Corneal Wavefront Aberration
Corneal Topography
Aberrometry
Refractive Errors
Accommodation, Ocular
Astigmatism
Lenses
Myopia
Keratomileusis, Laser In Situ
Retinoscopes
Cornea
Diagnostic Techniques, Ophthalmological
Lasers, Excimer
Chromosome Aberrations
Visual Acuity
Ocular wavefront aberrations in patients with macular diseases. (1/53)
(+info)Aberration control and vision training as an effective means of improving accommodation in individuals with myopia. (2/53)
(+info)Study of ocular aberrations with age. (3/53)
(+info)The effect of the asphericity of myopic laser ablation profiles on the induction of wavefront aberrations. (4/53)
(+info)Measurement of the time course of optical quality and visual deterioration during tear break-up. (5/53)
(+info)Detection of subclinical keratoconus by using corneal anterior and posterior surface aberrations and thickness spatial profiles. (6/53)
(+info)Corneal aberrations and visual acuity after laser in situ keratomileusis: femtosecond laser versus mechanical microkeratome. (7/53)
(+info)Estimation of the depth of focus from wavefront measurements. (8/53)
(+info)Corneal wavefront aberration is a measurement of the irregularities in the shape and curvature of the cornea, which can affect the way light enters the eye and is focused on the retina. A wavefront aberration test uses a device to measure the refraction of light as it passes through the cornea and calculates the degree of any distortions or irregularities in the wavefront of the light. This information can be used to guide treatment decisions, such as the prescription for eyeglasses or contact lenses, or the planning of a surgical procedure to correct the aberration.
Corneal wavefront aberrations can be classified into two types: low-order and high-order aberrations. Low-order aberrations include myopia (nearsightedness), hyperopia (farsightedness), and astigmatism, which are common refractive errors that can be easily corrected with glasses or contact lenses. High-order aberrations are more complex irregularities in the wavefront of light that cannot be fully corrected with traditional eyeglasses or contact lenses. These may include coma, trefoil, and spherical aberration, among others.
High-order corneal wavefront aberrations can affect visual quality, causing symptoms such as glare, halos around lights, and decreased contrast sensitivity. They are often associated with conditions that cause changes in the shape of the cornea, such as keratoconus or corneal surgery. In some cases, high-order aberrations can be corrected with specialized contact lenses or refractive surgery procedures such as wavefront-guided LASIK or PRK.
Corneal topography is a non-invasive medical imaging technique used to create a detailed map of the surface curvature of the cornea, which is the clear, dome-shaped surface at the front of the eye. This procedure provides valuable information about the shape and condition of the cornea, helping eye care professionals assess various eye conditions such as astigmatism, keratoconus, and other corneal abnormalities. It can also be used in contact lens fitting, refractive surgery planning, and post-surgical evaluation.
Aberrometry is a medical diagnostic technique used to measure the amount and type of aberration or distortion in the optical system of the eye. It is often used to evaluate the quality of vision, particularly in cases where traditional methods of measuring visual acuity are not sufficient.
During an aberrometry test, the patient looks into a specialized instrument called a wavefront sensor while a series of light patterns are projected onto the retina. The sensor then measures how the light is distorted as it passes through the eye's optical system, including the cornea and lens. This information is used to create a detailed map of the eye's aberrations, which can help doctors identify any irregularities that may be contributing to visual symptoms such as blurred vision, glare, or halos around lights.
Aberrometry is often used in conjunction with other diagnostic tests to evaluate patients who are considering refractive surgery, such as LASIK or PRK. By identifying any abnormalities in the eye's optical system, doctors can determine whether a patient is a good candidate for surgery and make more informed decisions about how to proceed with treatment.
Ocular refraction is a medical term that refers to the bending of light as it passes through the optical media of the eye, including the cornea and lens. This process allows the eye to focus light onto the retina, creating a clear image. The refractive power of the eye is determined by the curvature and transparency of these structures.
In a normal eye, light rays are bent or refracted in such a way that they converge at a single point on the retina, producing a sharp and focused image. However, if the curvature of the cornea or lens is too steep or too flat, the light rays may not converge properly, resulting in a refractive error such as myopia (nearsightedness), hyperopia (farsightedness), or astigmatism.
Ocular refraction can be measured using a variety of techniques, including retinoscopy, automated refraction, and subjective refraction. These measurements are used to determine the appropriate prescription for corrective lenses such as eyeglasses or contact lenses. In some cases, ocular refractive errors may be corrected surgically through procedures such as LASIK or PRK.
Refractive errors are a group of vision conditions that include nearsightedness (myopia), farsightedness (hyperopia), astigmatism, and presbyopia. These conditions occur when the shape of the eye prevents light from focusing directly on the retina, causing blurred or distorted vision.
Myopia is a condition where distant objects appear blurry while close-up objects are clear. This occurs when the eye is too long or the cornea is too curved, causing light to focus in front of the retina instead of directly on it.
Hyperopia, on the other hand, is a condition where close-up objects appear blurry while distant objects are clear. This happens when the eye is too short or the cornea is not curved enough, causing light to focus behind the retina.
Astigmatism is a condition that causes blurred vision at all distances due to an irregularly shaped cornea or lens.
Presbyopia is a natural aging process that affects everyone as they get older, usually around the age of 40. It causes difficulty focusing on close-up objects and can be corrected with reading glasses, bifocals, or progressive lenses.
