• Snellen visual acuity was developed at a time when the only possible refractive correction of the optical system of the eye was spherocylindrical glasses and the surgical techniques of treating eye diseases were less advanced. (medscape.com)
  • The 20/20 Snellen visual acuity was considered normal vision and the goal of treatments and surgeries. (medscape.com)
  • Many people have visual acuity that is better than 20/20, and real-world visual performance also includes low-contrast objects under low or high illumination. (medscape.com)
  • Investigators found that bilateral wavefront-guided LASIK provided excellent objective outcomes such as visual acuity, refraction, and aberrometry as well as high patient satisfaction and quality of life, as measured by the Refractive Status and Vision Profile questionnaire. (crstoday.com)
  • At 12 months, 76 eyes (90.5%) had an uncorrected distance visual acuity (UDVA) of 20/20 or better, and all eyes achieved 20/40 or better. (crstoday.com)
  • Five patients (11.9%) were dissatisfied or very dissatisfied with their visual acuity at 12 months. (crstoday.com)
  • The investigators found that bilateral wavefront-guided LASIK produced excellent visual acuity, refractive, and aberrometric outcomes. (crstoday.com)
  • PURPOSE: To illustrate the utility of wavefront aberrometry in delineating a subtle lenticular abnormality responsible for decreased best-corrected visual acuity in a patient. (northwestern.edu)
  • CONCLUSIONS: Wavefront aberrometry has an adjunctive and distinctive role in the preoperative screening process for refractive surgery candidates and in those with subtle unexplained loss of best-corrected visual acuity. (northwestern.edu)
  • Best-corrected visual acuity (BCVA) measurements and optical coherence tomography findings were recorded. (academic-accelerator.com)
  • Purpose: This study aimed to evaluate the effect of calcium dobesilate uptake on visual acuity (VA) and macular thickness by optical coherence tomography (OCT) of eyes with non-proliferative diabetic retinopathy (NPDR) in comparison with bilberry dried extract. (academic-accelerator.com)
  • Main outcome measures were refractive error and monocular corrected (CDVA) and uncorrected (UDVA) distance visual acuity values. (academic-accelerator.com)
  • Main outcome measures were best-corrected visual acuity (BCVA) change over time, BCVA, number of ranibizumab injections, and proportion of 3-line gainers/losers. (academic-accelerator.com)
  • Results The mean best-corrected visual acuity (BCVA) pertaining to all the patients significantly improved from the baseline value of 0. (academic-accelerator.com)
  • Mean best corrected visual acuity was 20/30 (20/20-20/80) in the affected eye. (academic-accelerator.com)
  • Best corrected visual acuity was decreased to 20/40 OD and 20/50 OS, spectral domain optical coherence tomography found outer retinal disruption of the fovea, and AOSLO imaging showed significant decrease in cone density of the fovea of both eyes. (academic-accelerator.com)
  • The outcome measures were the best-corrected visual acuity (BCVA) and central macular thickness (CMT) on spectral-domain optical coherence tomography. (academic-accelerator.com)
  • Analyze the relationships between foveal displacement, preoperative and postoperative best-corrected visual acuity, central foveal thickness and the stage of epiretinal membrane. (academic-accelerator.com)
  • The 3nethra aberro is a handheld autorefractometer equipped with the Shack-Hartmann Wavefront sensor aberrometry technology to detect visual acuity and refractive errors. (forushealth.com)
  • The system features full auto‐alignment, a large color touch screen, onboard evaluation software, wavefront image sequence and simulated visual acuity assessment. (metroophthalmic.com)
  • It is known that healthy young eyes with good visual acuity have some positive ocular SA [ 6 ]. (hindawi.com)
  • Optical quality is a subjective construct that can only be described indirectly by objective metrics such as wavefront error measurements and visual quality metrics or functional data like visual acuity and contrast sensitivity. (hindawi.com)
  • RESULTS: The mean corrected visual acuity improved from a mean of 0.32 ± 0.2 logMAR (20/40) preoperatively to 0.14 ± 0.11 logMAR (20/25) 1 year postoperatively (P = 0.001). (bvsalud.org)
  • When analyzing the correlation between visual acuity and VFQ composite score, a significant correlation was found between both variables (Pearson correlation coefficient of -0.40, P = 0.001). (bvsalud.org)
