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Zhao Y, Fang F. Dynamic opto-mechanical eye model with peripheral refractions. OPTICS EXPRESS 2023; 31:12097-12113. [PMID: 37157376 DOI: 10.1364/oe.485252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Many myopia control methods based on the peripheral defocus theory have emerged towards applications in recent years. However, peripheral aberration is a critical issue, which is still not well-addressed. To validate the aberrometer for peripheral aberration measurement, a dynamic opto-mechanical eye model with a wide visual field is developed in this study. This model consists of a plano-convex lens representing cornea (f' = 30 mm), a double-convex lens representing crystalline lens (f' = 100 mm), and a spherical retinal screen with a radius of 12 mm. To optimize the quality of spot-field images from the Hartman-Shack sensor, the materials and surface topography for the retina are studied. The model has an adjustable retina to achieve Zernike 4th item (Z4 focus) ranging from -6.28 µm to +6.84 µm. As for mean sphere equivalent, it can achieve -10.52 D to +9.16 D at 0° visual field and -6.97 D to +5.88 D at 30° visual field with a pupil size of 3 mm. To realize a changing pupil size, a slot at the back of the cornea mount and a series of thin metal sheets with 2, 3, 4, and 6 mm holes are generated. Both on-axis aberrations and peripheral aberrations of the eye model are verified by a well-used aberrometer and the eye model to mimic a human eye in a peripheral aberration measurement system is illustrated.
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Amorim AR, Bret B, González-Méijome JM. Opto-Mechanical Eye Models, a Review on Human Vision Applications and Perspectives for Use in Industry. SENSORS (BASEL, SWITZERLAND) 2022; 22:7686. [PMID: 36236784 PMCID: PMC9573708 DOI: 10.3390/s22197686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/22/2022] [Accepted: 06/25/2022] [Indexed: 06/16/2023]
Abstract
The purpose of this review is to aggregate technical information on existent optomechanical eye models (OME) described in the literature, for image quality assessment in different applications. Several physical eye models have been reviewed from peer-reviewed papers and patent applications. A typical eye model includes an artificial cornea, an intraocular lens or other lens to simulate the crystalline lens, an aperture as the pupil, and a posterior retinal surface, which may be connected to a light sensor. The interior of the eye model may be filled with a fluid to better emulate physiological conditions. The main focus of this review is the materials and physical characteristics used and the dimensional aspects of the main components including lenses, apertures, chambers, imaging sensors and filling medium. Various devices are described with their applications and technical details, which are systematically tabulated highlighting their main characteristics and applications. The models presented are detailed and discussed individually, and the features of different models are compared when applicable, highlighting strengths and limitations. In the end there is a brief discussion about the potential use of artificial eye models for industrial applications.
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Affiliation(s)
- André Rino Amorim
- Clinical and Experimental Optometry Research Lab, Center of Physics, University of Minho, 4710-057 Braga, Portugal
| | - Boris Bret
- Bosch Car Multimedia Portugal, S.A., 4705-285 Braga, Portugal
| | - José M. González-Méijome
- Clinical and Experimental Optometry Research Lab, Center of Physics, University of Minho, 4710-057 Braga, Portugal
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Customized eye modeling for optical quality assessment in myopic femto-LASIK surgery. Sci Rep 2021; 11:16049. [PMID: 34362982 PMCID: PMC8346559 DOI: 10.1038/s41598-021-95730-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 07/27/2021] [Indexed: 02/07/2023] Open
Abstract
Refractive surgery is recognized as an effective method for myopia treatment, but it can induce night vision disturbances such as glare. We present an eye modeling method for the optical quality assessment in response to the structural changes in the eyes by femto-LASIK surgery. Customized eye models were built from the measurements of 134 right eyes pre- and post-operatively. Optical performance was evaluated using spot diagrams, point spread functions (PSFs), modulation transfer functions (MTFs), and chromatic aberrations at various fields (0°-30°), different pupil diameters (2-6 mm), and initial myopias (- 1.25 to - 10.5 D). Pupil size and initial myopia are the two major factors that affect visual performance of post-operative eyes. The results of spot diagrams, PSFs, and MTFs indicated that post-operative visual performance deteriorated as the visual field and pupil size increased, and it was significantly influenced by initial myopia. Post-operative chromatic aberrations were also affected by initial myopia. As pupil size increased, the post-operative longitudinal chromatic aberrations tended to decrease slightly, while the transverse chromatic aberrations remained similar. The use of eye modeling for refractive surgery assessment could possibly provide a more personalized surgical approach, could improve the prediction accuracy of refractive surgery outcomes, and promote the invention and development of better surgical methods.
