Dissertations / Theses on the topic 'Higher order aberration'
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Yi, Fan. "Wavefront aberrations and the depth of focus of the human eye." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/40939/1/Fan_Yi_Thesis.pdf.
Full textYi, Fan, and n/a. "Optimal Algorithmic Techniques of LASIK Procedures." Griffith University. School of Engineering, 2006. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20070216.152339.
Full textYi, Fan. "Optimal Algorithmic Techniques of LASIK Procedures." Thesis, Griffith University, 2006. http://hdl.handle.net/10072/368097.
Full textThesis (Masters)
Master of Philosophy (MPhil)
School of Engineering
Full Text
Jinabhai, Amit. "Higher-order aberrations in keratoconus." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/higherorder-aberrations-in-keratoconus(32fcb499-fd7a-4764-b723-f58ef1a22633).html.
Full textYoung, Laura Kate. "Ocular higher-order aberrations and visual performance." Thesis, Durham University, 2011. http://etheses.dur.ac.uk/3282/.
Full textTahir, Humza. "The impact of higher-order aberrations on orientation selectivity." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.493940.
Full textMcCullough, Sara. "Higher order ocular aberrations in children with Down's syndrome." Thesis, University of Ulster, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.589518.
Full textMishor, Gabriel. "Higher order aberrations and age-related cataract : a pre- and post- operative study." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/39687/.
Full textEsser, Gregor. "Derivation of analytical refraction, propagation and reflection equations for higher order aberrations of wavefronts." Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/125065.
Full textHampson, Karen Mary. "The higher-order aberrations of the human eye : connection with the pulse and effect on vision." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415452.
Full textSalmon, Anne. "Higher-order aberrations in amblyopia : an analysis of pre- and post-wavefront-guided laser refractive correction." Thesis, Aston University, 2015. http://publications.aston.ac.uk/25159/.
Full textBerner, Andrea [Verfasser], Herbert [Gutachter] Gross, Alois [Gutachter] Herkommer, and Burkhard [Gutachter] Fleck. "Theory and application of induced higher order color aberrations / Andrea Berner ; Gutachter: Herbert Gross, Alois Herkommer, Burkhard Fleck." Jena : Friedrich-Schiller-Universität Jena, 2020. http://d-nb.info/1213348803/34.
Full textHughes, Rohan Phillip John. "Ocular characteristics of non-myopic and myopic children during relaxed and active accommodation." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/205850/1/Rohan_Hughes_Thesis.pdf.
Full textMoy, Alexa J. "Effects of Computer Usage on Ocular Health." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/scripps_theses/394.
Full textSarkar, Samrat. "Blur adaptation with source and observer methods." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/103277/1/Samrat_Sarkar_Thesis.pdf.
Full textNixon, Alex D. "Visual Performance of Scleral and Soft Contact Lenses in Normal Eyes." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1397498763.
Full textChao, Christopher Chi Ying. "Modelling retinal photoreceptor directionality in the human eye." Thesis, Queensland University of Technology, 2002. https://eprints.qut.edu.au/36173/1/36173_Chao_2002.pdf.
Full textHsieh, Yi-Ting, and 謝易庭. "Higher-Order Aberration Changes of Corneal Surface after Laser Refractive Surgery and the Affecting Factors." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/60363855584004264051.
Full text國立臺灣大學
臨床醫學研究所
94
Laser refractive surgery is performed by using Ar-F excimer laser to disrupt the inter-molecular bonding of corneal tissue and ablate the cornea, thereby changing the curvature and refractive power of anterior corneal surface. However, as soon as the spherical and cylindrical refractive errors are corrected by laser, higher-order aberrations of anterior corneal surface also result. This is due to the irregular change of anterior corneal surface by wound healing process or the laser treatment itself. The surgical and mechanical techniques of laser refractive surgery have been processing during the past decade. Photorefractive keratectomy (PRK) was preformed in the past, whereas laser in situ keratomileusis (LASIK) is used most often at present time. The laser beams also evolve from broad beams to flying spots and mixed spots. Since the laser refractive surgery itself induces the higher order aberrations of anterior corneal surface, these different surgical techniques and machines attribute differently to the higher-order aberration (HOA). In this study, we calculate the HOAs of anterior corneal surface by computerized corneal topography and calculating software. We then analyze the affecting factors of HOA changes after surgery, including surgical techniques (PRK vs. LASIK), laser machines (Summit Apex Plus, Allegretto Wave, Bausch & Lomb Technolas 217z, and VISX S4), age, attempted sphere correction, attempted cylinder correction, optic zone size, and transitional zone size. Besides, we use questionnaires to evaluate the visual quality and the extent of satisfaction of patients, and analyze the relationships with corneal surface HOA changes. As the result shows, all HOAs increased significantly after surgery by various techniques and machines. LASIK induced more trivial HOAs (the 5th and 6th orders) after surgery than PRK did. The diopters of spherical equivalent corrected were highly correlated with surgical-induced HOA changes. Patients with older ages had less HOA changes. The larger the treatment zone sizes (including optic zones and transitional zones), the less the surgical-induced HOA changes. Some flying-spot machines induced less coma-like aberrations, while no obvious differences of spherical-like aberrations and total HOAs between broad-beam machines and flying-spot ones were noted. The visual quality and the extent of satisfaction of patients correlated most strongly with spherical-like aberrations, then with total HOAs, and then with coma-like aberrations. In the future, we can try to improve the surgical techniques and the preciseness of laser machines according to these results. We hope our efforts can contribute to more perfect visions of future patients!