  • This may include an examination to determine your eyeglass prescription (refraction), measurement of your vision with and without glasses (visual acuity), measurement of the pressures inside your eye (tonometry), microscopic examination of the front part of your eye (slit-lamp examination), and examination of the retina of your eye with your pupils dilated. (coastaleyecare.net)
  • NEW YORK (Reuters Health) - Individuals with low birthweight (BW) are more likely to have lower visual acuity and a higher myopic refractive error in adulthood, according to a new study from Germany. (medscape.com)
  • The low-BW group had significantly lower visual acuity compared with the normal-BW group, though there were no difference between the normal-BW and high-BW groups, according to Dr. Achim Fiess of the University Medical Center of the Johannes Gutenberg University Mainz and colleagues. (medscape.com)
  • Our results show that former low-birthweight newborns are more likely to be myopic and have reduced visual acuity in adulthood," Dr. Fiess told Reuters Health by email. (medscape.com)
  • Although the reported increase in myopia and decrease in visual acuity are statistically significant, the results of this study, while interesting, will have little impact on patient care and clinical decision-making," Dr. Stephen M. Lipsky, a spokesperson for the American Academy of Ophthalmology, told Reuters Health by email. (medscape.com)
  • a chart used to subjectively measure visual acuity. (dfweyes.com)
  • To the refractive surgery patient in year 2000, achieving an uncorrected visual acuity of 20/20 after refractive surgery was considered a success. (medscape.com)
  • therefore, visual acuity decreases in dark conditions (see the image below. (medscape.com)
  • It includes a wide variety of commonly used tests for visual acuity and binocular vision ancillary tests. (zeiss.com)
  • Asymmetries in the topography and refractive index of the corneal surface that affect visual acuity. (bvsalud.org)
  • We explained to the patient that since vigorous rubbing had preceded the drop in visual acuity, this habit may have caused the cornea to deform in his case. (defeatkeratoconus.com)
  • Chronos combines binocular autorefraction and keratometry measurements with binocular subjective testing and visual acuity in a single instrument that occupies a minimal amount of space and optimizes workflow. (topconhealthcare.ca)
  • If so, it may be possible to expedite the decision for therapeutic interventions, such as cross-linking, to preserve visual acuity and prevent irreversible progression. (biomedcentral.com)
  • This review outlines key issues surround- ing 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. (manchester.ac.uk)
  • Furthermore, it is typically performed using devices similar to the Hartmann-Shack wavefront sensors. (news-medical.net)
  • To evaluate a system based on a Hartmann-Shack wavefront sensor attached to a phoropter that allows the user to obtain real-time information about the refractive state of the eye and the accommodation response (AR). (arvojournals.org)
  • Allon Barsam was the first British surgeon to use laser vision correction technology for cataract surgery with the use of intraoperative aberrometry. (wikipedia.org)
  • Aim To explore the application of intraoperative wavefront aberrometry (IWA) for aphakia-based biometry using three existing formulae derived from autorefractive retinoscopy and introducing new improved formulae. (bmj.com)
  • Numerous studies argue that intraoperative wavefront aberrometry (IWA) may well become an indispensible tool in future cataract surgery. (bmj.com)
  • ORA utilizes intraoperative wavefront aberrometry, which helps us choose the best possible IOL for your eye. (coastaleyecare.net)
  • Dr. Reck specializes in cataract and glaucoma surgery, employing state-of-the-art technologies, such as laser-assisted cataract surgery, microincision, no-stitch cataract surgery, intraoperative wavefront aberrometry, astigmatism-correcting (toric) lens implants, and multifocal lens implants. (claruseye.com)
  • Wavefront analysis technology has enabled physicians to measure higher-order optical aberrations in addition to spherocylinders in clinical practice. (medscape.com)
  • If it is presumed (that is not entirely true) that the light travels to the eye the same way as out of the eye, the wavefront directly measures the aberrations of the eye. (medscape.com)
  • Ideal wavefront of an optical system with no aberrations in place. (medscape.com)
  • Wavefront analysis instruments do not analyze degradation of the image caused by the chromatic aberrations. (medscape.com)
  • Wavefront-optimized tries to minimize the induction of aberrations in the eye during surgery. (presenternet.com)
