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Morgan PB, Efron N, Papas E, Barnett M, Carnt N, Dutta D, Hepworth A, Little JA, Nagra M, Pult H, Schweizer H, Shen Lee B, Subbaraman LN, Sulley A, Thompson A, Webster A, Markoulli M. BCLA CLEAR Presbyopia: Management with contact lenses and spectacles. Cont Lens Anterior Eye 2024; 47:102158. [PMID: 38631935 DOI: 10.1016/j.clae.2024.102158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
This paper seeks to outline the history, market situation, clinical management and product performance related to the correction of presbyopia with both contact lenses and spectacles. The history of the development of various optical forms of presbyopic correction are reviewed, and an overview is presented of the current market status of contact lenses and spectacles. Clinical considerations in the fitting and aftercare of presbyopic contact lens and spectacle lens wearers are presented, with general recommendations for best practice. Current options for contact lens correction of presbyopia include soft simultaneous, rigid translating and rigid simultaneous designs, in addition to monovision. Spectacle options include single vision lenses, bifocal lenses and a range of progressive addition lenses. The comparative performance of both contact lens and spectacle lens options is presented. With a significant proportion of the global population now being presbyopic, this overview is particularly timely and is designed to act as a guide for researchers, industry and eyecare practitioners alike.
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Affiliation(s)
- Philip B Morgan
- Eurolens Research, Division of Pharmacy and Optometry, University of Manchester, United Kingdom.
| | - Nathan Efron
- Optometry and Vision Science, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Eric Papas
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | | | - Nicole Carnt
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Debarun Dutta
- Optometry and Vision Science Research Group, Aston University, Birmingham, United Kingdom
| | - Andy Hepworth
- EssilorLuxottica Europe North, Bristol, United Kingdom
| | - Julie-Anne Little
- Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, United Kingdom
| | - Manbir Nagra
- Vision and Eye Research Institute, ARU, Young Street, Cambridge, United Kingdom
| | - Heiko Pult
- Dr Heiko Pult - Optometry and Vision Research, Weinheim, Germany
| | - Helmer Schweizer
- CEO Helmer Schweizer Consulting Group (HSCG), Bassersdorf, Switzerland
| | - Bridgitte Shen Lee
- Vision Optique and Ocular Aesthetics dba Ocular Clinical Trials, Houston, TX, United States
| | | | - Anna Sulley
- CooperVision International Ltd, Chandlers Ford, United Kingdom
| | | | | | - Maria Markoulli
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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Applegate RA, Hastings GD, Jiménez-García M, Francis S, Koppen C, Rozema JJ. Allowable movement of wavefront-guided contact lens corrections in normal and keratoconic eyes. Ophthalmic Physiol Opt 2024; 44:746-756. [PMID: 38389207 DOI: 10.1111/opo.13286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 02/24/2024]
Abstract
PURPOSE The goal was to use SyntEyes modelling to estimate the allowable alignment error of wavefront-guided rigid contact lens corrections for a range of normal and keratoconic eye aberration structures to keep objectively measured visual image quality at or above average levels of well-corrected normal eyes. Secondary purposes included determining the required radial order of correction, whether increased radial order of the corrections further constrained the allowable alignment error and how alignment constraints vary with keratoconus severity. METHODS Building on previous work, 20 normal SyntEyes and 20 keratoconic SyntEyes were fitted with optimised wavefront-guided rigid contact lens corrections targeting between three and eight radial orders that drove visual image quality, as measured objectively by the visual Strehl ratio, to near 1 (best possible) over a 5-mm pupil for the aligned position. The resulting wavefront-guided contact lens was then allowed to translate up to ±1 mm in the x- and y-directions and rotate up ±15°. RESULTS Allowable alignment error changed as a function of the magnitude of aberration structure to be corrected, which depends on keratoconus severity. This alignment error varied only slightly with the radial order of correction above the fourth radial order. To return the keratoconic SyntEyes to average levels of visual image quality depended on maximum anterior corneal curvature (Kmax). Acceptable tolerances for misalignment that returned keratoconic visual image quality to average normal levels varied between 0.29 and 0.63 mm for translation and approximately ±6.5° for rotation, depending on the magnitude of the aberration structure being corrected. CONCLUSIONS Allowable alignment errors vary as a function of the aberration structure being corrected, the desired goal for visual image quality and as a function of keratoconus severity.
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Affiliation(s)
| | | | - Marta Jiménez-García
- Visual Optics Lab Antwerp (VOLANTIS), Faculty of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
| | - Sharon Francis
- Visual Optics Lab Antwerp (VOLANTIS), Faculty of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium
| | - Carina Koppen
- Visual Optics Lab Antwerp (VOLANTIS), Faculty of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
| | - Jos J Rozema
- Visual Optics Lab Antwerp (VOLANTIS), Faculty of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
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Walther G, Meyer D, Richards J, Rickert M, Kollbaum P. On-eye centration of soft contact lenses. Ophthalmic Physiol Opt 2024; 44:737-745. [PMID: 38217323 DOI: 10.1111/opo.13278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/28/2023] [Accepted: 01/03/2024] [Indexed: 01/15/2024]
Abstract
PURPOSE To evaluate the relative positions of modern soft contact lenses (SCLs) relative to the limbus/cornea and the pupil. METHODS Sixty images of the anterior eyes of 101 subjects were acquired over 10 s while participants fixated the centre of the camera lens located 33 cm in front of the eye in a well-lit (300 lux) clinic. Custom validated image analysis software was used to locate the boundaries of the contact lenses, pupils and corneas (limbus). Horizontal and vertical relative positions of the contact lens, pupil and limbus were calculated from the fitted boundaries. RESULTS The mean (standard deviation) pupil and corneal diameters for all subjects were 3.84 mm, (0.83) and 11.97 mm (0.48), respectively. The mean [95% confidence interval] pupil centre was located 0.28 mm [0.26, 0.30] nasally and 0.07 mm [0.05, 0.10] superiorly to the corneal centre. Consistent with clinical observations, the contact lenses centred accurately relative to the corneal centre both nasally 0.04 mm [0.01, 0.07] and inferiorly -0.01 mm [-0.06, 0.03]. However, regardless of the eye, the contact lens was significantly (p < 0.001) decentred relative to the pupil centre both temporally -0.23 mm [-0.26, -0.20] and inferiorly -0.08 mm [-0.12, -0.04]. Decentration magnitudes were significantly correlated between the right and left eyes. CONCLUSIONS Spherical SCLs centred well on the cornea but temporally and inferiorly from the primary line of sight (pupil centre), due to the differences in the location of the pupil and corneal centres. Contrary to some previous reports, there was no evidence that lens optics or material affected lens centration significantly.
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Affiliation(s)
| | - Dawn Meyer
- Indiana University, Bloomington, Indiana, USA
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Cheng M, Chen X, Lei Y, Li B, Jiang Y, Xu Y, Zhou X, Wang X. Clinical Evaluation Of a 0.05 D-step Binocular Wavefront Optometer in Young Adults in China. Clin Exp Optom 2024; 107:395-401. [PMID: 36794379 DOI: 10.1080/08164622.2023.2175603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 01/13/2023] [Accepted: 01/28/2023] [Indexed: 02/17/2023] Open
Abstract
CLINICAL RELEVANCE Myopia has become a public health priority as its prevalence increases worldwide, and in clinical practice, the precise evaluation of refraction errors is necessary. BACKGROUND This study aimed to compare objective and subjective refraction measured by a binocular wavefront optometer (BWFOM) in adults with conventional objective and subjective refractions measured by an optometrist. METHODS This cross-sectional study included 119 eyes of 119 participants (34 men and 85 women; mean age:27.5 ± 6.3 years). Refractive errors were measured using BWFOM and conventional methods, with and without cycloplegia. The mean outcome measures were spherical power, cylindrical power, and spherical equivalence (SE). The agreement test was assessed using a two-tailed paired t-test and Bland - Altman plots. RESULTS Under noncycloplegic conditions, there were no significant differences in the objective SE between BWFOM and Nidek. Significant differences in subjective SE were observed between BWFOM and conventional subjective refraction (-5.79 ± 1.86 vs -5.65 ± 1.75 D, P < 0.01). Under cycloplegic conditions, the mean objective SE was significantly different between BWFOM and Nidek (-5.70 ± 1.76 vs -5.50 ± 1.83 D, P < 0.001); the mean subjective SE was significantly different between BWFOM and conventional subjective refractions (-5.52 ± 1.77 vs -5.62 ± 1.79 D, P < 0.001). The Bland - Altman plots revealed mean percentages of 95.38% and 95.17% for the points within the limits of agreement between BWFOM and conventional measurements and those between noncycloplegic and cycloplegic refractions, respectively. CONCLUSION The BWFOM is a new device that measures both objective and subjective refraction. It is more convenient and faster to obtain a proper prescription at a 0.05-D interval. The subjective refraction results of the BWFOM and the conventional subjective refraction were in good agreement.