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Arba-Mosquera S, Naubereit P, Sobutas S, Verma S. Analytical optimization of the cutting efficiency for generic cavitation bubbles. BIOMEDICAL OPTICS EXPRESS 2021; 12:3819-3835. [PMID: 34457382 PMCID: PMC8367260 DOI: 10.1364/boe.425895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 06/07/2023]
Abstract
A theoretical method to determine the optimum laser parameters for maximizing the cutting efficiency for different materials (in particular human cornea) is proposed. The model is simple and reduced to laser beam characteristics and cavitation properties. The model further provides a method to convert energy fluctuations during the cutting process to equivalent deviations in the cavitation bubbles. The proposed model can be used for calibration, verification and validation purposes of laser systems used for cutting processes at relatively low cost and may improve the quality of the results.
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Affiliation(s)
| | | | | | - Shwetabh Verma
- SCHWIND eye-tech-solutions, Kleinostheim, D- 63801, Germany
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González-Galicia MA, Pottiez O, Reyes-Ramírez B, Lozano-Crisóstomo N. Experimental evolution of the temporal and spectral profiles of noise-like pulses within the mode-locked regions of a figure-eight fiber laser. APPLIED OPTICS 2020; 59:11215-11224. [PMID: 33362042 DOI: 10.1364/ao.409220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
We present an experimental analysis of the pulse profile variability within the mode-locked regions of an erbium-doped figure-eight fiber laser (EDFEFL). The tuning of the mode-locked regions was carried out by varying and recording the values of the angle of the polarization controllers in the ring section and in the nonlinear optical loop mirror (NOLM). Within the mode-locked regions, we obtained a large variability of the temporal profile, specifically amplitude and width of the noise-like pulses (NLPs). Subsequently, we recorded and studied the changes in the spectral domain. We identified the mode-locked regions where the temporal profile of the pulse remains constant (stationary state), and where it expels sub-packets (non-stationary state). Finally, a theoretical analysis of the power transmission through the polarizing in the ring section and in the NOLM switching characteristic as a function of wave plate angles is also performed, which allows an understanding of the existence of the multiple mode-locked regions and pulse profile adjustability. We analyze NLPs with a carrier wavelength of 1560 nm with duration of the order of nanoseconds and a repetition rate of 0.9 MHz.
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Elahi S, Gatinel D. In Vivo Visualization of Rainbow Glare and Treatment With Undersurface Flap Phototherapeutic Keratectomy. J Refract Surg 2020; 36:400-404. [PMID: 32521028 DOI: 10.3928/1081597x-20200522-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 05/06/2020] [Indexed: 11/20/2022]
Abstract
PURPOSE To analyze a case of unilateral rainbow glare that required repeated undersurface photoablation using an excimer laser. METHODS A 31-year-old man with bilateral myopia of 6.50 diopters treated with femtosecond laser-assisted in situ keratomileusis immediately experienced a 2-year life-incapacitating rainbow glare exclusively in the right eye. The laser settings were similar for both eyes, but a subtle raster pattern was noticed intraoperatively in the right eye. Postoperative uncorrected distance visual acuity (UDVA) was 20/12.5, but with important subjective visual quality impairment in the right eye. Slit-lamp examination and investigations were unremarkable except for hyperreflective dots arranged in a regular grating pattern on confocal microscopy in the right eye. RESULTS A 10-µm undersurface photoablation was performed with immediate but incomplete improvement of both subjective symptoms and objective reduction of the grating pattern on confocal microscopy. After 12 months, the patient asked for additional treatment and another 10-µm undersurface photoablation was performed, this time with resolution of the symptoms. At last follow-up, 6 months after the second revision, UDVA was maintained with total absence of rainbow glare and no hypermetropic shift was observed. CONCLUSIONS Rainbow glare is typically a benign and often spontaneously resolving condition that can rarely cause dramatic life impairment. This case reinforces the hypothesis that it is caused by diffraction created by the raster spot pattern of the femtosecond laser, which can be followed by confocal microscopy. It also further proves that undersur-face photoablation is an efficient, repeatable, and safe treatment for rainbow glare, and should include a thickness of at least 16 to 20 µm. [J Refract Surg. 2020;36(6):400-404.].