  • Recent advances such as the development of wavefront-guided and wavefront-optimized LASIK can help surgeons minimize higher-order aberrations and enhance quality of vision. (crstoday.com)
  • METHODS: Clinical data, corneal topography, and wavefront aberrometry with separation of corneal and lenticular components of the higher-order aberrations are analyzed in a patient who presented for refractive surgery evaluation. (northwestern.edu)
  • For nearly 30 years, Dr. Neal and his team have made continued advancements of wavefront technology to measure the imperfections, or aberrations, of the human eye to improve visual performance. (wavefrontdynamics.com)
  • The WaveDyn Vision Analyzer represents the next generation in wavefront technology for measuring full ocular aberrations, providing the data necessary for optimization of visual performance. (wavefrontdynamics.com)
  • Wavefront analysis isolates the effect of lower-order aberrations (defocus and astigmatism) and higher-order aberrations as well as the contribution of individual aberrations on optical quality. (hindawi.com)
  • And each minor rod is actually the rays of light or the rays of energy from the retina, and as they pass through the pupillary aperture, there will be several aberrations that they suffer, when they pass through the optical medium of the eye, which produces a composite structure, which can be represented by a composite wavefront. (cybersight.org)
  • Dr. Vakharia then performs a full eye examination including a dilated retinal exam, all pertinent testing of your eyes including corneal mapping, ultrasound corneal thickness and intraocular pressure, and a custom wavefront measurement of the higher order aberrations in your visual system. (newvisionrockford.com)
  • iZon Wavefront Aberrometry helps our doctors detect higher order aberrations which are irregularities that affect vision. (stonehengevisionsource.com)
  • The human eye can be affected by a number of aberrations which can reduce the quality of retinal images and general visual perception. (news-medical.net)
  • Described as small optical irregularities, aberrations are imperfections of the eye that result in light being unable to focus onto the retina effectively as well as defects in visual image. (news-medical.net)
  • Wavefront analysis is used to measure aberrations of the optical system. (news-medical.net)
  • There are a variety of methods that can be used to assess ocular aberrations including Shack-Hartmann wavefront sensing, Tscherning, spatially resolved refractometry and optical path difference aberrometry. (news-medical.net)
  • Although Wavefront Optimized is superior to conventional LASIK, it lacks the ability to correct higher order aberrations in the vision that "true" Custom Wavefront Guided treatment is designed to correct. (arizonalasik.com)
  • VISX CustomVue is superior to conventional LASIK and superior to Wavefront Optimized because VISX CustomVue corrects all higher order aberrations. (arizonalasik.com)
  • The Wavefront Dynamic's team has developed their fifth generation multi-measurement system called the WaveDyn Vision Analyzer. (wavefrontdynamics.com)
  • The 5-in-1 KR‐1W Wavefront Analyzer boasts the combined technologies of wavefront aberration, corneal topography and auto‐refraction. (metroophthalmic.com)
  • Here are the Orbscan quadmaps, Pentacam maps, OPDscan (topography and aberrometry) maps and Ocular Response Analyzer (ORA) results of the first visit. (defeatkeratoconus.com)
  • The KR-1W is a versatile wavefront analyzer, combining aberrometry, topography, keratometry, pupillometry and autorefraction in one unit. (topconhealthcare.ca)
  • Assuming that the center of the visual axis has a spherical refraction of 4.0, the middle ring has a spherical refraction of 5.5, and the outer ring has a spherical refraction of 6.0. (medscape.com)
  • RESULTS: Clinical evaluation indicated that the cause of visual loss was lenticular, and wavefront aberrometry indicated high negative spherical aberration, leading to the diagnosis of anterior lenticonus. (northwestern.edu)
  • Our study aimed to evaluate the optical quality and potential benefits on visual outcome of an aberration-free aspherical IOL compared to those of an aspherical IOL with negative SA. (hindawi.com)
  • The degree of which the image deviates from the expected focal point of each lens in the system represents a 'wavefront error' or aberration. (news-medical.net)
  • The wavefront error produced from the wavefront analysis is further broken down into components that mathematically and visually describe the specific elements of the aberration. (news-medical.net)
  • The corneal deformation causes the ocular wavefront to be distorted (coma, negative spherical aberration, trefoil). (defeatkeratoconus.com)