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Affiliation(s)
- Mingrui Cheng
- Department of Ophthalmology, Fudan University Eye Ear Nose and Throat Hospital, Shanghai, China
- Department of Ophthalmology, Jinshan Hospital Affiliated to Fudan University, Shanghai, China
- National Health Commission Key Lab of Myopia, Fudan University, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xun Chen
- Department of Ophthalmology, Fudan University Eye Ear Nose and Throat Hospital, Shanghai, China
- National Health Commission Key Lab of Myopia, Fudan University, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yadi Lei
- Department of Ophthalmology, Fudan University Eye Ear Nose and Throat Hospital, Shanghai, China
- National Health Commission Key Lab of Myopia, Fudan University, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Bailiang Li
- Department of Ophthalmology, Fudan University Eye Ear Nose and Throat Hospital, Shanghai, China
- National Health Commission Key Lab of Myopia, Fudan University, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yinjie Jiang
- Department of Ophthalmology, Fudan University Eye Ear Nose and Throat Hospital, Shanghai, China
- National Health Commission Key Lab of Myopia, Fudan University, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Yilin Xu
- Department of Ophthalmology, Fudan University Eye Ear Nose and Throat Hospital, Shanghai, China
- National Health Commission Key Lab of Myopia, Fudan University, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xiaodong Zhou
- Department of Ophthalmology, Jinshan Hospital Affiliated to Fudan University, Shanghai, China
| | - Xiaoying Wang
- Department of Ophthalmology, Fudan University Eye Ear Nose and Throat Hospital, Shanghai, China
- National Health Commission Key Lab of Myopia, Fudan University, Shanghai, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
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Small Incision Lenticule Extraction (SMILE) Versus Laser Assisted Stromal In Situ Keratomileusis (LASIK) for Astigmatism Corrections: A Systematic Review and Meta-analysis. Am J Ophthalmol 2023; 247:181-199. [PMID: 36410469 DOI: 10.1016/j.ajo.2022.11.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 10/30/2022] [Accepted: 11/07/2022] [Indexed: 11/21/2022]
Abstract
PURPOSE To compare small incision lenticule extraction (SMILE) and laser assisted stromal in situ keratomileusis (LASIK) for astigmatism correction. DESIGN Systematic review and meta-analysis METHODS: We reviewed published studies comparing outcomes after LASIK and SMILE for astigmatism correction by querying PubMed, EMBASE, Cochrane, and Web of Science, with a cut-off date of September 3, 2022. We also compared the changes in visual acuity, refraction, and high-order aberrations between the surgeries. Astigmatism correction outcomes in the low-to-moderate group (less than or equal to -2.00 D) and high group (greater than -2.00 D) were evaluated using vector analysis. The Cochrane risk of bias tool in RevMan software was used for randomized studies (RCT), and Risk Of Bias In Nonrandomized Studies - of Interventions (ROBINS-I) was used for the nonrandomized studies (NRSs). RESULTS There were 17 studies (5 randomized studies and 12 cohort studies), including 1,985 eyes. A statistically significant difference was found in the correction index (mean difference [MD] = -0.02, 95% confidence interval [CI] = -0.04 to -0.01, P =0.01), although there was no significant difference in the index of success (MD = 0.01, 95% CI = -0.03 to 0.05, P =0.51), different vector (MD = 0.07, 95% CI = 0.00 to 0.13, P =0.04), and angle of error (MD = 0.56, 95% CI = -0.34 to 1.45, P =0.22) between SMILE and LASIK. However, for low-to-moderate astigmatism correction, SMILE exhibited a smaller correction index (MD = -0.08, 95% CI= -0.13 to -0.02, P =0.008) and a larger difference vector (MD = 0.18, 95% CI = 0.09 to 0.27, P <0.0001) than LASIK. There was no significant difference between the different procedures in visual acuity and refraction (spherical equivalent: MD = -0.04, 95% CI = -0.08 to 0.01, P =0.15) or high-order aberration (MD = -0.01, 95% CI = -0.07 to 0.04, P =0.67), except spherical aberration (MD = -0.12, 95% CI = -0.23 to -0.01, P =0.04). The risk of bias was moderate in most studies because of poor reporting of several bias domains for RCTs, and because of confounding and selective outcome reporting for NRSs. CONCLUSIONS When used to treat severe astigmatism, both SMILE and LASIK provide effective and predictable results and generally have equivalent outcomes. However, evidence reveals a tendency toward undercorrection in the SMILE groups for astigmatism correction. In addition, LASIK has a greater probability of causing postoperative spherical aberration.
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Rozema JJ, Hastings GD, Jiménez-García M, Koppen C, Applegate RA. Influence of rigid lens decentration and rotation on visual image quality in normal and keratoconic eyes. Ophthalmic Physiol Opt 2022; 42:1204-1213. [PMID: 36111637 PMCID: PMC9547948 DOI: 10.1111/opo.13045] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 08/05/2022] [Accepted: 08/07/2022] [Indexed: 10/25/2023]
Abstract
PURPOSE To investigate whether the movement of a rigid sphero-cylindrical contact lens has a greater impact on the visual image quality in highly aberrated eyes than in normal eyes. METHODS For 20 normal and 20 keratoconic SyntEyes, a previously determined best sphero-cylindrical rigid lens was permitted to shift by up to ±1 mm from the line of sight and rotate up to ±15°. Each of the 52,111 lens locations sampled was ray-traced to determine the influence on the wavefront aberration. In turn, the logarithm of visual Strehl ratio (log10 [VSX]) was calculated for each aberration structure and was used to estimate the associated changes in logMAR visual acuity. Finally, contour surfaces of two-letter change in visual acuity were plotted in three-dimensional misalignment space, consisting of decentrations in the x and y directions and rotation, and volumes within these surfaces were calculated. RESULTS The variations in image quality within the misalignment space were unique to each eye. A two-letter loss was generally reached with smaller misalignments in keratoconic eyes (10.5 ± 4.7° of rotation or 0.27 ± 0.13 mm of shift) than in normal eyes (13.4 ± 1.8° and 0.39 ± 0.15 mm, respectively) due to larger cylindrical errors. For keratoconic eyes, on average, 14.4 ± 14.9% of misalignment space saw VSX values above the lower normal VSX threshold, well below the values of normal eyes of 48.5 ± 18.5%. In some eyes, a specific combination of lens shift and lens rotation away from the line of sight leads to a simulated improvement in visual image quality. CONCLUSION Variations in visual image quality due to the misalignment of rigid sphero-cylindrical contact lens corrections are larger for keratoconic eyes than for normal eyes. In some cases, a specific misalignment may improve visual image quality, which could be considered in the design of the next generation of rigid contact lenses.
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Affiliation(s)
- Jos J Rozema
- Visual Optics Lab Antwerp (VOLANTIS), Faculty of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
| | - Gareth D Hastings
- College of Optometry, University of Houston, Houston, Texas, USA
- Center for Innovation in Optics and Vision, School of Optometry, University of California, Berkeley, California, USA
| | - Marta Jiménez-García
- Visual Optics Lab Antwerp (VOLANTIS), Faculty of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
| | - Carina Koppen
- Visual Optics Lab Antwerp (VOLANTIS), Faculty of Medicine and Health Sciences, Antwerp University, Wilrijk, Belgium
- Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium
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Carballo-Alvarez J, Caballero-Magro E, Cortes-Escudero I, Carpena-Torres C. Correction of Ocular Aberrations with Prismatic Rigid Gas-permeable Contact Lenses in Keratoconic Eyes. Optom Vis Sci 2021; 98:1279-1286. [PMID: 34510143 DOI: 10.1097/opx.0000000000001801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE A base-down prism was incorporated on the anterior surface of rigid gas-permeable (RGP) contact lenses to explore potential effects on the residual ocular aberrations after contact lens fitting in keratoconic eyes. PURPOSE This study aimed to evaluate the correction of ocular aberrations with corneal prismatic RGP contact lenses in keratoconic eyes and their impact on visual function. METHODS A cross-sectional and randomized study was performed. Seventeen eyes of 17 keratoconus patients (34.6 ± 11.1 years) were evaluated. Two designs (standard and prismatic) of a corneal RGP contact lens (KAKC; Conoptica, Barcelona, Spain) were fitted to the same eye of each patient in a random order: a standard RGP contact lens as control and a prismatic RGP contact lens with a base-down prism of 1.6 prism diopters. Ocular aberrations were measured for a pupil diameter of 3 mm with and without both contact lenses, whereas high-contrast distance visual acuity, low-contrast distance visual acuity, and contrast sensitivity were measured under photopic and mesopic conditions. RESULTS Both contact lenses improved oblique primary astigmatism, defocus, vertical coma, coma-like, and root-mean-square higher-order aberrations compared with the unaided eyes (P < .05). Furthermore, the prismatic RGP contact lenses offered lower values of vertical coma and root-mean-square higher-order aberrations than the standard RGP contact lenses (P < .05). Both designs (standard and prismatic) produced a positive vertical coma of lower magnitude than the negative vertical coma of the unaided eyes. On the other hand, the improvement achieved in all visual function variables was the same for both contact lens designs (P ≥ .05). CONCLUSIONS The prismatic RGP contact lenses corrected higher levels of higher-order aberrations compared with the standard RGP contact lenses. However, both contact lens designs with the same refractive power were equally efficient at improving visual function.
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Zhang Y, Wang S, Xian H, Rao C. Unified analytical method for Zernike coefficient transformation of scaled, rotated, and translated pupils based on Shack's vector multiplication. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2021; 38:1131-1139. [PMID: 34613307 DOI: 10.1364/josaa.427851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/12/2021] [Indexed: 06/13/2023]
Abstract
Zernike polynomials play an essential role in characterizing and analyzing wavefront aberrations. Transformation of weighted coefficients for Zernike modes is required when pupil scaling, rotation, and/or translation exist. Here, a novel method based on Shack's vector multiplication is first proposed to derive the transformation relation. The derived modes resulting from pupil scaling, rotation, and/or translation for each individual mode are easily indicated via this method; thus, the effect of each kind of pupil change could be studied qualitatively and quantitatively. Its remarkable computational efficiency against the direct integral is demonstrated by simulation. The method introduced here provides a generalized methodology to analyze the relationship between weighted coefficients for different description basis sets.