Refractive errors can be diagnosed through a comprehensive eye exam and are typically corrected with eyeglasses, contact lenses, or refractive surgery such as LASIK.
Ocular accommodation is the process by which the eye changes optical power to maintain a clear image or focus on an object as its distance varies. This is primarily achieved by the lens of the eye changing shape through the action of the ciliary muscles inside the eye. When you look at something far away, the lens becomes flatter, and when you look at something close up, the lens thickens. This ability to adjust focus allows for clear vision at different distances.
A pupil, in medical terms, refers to the circular opening in the center of the iris (the colored part of the eye) that allows light to enter and reach the retina. The size of the pupil can change involuntarily in response to light intensity and emotional state, as well as voluntarily through certain eye exercises or with the use of eye drops. Pupillary reactions are important in clinical examinations as they can provide valuable information about the nervous system's functioning, particularly the brainstem and cranial nerves II and III.
Astigmatism is a common eye condition that occurs when the cornea or lens has an irregular shape, causing blurred or distorted vision. The cornea and lens are typically smooth and curved uniformly in all directions, allowing light to focus clearly on the retina. However, if the cornea or lens is not smoothly curved and has a steeper curve in one direction than the other, it causes light to focus unevenly on the retina, leading to astigmatism.
Astigmatism can cause blurred vision at all distances, as well as eye strain, headaches, and fatigue. It is often present from birth and can be hereditary, but it can also develop later in life due to eye injuries or surgery. Astigmatism can be corrected with glasses, contact lenses, or refractive surgery such as LASIK.
In the context of medical terminology, "lenses" generally refers to optical lenses used in various medical devices and instruments. These lenses are typically made of glass or plastic and are designed to refract (bend) light in specific ways to help magnify, focus, or redirect images. Here are some examples:
1. In ophthalmology and optometry, lenses are used in eyeglasses, contact lenses, and ophthalmic instruments to correct vision problems like myopia (nearsightedness), hypermetropia (farsightedness), astigmatism, or presbyopia.
2. In surgical microscopes, lenses are used to provide a magnified and clear view of the operating field during microsurgical procedures like ophthalmic, neurosurgical, or ENT (Ear, Nose, Throat) surgeries.
3. In endoscopes and laparoscopes, lenses are used to transmit light and images from inside the body during minimally invasive surgical procedures.
4. In ophthalmic diagnostic instruments like slit lamps, lenses are used to examine various structures of the eye in detail.
In summary, "lenses" in medical terminology refer to optical components that help manipulate light to aid in diagnosis, treatment, or visual correction.
Myopia, also known as nearsightedness, is a common refractive error of the eye. It occurs when the eye is either too long or the cornea (the clear front part of the eye) is too curved. As a result, light rays focus in front of the retina instead of directly on it, causing distant objects to appear blurry while close objects remain clear.
Myopia typically develops during childhood and can progress gradually or rapidly until early adulthood. It can be corrected with glasses, contact lenses, or refractive surgery such as LASIK. Regular eye examinations are essential for people with myopia to monitor any changes in their prescription and ensure proper correction.
While myopia is generally not a serious condition, high levels of nearsightedness can increase the risk of certain eye diseases, including cataracts, glaucoma, retinal detachment, and myopic degeneration. Therefore, it's crucial to manage myopia effectively and maintain regular follow-ups with an eye care professional.
Laser In Situ Keratomileusis (LASIK) is a type of refractive surgery used to correct vision issues such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. The procedure involves reshaping the cornea, which is the clear, dome-shaped surface at the front of the eye, using an excimer laser.
In LASIK, a thin flap is created on the surface of the cornea using a femtosecond or microkeratome laser. The flap is then lifted, and the excimer laser is used to reshape the underlying tissue. After the reshaping is complete, the flap is replaced, allowing for quicker healing and visual recovery compared to other refractive surgery procedures.
LASIK is an outpatient procedure that typically takes about 30 minutes or less per eye. Most people can expect to see improved vision within a few days of the procedure, although it may take several weeks for vision to fully stabilize. LASIK has a high success rate and is generally considered safe when performed by a qualified surgeon. However, as with any surgical procedure, there are risks involved, including dry eye, infection, and visual complications such as glare or halos around lights.
A retinoscope is an ophthalmic instrument used by eye care professionals to perform a retinoscopy examination, which is a subjective test used to estimate the refractive error and determine the prescription for eyeglasses or contact lenses. The retinoscope emits a beam of light that is shined onto the patient's retina, and the practitioner observes the reflection of the light (called the "reflex") as it passes through the pupil.
By adjusting the orientation and focus of the retinoscope's light, the practitioner can observe how the reflex changes, which provides information about the patient's refractive error. The retinoscope is an essential tool in eye examinations, particularly for children who may not be able to provide reliable answers to subjective questions about their vision.
The cornea is the clear, dome-shaped surface at the front of the eye. It plays a crucial role in focusing vision. The cornea protects the eye from harmful particles and microorganisms, and it also serves as a barrier against UV light. Its transparency allows light to pass through and get focused onto the retina. The cornea does not contain blood vessels, so it relies on tears and the fluid inside the eye (aqueous humor) for nutrition and oxygen. Any damage or disease that affects its clarity and shape can significantly impact vision and potentially lead to blindness if left untreated.