  • At the core of Wavefront Dynamic's continued innovation is the Shack-Hartmann wavefront sensor, a technology that has long been used in astronomy to improve the image quality of telescopes. (wavefrontdynamics.com)
  • The system is anticipated to have the highest resolution, Shack-Hartmann wavefront sensor commercially available, with approximately 2,870 distinct measurements over a 7.0 mm pupil. (wavefrontdynamics.com)
  • This measurement of visual function does not suffice for a full understanding of quality of vision, nor is it adequate for the current clinical practice of refractive surgery. (medscape.com)
  • QOL was evaluated using the Refractive Status and Vision Profile (RSVP), a 42-item validated questionnaire for refractive surgery with subcategories in driving, visual function, perception, visual symptoms, problems with corrective lenses, and expectations. (crstoday.com)
  • The LASIK surgeons at Assil Gaur Eye Institute in Beverly Hills, California have successfully treated many persons from China who have previously undergone either cataract surgery or refractive surgery (with RK, PRK, LASIK, or SMILE) and were left with inadequate vision correction or with irritating visual symptoms after their surgery. (assileye.com)
  • 5-in-1 instrument features aberrometry, topography, keratometry, pupillometry and autorefraction all in one unit! (metroophthalmic.com)
  • Five eyes were treated with standard noncustomized PlanoScan treatment (Bausch & Lomb, Rochester, New York), 20 eyes were treated with a tissue-sparing algorithm customized to keratometry, and 432 eyes were treated with Zyoptix 217z100 (Bausch & Lomb) wavefront-guided LASIK (Figure 1). (crstodayeurope.com)
  • Only proven superior results to results of conventional LASIK treatment, not "true" Custom Wavefront Guided LASIK. (arizonalasik.com)
  • The total wavefront error is the difference between an ideal perfect wavefront and the actual real wavefront of the eye and gives an idea of the total distortion in the eye. (medscape.com)
  • So when light passes through any optical media, it actually is diffracted or refracted, and if it is a perfect wavefront, it will have a particular orientation, which will differ from person to person. (cybersight.org)
  • The ORA SYSTEM® technology utilizes wavefront aberrometry data to measure and analyze the refractive power of the eye (i.e. sphere, cylinder, and axis measurements) to support cataract surgical procedures. (remowz.com)
  • Is wavefront better than LASIK? (presenternet.com)
  • There is a greater degree of precision attainable in LASIK wavefront vs standard LASIK. (presenternet.com)
  • Wavefront-guided custom LASIK can measure visual correction to 0.01 Diopters, whereas traditional LASIK is only able to correct 0.25 Diopters. (presenternet.com)
  • Therefore, the visual potential is better optimized in wavefront LASIK. (presenternet.com)
  • Investigators evaluated visual outcomes and patient satisfaction ratings for bilateral wavefront-guided LASIK. (crstoday.com)
  • This study used objective measures and one of the first validated refractive quality-of-life questionnaires to demonstrate that bilateral wavefront-guided LASIK yielded high-quality vision. (crstoday.com)
  • In this study, 90.5% of patients achieved UDVA of 20/20 or better compared with rates of 91% to 99% reported in other studies of wavefront-guided LASIK. (crstoday.com)
  • The FDA has extensive information for consumers and health care professionals on the benefits and risks of LASIK on its website , including patient labeling (information booklet), which discloses visual symptoms as potential risks of LASIK devices, and a summary of safety and effectiveness data for each LASIK device detailing information about the visual symptoms observed in the clinical studies. (medscape.com)
  • QuickSee runs on a modified version of a wavefront aberrometer, an advanced device used to map the eye prior to LASIK surgery. (mit.edu)
  • Allegretto Wavelight cannot take a fingerprint of the visual system of the eye and correct for irregularities, as does VISX CustomVue. (arizonalasik.com)
  • Allegretto Wavelight with its Wavefront Optimized system will not obtain a pre-op aberrometry map, will not perform "iris registration", and will not identify the the center of the pupil. (arizonalasik.com)
  • It is performed by using a wavefront aberrometer machine. (presenternet.com)
  • A wavefront aberrometer works by measuring the light passing through your eye's optical system (the lens and cornea). (presenternet.com)