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Miraftab M, Hashemi H, Aghamirsalim M, Fayyaz S, Asgari S. Matched comparison of corneal higher order aberrations induced by SMILE to femtosecond assisted LASIK and to PRK in correcting moderate and high myopia: 3.00mm vs. 6.00mm. BMC Ophthalmol 2021; 21:216. [PMID: 33992084 PMCID: PMC8122548 DOI: 10.1186/s12886-021-01987-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/10/2021] [Indexed: 11/25/2022] Open
Abstract
Background The refractive surgeries induce corneal higher order aberrations (C-HOAs). In this study, change of C-HOAs after small-incision lenticule extraction (SMILE) compared to femtosecond assisted laser in situ keratomileusis (femto-LASIK), and to photorefractive keratectomy with mitomycin-C (PRK) under photopic and mesopic conditions. Methods In this prospective study, age, gender, and apical corneal thickness (ACT) matched cases with moderate myopia [spherical equivalent (SE) 3.00 to 6.00D) to high myopia (SE > 6.00D)] were enrolled. In addition to visual acuity and refraction, total C-HOA, coma, spherical aberration (SA), and trefoil in the 3- and 6-mm zones were measured before and 3 and 6 months after surgery. Results Overall, 372 moderate myopia cases (124 eyes of 124 individuals in each surgical group) and 171 high myopia cases (57 eyes of 57 individuals in each surgical group) were enrolled. At baseline, the differences in age, gender, ACT, uncorrected and corrected visual acuity, and SE were not statistically significant between subgroups of surgical methods within each myopia group (all P > 0.05). At 12 months, in the moderate myopia group, there was less increase in 6-mm zone total C-HOA, coma, and SA with SMILE compared to the other groups (all P < 0.05). In the high myopia group, there was greater increase in photopic total C-HOA and trefoil and less increase in mesopic SA with SMILE (all P < 0.05). Conclusions In correction of moderate myopia, SMILE has better results in mesopic condition. In high myopia correction, femto-LASIK and PRK have better results in photopic and SMILE in mesopic condition.
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Affiliation(s)
- Mohammad Miraftab
- Noor Ophthalmology Research Center, Noor Eye Hospital, No. 96 Esfandiar Blvd., Vali'asr Ave, Tehran, Iran
| | - Hassan Hashemi
- Noor Ophthalmology Research Center, Noor Eye Hospital, No. 96 Esfandiar Blvd., Vali'asr Ave, Tehran, Iran.
| | | | - Shiva Fayyaz
- Noor Ophthalmology Research Center, Noor Eye Hospital, No. 96 Esfandiar Blvd., Vali'asr Ave, Tehran, Iran
| | - Soheila Asgari
- Noor Ophthalmology Research Center, Noor Eye Hospital, No. 96 Esfandiar Blvd., Vali'asr Ave, Tehran, Iran
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Rijal S, Hastings GD, Nguyen LC, Kauffman MJ, Applegate RA, Marsack JD. The Impact of Misaligned Wavefront-guided Correction in a Scleral Lens for the Highly Aberrated Eye. Optom Vis Sci 2021; 97:732-740. [PMID: 32976324 DOI: 10.1097/opx.0000000000001577] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SIGNIFICANCE To achieve maximum visual benefit, wavefront-guided scleral lens corrections (WGCs) are aligned with the underlying wavefront error of each individual eye. This requirement adds complexity to the fitting process. With a view toward simplification in lens fitting, this study quantified the consequences of placing WGCs at two pre-defined locations. PURPOSE This study aimed to quantify performance reduction accompanying the placement of the WGC at two locations: (1) the average decentered location (ADL; average decentration observed across individuals wearing scleral lenses) and (2) the geometric center (GC) of the lens. METHODS Deidentified residual aberration and lens translation data from 36 conventional scleral lens-wearing eyes with corneal ectasia were used to simulate WGC correction in silico. The WGCs were decentered from the eye-specific pupil position to both the ADL and GC locations. The impact of these misalignments was assessed in terms of change (from the aligned, eye-specific pupil position) in higher-order root mean square (HORMS) wavefront error, change in log of the visual Strehl ratio (logVSX), and predicted change in logMAR visual acuity (VA). RESULTS As expected, HORMS increased, logVSX decreased, and predicted VA was poorer at both ADL and GC compared with the aligned condition (P < .001). Thirty-four of 36 eyes had greater residual HORMS, and 33 of 36 eyes had worse logVSX values at the GC than at the ADL. In clinical terms, 19 of 36 eyes at the ADL and 35 of 36 eyes at the GC had a predicted loss in VA of three letters or greater. CONCLUSIONS The placement of the WGC at either ADL or GC is predicted to lead to a noticeable reduction in VA for more than half of the eyes studied, suggesting the simplification of the fitting process is not worth the cost in performance.
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Affiliation(s)
- Sujata Rijal
- College of Optometry, University of Houston, Houston, Texas
| | | | - Lan Chi Nguyen
- College of Optometry, University of Houston, Houston, Texas
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Meister DJ, Fisher SW. Progress in the spectacle correction of presbyopia. Part 2: Modern progressive lens technologies. Clin Exp Optom 2021; 91:251-64. [DOI: 10.1111/j.1444-0938.2008.00246.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Rae SM, Price HC. The effect of soft contact lens wear and time from blink on wavefront aberration measurement variation. Clin Exp Optom 2021; 92:274-82. [DOI: 10.1111/j.1444-0938.2009.00377.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Sheila M Rae
- Vision and Eye Research Unit, Anglia Ruskin University, Cambridge, United Kingdom
E‐mail:
| | - Holly C Price
- Vision and Eye Research Unit, Anglia Ruskin University, Cambridge, United Kingdom
E‐mail:
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13
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Downie LE, Lindsay RG. Contact lens management of keratoconus. Clin Exp Optom 2021; 98:299-311. [DOI: 10.1111/cxo.12300] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 03/30/2015] [Accepted: 04/04/2015] [Indexed: 11/29/2022] Open
Affiliation(s)
- Laura E Downie
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
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Atchison DA. Recent advances in measurement of monochromatic aberrations of human eyes. Clin Exp Optom 2021; 88:5-27. [PMID: 15658922 DOI: 10.1111/j.1444-0938.2005.tb06659.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2004] [Revised: 11/18/2004] [Accepted: 11/27/2004] [Indexed: 11/29/2022] Open
Abstract
The field of aberrations of the human eye is moving rapidly, being driven by the desire to monitor and optimise vision following refractive surgery. It is important for ophthalmologists and optometrists to have an understanding of the magnitude of various aberrations and how these are likely to be affected by refractive surgery and other corrections. In this paper, I consider methods used to measure aberrations, the magnitude of aberrations in general populations and how these are affected by various factors (for example, age, refractive error, accommodation and refractive surgery) and how aberrations and their correction affect spatial visual performance.
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Affiliation(s)
- David A Atchison
- School of Optometry, Queensland University of Technology, Kelvin Grove, QLD 4059, Australia
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Richdale K, Cox I, Kollbaum P, Bullimore MA, Bakaraju RC, Gifford P, Plainis S, McKenney C, Newman S, Tomiyama ES, Morgan PB. CLEAR – Contact lens optics. Cont Lens Anterior Eye 2021; 44:220-239. [DOI: 10.1016/j.clae.2021.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 02/01/2021] [Indexed: 12/27/2022]
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16
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Corneal aberrations measured with a high-resolution Scheimpflug tomographer: repeatability and reproducibility. J Cataract Refract Surg 2021; 46:581-590. [PMID: 32050208 DOI: 10.1097/j.jcrs.0000000000000084] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the precision of elevation and wavefront aberration measurements with the Pentacam HR (Oculus Optikgeräte GmbH). SETTING Flinders University, Australia. DESIGN Instrument evaluation study. METHODS A randomly selected eye of 100 participants was scanned twice with the Pentacam HR by 1 observer on the 3 measurement modes: 25-picture, 50-picture, and cornea fine. A second observer performed 2 scans on the same random eye with the 25-picture mode. Repeatability and reproducibility were assessed using the within-subject SD (Sw) statistic from a 1-way analysis of variance. RESULTS From the 100 scanned eyes, the higher-order aberration root mean square (RMS) repeatability limit for both elevation and wavefront, and anterior and posterior measurements was 0.03 μm for all 3 measurement modes. Anterior, posterior, and total corneal wavefront Zernike terms were highly precise, with most Zernike terms displaying a repeatability limit of 0.03 μm. The least repeatable measurement was the posterior elevation Zernike term with the 25-picture scan (repeatability limit 1.50 μm). The cornea fine measurement mode provided the most precise measurements. Reproducibility limits (second observer) were similar to repeatability limits with the 25-picture scan mode. CONCLUSIONS The Pentacam HR provided highly precise aberration outputs. The most precise measurements are achievable with the cornea fine measurement mode and wavefront aberrations. One should be cognizant of posterior elevation aberration precision, particularly for lower radial order and higher azimuthal frequency terms. Accounting for tilt and misalignment of aberrations, all RMS and Zernike aberrations were extremely precise (repeatability and reproducibility limit less than 0.000001 μm).
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Srujana D, Singh R, Titiyal JS, Sinha R. Assessment of posture-induced cyclotorsion during cataract surgery using the Verion image-guided system. Med J Armed Forces India 2020; 77:293-296. [PMID: 34305282 DOI: 10.1016/j.mjafi.2020.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 08/29/2020] [Indexed: 10/23/2022] Open
Abstract
Background The purpose of this prospective observational study is to analyse posture-induced cyclotorsion in eyes undergoing conventional phacoemulsification with toric intraocular lens (IOL) implantation and femtolaser-assisted cataract surgery (FLACS) using the Verion image-guided system. Methods Cyclotorsion was assessed in patients who underwent conventional phacoemulsification with toric IOL implantation and FLACS between June 2017 and November 2017 with registration of iris architecture, limbal and bulbar conjunctival blood vessels acquired preoperatively using the Verion Reference Unit (the patient in sitting position) and intraoperatively under the microscope using the digital marker of the Verion image-guided system with the patient in supine position. Results Forty-four eyes of 30 patients (21 men and 9 women) were included with the mean age of 56.5 ± 17.1 (range, 19-89; median, 62) years. The mean cyclotorsion induced by change in posture from sitting to supine position was 5.84 ± 3.25° (range, 1-17; median, 5). Overall, clockwise (CW) rotation (59.1%) was noted to be more common than counter clockwise (CCW) rotation (40.9%). Furthermore, CW rotation was more common in men than in women, and CCW rotation was significantly more common in women. Patients who underwent bilateral sequential cataract surgery show similar cyclorotation (CW or CCW) in both eyes more often than mixed rotation (85.7% vs 14.3%). Conclusion Significant cyclotorsion can occur in supine position during cataract surgery. Accurate assessment of the amount and direction of cyclotorsion aids in appropriate alignment of the toric IOL for optimal visual outcomes.