Diagnostic techniques in ophthalmology refer to the various methods and tests used by eye specialists (ophthalmologists) to examine, evaluate, and diagnose conditions related to the eyes and visual system. Here are some commonly used diagnostic techniques:
1. Visual Acuity Testing: This is a basic test to measure the sharpness of a person's vision. It typically involves reading letters or numbers from an eye chart at a specific distance.
2. Refraction Test: This test helps determine the correct lens prescription for glasses or contact lenses by measuring how light is bent as it passes through the cornea and lens.
3. Slit Lamp Examination: A slit lamp is a microscope that allows an ophthalmologist to examine the structures of the eye, including the cornea, iris, lens, and retina, in great detail.
4. Tonometry: This test measures the pressure inside the eye (intraocular pressure) to detect conditions like glaucoma. Common methods include applanation tonometry and non-contact tonometry.
5. Retinal Imaging: Several techniques are used to capture images of the retina, including fundus photography, fluorescein angiography, and optical coherence tomography (OCT). These tests help diagnose conditions like macular degeneration, diabetic retinopathy, and retinal detachments.
6. Color Vision Testing: This test evaluates a person's ability to distinguish between different colors, which can help detect color vision deficiencies or neurological disorders affecting the visual pathway.
7. Visual Field Testing: This test measures a person's peripheral (or side) vision and can help diagnose conditions like glaucoma, optic nerve damage, or brain injuries.
8. Pupillary Reactions Tests: These tests evaluate how the pupils respond to light and near objects, which can provide information about the condition of the eye's internal structures and the nervous system.
9. Ocular Motility Testing: This test assesses eye movements and alignment, helping diagnose conditions like strabismus (crossed eyes) or nystagmus (involuntary eye movement).
10. Corneal Topography: This non-invasive imaging technique maps the curvature of the cornea, which can help detect irregularities, assess the fit of contact lenses, and plan refractive surgery procedures.
An excimer laser is a type of laser that is used in various medical procedures, particularly in ophthalmology and dermatology. The term "excimer" is derived from "excited dimer," which refers to a short-lived molecule formed when two atoms combine in an excited state.
Excimer lasers emit light at a specific wavelength that is determined by the type of gas used in the laser. In medical applications, excimer lasers typically use noble gases such as argon, krypton, or xenon, combined with halogens such as fluorine or chlorine. The most commonly used excimer laser in medical procedures is the excimer laser that uses a mixture of argon and fluoride gas to produce light at a wavelength of 193 nanometers (nm).
In ophthalmology, excimer lasers are primarily used for refractive surgery, such as LASIK and PRK, to correct vision problems like myopia, hyperopia, and astigmatism. The laser works by vaporizing tiny amounts of tissue from the cornea, reshaping its curvature to improve the way light is focused onto the retina.
In dermatology, excimer lasers are used for various skin conditions, including psoriasis, vitiligo, and atopic dermatitis. The laser works by emitting high-energy ultraviolet (UV) light that selectively targets and destroys the abnormal cells responsible for these conditions while leaving surrounding healthy tissue intact.
Excimer lasers are known for their precision, accuracy, and minimal side effects, making them a popular choice in medical procedures where fine detail and tissue preservation are critical.
Chromosome aberrations refer to structural and numerical changes in the chromosomes that can occur spontaneously or as a result of exposure to mutagenic agents. These changes can affect the genetic material encoded in the chromosomes, leading to various consequences such as developmental abnormalities, cancer, or infertility.
Structural aberrations include deletions, duplications, inversions, translocations, and rings, which result from breaks and rearrangements of chromosome segments. Numerical aberrations involve changes in the number of chromosomes, such as aneuploidy (extra or missing chromosomes) or polyploidy (multiples of a complete set of chromosomes).
Chromosome aberrations can be detected and analyzed using various cytogenetic techniques, including karyotyping, fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH). These methods allow for the identification and characterization of chromosomal changes at the molecular level, providing valuable information for genetic counseling, diagnosis, and research.
Visual acuity is a measure of the sharpness or clarity of vision. It is usually tested by reading an eye chart from a specific distance, such as 20 feet (6 meters). The standard eye chart used for this purpose is called the Snellen chart, which contains rows of letters that decrease in size as you read down the chart.
Visual acuity is typically expressed as a fraction, with the numerator representing the testing distance and the denominator indicating the smallest line of type that can be read clearly. For example, if a person can read the line on the eye chart that corresponds to a visual acuity of 20/20, it means they have normal vision at 20 feet. If their visual acuity is 20/40, it means they must be as close as 20 feet to see what someone with normal vision can see at 40 feet.
It's important to note that visual acuity is just one aspect of overall vision and does not necessarily reflect other important factors such as peripheral vision, depth perception, color vision, or contrast sensitivity.
I'm sorry for any confusion, but "Optics and Photonics" is a broad field that encompasses various scientific and engineering disciplines. It doesn't have a specific medical definition, as it's not a term typically used in a medical context.
However, I can provide a general definition:
Optics is the study of light and its interactions with matter. This includes how light is produced, controlled, transmitted, and detected. It involves phenomena such as reflection, refraction, diffraction, and interference.
Photonics, on the other hand, is a branch of optics that deals with the generation, detection, and manipulation of individual photons, the basic units of light. Photonics is often applied to technologies such as lasers, fiber optics, and optical communications.
In a medical context, these fields might be used in various diagnostic and therapeutic applications, such as endoscopes, ophthalmic devices, laser surgery, and imaging technologies like MRI and CT scans. But the terms "Optics" and "Photonics" themselves are not medical conditions or treatments.
