index (1.00 ± 0.03 vs 1.00 ± 0.04; P = .19) and Alpins correction index (1.00 ± 0.39 vs 1.01 ± 0.43; P = .53) were also identical. The mean postoperative refractive astigmatism difference between the shallow (0.15 D) and deep (0.20 D) groups was 0.05 D. The 3-month laser re-treatment rate was greater in the deep group (0.83% vs 0.37%; P = .02), but less than 1% for both groups. CONCLUSIONS The contribution of topography-guided HOA-AD to clinical outcomes in most virgin eyes is negligible, with excellent efficacy, accuracy, and safety in both the deep and shallow ablation groups. Eyes with deep HOA-AD greater than 15 µm trend to lesser outcomes, but should not be excluded from topography-guided surgery. [J Refract Surg. 2019;35(12):754-762].
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Suliman A, Rubin A. A review of higher order aberrations of the human eye. AFRICAN VISION AND EYE HEALTH 2019. [DOI: 10.4102/aveh.v78i1.501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Wallerstein A, Gauvin M, Qi SR, Bashour M, Cohen M. Primary Topography-Guided LASIK: Treating Manifest Refractive Astigmatism Versus Topography-Measured Anterior Corneal Astigmatism. J Refract Surg 2019; 35:15-23. [PMID: 30633783 DOI: 10.3928/1081597x-20181113-01] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/12/2018] [Indexed: 11/20/2022]
Abstract
PURPOSE To investigate whether topography-guided laser in situ keratomileusis (LASIK) with anterior corneal astigmatism measured on the WaveLight Contoura (Alcon Laboratories, Inc., Fort Worth, TX) leads to better refractive outcomes compared to treating on the clinically measured manifest refractive astigmatism axis in eyes with primary myopic astigmatism. METHODS Retrospective analysis of 1,274 consecutive LASIK eyes treated on the topography-measured anterior corneal astigmatism axis compared to eyes treated on the conventional clinical manifest refractive astigmatism axis. RESULTS In eyes with a small axis discrepancy between anterior corneal astigmatism and refractive astigmatism of 5° to 20°, there was no significant difference in efficacy index, refractive astigmatism accuracy, and most Alpins vector analysis parameters. Both treatment modalities achieved 20/20 uncorrected distance visual acuity (UDVA) in 90% of eyes, with 95% having postoperative cylinder of 0.50 diopters (D) or less. In eyes with a large axis discrepancy between 21° and 45° treated on the anterior corneal astigmatism axis, outcomes were both statistically and clinically inferior. Fewer eyes achieved UDVA of 20/20 (88.9% vs 73.6%; P = .01) and fewer had a defocus equivalent of 0.25 (65.6% vs 52.7%), 0.50 (86.9% vs 80.0%), and 0.75 (97.5% vs 90.9%) D or less (P < .05 for all). Significantly more eyes achieved an angle of error greater than 15° (25.4% vs 8.1%; P = .004), had postoperative residual astigmatism of 0.75 D or less (18.2% vs 7.4%; P = .03), and needed an excimer laser re-treatment (11% vs 1.6%; P = .007). CONCLUSIONS Topography-guided myopic astigmatism LASIK treated on the topography-measured anterior corneal astigmatism axis resulted in inferior refractive and visual outcomes compared to treating on the clinical manifest refractive astigmatism axis. [J Refract Surg. 2019;35(1):15-23.].
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Excimer Laser Surgery: Biometrical Iris Eye Recognition with Cyclorotational Control Eye Tracker System. SENSORS 2017; 17:s17061211. [PMID: 28587100 PMCID: PMC5492327 DOI: 10.3390/s17061211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Revised: 05/22/2017] [Accepted: 05/23/2017] [Indexed: 11/17/2022]
Abstract
A prospective comparative study assessing the importance of the intra-operative dynamic rotational tracking-especially in the treatment of astigmatisms in corneal refractive Excimer laser correction-concerning clinical outcomes is presented. The cyclotorsion from upright to supine position was measured using iris image comparison. The Group 1 of patients was additionally treated with cyclorotational control and Group 2 only with X-Y control. Significant differences were observed between the groups regarding the mean postoperative cylinder refraction (p < 0.05). The mean cyclotorsion can be calculated to 3.75° with a standard deviation of 3.1°. The total range of torsion was from -14.9° to +12.6°. Re-treatment rate was 2.2% in Group 1 and 8.2% in Group 2, which is highly significant (p < 0.01). The investigation confirms that the dynamic rotational tracking system used for LASIK results in highly predictable refraction quality with significantly less postoperative re-treatments.
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Delgado S, Velazco J, Delgado Pelayo RM, Ruiz-Quintero N. Correlation of higher order aberrations in the anterior corneal surface and degree of keratoconus measured with a Scheimpflug camera. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2016; 91:316-319. [PMID: 26907199 DOI: 10.1016/j.oftal.2016.01.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 01/02/2016] [Accepted: 01/04/2016] [Indexed: 06/05/2023]
Abstract
OBJECTIVE To determine the correlation of higher order aberrations in anterior corneal surface and degree of keratoconus measured with a Scheimpflug camera. MATERIAL AND METHODS A descriptive, cross-sectional study was conducted on 152 eyes (both eyes of each patient) of patients with keratoconus, from January 2009 to April 2014. An examination was performed on the corneal aberrometry in the anterior corneal surface, and topographic mapping (by Amsler and Muckenhirn classification) was used to determine the degree of keratoconus. The correlation between high-order aberrations in anterior corneal surface and the degree of keratoconus was determined. RESULTS Coma aberration significantly correlated with keratoconus severity (r=.60, P<.01), as well as with the high order aberration (r=.61, P<.01). Trefoil and keratoconus were weakly correlated (r=.34, P<.01). CONCLUSION Higher order aberrations in anterior corneal surface were positively correlated with the degree of keratoconus in a similar way to the entire optical system.