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Affiliation(s)
- Dubbaka Srujana
- Associate Professor, Dept of Ophthalmology, Armed Forces Medical College, Pune, India
| | - Reena Singh
- Senior Resident, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Jeewan S Titiyal
- Professor & HOD, Cornea, Lens & Refractive Surgery Services, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Rajesh Sinha
- Professor, Cornea, Lens & Refractive Surgery Services, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
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Nguyen LC, Hastings GD, Kauffman MJ, Applegate RA, Marsack JD. Alignment of a wavefront-guided scleral lens correction in the presence of a lens capsulotomy. Cont Lens Anterior Eye 2020; 43:613-616. [PMID: 32146116 DOI: 10.1016/j.clae.2020.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 12/13/2019] [Accepted: 02/12/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE To demonstrate the necessity of aligning a wavefront-guided scleral lens (WGSL) optical correction to the eye's effective pupil, with misalignments leading to reduced performance. CASE REPORT A 34 year old subject with a history of failed LASIK in the left eye, leading to penetrating keratoplasty, extracapsular extraction of the crystalline lens and neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy, enrolled in a study examining WGSL performance. Habitual logMAR acuity OS (aided with a scleral lens) was +0.04. Residual higher order root mean square (HORMS) wavefront error (WFE) was 0.28 μm (Φ =4.75 mm, mean age-matched norm =0.17 μm), and objective over-refraction was -0.30 -0.54 × 008. When a WGSL (targeting aberrations up to the 5 th radial order) was manufactured with the wavefront-guided optics aligned to the center of the dilated pupil, logMAR acuity worsened to +0.15, residual HORMS WFE worsened to 0.44 μm (Φ =4.75 mm), and objective over-refraction increased to +1.19 -0.30 × 122. Slit lamp imagery revealed that the effective pupil was no longer defined by the iris of the eye, but rather the capsular opening created by the capsulotomy. When the WGSL was redesigned to align the wavefront-guided optics to the center of the capsular opening, logMAR acuity improved to -0.14, residual HORMS WFE reduced to 0.17 μm (Φ =4.75 mm) and objective over-refraction reduced to +0.20 -0.15 × 111. CONCLUSION WGSLs are an emerging option for patients with highly aberrated, ectatic and post-surgical corneas whose visual symptoms cannot be alleviated with conventional corrections. However, alignment of the optics of the WGSL to the underlying optics of the eye over the effective pupil is critical in achieving good optical and visual performance.
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Affiliation(s)
- Lan Chi Nguyen
- Visual Optics Institute, College of Optometry, University of Houston, 4901 Calhoun Rd, Houston, TX 77204 USA.
| | - Gareth D Hastings
- Visual Optics Institute, College of Optometry, University of Houston, 4901 Calhoun Rd, Houston, TX 77204 USA.
| | - Matthew J Kauffman
- Visual Optics Institute, College of Optometry, University of Houston, 4901 Calhoun Rd, Houston, TX 77204 USA.
| | - Raymond A Applegate
- Visual Optics Institute, College of Optometry, University of Houston, 4901 Calhoun Rd, Houston, TX 77204 USA.
| | - Jason D Marsack
- Visual Optics Institute, College of Optometry, University of Houston, 4901 Calhoun Rd, Houston, TX 77204 USA.
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Hastings GD, Zanayed JZ, Nguyen LC, Applegate RA, Marsack JD. Do Polymer Coatings Change the Aberrations of Conventional and Wavefront-guided Scleral Lenses? Optom Vis Sci 2020; 97:28-35. [PMID: 31895275 PMCID: PMC7004490 DOI: 10.1097/opx.0000000000001462] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE The findings of this study indicate that patients could simultaneously be offered the individualized optical correction of wavefront-guided (WFG) lenses and the superior comfort afforded by polymer coatings. This could be helpful to patients with ectasia suffering ocular dryness or dependent on scleral lenses for lengthy periods of wear. PURPOSE Wavefront-guided scleral lenses target lower- and higher-order aberrations of individual eyes using submicrometer-level contours in the anterior lens surface. Hydrophilic polyethylene glycol (PEG) polymer coatings applied to lens surfaces improve comfort and wettability. This study aimed to quantify aberration changes (e.g., masking) when applying polymer coatings to WFG and conventional scleral lenses. METHODS Two control lenses (remained uncoated) and 14 experimental lenses (two repeated builds of seven aberration designs: one spherical, two coma, four full WFG [second- to fifth-order aberrations]) were manufactured, and aberrations were measured (mean of three) by two operators before and after coating. Root mean square (RMS) and visual image quality (logVSX) differences were calculated for 6-mm diameters. RESULTS Median RMS aberration change due to coating was 0.012 μm (range, 0.008 to 0.057 μm). Maximum logVSX change due to coating was 0.073, predicting an approximately one letter change in acuity. Instrument sensitivity was 0.002 μm. Acute instrument and operator variabilities (standard deviations of individual [second- to fifth-order Zernikes] were all <0.027 μm). Longitudinal variability (control lenses) was low: all less than 0.017 μm. Although RMS of differences between repeated builds of all lenses was less than 0.25 D and not statistically significant, relatively, manufacture constituted the major variability, and RMS difference between repeated builds was at least four times greater than the effect of coating (median, 0.167 μm; range, 0.088 to 0.312 μm). CONCLUSIONS Application of polymer coatings caused measurable changes in aberrations of WFG and conventional scleral lenses; however, these were clinically and statistically insignificant and within variability of repeated lens manufacture. In their current states, WFG lenses and polymer coatings could be used simultaneously.
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Affiliation(s)
| | | | - Lan Chi Nguyen
- Visual Optics Institute, College of Optometry, University of Houston, Houston, Texas
| | - Raymond A Applegate
- Visual Optics Institute, College of Optometry, University of Houston, Houston, Texas
| | - Jason D Marsack
- Visual Optics Institute, College of Optometry, University of Houston, Houston, Texas
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Comparison of Wavefront-guided and Best Conventional Scleral Lenses after Habituation in Eyes with Corneal Ectasia. Optom Vis Sci 2019; 96:238-247. [PMID: 30943184 DOI: 10.1097/opx.0000000000001365] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SIGNIFICANCE Visual performance with wavefront-guided (WFG) contact lenses has only been reported immediately after manufacture without time for habituation, and comparison has only been made with clinically unrefined predicate conventional lenses. We present comparisons of habitual corrections, best conventional scleral lenses, and WFG scleral lenses after habituation to all corrections. PURPOSE The purpose of this study was to compare, in a crossover design, optical and visual performance of eyes with corneal ectasias wearing dispensed best conventional scleral lens corrections and dispensed individualized WFG scleral lens corrections. METHODS Ten subjects (20 eyes) participated in a randomized crossover study where best conventional scleral lenses and WFG scleral lenses (customized through the fifth radial order) were worn for 8 weeks each. These corrections, as well as each subject's habitual correction and normative data for normal eyes, were compared using (1) residual higher-order aberrations (HORMS), (2) visual acuity (VA), (3) letter contrast sensitivity (CS), and (4) visual image quality (logarithm of the visual Strehl ratio, or logVSX). Correlations were performed between Pentacam biometric measures and gains provided by WFG lenses. RESULTS Mean HORMS was reduced by 48% from habitual to conventional and 43% from conventional to WFG. Mean logMAR VA improved from habitual (+0.12) to conventional (-0.03) and further with WFG (-0.09); six eyes gained greater than one line with WFG over conventional. Area under the CS curve improved by 26% from habitual to conventional and 14% from conventional to WFG. The percentage of the eyes achieving normal levels were as follows: HORMS, 40% for conventional and 85% for WFG; VA, 50% for conventional and 85% for WFG; and CS, 60% for conventional and 90% for WFG. logVSX improved by 16% from habitual to conventional and 25% further with WFG. Reduction in aberrations with WFG lenses best correlated with posterior cornea radius of curvature. CONCLUSIONS Visual performance was superior to that reported with nonhabituated WFG lens wear. With WFG lenses, HORMS and logVSX significantly improved, allowing more eyes to reach normal levels of optical and visual performance compared with conventional lenses.
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Yang W, Liu S, Li M, Shen Y, Zhou X. Visual Outcomes after Small Incision Lenticule Extraction and Femtosecond Laser-Assisted LASIK for High Myopia. Ophthalmic Res 2019; 63:427-433. [PMID: 31805561 DOI: 10.1159/000504304] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/22/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE The aim of this study was to compare visual outcomes after small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) for high myopia. METHODS In this prospective, comparative study, a total of 52 eyes of 34 consecutive highly myopic patients with spherical equivalent within the range of -8.00 to -10.00 diopters were recruited. Twenty-three eyes of 16 patients were in the FS-LASIK group and 29 eyes of 18 patients were in the SMILE group. Visual outcomes and wavefront aberrations were analyzed preoperatively and 6 months postoperatively. RESULTS At the postoperative 6-month visit, 96.6% in the SMILE group and 91.3% in the FS-LASIK group achieved unchanged or better corrected distance visual acuity (CDVA). As for uncorrected distance visual acuity (UDVA), 96.6% in the SMILE group and 95.7% in the FS-LASIK group achieved UDVA of 20/20 or better. As for wavefront aberrations, high-order aberrations (HOAs) and spherical aberrations increased significantly after surgery in both groups relative to corresponding preoperative values (p < 0.001), and vertical coma increased after SMILE (p < 0.001). No statistically significant differences in changes of HOAs (p =0.90), spherical aberrations (p = 0.07), horizontal coma (p = 0.56), coma (p =0.08), horizontal trefoil (p =0.19), vertical trefoil (p = 0.90), and trefoil (p = 0.45) were detected between the 2 groups, except for vertical coma (p < 0.01). CONCLUSIONS SMILE is as effective as FS-LASIK in correcting high myopia, but attention should be paid to the induction of vertical coma in highly myopic patients following a SMILE procedure.