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Ryan DS, Sia RK, Eaddy JB, Logan LA, Familoni JO, Beydoun H, Rodgers SB, Rivers BA. Preliminary evaluation of the VIsion PERformance (VIPER) simulator. Mil Med Res 2020; 7:2. [PMID: 31941553 PMCID: PMC6964099 DOI: 10.1186/s40779-020-0231-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 01/06/2020] [Indexed: 03/21/2023] Open
Abstract
BACKGROUND This study evaluated the VIsion PERformance (VIPER) simulator's ability to assess the functional visual performance in warfighters conducting civilian and military tasks. METHODS Thirty service members, aged 25-35 years old with a best corrected distance visual acuity (VA) better than or equal to 20/20 or logarithm of the minimum angle of resolution (logMAR) 0.00, were randomized to locate and identify road signs and mock improvised explosive devices (IEDs) under either daytime conditions or with infrared imagery, with (cc) and without (sc) wearing their habitual correction. Participants also underwent binocular uncorrected (UDVA) and corrected (CDVA) visual assessment, refraction, contrast sensitivity testing and wavefront aberrometry. RESULTS The mean age was 28.47 years. The manifest spherical equivalent was - 3.16 ± 1.75 diopters (D), the UDVA in both eyes (OU) was logMAR 0.83 ± 0.47, and the CDVA OU was - 0.11 ± 0.06. For VIPER, the mean difference in the detection distance (DD) for road signs ccDD vs. scDD was 76.7 ± 52.8 m (P < 0.001). The average difference in identification distance (ID) ccID vs. scID was 13.9 ± 6.3 m (P < 0.001). The mean accuracies were 83.5 and 27.9% for cc and sc, respectively (P < 0.001). The regression analysis indicated that a 1.6 m change in the distance accounts for a 1% change in the accuracy (P = 0.002). Without correction, a 4.1 m change accounts for a 1% change in the accuracy (P < 0.001). The average IED ccDD was 29.9 ± 8.2 m, and that for scDD was 13.2 ± 13.6 m (P < 0.001). The average IED ccID was 32.2 ± 6.2 m and that for the scID was 7.4 ± 10.3 m (P < 0.001). The mean IED identification accuracy was 46.7 and 11.4% for cc and sc, respectively (P < 0.001). CONCLUSIONS The preliminary results reflect VIPER's ability to assess functional visual performance when detecting and identifying signs and IEDs. Furthermore, VIPER is able to detect performance changes with and without correction.
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Affiliation(s)
- Denise S Ryan
- Warfighter Refractive Eye Surgery Program and Research Center, Fort Belvoir Community Hospital, Fort Belvoir, VA, 22060, USA.