Shack-Hartmann wavefront sensor
Aberrations of the eye
LASIK
UltraVision
Coma (optics)
Keratoconus
Refractive error
Zernike polynomials
Adaptive optics
Peter Hersh
Intraocular lens
Astigmatism (optical systems)
Optician
Randomized Clinical Trial Comparing Femtosecond LASIK and Small-Incision Lenticule Extraction
US20120157377A1 - Methods to enhance night vision and treatment of night blindness - Google Patents
Shack-Hartmann wavefront sensor - Wikipedia
Effect of Spherical Aberration on the Optical Quality after Implantation of Two Different Aspherical Intraocular Lenses
Intrascleral Fixation of an Intraocular Lens through the Pars Plana Prevents Corneal Endothelial Damage | Case Reports in...
JKU-FoDok Forschungsdokumentation der Universit t Linz - Publikation - Simulation of Corneal imaging properties for near objects
CRSToday | Why We Should Tailor the Asphericity of Monofocal IOLs to Each Eye
Mr Mayank Nanavaty</span><i class="icon" aria-hidden=...
DeCS
LASIK Future Advances: Overview, Super Vision by Custom Ablation, IntraLase
Laser Eye Technology | Research | Downloads
CRSTG | Europe Edition | Say Anything
Comparison of corneal epithelial remodeling and corneal aberration changes after FS-LASIK and FS-LASIK Xtra - CJEO Journal
KR-1W | metroophthalmic
Physiotherapy & Medical Books | The Ophthalmic Assistant, 11th Edition
Clinical Outcomes of Small Incision Lenticule Extraction in Myopia: Study of Vector Parameters and Corneal Aberrations
Hyperopia | Harvard Catalyst Profiles | Harvard Catalyst
Full team - Eye Hospital Luxor
Research - University of Galway
PDF) The 25th Anniversary of Laser Vision Correction in the United States
Pesquisa | Portal Regional da BVS
MyCAA Courses for Military Spouses | Ophthalmic Assistant Specialist Certificate Program
PUPIL RELATED STUDIES & ARTICLES
Can I Wear Zero Power Glasses After LASIK Surgery? - Freshersnews
Douglas Donald Koch, M.D. | BCM
The PULZAR Z1
Corneal Ectatic Diseases - A Review of the Latest Treatments, Including Therapeutic Contact Lenses and Surgery | Contact Lens...
Aberrometry and Wavefront Imaging: Historical Perspective, Wavefront Error, Optical Aberrations of the Eye
Case #1 - Defeat Keratoconus
A randomised, prospective study to investigate the efficacy of riboflavin/ultraviolet A (370 nm) corneal collagen cross-linkage...
Higher-order aberrations17
- It is known that aspherical lenses significantly decrease higher-order aberrations (HOA) postoperatively [ 1 ]. (hindawi.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)
- Monochromatic aberrations can be subdivided further into spherical refractive error, cylindrical refractive error, spherical aberration, coma, and higher order aberrations. (medscape.com)
- There are many devices that provide topography and concomitant measurement of higher-order aberrations in one capture that are excellent. (crstodayeurope.com)
- While total corneal root mean square higher order aberrations, coma and trefoil showed statistically significant increase, spherical aberration did not show statistically significant change after SMILE. (ekjo.org)
- Wavefront-guided excimer laser surgery is designed to minimize surgically induced higher order aberrations or compensate for pre-existing higher order aberrations [ 2 ]. (ekjo.org)
- The induced higher-order aberrations from the anterior corneal surface included spherical aberration, y-Trefoil, and x-Tetrafoil. (bvsalud.org)
- Influence of pupil and optical zone diameter on higher-order aberrations. (lasiksucks4u.com)
- PURPOSE: To investigate the influence of pupil and optical zone (OZ) diameter on higher-order aberrations (HOAs) after myopic wavefront-guided laser in situ keratomileusis (LASIK). (lasiksucks4u.com)
- Higher-order aberrations are vision issues that regular eyeglasses cannot treat and require specialized diagnostic testing. (freshersnews.co.in)
- Wang L, Koch DD " Age-related changes in corneal and ocular higher-order aberrations. . (bcm.edu)
- The rate of fractional change was higher for aberrometric parameters (anterior corneal higher-order aberrations root mean square and anterior coma) compared to pachymetric and keratometric parameters ( P values ranging from 1.4 × 10 −4 to 7.4 × 10 −10 , Mann-Whitney test, effect size ranging from 0.4-0.7). (biomedcentral.com)
- iZon Wavefront Aberrometry helps our doctors detect higher order aberrations which are irregularities that affect vision. (stonehengevisionsource.com)
- Some people have higher-order aberrations in the upper eye, gauged in micrometers. (xtgem.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)
- By measuring and mapping both lower and higher-order aberrations, wavefront technology creates a precise three-dimensional representation of the complete optical system. (rub-md.com)
- 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)
Topography14
- Asymmetries in the topography and refractive index of the corneal surface that affect visual acuity. (bvsalud.org)
- Decentration measurements using Placido corneal tangential curvature topography and Scheimpflug tomography pachymetry difference maps after small-incision lenticule extraction Journal of Cataract and Refractive Surgery. (londonvisionclinic.com)
- My first priority is to measure corneal topography and wavefront aberrometry at the initial cataract consultation. (crstodayeurope.com)
- If the patient is interested in a presbyopia-correcting or even a toric IOL but the cornea demonstrates corneal staining and irregular topography, I am hyper-aggressive in optimizing the ocular surface. (crstodayeurope.com)
- I believe that patient education is key, so I often rely on visual aids in the clinic, especially irregular corneal topography images, to demonstrate how keratopathy affects the accuracy of IOL calculations. (crstodayeurope.com)