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Affiliation(s)
- S Delgado
- Departamento de Córnea, Asociación para Evitar la Ceguera en México D.F, Coyoacán, México.
| | - J Velazco
- Departamento de Córnea, Asociación para Evitar la Ceguera en México D.F, Coyoacán, México
| | - R M Delgado Pelayo
- Departamento de Córnea, Centro Cardio-Neuro-Oftlamológico y Trasplante, Santo Domingo, República Dominicana
| | - N Ruiz-Quintero
- Departamento de Córnea, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, D.F, México
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Oberholzer M, Gillan WD, Rubin A. Higher order aberrations of the eye: Part two. AFRICAN VISION AND EYE HEALTH 2016. [DOI: 10.4102/aveh.v75i1.335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
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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Oberholzer M, Gillan WD, Rubin A. Higher order aberrations of the eye: Part one. AFRICAN VISION AND EYE HEALTH 2016. [DOI: 10.4102/aveh.v75i1.321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
This article is the first in a series of two articles that provide a comprehensive literature review of higher order aberrations (HOAs) of the eye. The present article mainly explains the general principles of such HOAs as well as HOAs of importance, and the measuring apparatus used to measure HOAs of the eye. The second article in the series discusses factors contributing to variable results in measurements of HOAs of the eye.Keywords: Higher order aberrations; wavefront aberrations; aberrometer
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Abstract
Purpose To determine normative reference ranges for higher-order wavefront error (HO-WFE), compare these values with those in common ocular pathologies, and evaluate treatments. Methods A review of 17 major studies on HO-WFE was made, involving data for a total of 31,605 subjects. The upper limit of the 95% confidence interval (CI) for HO-WFE was calculated from the most comprehensive of these studies using normal healthy patients aged 20 to 80 years. There were no studies identified using the natural pupil size for subjects, and for this reason, the HO-WFE was tabulated for pupil diameters of 3 to 7 mm. Effects of keratoconus, pterygium, cataract, and dry eye on HO-WFE were reviewed and treatment efficacy was considered. Results The calculated upper limit of the 95% CI for HO-WFE in a healthy normal 35-year-old patient with a mesopic pupil diameter of 6 mm would be 0.471 μm (471 nm) root-mean-square or less. Although the normal HO-WFE increases with age for a given pupil size, it is not yet completely clear how the concurrent influence of age-related pupillary miosis affects these findings. Abnormal ocular conditions such as keratoconus can induce a large HO-WFE, often in excess of 3.0 μm, particularly attributed to coma. For pterygium or cortical cataract, a combination of coma and trefoil was more commonly induced. Nuclear cataract can induce a negative spherical HO-WFE, usually in excess of 1.0 μm. Conclusions The upper limit of the 95% CI for HO-WFE root-mean-square is about 0.5 μm with normal physiological pupil sizes. With ocular pathologies, HO-WFE can be in excess of 1.0 μm, although many devices and therapeutic and surgical treatments are reported to be highly effective at minimizing HO-WFE. More accurate normative reference ranges for HO-WFE will require future studies using the subjects’ natural pupil size.
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Affiliation(s)
- Adrian S Bruce
- *BScOptom, PhD, FAAO †OD, DSc (Hon), FAAO Australian College of Optometry, Carlton, Victoria, Australia (ASB); Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Australia (ASB); and Nicolitz Eye Consultants, Jacksonville, Florida (LJC)
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Zhou XY, Wang L, Zhou XT, Yu ZQ. Wavefront aberration changes caused by a gradient of increasing accommodation stimuli. Eye (Lond) 2014; 29:115-21. [PMID: 25341432 DOI: 10.1038/eye.2014.244] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 09/02/2014] [Indexed: 12/16/2022] Open
Abstract
PURPOSE The aim of this study was to investigate the wavefront aberration changes in human eyes caused by a gradient of increasing accommodation stimuli. DESIGN This is a prospective, single-site study. METHODS Healthy volunteers (n=22) aged 18-28 years whose refraction states were emmetropia or mild myopia, with astigmatism <1 diopter (D), were included in this study. After dilating the right pupil with 0.5% phenylephrine drops, the wavefront aberration of the right eye was measured continuously either without or with 1, 2, 3, 4, 5, or 6D accommodation stimuli (WFA1000B psychophysical aberrometer). The root mean square (RMS) values of the total wavefront aberrations, higher-order aberrations, and 35 individual Zernike aberrations under different accommodation stimuli were calculated and compared. RESULTS The average induced accommodations using 1, 2, 3, 4, 5, or 6D accommodation stimuli were 0.848, 1.626, 2.375, 3.249, 4.181, or 5.085 D, respectively. The RMS of total wavefront aberrations, as well as higher-order aberrations, showed no significant effects with 1-3 D accommodation stimuli, but increased significantly under 4, 5, and 6 D accommodation stimuli compared with relaxed accommodation. Zernike coefficients of significantly decreased with increasing levels of accommodation. CONCLUSION Higher-order wavefront aberrations in human eyes changed with increased accommodation. These results are consistent with Schachar's accommodation theory.
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Affiliation(s)
- X-Y Zhou
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
| | - L Wang
- Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
| | - X-T Zhou
- 1] Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China [2] Key Laboratory of Myopia, Ministry of Health, Shanghai, China
| | - Z-Q Yu
- 1] Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China [2] Key Laboratory of Myopia, Ministry of Health, Shanghai, China
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