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Affiliation(s)
- Weiming Yang
- Department of Ophthalmology and Optometry, Children's Hospital of Fudan University, Shanghai, China
| | - Shengtao Liu
- Jiangxi Research Institute of Ophthalmology and Visual Sciences, Department of Affiliated Eye Hospital of Nanchang University, Nanchang, China
| | - Meiyan Li
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China, .,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China, .,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China,
| | - Yang Shen
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
| | - Xingtao Zhou
- Department of Ophthalmology and Optometry, Eye and ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Fudan University, Shanghai, China.,Shanghai Research Center of Ophthalmology and Optometry, Shanghai, China
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Vincent SJ, Fadel D. Optical considerations for scleral contact lenses: A review. Cont Lens Anterior Eye 2019; 42:598-613. [DOI: 10.1016/j.clae.2019.04.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/24/2019] [Accepted: 04/25/2019] [Indexed: 01/07/2023]
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Kollbaum PS, Bradley A. Correction of presbyopia: old problems with old (and new) solutions. Clin Exp Optom 2019; 103:21-30. [PMID: 31734940 DOI: 10.1111/cxo.12987] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/05/2019] [Accepted: 09/20/2019] [Indexed: 12/23/2022] Open
Abstract
We live in a three-dimensional world and the human eye can focus images from a wide range of distances by adjusting the power of the eye's lens (accommodation). Progressive senescent changes in the lens ultimately lead to a complete loss of this ability by about age 50, which then requires alternative strategies to generate high-quality retinal images for far and close viewing distances. This review paper highlights the biomimetic properties and underlying optical mechanisms of induced anisometropia, small apertures, dynamic lenses, and multi-optic lenses in ameliorating the visual consequences of presbyopia. Specifically, the advantages and consequences of non-liner neural summation leveraged in monovision treatments are reviewed. Additionally, the value of a small pupil is quantified, and the impact of pinhole pupil location and their effects on neural sensitivity are examined. Different strategies of generating multifocal optics are also examined, and specifically the interaction between ocular and contact or intraocular lens aberrations and their effect on resulting image quality are simulated. Interestingly, most of the novel strategies for aiding presbyopic and pseudophakic eyes (for example, monovision, multifocality, pinhole pupils) have emerged naturally via evolution in a range of species.
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Affiliation(s)
- Pete S Kollbaum
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Arthur Bradley
- School of Optometry, Indiana University, Bloomington, Indiana, USA
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Ozulken K, Ilhan C. Effects of Cyclotorsion Orientation and Magnitude in Eyes with Compound Myopic Astigmatism on the Compensation Capacity of WaveLight EX500 Photorefractive Keratectomy. KOREAN JOURNAL OF OPHTHALMOLOGY 2019; 33:458-466. [PMID: 31612657 PMCID: PMC6791944 DOI: 10.3341/kjo.2019.0042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/01/2019] [Accepted: 08/08/2019] [Indexed: 11/23/2022] Open
Abstract
Purpose To investigate the clinical effects of different orientation and magnitude of cyclotorsion on the compensation capacity of the WaveLight EX500 photorefractive keratectomy (PRK) platform. Methods This retrospective study comprised 400 eyes of 200 patients who underwent bilateral simultaneous PRK due to compound myopic astigmatism. The subjects were separated according to the orientation of cyclotorsion into incyclotorsion and excyclotorsion groups, and by the magnitude of cyclotorsion into group 1 (0.50 to 2.50 degrees), group 2 (3.00 to 5.00 degrees), group 3 (5.50 to 7.50 degrees), and group 4 (8.00 to 9.50 degrees). Results The mean magnitude of cyclotorsion was 3.50 ± 2.4 degrees (0.50 to 9.50 degrees) in the incyclotorsion group and 3.32 ± 2.3 degrees (0.50 to 9.50 degrees) in the excyclotorsion group (p = 0.617). The postoperative refractive outcomes of the incyclotorsion and excyclotorsion groups were similar (p > 0.05 for all). The postoperative mean cylindrical refractive error was −0.32 ± 0.3 diopters (D, −1.25 to 0.00 D) in group 1, −0.47 ± 0.2 D (−2.00 to 0.00 D) in group 2, −0.62 ± 0.2 D (−1.00 to −0.25 D) in group 3, and −0.91 ± 0.2 D (−1.50 to −0.50 D) in group 4 (p < 0.001). Preoperative cylindrical refractive error was positively correlated with magnitude of cyclotorsion (r = 0.125 and p = 0.013), which was also positively correlated with postoperative cylindrical refractive error (r = 0.600 and p < 0.001). Conclusions Incyclotorsion and excyclotorsion can be equally compensable in the WaveLight EX500 PRK platform for compound myopic astigmatism. A value of ≤2.50 degrees cyclotorsion magnitude was observed to be more compensable than higher degrees of cyclotorsion magnitude. Preoperative high astigmatism was associated with high cyclotorsion magnitude, which was also associated with a high degree of postoperative astigmatism.
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Affiliation(s)
- Kemal Ozulken
- Department of Ophthalmology, TOBB ETU Hospital, Ankara, Turkey
| | - Cagri Ilhan
- Department of Ophthalmology, Hatay State Hospital, Hatay, Turkey.
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25
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Jinabhai AN. Customised aberration-controlling corrections for keratoconic patients using contact lenses. Clin Exp Optom 2019; 103:31-43. [PMID: 31264266 DOI: 10.1111/cxo.12937] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/20/2019] [Accepted: 05/23/2019] [Indexed: 12/12/2022] Open
Abstract
Technological advancements in the design of soft and scleral contact lenses have led to the development of customised, aberration-controlling corrections for patients with keratoconus. As the number of contact lens manufacturers producing wavefront-guided corrections continues to expand, clinical interest in this customisable technology is also increasing among both patients and practitioners. This review outlines key issues surrounding the measurement of ocular aberrations for patients with keratoconus, with a particular focus on the possible factors affecting the repeatability of Hartmann-Shack aberrometry measurements. This review also discusses and compares the relative successes of studies investigating the design and fitting of soft and scleral customised contact lenses for patients with keratoconus. A series of key limitations that should be considered before designing customised contact lens corrections is also described. Despite the challenges of producing and fitting customised lenses, improvements in visual performance and comfortable wearing times, as provided by these lenses, could help to reduce the rate of keratoplasty in keratoconic patients, thereby significantly reducing clinical issues related to corneal graft surgery. Furthermore, enhancements in optical correction, provided by customised lenses, could lead to increased independence, particularly among young adult keratoconic patients, therefore leading to improvements in quality of life.
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Affiliation(s)
- Amit Navin Jinabhai
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology Medicine and Health, The University of Manchester, Manchester, UK
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Plaza-Puche AB, Salerno LC, Versaci F, Romero D, Alio JL. Clinical evaluation of the repeatability of ocular aberrometry obtained with a new pyramid wavefront sensor. Eur J Ophthalmol 2018; 29:585-592. [PMID: 30516061 DOI: 10.1177/1120672118816060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To evaluate the intrasubject repeatability of the ocular aberrometry obtained with a new ocular pyramidal aberrometer technology in a sample of normal eyes. METHODS A total of 53 healthy eyes of 53 subjects with ages ranging from 18 to 45 years were included in this study. In all cases, three consecutive acquisitions were obtained. Intrasubject repeatability of the measurements with a pyramidal aberrometer was calculated. Intrasubject repeatability for 4.0- and 6.0-mm pupils was evaluated within the subject standard deviation (Sw) and intraclass correlation coefficient. RESULTS Low values of the Sw and intraclass correlation coefficient outcomes close to 1 were observed for the sphere and cylinder at 3.0-mm pupil size. Most low Sw and intraclass correlation coefficient values close to 1 were observed for total, low-order aberrations and higher-order aberrations root mean square and for each Zernike coefficient analysis (intraclass correlation coefficient ⩾0.798) at 4.0-mm pupil size, with more limited outcomes for the aberrometric coefficient of Z(4, 4) with an intraclass correlation coefficient of 0.683. For a 6.0 mm pupil diameter, low Sw and intraclass correlation coefficient values close to 1 were observed for all aberrometric parameters or Zernike coefficients analyzed (intraclass correlation coefficient ⩾0.850). CONCLUSION The new pyramidal aberrometer Osiris provides repeatable and consistent measurements of ocular aberrometry measurements in normal eyes.
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Affiliation(s)
| | | | - Francesco Versaci
- R&D Department, Costruzione Strumenti Oftalmici (CSO), Florence, Italy
| | - Daniel Romero
- Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain
| | - Jorge L Alio
- Vissum, Alicante, Spain.,Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain
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Li L, Zhang B, Xu Y, Wang D. Analytical method for the transformation of Zernike polynomial coefficients for scaled, rotated, and translated pupils. APPLIED OPTICS 2018; 57:F22-F30. [PMID: 30645277 DOI: 10.1364/ao.57.000f22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 08/01/2018] [Indexed: 06/09/2023]
Abstract
Zernike polynomials provide an excellent metric basis for characterizing the wavefront aberrations of human eyes and optical systems. Since the Zernike expansion is dependent on the size, position, and orientation of the pupil in which the function is defined, it is often necessary to transform the Zernike coefficients between different pupils. An analytic method of transforming the Zernike coefficients for scaled, rotated, and translated pupils is proposed in this paper. The normalized coordinate transformation functions between the polar coordinates of the transformed pupil and the Cartesian coordinates of the original pupil are given. Based on the Cartesian and polar representations of Zernike polynomials, the coefficients' transformation matrix can be derived directly and conveniently. The first 36 terms of standard Zernike polynomials are used to validate the proposed method. For different types of transformation, transformation rules of individual Zernike terms are systematically analyzed, revealing how individual terms of the original pupil transform into terms of the transformed pupil. Numerical examples are presented to demonstrate the validity of the proposed method. Further application of the proposed method to the alignment of pupil-decentered off-axis optical systems is discussed.