| | - Rose K Sia
- Warfighter Refractive Eye Surgery Program and Research Center, Fort Belvoir Community Hospital, Fort Belvoir, VA, 22060, USA
| | - Jennifer B Eaddy
- Warfighter Refractive Eye Surgery Program and Research Center, Fort Belvoir Community Hospital, Fort Belvoir, VA, 22060, USA
| | - Lorie A Logan
- Warfighter Refractive Eye Surgery Program and Research Center, Fort Belvoir Community Hospital, Fort Belvoir, VA, 22060, USA
| | - Jide O Familoni
- Night Vision and Electronic Sensors Directorate, Fort Belvoir, VA, 22060, USA
| | - Hind Beydoun
- Department of Research Programs, Fort Belvoir Community Hospital, Fort Belvoir, VA, 22060, USA
| | - Samantha B Rodgers
- Warfighter Refractive Eye Surgery Program and Research Center, Fort Belvoir Community Hospital, Fort Belvoir, VA, 22060, USA
| | - Bruce A Rivers
- Warfighter Refractive Eye Surgery Program and Research Center, Fort Belvoir Community Hospital, Fort Belvoir, VA, 22060, USA
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Rocha KM, Mercer RN, Dupps WJ, Krueger RR. The Incidence and Natural History of Subjectively and Objectively Determined Metrics of Light Scattering in Femtosecond Laser-Assisted In Situ Keratomileusis. EC OPHTHALMOLOGY 2019; 10:586-591. [PMID: 35463040 PMCID: PMC9022719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
PURPOSE To assess the incidence and long-term persistence of both subjective (rainbow glare phenomenon) and objective metrics of light scattering (stray light measurement) in femtosecond laser-assisted in situ keratomileusis (FS-LASIK). SETTINGS Cleveland Clinic Foundation, Cole Eye Institute. DESIGN Prospective, contralateral eye study in which 54 myopic eyes of 27 patients underwent LASIK using the ALLEGRETTO® Eye-Q excimer laser. Flap creation was created by IntraLASE FS60 (IL) in one eye and Wave Light FS200 (FS) in the contralateral eye. Rainbow glare and stray light measurements (C-Quant, Oculus Inc, Lynnwood, WA) were obtained preoperatively, and at 1 week, 1, 3, and 9 months postoperatively. Manifest and wavefront refractions were performed at each postoperative visit. RESULTS Stray light measurements in both IL and FS groups peaked at 1 week postoperatively (log 1.28 ± 0.16, p = 0.02 and log 1.26 ± 0.12, p = 0.039, respectively) with statistically significant improvement at 3 months (log 1.12 ± 0.35, p = 0.007 and log 1.20 ± 0.15, p = 0.04) and 9 months (log 1.11 ± 0.17, p = 0.008 and log 1.15 ± 0.14, p = 0.011). No statistically significant differences were found between IL and FS eyes at all time points. 11 patients reported postoperative rainbow glare at 1 week (42%), which decreased to 6 patients at 9 months (33%) in the IL treated eye. 14 patients reported postoperative rainbow glare at 1 week (54%), which decreased to 7 patients at 9 months (39%) in the FS treated eye. CONCLUSION Both rainbow glare and objective light scatter were greatest at 1 week and were significantly reduced by 1 to 3 months postoperatively. Rainbow glare is a mild optical side effect of femtosecond laser LASIK that improves with time.
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Affiliation(s)
- Karolinne M Rocha
- Medical University of South Carolina (MUSC), Storm Eye Institute, Charleston, South Carolina, USA
- Cleveland Clinic Foundation, Cole Eye Institute, Cleveland, Ohio, USA
| | - Ryan N Mercer
- University of Missouri, Columbia, Mason Eye Institute, Columbia, Missouri, USA
| | - William J Dupps
- Cleveland Clinic Foundation, Cole Eye Institute, Cleveland, Ohio, USA
| | - Ronald R Krueger
- Cleveland Clinic Foundation, Cole Eye Institute, Cleveland, Ohio, USA
- Stanley H Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Zhang Y, Chen YG. High incidence of rainbow glare after femtosecond laser assisted-LASIK using the upgraded FS200 femtosecond laser. BMC Ophthalmol 2018; 18:71. [PMID: 29506498 PMCID: PMC5838985 DOI: 10.1186/s12886-018-0734-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 02/27/2018] [Indexed: 11/30/2022] Open
Abstract
Background To compare the incidence of rainbow glare (RG) after femtosecond laser assisted-LASIK (FS-LASIK) using the upgraded FS200 femtosecond laser with different flap cut parameter settings. Methods A consecutive series of 129 patients (255 eyes) who underwent FS-LASIK for correcting myopia and/or astigmatism using upgraded WaveLight FS200 femtosecond laser with the original settings was included in group A. Another consecutive series of 129 patients (255 eyes) who underwent FS-LASIK using upgraded WaveLight FS200 femtosecond laser with flap cut parameter settings changed (decreased pulse energy, spot and line separation) was included in group B. The incidence and fading time of RG, confocal microscopic image and postoperative clinical results were compared between the two groups. Results There were no differences between the two groups in age, baseline refraction, excimer laser ablation depth, postoperative uncorrected visual acuity and refraction. The incidence rate of RG in group A (35/255, 13.73%) was significantly higher than that in group B (4/255, 1.57%) (P < 0.05). The median fading time was 3 months in group A and 1 month in group B (P > 0.05).The confocal microscopic images showed wider laser spot spacing in group A than group B. The incidence of RG was significantly correlated with age and grouping (P < 0.05). Conclusions The upgraded FS200 femtosecond laser with original flap cut parameter settings could increase the incidence of RG. The narrower grating size and lower pulse energy could ameliorate this side effect.