Hampson, Karen M., Edward A. H. Mallen, and C. Dainty. "Coherence function analysis of the higher-order aberrations of the human eye." 2006. http://hdl.handle.net/10454/3748.
Full textWe measured the wavefront aberrations of the eyes of five subjects with a Shack-Hartmann sensor sampling at 21.2 Hz and decomposed the measurements into Zernike aberration terms up to and including the fifth radial order. Coherence function analysis was used to determine the common frequency components between the aberrations within subjects. We found the results to be highly subject dependent. The coherence values were typically <0.4. Possible reasons for this are discussed. Coherence function analysis is a useful tool that can be used in future investigations to determine correlations between the aberration dynamics of the eye and other physiological mechanisms.
Su, Pei-Yuang, and 蘇姵元. "Impact of Cataract Surgery on High-Order Aberration And Functional Vision." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/49783927895505762118.
Full text臺灣大學
臨床醫學研究所
95
With the advances in surgical instruments, IOL design and material, IOL delivery system and surgical technique, the small cornea incision cataract surgery with implantation of IOL have become a successful procedure that provides fast visual rehabilitation and minimum surgical complications. However, improvement of postoperative visual acuity is not the only concern today but also the visual quality and functional vision. Therefore, eliminating optical aberrations,especially high-order aberrations(HOAs)is one way to achieve the goal. The optical aberrations are mainly from two parts of the eye, cornea and lens. Both corneal and lenticular HOAs increase during the aging process, therefore affect the functional vision. Though the opacified lens is replaced by a crystal clear optics during the cataract surgery, the disturbance of the compensatory effect of nature lens to positive corneal spherical aberration has been made by the conventional spherical intraocular lens. Therefore a new IOL design with aspherical anterior surface was developed during recent years, which generate negative spherical aberrations to compensate for corneal aberration, in order to improve functional visions for cataract patients. In this study, we use corneal topography and wavefront aberrometer to analyze corneal and total ocular high-order aberrations. In addition, we use contrast sensitivity and contrast acuity as indicators of visual function and try to investigate: 1) the impact of aging on corneal and total ocular HOAs 2) the change of HOAs after the cataract surgery 3) to compare intraindividually the HOAs and functional vision between implantation of spherical and aspherical IOLs. The results reveal that: Corneal HOAs, including total 3rd, total 4th, total 5th order, coma and primary spherical aberrations, have minimal changes with increase of age. After the small incision clear cornea cataract surgery with , the corneal HOAs increase minimally, but the total ocular HOAs increase significantly compare to normal phakic eyes, especially the total 4th –order and primary spherical aberrations. Compare to conventional spherical IOLs, implantation of aspherical IOLs indeed reduce the ocular spherical aberrations. As for the functional vision, we don’t see significant improvement of aspherical IOLs over conventional spherical IOLs. We speculated that patients with smaller pupil size may not gain the visual benefit provided by the aspherical IOLs. Aberrations affect vision differently, further investigation for customized IOLs, with ranges of aberrations corrected to suit individual needs, may be needed.
Yang, Sung-Hua, and 楊松樺. "Influences of Myopia, Refractive Factors and Age on Corneal and Ocular Higher-order Aberrations." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/39393763484387103985.