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Coughlan MF, Goncharov AV. Nonpupil adaptive optics for visual simulation of a customized contact lens. APPLIED OPTICS 2018; 57:E57-E63. [PMID: 30117922 DOI: 10.1364/ao.57.000e57] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 05/21/2018] [Indexed: 06/08/2023]
Abstract
We present a method for determining the deformable mirror profile to simulate the optical effect of a customized contact lens in the central visual field. Using nonpupil-conjugated adaptive optics allows a wider field simulation compared to traditional pupil-conjugated adaptive optics. For a given contact lens, the mirror shape can be derived analytically using Fermat's principle of the stationary optical path or numerically using optimization in ray-tracing programs. An example of an aspheric contact lens simulation is given to illustrate the method, and the effect of eye misalignment with respect to the deformable mirror position is investigated. The optimal deformable mirror conjugation position is found to be near the posterior corneal surface. Chromatic aberration analysis is also presented, and our findings indicate that the polychromatic simulation quality is similar to that of the monochromatic case, even though the mirror is a reflective component. The limitations of a single continuous surface deformable mirror to mimic a contact lens are outlined, with some recommendations for improving the quality of simulation.
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Abstract
PURPOSE To analyze the variation in vertical coma and the rest of ocular aberrations before and after fitting prismatic soft contact lenses (PSCL). METHODS Thirty-seven eyes of 20 healthy subjects (24.30±2.03 years) were evaluated to analyze the variation in ocular wavefront aberrations before and after fitting PSCL of different base-down prism values (1.0, 1.5, and 2.0 prism diopters [PD]), designed to study its influence in the compensation of vertical coma aberration. A Hartmann-Shack sensor with a wavelength of 780 nm was used, considering a pupil size of 3 mm. In addition, the influence of PSCL in visual function under photopic conditions in terms of high-contrast visual acuity and contrast sensitivity was evaluated. RESULTS There was statistically significant differences (P<0.05) in ocular aberrations from first to seventh order after fitting PSCL, but only the differences in vertical tilt, horizontal tilt, defocus, vertical astigmatism, and vertical coma were clinically relevant (Strehl ratio <0.8). The mean of vertical coma (μm) was 0.022±0.030 for control, 0.045±0.064 for 1.0 PD (P=0.645), 0.048±0.053 for 1.5 PD (P=0.037), and 0.074±0.047 for 2.0 PD (P<0.001). The changes in visual function under photopic conditions were not clinically relevant. CONCLUSIONS PSCL induce a magnitude of vertical coma aberration directly proportional to prism value without affecting the rest of ocular high-order aberrations.
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Alipour F, Veisi Hampa F, Ashrafi E, Dehghani S. Factors Influencing Cyclotorsion During Photorefractive Keratectomy. J Refract Surg 2018; 34:106-112. [PMID: 29425389 DOI: 10.3928/1081597x-20171128-02] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 11/09/2017] [Indexed: 11/20/2022]
Abstract
PURPOSE To determine predictive factors for intra-operative cyclotorsion in photorefractive keratectomy (PRK). METHODS A retrospective statistical analysis of medical records pertaining to 3,996 eyes undergoing PRK was conducted. Outcome measures of this study were the likely existence of statistically significant relations between diverse and potentially influential factors and the occurrence of intraoperative cyclotorsion. RESULTS A total of 96% of examined medical records indicated some degree of cyclotorsion with the absolute mean intraoperative value of 1.38° ± 1.67° (range: 0° to 13.6°). Absolute mean cyclotorsion showed no significant correlation with age (r = 0.14, P = .37). Female patients had significantly higher degrees of cyclotorsion versus males (P < .001). Right and left eyes showed no significant difference in absolute mean torsion (P = .05). Higher diopters of refractive errors, hyperopia, more than 2.00 diopters of cylinder, high pulse numbers (r = 0.26), and use of the advanced personalized treatment ablation algorithm were all significantly related to higher degrees of torsion (P < .0001). Ablation depth (r = 0.13) and surgeon appeared to be dependent factors. CONCLUSIONS Incidence of intraoperative cyclotorsion is high in eyes undergoing PRK and most of them will experience some degree of torsion. Several diverse factors (sex, refractive error diopters, hyperopia, high cylinder, pulse numbers, and ablation algorithm) were significant predictors for higher degrees of the observed torsion. [J Refract Surg. 2018;34(2):106-112.].
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Altoaimi BH, Kollbaum P, Meyer D, Bradley A. Experimental investigation of accommodation in eyes fit with multifocal contact lenses using a clinical auto-refractor. Ophthalmic Physiol Opt 2018; 38:152-163. [DOI: 10.1111/opo.12438] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 12/06/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Basal H. Altoaimi
- School of Optometry; Indiana University; Bloomington USA
- Department of Optometry; College of Applied Medical Sciences; King Saud University; Riyadh Saudi Arabia
| | - Pete Kollbaum
- School of Optometry; Indiana University; Bloomington USA
| | - Dawn Meyer
- School of Optometry; Indiana University; Bloomington USA
| | - Arthur Bradley
- School of Optometry; Indiana University; Bloomington USA
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Accommodative Behavior of Eyes Wearing Aspheric Single Vision Contact Lenses. Optom Vis Sci 2017; 94:971-980. [DOI: 10.1097/opx.0000000000001121] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Kaya A, Keçeli AS, Can AB, Çakmak HB. Cyclotorsion measurement using scleral blood vessels. Comput Biol Med 2017; 87:152-161. [PMID: 28595130 DOI: 10.1016/j.compbiomed.2017.05.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 05/29/2017] [Accepted: 05/29/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND AND OBJECTIVES Measurements of the cyclotorsional movement of the eye are crucial in refractive surgery procedures. The planned surgery pattern may vary substantially during an operation because of the position and eye movements of the patient. Since these factors affect the outcome of an operation, eye registration methods are applied in order to compensate for errors. While the majority of applications are based on features of the iris, we propose a registration method which uses scleral blood vessels. Unlike previous offline techniques, the proposed method is applicable during surgery. METHODS The sensitivity of the proposed registration method is tested on an artificial benchmark dataset involving five eye models and 46,305 instances of eye images. The cyclotorsion angles of the dataset vary between -10° and +10° at 1° intervals. Repeated measurements and ANOVA and Cochran's Q tests are applied in order to determine the significance of the proposed method. Additionally, a pilot study is carried out using data obtained from a commercially available device. The real data are validated using manual marking by an expert. RESULTS AND CONCLUSIONS The results confirm that the proposed method produces a smaller error rate (mean = 0.44 ± 0.41) compared to the existing method in [1] (mean = 0.64 ± 0.58). A further conclusion is that feature extraction algorithms affect the results of the proposed method. The SIFT (mean = 0.74 ± 0.78), SURF64 (mean = 0.56 ± 0.46), SURF128 (mean = 0.57 ± 0.48) and ASIFT (mean = 0.29 ± 0.25) feature extraction algorithms were examined; the ASIFT method was the most successful of these algorithms. Scleral blood vessels are observed to be useful as a feature extraction region due to their textural properties.
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Affiliation(s)
- Aydın Kaya
- Hacettepe University, Faculty of Engineering, Department of Computer Engineering, 06800, Ankara, Turkey.
| | - Ali Seydi Keçeli
- Hacettepe University, Faculty of Engineering, Department of Computer Engineering, 06800, Ankara, Turkey.
| | - Ahmet Burak Can
- Hacettepe University, Faculty of Engineering, Department of Computer Engineering, 06800, Ankara, Turkey.
| | - Hasan Basri Çakmak
- Hitit University, Faculty of Medicine, Department of Ophthalmology, 19030, Çorum, Turkey.
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Ortiz-Toquero S, Rodriguez G, de Juan V, Martin R. Repeatability of Wavefront Aberration Measurements With a Placido-Based Topographer in Normal and Keratoconic Eyes. J Refract Surg 2017; 32:338-44. [PMID: 27163620 DOI: 10.3928/1081597x-20160121-04] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 12/03/2015] [Indexed: 12/26/2022]
Abstract
PURPOSE To determine and compare the repeatability of anterior corneal higher order aberrations (HOAs) using a Placido-based topographer (Allegro Topolyzer; WaveLight Technologie AG, Alcon Laboratories, Erlangen, Germany) in a sample of normal and keratoconic eyes. METHODS Three repeated measurements of each cornea of normal and keratoconic eyes were taken with the Allegro Topolyzer. Repeatability of the HOAs (3rd- and 4th-order individual values and normalized polar Zernike coefficients, coma-like, root mean square (RMS) up to 8th-order values, HOA RMS, and total RMS for 6-mm pupil diameter) and central corneal power (3-mm pupil) were analyzed. Within-subject standard deviation (Sw), precision, repeatability, coefficient of variation (CV), and the intraclass correlation coefficient (ICC) were calculated. RESULTS Zernike coefficients were significantly different between the normal (36 eyes of 36 patients) and keratoconus (36 eyes of 36 patients) groups (P ≤ .03) except in Z(+1) 3, Z(+3) 3, Z(-4) 4, and Z(+4) 4. In the normal group, Sw was 0.031 µm or less, CV ranged from 6.49% (spherical aberration) to 37.18% (secondary astigmatism), and ICC values ranged from 0.227 to 0.982. In the keratoconus group, Sw was 0.059 µm or less, CV ranged from 2.06% (total RMS) to 25.82% (tetrafoil), and ICC values ranged from 0.839 to 0.996. In analyzing the keratoconus stages (Amsler-Krumeich classification), the repeatability of the Zernike coefficients tended to improve with increasing keratoconus stage. CONCLUSIONS The repeatability of corneal wavefront aberration provided by the Allegro Topolyzer was better in keratoconic eyes (good and moderate repeatability) than in normal eyes (moderate and poor repeatability). These results are important to eye care practitioners and refractive surgeons during refractive surgery planning or keratoconus detection, classification, and management. [J Refract Surg. 2016;32(5):338-344.].