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Affiliation(s)
- Yu Zhang
- Department of Ophthalmology, Peking University Third Hospital, 49 North Huayuan Road, Haidian District, Beijing, 100191, China
| | - Yue-Guo Chen
- Department of Ophthalmology, Peking University Third Hospital, 49 North Huayuan Road, Haidian District, Beijing, 100191, China.
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Lapointe J, Kashyap R. A simple technique to overcome self-focusing, filamentation, supercontinuum generation, aberrations, depth dependence and waveguide interface roughness using fs laser processing. Sci Rep 2017; 7:499. [PMID: 28356554 PMCID: PMC5428688 DOI: 10.1038/s41598-017-00589-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/03/2017] [Indexed: 11/08/2022] Open
Abstract
Several detrimental effects limit the use of ultrafast lasers in multi-photon processing and the direct manufacture of integrated photonics devices, not least, dispersion, aberrations, depth dependence, undesirable ablation at a surface, limited depth of writing, nonlinear optical effects such as supercontinuum generation and filamentation due to Kerr self-focusing. We show that all these effects can be significantly reduced if not eliminated using two coherent, ultrafast laser-beams through a single lens - which we call the Dual-Beam technique. Simulations and experimental measurements at the focus are used to understand how the Dual-Beam technique can mitigate these problems. The high peak laser intensity is only formed at the aberration-free tightly localised focal spot, simultaneously, suppressing unwanted nonlinear side effects for any intensity or processing depth. Therefore, we believe this simple and innovative technique makes the fs laser capable of much more at even higher intensities than previously possible, allowing applications in multi-photon processing, bio-medical imaging, laser surgery of cells, tissue and in ophthalmology, along with laser writing of waveguides.
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Affiliation(s)
- Jerome Lapointe
- FABULAS, Department of Engineering Physics, Polytechnique Montreal, 2900 Edouard-Montpetit, Montreal H3T 1J4, Canada.
- Poly-Grames Research Center, 2500 Chemin Polytechnique, Montreal H3T 1J4, Canada.
| | - Raman Kashyap
- FABULAS, Department of Engineering Physics, Polytechnique Montreal, 2900 Edouard-Montpetit, Montreal H3T 1J4, Canada
- Department of Electrical Engineering, Polytechnique Montreal, 2900 Edouard-Montpetit, Montreal H3T 1J4, Canada
- Poly-Grames Research Center, 2500 Chemin Polytechnique, Montreal H3T 1J4, Canada
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Moshirfar M, Desautels JD, Quist TS, Skanchy DF, Williams MT, Wallace RT. Rainbow glare after laser-assisted in situ keratomileusis: a review of literature. Clin Ophthalmol 2016; 10:2245-2249. [PMID: 27877015 PMCID: PMC5108617 DOI: 10.2147/opth.s117971] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
This article reviews the current literature pertaining to rainbow glare (RG), including incidence rate, clinical presentation, etiology, prognosis, and management. RG is a rare optical complication of femtosecond laser-assisted in situ keratomileusis that results in patients seeing an array of spectral bands surrounding point sources of light under mesopic and scotopic conditions. The mechanism is thought to be a consequence of the formation of a transmissive diffraction grating on the posterior surface of the corneal flap created by the FS laser. RG has a good prognosis and is usually self-limiting. Persistent RG with concomitant residual refractive error may warrant lifting the flap and photoablating the posterior surface of the flap. Patients with persistent RG and no residual refractive error should be considered candidates for phototherapeutic keratectomy on the posterior flap surface.