Full text高雄醫學大學
醫學研究所
97
2. Abstract 2.1. Purpose: To investigate the influence of myopia, refractive factors and age on corneal or ocular aberrations and the changes in contrast sensitivity. 2.2. Methods: A total of 82 eyes of 52 subjects were evaluated, using Wavelight Topolyzer and Wavelight Analyzer.Other measurements included age, contrast sensitivity functions, intraocular pressure, keratometry readings, axial length, basic secretion tests, central cornea thickness, manifest and cycloplegic refraction. We analyzed the association of higher-order aberrations between cornea and globe, and the differences among other ocular parameters. 2.3. Results: The data showed that ocular aberration C8 (r=0.272,p<0.05) and C18 (r=0.300,p<0.01) increased with tear volume. Ocular aberration C11 increased with axial length (r=-0.297,p<0.01). Both corneal (r=0.574,p<0.05) and ocular (r=0.919,p<0.01) C7 showed positive correlations with corneal thickness in participants aged older than 40. Ocular C17 (r=0.257,p<0.05)increased with higher vertical keratometry values, and horizontal keratometry values was associated with total-higher order aberrations (RMSh)(r=0.267,p<0.05). Myopia diopter affects ocular C7 (r=0.262,p<0.05) which influences contrast sensitivity function at 18 cpd (r=-0.245,p<0.05).Ocular C8 increased with age (r=0.106,p<0.01), but had no association with contrast sensitivity. 2.4. Conclusion: Corneal and ocular aberrations are different for many ocular factors such as refractive errors, axial length, corneal thickness, keratometry, tear volume and age.Ocular aberration C8 and C18 increased with tear volume. Ocular aberration C11 showed positive correlation with axial length.Both corneal and ocular aberration C7 showed positive correlations with corneal thickness.Higher vertical corneal k-value was associated with ocular aberration C17,and higher horizontal corneal k-value was associated with total higher- order ocular aberrations (RMSh). Higher myopia was associated with increasing ocular aberration C7 and reduced contrast sensitivity in 18 cpd.Older age was associated with higher ocular aberration C8, but C8 did not interfere with contrast sensitivity at any spatial frequency indepdently.
Keir, Nancy. "Impact of Wavefront-Guided Laser in situ Keratomileusis on Monochromatic Higher Order Aberrations and Vision." Thesis, 2008. http://hdl.handle.net/10012/3813.
Full textCox, Michael J. "Visual Optics: Astigmatism." 2010. http://hdl.handle.net/10454/4765.
Full textLIN, SHU-YUAN, and 林淑媛. "Comparison of Higher and Low Order Aberrations Measured by NIDEK OPD-Scan III and HUVITZ 8000A Aberrometers." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/07595925042356059756.
Full text中臺科技大學
醫學工程暨材料研究所
104
Purpose: In order to analysis the photography from the space accurately, NASA has invented a new technology called wavefront. Because the new technology has been used on Optometry widely recent year, different wavefront aberrometers have been designed and applied on clinic. Although the visual acuity improves after LASIK, visual quality becomes worse because of the increase of wavefront aberration. Visual quality is multifactorial which is not only decided by the prescription of diopter but also many other factors so that we should pay more attention to the study of the application of wavefront aberration and know all of aberrations of human eyes correctly which can help the clinical application. Here, we study different aberrometers on correlation between the high-order aberrations and the low-oder aberrations. Methods: In total,32 adults (64 eyes) including 15 females and 17 males whose average age is 31.41±3.82(from 24 to 38), average spherical diopter is -3.92±3.01D and average astigmatism is -1.07±0.98D by using NIDEK OPD SCAN III and HUVITZ 8000A aberraometor and each system was measured three times. Then we analyzed data by paired-samples T, correlation analysis and repeat measure (Bonferroni correction). Results: There is no difference between HUVITZ aberrometor and subjective refraction in low-order aberrations by using paired-samples T, but it has a significant difference from HUVITZ 8000A. According to the statistical analysis about high-order, there is just a postive correlation between NIDEK OPD SCAN III and HUVITZ 8000A aberraomteor in tile clover aberration and verical coma aberration, and has negative correlation between spherical aberration and horizontal clover, and no difference in horizontal coma aberration. Conclusion: There is high correlation between NEDIK OPD SCAN III and HUVITZ 8000A aberraometor when testing the high-order aberrations. However we must pay more attention to the difference about the astigmatism axial and diopter testing by aberraometor and overrefraction. Although NEDIK OPD SCAN III and HUVITZ 8000A aberraometor are lastest phoropter, they still need a large number of clinical sample so that they will have high reliability on testing high-order aberration. Key word: wavefront, high-order aberration, NEDIK OPD SCAN III, HUVITZ 8000A
Chen, Tzu-Lan, and 陳資嵐. "High Order Aberration, Contrast Sensitivity, and tear secretion after LASIK Surgery with Different Femtosecond Laser Platforms and Mechanical Microkeratome." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/rp5ap3.