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Chen X, Wang Y, Zhang J, Yang SN, Li X, Zhang L. Comparison of ocular higher-order aberrations after SMILE and Wavefront-guided Femtosecond LASIK for myopia. BMC Ophthalmol 2017; 17:42. [PMID: 28388896 PMCID: PMC5384151 DOI: 10.1186/s12886-017-0431-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 03/31/2017] [Indexed: 11/17/2022] Open
Abstract
Background To compare changes in higher-order aberrations (HOAs) following small incision lenticule extraction (SMILE) and wavefront-guided femtosecond laser-assisted in situ keratomileusis (WFG FS-LASIK), and to investigate correlations between preoperative spherical equivalence (SE) and components of HOAs affecting visual quality. Methods Sixty-five myopic eyes from 38 patients were enrolled in the study retrospectively, either having undergone SMILE or WFG FS-LASIK. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, and individual Zernike coefficients of 3rd- to 6th-order HOAs were measured before and 3 months after the surgeries and were compared using the Mann-Whitney test or Student’s t-test. Additional generalized estimating equation analyses (GEE) were used to control for within-subject biases in individual Zernike coefficients between the right and left eyes of the same patients. Results There was no significant difference in UDVA or CDVA after WFG FS-LASIK (Mean ± SD: −0.02 ± 0.07 and −0.04 ± 0.22 respectively, in logMAR) and after SMILE (−0.01 ± 0.06 and −0.04 ± 0.04 respectively). However, greater vertical coma aberration was found after SMILE (p = 0.036). Preoperative SE was correlated to induced horizontal coma (r = −0.608, p = 0.001) in WFG FS-LASIK, and correlated to induced vertical coma (r = −0.459, p = 0.003) in SMILE. Conclusions Both SMILE and WFG FS-LASIK can achieve planned visual outcomes in correcting myopia and myopic astigmatism. However, higher vertical coma was shown in SMILE than WFG FS-LASIK which might be a potentially impact factor for patients’ vision under certain lighting conditions and needs further investigation.
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Affiliation(s)
- Xiaoqin Chen
- Tianjin Eye Hospital & Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Medical University, No 4. Gansu Rd, Heping District, Tianjin, 300020, China
| | - Yan Wang
- Tianjin Eye Hospital & Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Medical University, No 4. Gansu Rd, Heping District, Tianjin, 300020, China.
| | - Jiamei Zhang
- Tianjin Eye Hospital & Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Medical University, No 4. Gansu Rd, Heping District, Tianjin, 300020, China
| | - Shun-Nan Yang
- Vision Performance Institute, Pacific University College of Optometry, Forest Grove, OR, USA
| | - Xiaojing Li
- First Hospital of Qinhuangdao, Qinhuangdao, Hebei, China
| | - Lin Zhang
- Tianjin Eye Hospital & Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin Medical University, No 4. Gansu Rd, Heping District, Tianjin, 300020, China
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Piao J, Li YJ, Whang WJ, Choi M, Kang MJ, Lee JH, Yoon G, Joo CK. Comparative evaluation of visual outcomes and corneal asphericity after laser-assisted in situ keratomileusis with the six-dimension Amaris excimer laser system. PLoS One 2017; 12:e0171851. [PMID: 28187180 PMCID: PMC5302827 DOI: 10.1371/journal.pone.0171851] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 01/26/2017] [Indexed: 11/25/2022] Open
Abstract
Purpose To compare the visual and refractive outcomes after laser-assisted in situ keratomileusis (LASIK) surgery for correction of myopia or myopic astigmatism using a six-dimensional Amaris excimer laser. Methods In this retrospective cohort study, we enrolled 47 eyes of 28 patients (age: 19–36 years) with myopia or myopic astigmatism. We used the Custom Ablation Manager protocol and performed ablations with the SCHWIND AMARIS system. LASIK flaps were cut with an iFS Advanced Femtosecond Laser. Mean static (SCC) and dynamic cyclotorsion (DCC) were evaluated. Visual and refractive outcomes were evaluated during 6 months’ follow-up. Corneal asphericity (Q-value) was analyzed at 4 months postoperatively. Results The spherical equivalent (SE) reduction was statistically significant reduce 1 day after refractive surgery (P < 0.001), with no additional significant changes during follow-up (P = 0.854). SCC registration rates were 81% in the Aberration-Free mode (AF) and 90% in the Corneal Wavefront mode (CW). SCC measurements were within ± 5 degrees in 57% (AF) and 68% (CW) of eyes. Mean DCC was within ± 1 degree in 96% (AF) or 95% (CW) of cases. At 6 months, the uncorrected distance visual acuity was 20/25 or better in all eyes. At last follow-up, both steep and flat keratometry values had significantly flattened in both groups (P < 0.001). Corneal asphericity also increased significantly during the postoperative period for an 8-mm corneal diameter (P < 0.001). Conclusions LASIK for myopia or myopic compound astigmatism correction using the six-dimensional AMARIS 750S excimer laser is safe, effective, and predictable. Postoperative corneal asphericity can be analyzed by linear regression to predict the changes in postoperative corneal asphericity with this approach.
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Affiliation(s)
- JunJie Piao
- Catholic Institute for Visual Science, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Ying-Jun Li
- Department of Ophthalmology, Affiliated Hospital, Yanbian University Medical College, Jilin, China
| | - Woong-Joo Whang
- Department of Ophthalmology, Catholic Institute for Visual Science, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Mihyun Choi
- Department of Ophthalmology, Catholic Institute for Visual Science, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Min Ji Kang
- Department of Ophthalmology, Catholic Institute for Visual Science, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Jee Hye Lee
- Department of Ophthalmology, Catholic Institute for Visual Science, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Geunyoung Yoon
- Flaum Eye Institute, Center for Visual Science, The Institute of Optics, University of Rochester, Rochester, New York, United States of America
| | - Choun-Ki Joo
- Department of Ophthalmology, Catholic Institute for Visual Science, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
- * E-mail:
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Sasse AC, Shajari M, Kohnen T. Influence of blurred vision, accommodation, and target laser settings on eye movements during LASIK. J Cataract Refract Surg 2016; 42:1424-1430. [PMID: 27839596 DOI: 10.1016/j.jcrs.2016.07.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 07/19/2016] [Accepted: 07/22/2016] [Indexed: 10/20/2022]
Abstract
PURPOSE To analyze the influence of blurred vision, accommodation, and target laser settings on eye movements during laser in situ keratomileusis (LASIK). SETTING Department of Ophthalmology, Goethe University, Frankfurt, Germany. DESIGN Prospective randomized study. METHODS Participants had simulated LASIK treatment. They were instructed to focus on the fixation light; the treatment laser was blocked, and all other settings were applied according to standard LASIK treatments. To simulate blurred vision a 0.0 diopter (D) soft contact lens received a 5.0 D myopia laser treatment and was then applied to the participant's eye. To diminish accommodation, a second lens that had a refraction of the patient's spherical equivalent, plus 3.0 D to compensate for accommodation, was used. There were 4 treatment modalities as follows: (1) blurred lens with target laser on, (2) blurred lens with target laser turned off, (3) +3.0 D lens with target laser on, and (4) +3.0 D lens with target laser turned off. Lateral and torsional eye movements were recorded. Fourier analysis was used to obtain temporal power spectra from dynamic eye movements. The Fn criterion was set as the frequency below which n% of eye movements in the cohort occurred (n = 95%, 80%, and 50%). RESULTS The study comprised 11 eyes of 11 participants. There was 1 significant difference between the eye movements based on measurement modalities. In 1 variable in the y-axis, there was movement that showed a significant difference in the F80 criterion. CONCLUSION Surgical circumstances such as blurred vision, accommodation, and target light had little influence on eye movements during LASIK. FINANCIAL DISCLOSURE Proprietary or commercial disclosures are listed after the references.
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Affiliation(s)
- Anna Christina Sasse
- From the Department of Ophthalmology, Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Mehdi Shajari
- From the Department of Ophthalmology, Goethe-University Frankfurt am Main, Frankfurt, Germany
| | - Thomas Kohnen
- From the Department of Ophthalmology, Goethe-University Frankfurt am Main, Frankfurt, Germany.
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Abstract
PURPOSE To quantify on-eye rotational and translational stability of three scleral contact lens stabilization methods and to 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 8 eyes as the average SD of the observed translations and rotations over 60 min of wear. In addition, the predicted changes in acuity for five 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 3 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 with the loss of over 0.14 logMAR (7 letters) for the lens with the spherical periphery. CONCLUSION All three stabilization methods provided superior stability, as compared with the spherical lens design. Simulations of the optical and visual performance suggest that all three stabilization designs can provide desirable results when used in the delivery of a wavefront-guided correction for a highly aberrated eye.
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Moore DB, Fienup JR. Subaperture translation estimation accuracy in transverse translation diversity phase retrieval. APPLIED OPTICS 2016; 55:2526-2536. [PMID: 27139653 DOI: 10.1364/ao.55.002526] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
For optical metrology by transverse translation diversity phase retrieval (or ptychography), information theoretic limits on the ability to estimate subaperture translation, essential for accurate metrology, are assessed as a function of the optical aberrations of the system being measured. Special attention is given to the case that an unknown linear phase aberration, or equivalent detector or target motion, is present that varies with each point spread function in the measured data.