- The 5-in-1 KR‐1W Wavefront Analyzer boasts the combined technologies of wavefront aberration, corneal topography and auto‐refraction. (metroophthalmic.com)
- Visual acuity measurement, manifest refraction, slit-lamp examination, autokeratometry, corneal topography, and evaluation of corneal wavefront aberration were performed preoperatively and at 1 and 3 months after surgery. (ekjo.org)
- The information includes pupilometry, refraction, topography and wavefront data. (ater-medical.com)
- Alterations in corneal biomechanics lead to abnormalities in the surface topography and affect ocular aberrations that degrade retinal image quality. (rochester.edu)
- Topography-guided The treatment plan for LASIK is customized using information from the corneal topography, which is a novel approach. (rub-md.com)
- A thorough map of the corneal surface is provided by corneal topography, emphasizing even minute abnormalities. (rub-md.com)
- For the evaluation of the performances of a toric system, the combination of corneal topography imported from CSO topographers and ocular aberration, makes it possible to distinguish whether any astigmatic residue is due to a rotation of the lens or to an incorrect calculation. (csoitalia.it)
- Also iDesign captures the detailed topography of the outside of the eye, i.e. the corneal shape. (lipstocklaser.com)
- So, not only is your wavefront data guiding treatment, also each pulse of the laser's energy is altered relative to your outside corneal topography. (lipstocklaser.com)
Order aberrations1
- The ability to measure high order aberrations as well as standard refraction has become the new standard of care for your patients. (csoitalia.it)
Cornea17
- Therefore, we proposed that corneal endothelial cells could be preserved by performing all intraocular manipulations posterior to the iris through a scleral incision at the pars plana, thereby avoiding the cornea. (karger.com)
- The best (wavefront) focus was systematically closer to the cornea compared with the paraxial focus, and the overestimation of focal length with the paraxial focus was larger for large aperture sizes and small object distances. (uni-linz.ac.at)
- Conclusions: The imaging properties of the cornea, especially spherical aberration, increase strongly as the object distance decreases. (uni-linz.ac.at)
- One of the most important discoveries affecting our understanding of human visual optics 1 (and subsequently IOL design 2 ) was that the youthful eye's crystalline lens offsets the spherical aberration (SA) of the cornea, 1,3,4 which averages +0.27 μm. (crstoday.com)
- Optical aberrations are increased because the normal cornea is prolate in shape (steeper in the center), but it becomes oblate (steeper in the periphery) after successful conventional laser ablation profile. (medscape.com)
- In my experience, these patients, if compliant, will quickly separate into two groups: those who return with a cornea that is almost completely normalized (objectively and topographically) and those who return with ongoing corneal pathology. (crstodayeurope.com)
- Carl Zeiss Meditec AG, Jena, Germany) is a relatively new flapless refractive surgery that utilizes a femtosecond laser to create a lenticule of the desired correction within the cornea, which is then extracted through a small corneal incision. (ekjo.org)
- Ectatic corneal disease (ECD) comprises a group of disorders characterized by progressive thinning and protrusion of the cornea, leading to visual impairment. (contactlensupdate.com)
- The irregularity in the corneal tissue between the undisturbed and altered portions of the cornea may be the cause of this association. (freshersnews.co.in)
- Contoura vision, is a form of corneal wavefront topo guided treatment, which removes the aberrations in cornea and gives you clearer vision. (mantracare.in)
- In contrast to conventional LASIK, which includes making a corneal flap, SMILE creates a tiny, lens-shaped piece of corneal tissue (lenticule) inside the cornea using a femtosecond laser. (rub-md.com)
- You may not undergo the procedure if you don't have enough corneal tissue or have other problems with your cornea. (spectrumeye.com)
- Wavefront technology creates a personalized 3-D map of the patient's visual pathway (from the front of the cornea to the back of the retina). (lipstocklaser.com)
- It then gently reshapes the cornea based on the digital information from your personalized wavefront guided 3-D eye map. (lipstocklaser.com)
- Today's most sophisticated LASIK procedure involves totally customized flaps, preplanned on a dashboard using a high-frequency laser and a second pupil-tracking laser to reshape the cornea to correct not only refractive error but corneal aberrations. (seegreat.net)
- An automated device called 'corneal topographer' will be used to measure the curvature of the eye's front surface and a sketch or map of your cornea would be created. (findhealthtips.com)
- The surgeon will fold the 'flap' to get access to the underlying cornea which is called stroma, to remove some corneal tissue by using an excimer laser. (findhealthtips.com)
Laser in situ keratomileusis4
- To investigate the status of corneal epithelial remodeling and changes in corneal aberration after femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) and FS-LASIK combined with corneal collagen cross-linking (FS-LASIK Xtra), and to analyze the relationship between corneal epithelial thickness (CET) and corneal aberration. (cjeo-journal.org)
- Since Jose Barraquer invented keratomileusis for correction of high myopia in 1949, researchers have combined keratomileusis with excimer laser surface ablation to develop one of the most commonly used laser corneal refractive surgery techniques, laser in situ keratomileusis (LASIK) [ 1 ]. (ekjo.org)