Full text中山醫學大學
生物醫學科學學系碩士班
102
Laser in situ keratomileusis (LASIK) is one of the common ways to improve myopia. Producing a high quality corneal flap is the key to a successful LASIK, where complications usually take place thus affecting the visual quality. Different instruments and methods used would create different corneal flaps. In the past corneal flaps were produced using Mechanical Microleratome, but Femtosecond Laser has slowly took over Mechanical Microleratome recently. Therefore, this study was to evaluate the visual quality and dry eye after LASIK surgery by the means of IntraLase FS60 femtosecond laser, Technolas 520F femtosecond laser, Ziemer FEMTO LDV femtosecond laser and Microkeratome to create corneal flap. This retrospective study, seventy eyes of 36 patients underwent LASIK where IntraLase FS60 femtosecond laser were performed on twenty-three eyes of 11 patients, Technolas 520F femtosecond laser were performed on nineteen eyes of 10 patients, Ziemer FEMTO LDV femtosecond laser were performed on sixteen eyes of 9 patients, and Microkeratome were performed on twelve eyes of 6 patients. All eyes were examined with wavefront analysis and with the use of VISX STAR S4 Excimer Laser System (VISX Inc., Santa Clara, USA) to carry out the excimer laser ablation. All patients had undergone clinical examination 6 months prior to the surgery and 6 months after the surgery which includes Visual Acuity, Spherical refraction, Astigmatism, Spherical Equivalent (SE), Contrast Sensitivity, High Order Aberrations (HOAs), tear secretion and corneal sensation. The results show there were no significant difference between Uncorrected Distance Visual Acuity (UDVA), Corrected Distance Visual Acuity (CDVA), Spherical refraction, Astigmatism, SE, and Schirmer’s tear secretion 6 months after the surgery (all P > 0.05). Contrast sensitivity part, only 6 cpd in mesopic that Femtec group were significantly lower than others (P< 0.05). For the all HOAs, Femtec group were significantly higher than the Ziemer group (P < 0.05) ; for the Coma aberration, Femtec group were also higher than the IntraLase group, Ziemer group, MK group (all P < 0.05); for Spherical aberration, Ziemer group were higher than IntraLase group and MK group (all P < 0.05); for RMS3, Femtec group are higher than IntraLase group, Ziemer group, MK group (all P < 0.05) ; as for Trefoil aberration there are no significant difference between the RMS4, RMS5 and RMS6 group (all P > 0.05 ). For corneal sensation, Femtec group were significantly lower than others. (all P < 0.05). According to the results that there are no significant difference in the visual acuity and refractive errors with the use of different instruments to create corneal flap 6 months after surgery. However, there is a significant worse in the HOA with the use of Technolas 520F femtosecond laser to create corneal flap compare to the other instruments.
Lin, I.-Chan, and 林怡嬋. "Visual acuity, high order aberration and vision-related quality of life comparison between patients implanted with spherical and aspherical intraocular lens." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/51914038118075380142.
Full textCheng, Yu-Ling, and 鄭郁齡. "The correlation between high order aberration and factors including manifest refractive error, age, corneal shape, gender, pupil size and tear quality in Taiwan adults." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/17098482785621537895.
Full text中山醫學大學
生物醫學科學學系碩士班
103
Background and Purpose: Apart from manifest refractive error, the quality of vision is affected by various factors. With the capability of analyzing most of the aberration in the eye, wavefront sensor has been widely used in many aspects of ophthalmic application. However, there were few analytical studies done regarding high-order aberration and its influencing factors. The purpose of this study is to analyze the distribution of ocular high-order aberration and to investigate its relationship with various physiological properties in Taiwanese adults. This retrospective study will help to better understand the effect of high-order aberration on human visual quality. Material and Method: This retrospective study data was obtained from 312 patients who underwent a comprehensive ocular-visual evaluation as a routine procedure prior to refractive laser surgery from the year 2008 to 2012. The age of the population ranged from 20 to 56.The spherical component of their manifest refraction ranged from -1.50D through -10.50 D. The cylinder component of the manifest refraction was less than -3.50 D.To obtain research data included basic information, auto- refractor measurement (TOPCON Auto Kerato-Refractometer KR-8900), subjective refraction, pupil size (in daylight and darkroom), Wavefront scan: AMO WaveScan WaveFront™ System (wavescan mode),corneal thickness, and tear test result.Data analysis: Statistical analysis was conducted using Statistical Package for Social Science (SPSS, PASW Statistics 18 SPSS18).Repeated-measures one way analysis of variance (One way ANOVA) was performed to examine the statistical significance of variations in aberrations between various groups. We were also used Independent-Samples t Test, Partial Correlation, and linear regression to compare groups and post hoc to check the correlation.Results:Our results showed the scotopic pupil size is significantly correlated with spherical aberration (r=0.154, F=0.007),coma (r=0.201, F=0.000), and trefoil (r=0.240, F=0.000). Spherical aberration and spherical equivalent are significantly correlated.(r=0.219, P=0.001).Spherical aberration increases with age, and they are positively correlated(r=0.193, F=0.002).Coma and astigmatism are significantly positively correlated(r=0.278, F=0.000).Trefoil and astigmatism are significantly correlated(r=-0.138, F=0.020). The spherical aberrations are different between genders. Spherical aberration is found to be higher in patients wearing RGP vs. Soft contact lens previously. Conclusion:Based on our result, the scotopic pupil size is significantly correlated to coma, trefoil and spherical aberration; therefore it has a great impact on the total higher-order aberration. Significant positive correlation was also found between spherical aberration and age, this suggests the compensation mechanism of spherical aberration between cornea and crystalline lens reduces with age. Although statistically we found many ocular physiological factors to be significantly correlated with higher-order aberrations, more research is needed to confirm the relationship. This project allows us to analyze the distribution of higher-order aberrations among Taiwanese adults and hopefully to identify its influencing factors and the effect on visual quality.