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Affiliation(s)
- Majid Moshirfar
- Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT; HDR Research Center, Hoopes Vision, Draper, UT
| | | | - Tyler S Quist
- University of Utah School of Medicine, Salt Lake City, UT
| | - David F Skanchy
- McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX
| | - Mark T Williams
- University of California, San Francisco School of Medicine, San Francisco, CA
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Application of 3-dimensional printing technology to construct an eye model for fundus viewing study. PLoS One 2014; 9:e109373. [PMID: 25393277 PMCID: PMC4230932 DOI: 10.1371/journal.pone.0109373] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 09/03/2014] [Indexed: 12/03/2022] Open
Abstract
Objective To construct a life-sized eye model using the three-dimensional (3D) printing technology for fundus viewing study of the viewing system. Methods We devised our schematic model eye based on Navarro's eye and redesigned some parameters because of the change of the corneal material and the implantation of intraocular lenses (IOLs). Optical performance of our schematic model eye was compared with Navarro's schematic eye and other two reported physical model eyes using the ZEMAX optical design software. With computer aided design (CAD) software, we designed the 3D digital model of the main structure of the physical model eye, which was used for three-dimensional (3D) printing. Together with the main printed structure, polymethyl methacrylate(PMMA) aspherical cornea, variable iris, and IOLs were assembled to a physical eye model. Angle scale bars were glued from posterior to periphery of the retina. Then we fabricated other three physical models with different states of ammetropia. Optical parameters of these physical eye models were measured to verify the 3D printing accuracy. Results In on-axis calculations, our schematic model eye possessed similar size of spot diagram compared with Navarro's and Bakaraju's model eye, much smaller than Arianpour's model eye. Moreover, the spherical aberration of our schematic eye was much less than other three model eyes. While in off- axis simulation, it possessed a bit higher coma and similar astigmatism, field curvature and distortion. The MTF curves showed that all the model eyes diminished in resolution with increasing field of view, and the diminished tendency of resolution of our physical eye model was similar to the Navarro's eye. The measured parameters of our eye models with different status of ametropia were in line with the theoretical value. Conclusions The schematic eye model we designed can well simulate the optical performance of the human eye, and the fabricated physical one can be used as a tool in fundus range viewing research.
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Abstract
Contrast sensitivity defines the threshold between the visible and invisible, which has obvious significance for basic and clinical vision science. Fechner's 1860 review reported that threshold contrast is 1% for a remarkably wide range of targets and conditions. While printed charts are still in use, computer testing is becoming more popular because it offers efficient adaptive measurement of threshold for a wide range of stimuli. Both basic and clinical studies usually want to know fundamental visual capability, regardless of the observer's subjective criterion. Criterion effects are minimized by the use of an objective task: multiple-alternative forced-choice detection or identification. Having many alternatives reduces the guessing rate, which makes each trial more informative, so fewer trials are needed. Finally, populations who may experience crowding or target confusion should be tested with one target at a time.
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Affiliation(s)
- Denis G Pelli
- Psychology Department & Center for Neural Science, New York University, USA.
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Merker M, Ackermann R, Kammel R, Kunert KS, Nolte S. An in vitro study on focusing fs-laser pulses into ocular media for ophthalmic surgery. Lasers Surg Med 2013; 45:589-96. [PMID: 24105636 DOI: 10.1002/lsm.22179] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2013] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVE To investigate femtosecond (fs)-laser patterns within ocular media for ophthalmic surgery. METHODS Vitreous and crystalline lens tissue from porcine eyes were treated with 2-dimensional fs-laser patterns and inspected under the optical microscope. Time resolved pump-probe experiments were conducted on vitreous tissue and gelatin, which should act as a model for crystalline lens tissue. RESULTS Within crystalline lens tissue, pulse overlap leads to the formation of large bubbles, which is caused by subsequent energy input from the surrounding plasma channel. This effect can be used for bubble size control. Vitreous tissue behaves similar to water under fs-laser treatment, but it still allows fs-laser cutting. CONCLUSION Bubble size control by laser bursts may reduce optical side-effects of fs-laser treatment. Furthermore, fs-laser treatment could be used for vitreoretinal applications.
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Affiliation(s)
- Marina Merker
- Institute of Applied Physics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, Jena, 07743, Germany; Faculty SciTec, Ernst-Abbe-Fachhochschule Jena, Carl-Zeiß-Promenade 2, Jena, 07745, Germany
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