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Mosquera SA, Verma S. Effects of torsional movements in refractive procedures. J Cataract Refract Surg 2015; 41:1752-66. [DOI: 10.1016/j.jcrs.2015.07.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 01/13/2015] [Accepted: 01/14/2015] [Indexed: 11/26/2022]
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Abstract
PURPOSE To evaluate optical quality and internal aberrations in patients with diabetic macular edema. METHODS In this prospective study, 33 eyes of patients with diabetic macular edema were scanned with a ray-tracing wavefront device. As a control group, wavefront aberrometry was performed in 31 patients. Ocular and internal aberrations and visual quality metrics were evaluated separately to determine whether the source of aberrations was ocular or internal. Main outcome measures included corrected visual acuities, ocular and internal aberrations, Strehl ratio, and modulation transfer function. RESULTS There was a statistically significant difference between the groups in internal higher order (HO) root mean square (0.34 ± 0.24 vs. 0.16 ± 0.05), HO Strehl ratio (0.08 ± 0.05 vs. 0.18 ± 0.09), and modulation transfer function (0.29 ± 0.1 vs. 0.4 ± 0.1). There was no statistically significant difference in Strehl ratio and HO root mean square between phakic and pseudophakic patients. Height of cystoid spaces was a significant predictor (P < 0.001) of Strehl ratio. Besides inner and outer segment integrity, HO Strehl ratio significantly determined best-corrected visual acuity. CONCLUSION In eyes with macular edema, internal HO wavefront aberrations were greater than in control eyes. This increase in HO wavefront error seems visually relevant. This study results suggest increased intraretinal edema as the source of HO aberrations.
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Marsack JD, Ravikumar A, Nguyen C, Ticak A, Koenig DE, Elswick JD, Applegate RA. Wavefront-guided scleral lens correction in keratoconus. Optom Vis Sci 2015; 91:1221-30. [PMID: 24830371 DOI: 10.1097/opx.0000000000000275] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
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 seven 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 root mean square (RMS) (p < 0.001) and higher-order RMS (HORMS) (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 HORMS than the normal group (p = 0.41). Of the 14 eyes studied, 10 successfully reached the exit criteria, achieving residual HORMS wavefront error 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 keratoconic 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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Affiliation(s)
- Jason D Marsack
- *PhD †BS ‡MBA §OD, MS, FAAO ∥OD, PhD, FAAO University of Houston College of Optometry, Visual Optics Institute, Houston, Texas (all authors)
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Arba Mosquera S, Verma S, McAlinden C. Centration axis in refractive surgery. EYE AND VISION 2015; 2:4. [PMID: 26605360 PMCID: PMC4655455 DOI: 10.1186/s40662-015-0014-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 02/10/2015] [Indexed: 11/10/2022]
Abstract
The human eye is an asymmetric optical system and the real cornea is not a rotationally symmetrical volume. Each optical element in the eye has its own optical and neural axes. Defining the optimum center for laser ablation is difficult with many available approaches. We explain the various centration approaches (based on these reference axes) in refractive surgery and review their clinical outcomes. The line-of-sight (LOS) (the line joining the entrance pupil center with the fixation point) is often the recommended reference axis for representing wavefront aberrations of the whole eye (derived from the definition of chief ray in geometrical optics); however pupil centration can be unstable and change with the pupil size. The corneal vertex (CV) represents a stable preferable morphologic reference which is the best approximate for alignment to the visual axis. However, the corneal light reflex can be considered as non-constant, but dependent on the direction of gaze of the eye with respect to the light source. A compromise between the pupil and CV centered ablations is seen in the form of an asymmetric offset where the manifest refraction is referenced to the CV while the higher order aberrations are referenced to the pupil center. There is a need for a flexible choice of centration in excimer laser systems to design customized and non-customized treatments optimally.
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Affiliation(s)
- Samuel Arba Mosquera
- SCHWIND eye-tech-solutions, Kleinostheim, Germany ; Recognized Research Group in Optical Diagnostic Techniques, University of Valladolid, Valladolid, Spain ; Department of Ophthalmology and Sciences of Vision, University of Oviedo, Oviedo, Spain
| | | | - Colm McAlinden
- Flinders University, Adelaide, South Australia Australia ; Wenzhou Medical University, Wenzhou, Zhejiang China
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Soft contact lens fitting after intrastromal corneal ring segment implantation to treat keratoconus. Cont Lens Anterior Eye 2014; 37:377-81. [DOI: 10.1016/j.clae.2014.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 06/01/2014] [Accepted: 06/04/2014] [Indexed: 11/24/2022]
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Jinabhai A, O'Donnell C, Tromans C, Radhakrishnan H. Optical quality and visual performance with customised soft contact lenses for keratoconus. Ophthalmic Physiol Opt 2014; 34:528-39. [DOI: 10.1111/opo.12133] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 03/18/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Amit Jinabhai
- Faculty of Life Sciences; The University of Manchester; Manchester UK
| | - Clare O'Donnell
- Faculty of Life Sciences; The University of Manchester; Manchester UK
- Optegra Eye Sciences; Optegra Eye Hospital; Manchester UK
- School of Life and Health Sciences; Aston University; Birmingham UK
| | - Cindy Tromans
- Faculty of Life Sciences; The University of Manchester; Manchester UK
- Manchester Academic Health Science Centre; Central Manchester University Hospitals NHS Foundation Trust; Manchester UK
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Optical quality of aspheric toric intraocular lenses at different degrees of decentering. Graefes Arch Clin Exp Ophthalmol 2014; 252:969-75. [DOI: 10.1007/s00417-014-2629-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/04/2014] [Accepted: 03/28/2014] [Indexed: 01/19/2023] Open
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Abstract
PURPOSE The purpose of the current study was to examine the on- and off-eye optical performance of two types of soft contact lenses (hydrogel and silicone hydrogel). METHODS The monochromatic aberrations (λ = 850 nm) of contact lenses were measured on-eye using a clinical Shack-Hartmann ocular aberrometer. In addition, we used an off-eye single-pass contact lens aberrometer (λ = 540 nm) in which the soft contact lens was placed within a wet cell. Comparison of the lower and higher order aberrations measured with these two methods required compensation for different wavelengths and knowledge of the refractive index of the contact lens materials. RESULTS The measured on-eye sphere and spherical aberration values were generally similar to those measured off-eye and those specified by the lens manufacturers for both types of soft contact lenses. However, there were notable differences, especially for high plus-powered lenses, which typically exhibited lower sphere power on the eye than expected from the lens specifications and from the off-eye measured powers, both of which were almost identical. Longitudinal spherical aberration varied with lens power in the hydrogel lenses, as expected from geometric optics theory. Longitudinal spherical aberration measurements on- and off-eye, however, deviated significantly from that expected of a thin lens with spherical surfaces due to surface asphericities. The difference between on- and off-eye optics can be modeled as a tear lens or as relative lens thickness changes caused by lens flexure. CONCLUSIONS The results of the current study reveal that the major difference between the on-eye lens optics and the manufacturers' specifications is not due to lens errors but due to eye-lens interactions, which could be either lens flexure or a tear lens forming behind the soft contact lens.
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Sun W, Chen L, Tuya W, He Y, Zhu R. Analysis of the impacts of horizontal translation and scaling on wavefront approximation coefficients with rectangular pupils for Chebyshev and Legendre polynomials. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2013; 30:2539-2546. [PMID: 24323015 DOI: 10.1364/josaa.30.002539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Chebyshev and Legendre polynomials are frequently used in rectangular pupils for wavefront approximation. Ideally, the dataset completely fits with the polynomial basis, which provides the full-pupil approximation coefficients and the corresponding geometric aberrations. However, if there are horizontal translation and scaling, the terms in the original polynomials will become the linear combinations of the coefficients of the other terms. This paper introduces analytical expressions for two typical situations after translation and scaling. With a small translation, first-order Taylor expansion could be used to simplify the computation. Several representative terms could be selected as inputs to compute the coefficient changes before and after translation and scaling. Results show that the outcomes of the analytical solutions and the approximated values under discrete sampling are consistent. With the computation of a group of randomly generated coefficients, we contrasted the changes under different translation and scaling conditions. The larger ratios correlate the larger deviation from the approximated values to the original ones. Finally, we analyzed the peak-to-valley (PV) and root mean square (RMS) deviations from the uses of the first-order approximation and the direct expansion under different translation values. The results show that when the translation is less than 4%, the most deviated 5th term in the first-order 1D-Legendre expansion has a PV deviation less than 7% and an RMS deviation less than 2%. The analytical expressions and the computed results under discrete sampling given in this paper for the multiple typical function basis during translation and scaling in the rectangular areas could be applied in wavefront approximation and analysis.
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Abstract
PURPOSE To present a predictive model of the registration tolerance for wavefront-guided correction to maintain acuity within fixed limits and demonstrate the potential utility using two typical keratoconic eyes. METHODS Change in log visual Strehl was plotted as a function of translation error for a series of rotations of a wavefront-guided correction. Contour lines were added at Δlog visual Strehl levels predicted to induce one- and two-line losses of logMAR visual acuity. The model was validated by regressing measured acuity loss from subjects viewing acuity charts that were degraded by the residual wavefront error resulting from the movement of wavefront-guided correction against the model's predicted acuity. RESULTS The model's predicted change in acuity can be substituted for measured change in acuity (R² = 0.91) within measurement error (±0.1 logMAR). Translation and/or rotation of a wavefront-guided correction induced asymmetric optical tolerance to movement. Induced errors depended on the wavefront error being corrected, the wavefront-guided correction design, and the amount of registration error. CONCLUSIONS Change in log visual Strehl can be used to determine the registration tolerance necessary to keep the variation in acuity within user-defined limits. This tolerance is unique for each wavefront error and wavefront-guided correction design.
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