Sun, Han-Ying, and 孫涵瑛. "How important is iris registration and femtosecond laser (Intralase)technology in postoperative high order aberrations (HOAs) afterWavefront-Guided laser situ keratomileusis (W G LASIK)?" Thesis, 2007. http://ndltd.ncl.edu.tw/handle/00575605329822540101.
Full text國防醫學院
航太醫學研究所
95
Introduction: It has long been appreciated that vision is limited by both optical and neural factors, but that only optical factors can be easily and effectively corrected for. Chief among these optical factors are spherical refractive error and astigmatism. Recent advances in wavefront technique make it possible to reduce postoperative order aberrations (HOAs) via modern refractive surgery such as wavefront guided laser in situ keratomileusis (WG LASIK). The goal of this research is to clarify an important question that has implications for both clinical and applied vision in aviation. “How important is iris registration and femtosecond laser (Intralase) technology in postoperative HOAs after WG LASIK?” Purpose: (1) To quantify the cyclotorsion occurring between upright sitting (measurement) position and supine (surgical) position in Taiwanese. (2) To compare the HOAs change after WG LASIK with iris registration (IR) and without iris registration (NIR) system. (3) To compare HOAs change after WG LASIK using a corneal flap with Moria microkenatome (M2) group and Intralase group based on the Hartmann-Shack wavefront aberrometer. Methods: (1) To determine the amount of cyclotorsion of eyeball between the measurement and surgery in 105 eyes (54 patients). (2) Twenty-eight eyes from 14 patients (refraction range -2.50D~-7.50D) treated by W G LASIK with IR group (12 eyes) or NIR group (16 eyes). Root-mean-square (RMS) of coma-like aberration, spherical aberration, total 3rd to 6th order HOAs were compared between the two groups. (3) M2 group (18 eyes) and Intralase group (12 eyes) whose degrees of myopia were-1.00 to –8.00 diopters (D) were treated with W G LASIK. Root-mean-square (RMS) of coma-like aberration, spherical aberration, total 3rd to 6th order HOAs were compared between the two groups. Result: (1) For all 105 eyes, mean ± standard deviation (SD) cyclotorsional deviation was 2.6 ± 2.0 degrees (right eye 2.4 ± 3.8 degrees counterclockwise, left eye 2.7 ± 2.9 degrees clockwise). (2)Compared with preoperative aberrations, both IR and NIR group showed postoperative decreased of total aberration (p<0.01) and increased of HOAs, vertical coma, and spherical aberration (p<0.01). Compared with NIR group, significant reduction of HOAs, vertical coma, and spherical aberration was observed in IR group. (3) There were no significant differences in RMS of coma-like aberration, spherical aberration, total 3rd to 6th order HOAs between M2 and Intralase group. Conclusions: (1) The difference of cyclotorsional eye movement was assessed significantly in the transition from seated to supine position with IR technology. (2) The WG LASIK with IR system significantly decreased postoperative induction of the amount of HOAs, vertical coma, and spherical aberration. (3) Although postoperative visual acuity improved significantly in Intralase group, there was no significant difference in all items of HOAs between the M2 group and Intralase group. Further study of multiple variants affecting postoperative HOAs after Intralase flap creation is mandatory. In summary, our study demonstrated that using IR system is essential element for reduction of postoperative HOAs after WG LASIK.