  • The ORA system allows our cataract surgeons to take precise measurements at any point in the surgery and change course if necessary to ensure each patient enjoys the best possible visual outcome. (remowz.com)
  • These measurements can be used to describe the optical properties of the eye and to detect optical irregularities of the visual system that contribute to visual quality. (medscape.com)
  • After surgery, contrast sensitivity and wavefront measurements as well as tilt and decentration measurements were performed. (hindawi.com)
  • It can provide advanced warning for many serious conditions with the retina, macula, optic nerve and visual system. (stonehengevisionsource.com)
  • ARMD - Age-related macular degeneration (ARMD) is an acquired degeneration of the retina that causes significant central visual impairment through a combination of non-neovascular (drusen and retinal pigment epithelium abnormalities), and neovascular derangement (choroidal neovascular membrane formation). (dfweyes.com)
  • CONCLUSIONS: Patients with keratoconus had increased psychological symptoms and lower QOL and improved psychosocial criteria associated with corneal remodeling and decreased visual dependence on others after surgery. (bvsalud.org)
  • This technology goes beyond routine assessments, helping us to customise a vision correction tailored to your unique visual needs and for both day and night vision conditions. (sparksferos.com.au)
  • The question whether correction of the total SA of the eye or some residual SA leads to better visual outcome and better optical quality remains to be elucidated. (hindawi.com)
  • Purpose: Compare the safety and efficacy of wavefront-guided photorefractive keratotomy (PRK) 6 months after cross-linking (CXL) to wavefront-guided PRK alone for refractive correction in patients with bilateral asymmetric corneal topography. (bvsalud.org)
  • Crystalens - an FDA-approved intraocular lens for the visual correction of adults with cataracts (clouding of the eye's natural lens secondary to age) with or without presbyopia, or lenses that have aged or become more rigid. (dfweyes.com)
  • Corneal tomography and wavefront data were acquired using Scheimpflug tomography (Pentacam, Oculus, Wetzlar, Germany). (biomedcentral.com)
  • Anterior corneal wavefront, especially anterior coma, were noted to have higher rate of fractional change compared to single point keratometric and pachymetric indices in progressive KC. (biomedcentral.com)
  • Wavefront technology, or aberrometry, diagnoses both lower- and higher-order vision errors represented by the way the eye refracts or focuses light. (presenternet.com)
  • Wavefront aberrometry is the refractory test to measure vision errors. (presenternet.com)
  • They reported no difference in vision quality while driving or visual symptoms such as eye irritation or photophobia. (crstoday.com)
  • The team is also developing processes of applying wavefront-based corrections to various vision correcting lens platforms. (wavefrontdynamics.com)
  • Osiris data can be combined with the topographic maps from other instruments produced by CSO, combining the total aberrometry with the corneal ones of Antares, Sirius or MS-39 it is possible to calculate the wavefront internal component and, for example, to evaluate the impact of a toric system on vision. (csoitalia.it)
  • The Visual Evoked Potential (VEP) and Electroretinography (ERG) provides information about the health of the back of the eye which is critical to vision. (stonehengevisionsource.com)
  • Visual Field Testing measures your central and peripheral vision. (stonehengevisionsource.com)
  • Realizing that 20/20 does not represent perfect vision is important because many young healthy adults have visual acuities of 20/15 to 20/12. (medscape.com)
  • With Visx CustomVue, the WaveScan, sometimes called the vision fingerprint or aberrometry map, is derived from the eye, based on anatomic landmarks. (arizonalasik.com)
  • Investigative Ophthalmology & Visual Science. (wikipedia.org)
  • Department of Ophthalmology and Visual Science, Duke-NUS Graduate Medical School, Singapore, Republic of Singapore. (nih.gov)
  • We analyzed 60 eyes of 30 patients aged 16 to 35 years who were treated at the Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, Brazil. (bvsalud.org)
  • In Investigative Ophthalmology & Visual Science (Vol. 55). (duke.edu)
  • Diopsys Visual Electrophysiology is a set of advanced diagnostic tools that help our doctors analyze the entire visual pathway for visual and neuro-visual disorders. (stonehengevisionsource.com)
  • A wavefront of parallel beams of light enters the eye and is distorted by the refractive error and imperfections of the eye's optical system. (medscape.com)