- Hamed AM, Wang L, Misra M, Koch DD " A comparative analysis of five methods of determining corneal refractive power in eyes that have undergone myopic laser in situ keratomileusis. . (bcm.edu)
- Comparison of the corneal response to laser in situ keratomileusis with flap creation using the FS15 and FS30 femtosecond lasers: clinical and confocal microscopy findings. (utswmed.org)
Astigmatism5
- Mr Nanavaty's areas of research interest include astigmatism, wavefront aberrations, ectatic corneal disorders, endothelial disease, lamellar corneal transplant surgeries, quality of vision after surgical interventions, cataracts surgical techniques, intraocular lenses and posterior capsule opacification. (nuffieldhealth.com)
- 0.001), 3 mm keratometry (p=0.008), simulated astigmatism (p=0.007), cone apex power (p=0.002), root mean square, coma, spherical aberration, secondary astigmatism and pentafoil (p=0.05) decreased from baseline. (bmj.com)
- Patients with uneven astigmatism or those who have had prior corneal operations have found this method to be especially helpful. (rub-md.com)
- This procedure not only helps correct common vision defects such as myopia, hyperopia and astigmatism (cylindrical vision), it is also capable of measuring and correcting even minute aberrations in the eye, giving results that were,untilnow,considered impossible. (eyenu.com)
- It enables us to not only treat nearsightedness, farsightedness and astigmatism (lower orders of aberration or LOA's) but also higher orders of aberration (HOA's). (lipstocklaser.com)
Aberrometry5
- the ocular wavefront (aberrometry examination) is unremarkable. (defeatkeratoconus.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)
- 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)
- 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)
- 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)
Thickness5
- Corneal epithelial thickness mapping after photorefractive keratectomy for myopia Journal of Refractive Surgery. (londonvisionclinic.com)
- Comparison of Dynamic Contour Tonometry and Goldmann Applanation Tonometry in Relation to Central Corneal Thickness. (eyereum.com)
- Pachymetry is a tool that measures the corneal thickness. (stonehengevisionsource.com)
- Creating the flap necessary for LASIK surgery requires corneal tissue of normal thickness. (spectrumeye.com)
- Differing roles for TCF4 and COL8A2 in central corneal thickness and fuchs endothelial corneal dystrophy. (utswmed.org)
Flap15
- Creation of a corneal flap allows early visual recovery, less discomfort, and reduced stromal inflammation. (ekjo.org)
- Unlike LASIK, surface ablation does not create a flap but uses an excimer laser to expose and remove the corneal stroma after removing the corneal epithelium by mechanical scraping (photorefractive keratectomy) or 20% alcohol (laser epithelial keratomileusis) [ 2 ]. (ekjo.org)
- If you scratch or touch your eyes, the corneal flap could get dislodged and cause serious problems. (freshersnews.co.in)
- This prevents unintentional eye rubbing that could cause the corneal flap to tear. (freshersnews.co.in)
- This lessens the possibility of your corneal flap being accidentally damaged, foreign objects getting into your eyes, or infection from tainted cosmetics. (freshersnews.co.in)
- Forms a thin corneal flap using a microkeratome or Femto Laser. (mantracare.in)
- Instead of using a blade to create the corneal flap, a Femtosecond laser is used to create the flap. (mantracare.in)
- After the laser is ready, the cosmetic surgeon gently peels back the flap as well as replaces it with a piece of corneal cells. (xtgem.com)
- The surgeon can lift and fold back the corneal flap by using the femtosecond laser because it causes tiny bubbles to form in the corneal tissue. (rub-md.com)
- This flap is then lifted, allowing for precise reshaping of the underlying corneal tissue with an excimer laser. (internationalvisioncenters.com)
- After the eye has been numbed, the laser creates an incredibly thin incision that allows a flap of the outer layer of corneal tissue, the epithelial layer, to be pulled aside. (spectrumeye.com)
- We have both an Intralase FS femtosecond laser for precise bladeless flap creation, and a VISX Star S4 IR excimer laser for wavefront-guided corneal shaping. (newvisionrockford.com)
- iLASIK first starts with the Intralase laser 100% blade-free approach to creating the corneal flap. (lipstocklaser.com)
- During the early days of LASIK-type procedures, the surgeon would use a mechanized tool with a blade to create the corneal flap and a somewhat crude (by today's standard) laser to reshape the corneal surface. (seegreat.net)
- After creation of the corneal flap, your surgeon will use computer to adjust the excimer laser for getting the perfect position. (findhealthtips.com)
Keratoconus5
- Femtosecond laser-assisted small incision sutureless intrastromal lamellar keratoplasty (SILK) for corneal transplantation in keratoconus Journal of Refractive Surgery. (londonvisionclinic.com)
- Clinical examination with the slit lamp revealed signs of keratoconus, with prominent corneal nerves in the left corneal stroma. (defeatkeratoconus.com)
- Conclusions Corneal collagen cross-linkage appears to be an effective and safe modality to halt the progression of keratoconus. (bmj.com)
- To compare the rate of fractional change for multiple corneal tomographic factors in progressive keratoconus (KC). (biomedcentral.com)
- Marked reduction of alcohol dehydrogenase in keratoconus corneal fibroblasts. (utswmed.org)
Refraction1
- The latter uses the data from your simple refraction and then adds to that the treatment of only one of your HOA's called spherical aberration. (lipstocklaser.com)