  • If the eye's visual power after surgery is considerably different than what was planned, surgical replacement of the IOL might be considered. (coastaleyecare.net)
  • How does wavefront analysis work? (presenternet.com)
  • The KR-1W provides the eye care professional with all the required information on the human refractive system to perform optimal wavefront analysis. (metroophthalmic.com)
  • The tool integrates with the Phoenix software, offering a wide range of analysis options, such as refractive error maps and visual simulations (PSF, MTF and convolution with optotype), which helps the clinician to understand and explain the patient's visual problems. (csoitalia.it)
  • The optical quality estimated from the ocular wavefront analysis is within normal range. (defeatkeratoconus.com)
  • What is wavefront technology Used For? (presenternet.com)
  • The process involves creating a 3D image of your eye structure with wavefront technology. (presenternet.com)
  • Committed to advancing wavefront technology for measuring and improving visual performance. (wavefrontdynamics.com)
  • Founded in 2019, Wavefront Dynamics is a privately held medical device company with decades of leadership in wavefront sensing technology for use in measuring and perfecting visual performance. (wavefrontdynamics.com)
  • The QuickSee Free is the only portable refracto-keratometer to use wavefront aberrometry technology. (silmoparis.com)
  • 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. (manchester.ac.uk)
  • Wavefront describes the curve corresponding to the position of multiple light rays exiting the eye that passed the different spots in the area of the pupil, emanating from the point source in the foveola after it passes through the optical system of the eye. (medscape.com)
  • The local slope of the wavefront curve at the particular spot within the pupil is derived from the actual image displacement of the point source from foveola as it passes through the optical system of the eye as compared to the ideal/predicted image of the ideal optical system. (medscape.com)
  • We analyzed visual outcomes, Scheimpflug topography, and corneal haze evaluation. (bvsalud.org)
  • Wavefront Dynamic's Founder and CEO Dan Neal Ph.D. developed a wide variety of applications for wavefront sensors, including measurement of aero-optic phenomena, the large telescope mirrors used in the James Webb Space Telescope, and silicon wafer metrology. (wavefrontdynamics.com)
  • And welcome to one more webinar on the continuation of the topography that we discussed last evening, and aberrometry in clinical practice. (cybersight.org)
  • And this produces a composite wavefront, which can have several components. (cybersight.org)
  • A point source in produces a spherical wavefront, as shown in the image below. (medscape.com)
  • We also encourage researchers to use robust questionnaires to elucidate the impact of visual symptoms on daily functioning," the spokesperson said. (medscape.com)
  • Impact of Delayed Time to Treatment on Visual Outcomes in Neovascular AMD: Data From the HARBOR Study. (academic-accelerator.com)
  • Corneal wavefront data was computed at a radius of 8 mm. (biomedcentral.com)
  • Wavefront-guided treatments use a wave of light to measure the exact optical abnormalities across many points. (presenternet.com)
  • That: What do you understand by optical wavefronts? (cybersight.org)
  • Which of the following statements would best describe optical wavefronts? (cybersight.org)
  • In this example, the power at the visual axis is 4 diopters. (medscape.com)
  • 001) at 12 months, primarily due to decreased subscores for visual function, perception, and problems with corrective lenses. (crstoday.com)
  • and a dual cross-cylinder utilising a split-prism that enables side-by-side comparison of visual impressions for patients. (zeiss.com)
  • CONCLUSION: Using filters in PMMA materials appears to improve visual quality in corneal implants, especially the red filter, due to greater absorbance of light leading to fewer light scattering phenomena through corneal rings. (bvsalud.org)
  • There are currently two types of wavefront surgery, wavefront-optimized and wavefront-guided. (presenternet.com)
  • Despite the challenges of producing and fitting customised lenses, improvements in visual performance and comfortable wear- ing 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. (manchester.ac.uk)
  • To face increasing demands on visual and refractive outcome, efforts have been made to further improve IOL designs. (hindawi.com)
  • However, results of other studies indicate that a postoperative SA of zero should be aimed in order to optimize visual outcome [ 3 , 7 ]. (hindawi.com)