Underlying corneal tissue1
- This variation on LASIK surgery employs a specialized device called an epikeratome that can separate the epithelial tissues from the underlying corneal tissue without cutting into it. (spectrumeye.com)
Negative spherical aberration2
- In a recent study, normal eyes were randomly assigned to receive either an aberration-free IOL (enVista, Bausch +Lomb) or a negative spherical aberration IOL (Tecnis, -0.27 μm) without customized selection for preexisting corneal SA. (crstoday.com)
- The corneal deformation causes the ocular wavefront to be distorted (coma, negative spherical aberration, trefoil). (defeatkeratoconus.com)
Excimer2
- Cases with previous history of ocular surgery, poor scans, corneal scars, severe dry eyes, post-excimer ectasia, pellucid marginal degeneration were excluded. (biomedcentral.com)
- Then the STAR S4 IR Excimer Laser, with the newest I Design 2.0 wavefront-guided software, is used. (lipstocklaser.com)
Visual acuity2
- 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)
- The system features full auto‐alignment, a large color touch screen, onboard evaluation software, wavefront image sequence and simulated visual acuity assessment. (metroophthalmic.com)
Changes in corneal2
- The postoperative ΔCET after FS-LASIK Xtra is smaller than that after FS-LASIK, but the homogeneity of ΔCET in each region is similar between the two groups.The changes in corneal HOA after surgery are similar in both groups, and there is a certain association between the overall epithelial distribution and corneal aberration. (cjeo-journal.org)
- A non-contact and non-invasive method was used to temporarily elevate IOP to multiple levels and the corresponding changes in corneal wavefront aberrations induced by the IOP elevations were measured. (rochester.edu)
Slope of the wavefront2
- While Shack-Hartmann sensors measure the localized slope of the wavefront error using spot displacement in the sensor plane, Pamplona et al. (wikipedia.org)
- 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)
Myopia1
- Photorefractive keratectomy combined with corneal wavefront-guided and hyperaspheric ablation profiles to correct myopia. (eyereum.com)
Coma2
- A small increase in postoperative corneal higher order aberration may be associated with increase in coma and trefoil. (ekjo.org)
- 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)
Transplantation2
- however, if possible, secondary IOL implantation procedures should be avoided requiring corneal transplantation. (karger.com)
- Dr. Mootha has delivered scores of national and international presentations, served as principal investigator for several National Institutes of Health-funded research projects, and published numerous academic articles on corneal transplantation and Fuchs' endothelial corneal dystrophy. (utswmed.org)
Individual corneal2
- We developed novel methods to characterize individual corneal material properties including the anisotropic collagen fibrils distribution, collagen fiber stiffness and nonlinearity using optical information to overcome the traditional challenges in corneal material characterization. (rochester.edu)
- Unlike standardized corrective methods, Wavefront Custom Vue compensates for all the little aberrations and variations in your individual corneal contours by using wavefront techniques to map the corneal surface in precise detail. (spectrumeye.com)
Endothelial9
- We report two cases of aphakia in whom an intraocular lens (IOL) was intrasclerally fixated through the pars plana to minimize further corneal endothelial damage. (karger.com)
- Corneal endothelial cells were preserved after surgery. (karger.com)
- Intrascleral fixation of an IOL through the pars plana effectively minimizes further damage to corneal endothelial cells in select cases. (karger.com)
- Therefore, intrascleral IOL fixation must be performed with utmost care to prevent further damage to the diminished corneal endothelial cells. (karger.com)
- Here, we report the successful preservation of corneal endothelial cells using this method in two cases. (karger.com)
- Koch DD, Liu JF, Glasser DB, Merin LM, Haft E " A comparison of corneal endothelial changes after use of Healon or Viscoat during phacoemulsification. . (bcm.edu)
- Corneal power measurement with a rotating Scheimpflug imaging system after Descemet-stripping automated endothelial keratoplasty. (utswmed.org)
- Fuchs' Endothelial Corneal Dystrophy and RNA Foci in Patients With Myotonic Dystrophy. (utswmed.org)
- TCF4 Triplet Repeat Expansion and Nuclear RNA Foci in Fuchs' Endothelial Corneal Dystrophy. (utswmed.org)
Measurement2
- Based upon the corneal wavefront measurement of SA, Packer et al customized selection between a Tecnis aspheric monofocal IOL (Johnson & Johnson Vision) with an SA of -0.27 μm, an AcrySof IQ (Alcon) with an SA of -0.2 μm, and a SofPort AO (Bausch + Lomb) with an SA of 0 μm SA. (crstoday.com)
- Real-time measurement of the ocular wavefront is indispensable during the evaluation of the accommodative phases. (csoitalia.it)
Myopic1
- To investigate clinical outcomes of small incision lenticule extraction (SMILE) including vector parameters and corneal aberrations in myopic patients. (ekjo.org)
Methods2
- Methods: This raytracing simulation determined the best focus (with the least root-mean-square (rms) ray scatter) and the best wavefront focus (with least rms wavefront error) for four schematic model eyes (Liou-Brennan (LBME), Atchison (ATCHME), Gullstrand (GULLME) and Navarro (NAVME)) with 4 aperture sizes (2-5 mm) and 30 object distances in a logscale from 10 cm to 10 m plus infinity. (uni-linz.ac.at)
- Traditional LASIK methods frequently failed to address specific corneal abnormalities since they relied on the patient's eyeglass prescription. (rub-md.com)
Custom wavefront2
- Over time, the laser systems used within LASIK have continued to develop, especially with the integration of Custom Wavefront technology. (seegreat.net)
- Custom Wavefront has given LASIK specialists a level of refinement that they didn't have previously. (seegreat.net)
Optical17
- A Shack-Hartmann (or Hartmann-Shack) wavefront sensor (SHWFS) is an optical instrument used for characterizing an imaging system. (wikipedia.org)
- To compare the effect of spherical aberration on optical quality in eyes with two different aspherical intraocular lenses. (hindawi.com)
- Optical quality was better in eyes with the aberration-correcting Tecnis IOL when pupils were large. (hindawi.com)
- IOL displacement such as tilt and decentration could not only impair its aberration-correcting effect but may even induce additional optical aberrations [ 4 , 5 ]. (hindawi.com)
- Some studies indicate that aberration-free aspheric IOLs may result in better optical quality compared to aberration-correcting aspheric IOLs-even in case of decentration and tilt of the IOL [ 8 ]. (hindawi.com)
- 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)
- Some studies in patients of cataract age without corneal disease or a history of keratorefractive surgery have shown a wide range of corneal SAs, generally measured at the 6-mm optical zone (eg, +0.076 to +0.544 μm 14 ). (crstoday.com)
- If optical aberrations in the eye could be eliminated, the theoretical limit of foveal acuity would be 20/12 for a small pupil and up to 20/5 for a dilated pupil. (medscape.com)
- The optical aberration produced by each individual's eye is as distinct as each individual's fingerprints. (medscape.com)
- Optical aberrations are classified into monochromatic and chromatic types. (medscape.com)
- Wavefront analysis technology has enabled physicians to measure higher-order optical aberrations in addition to spherocylinders in clinical practice. (medscape.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)
- 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)
- Ideal wavefront of an optical system with no aberrations in place. (medscape.com)
- ZCAD custom ablation software designs and refines a surgical plan to correct the optical systems aberrations. (ater-medical.com)
- The goal of this thesis work is aimed towards investigating the interaction of corneal biomechanical and optical behaviors through development of a corneal model. (rochester.edu)
- With this model, we studied the relative contribution of various geometrical and material parameters to corneal biomechanical and optical behaviors. (rochester.edu)
Biomechanical3
- However, this procedure can induce loss of corneal biomechanical strength and worsen dry eye [ 2 ]. (ekjo.org)
- To examine wavefront aberrations induced by biomechanical effects after Small Incision Lenticule Extraction (SMILE) surgery. (bvsalud.org)
- The results showed that the induced wavefront aberrations were noticeable from biomechanical effects after SMILE surgery. (bvsalud.org)
Compensate3
- Aberration-correcting aspherical IOLs are aiming to compensate for the corneal spherical aberration of the eye. (hindawi.com)
- 9 Studies in which one eye was randomly assigned to a spherical IOL and the other to an aspheric IOL have confirmed these findings for IOLs that partially 10 or fully 11 compensate for average corneal SA as well as for zero-aberration IOLs. (crstoday.com)
- The purpose of an ophthalmic adaptive optics system is to compensate for wavefront aberrations caused by a distorting ocular medium, which blurs the retinal field. (universityofgalway.ie)
Spherical aberrations2
- Today, it is widely recognized that implantation of spherical IOLs leads to increased spherical aberrations (SA), therefore decreasing retinal image quality [ 1 ]. (hindawi.com)
- We showed that SMILE did not induce spherical aberrations. (ekjo.org)
Pachymetry1
- Aborted SMILE due to false plane creation and strategy for subsequent removal based on corneal layered pachymetry imaging Journal of Cataract and Refractive Surgery. (londonvisionclinic.com)
Cataract3
- Mr Nanavaty works as a cataract, corneal and refractive surgeon at the University Hospitals Sussex NHS Foundation Trust. (nuffieldhealth.com)
- Mr Nanavaty specialises in cataract, corneal and refractive surgery. (nuffieldhealth.com)
- The 3-D Wave allows you to evaluate your patient comprehensively, perform refractive and cataract surgery screenings (including multifocal, accommodative and wavefront IOL's), evaluate postoperative complaints, determine pathology diagnoses and diagnose patient complaints which would not have been diagnosed before! (biomarcinc.com)
Ocular aberrations1
- Osiris, is a total ocular aberrometer, and is indispensable for the correct evaluation of critical patients who have, in addition to traditional low-order defects, even more complex ocular aberrations. (csoitalia.it)
Chromatic aberrations1
- Wavefront analysis instruments do not analyze degradation of the image caused by the chromatic aberrations. (medscape.com)
Refractive error1
- Since biological structures in the eye contain imperfections, these aberrations are not accounted for by spherical and cylindrical refractive error. (medscape.com)
IOLs3
- Aberration-free aspherical IOLs follow another concept of aspherical IOL design. (hindawi.com)
- IOLs that produce no aberrations (eg, zero-aberration aspheric IOLs) are also available. (crstoday.com)
- This makes it possible to now accurately measure patients with cataracts, corneal opacities, IOLs, and post LASIK. (biomarcinc.com)
Correction5
- Refractive Changes After Corneal Stromal Filler Injection for the Correction of Hyperopia. (harvard.edu)
- AO systems are comprised of three main elements: a wavefront sensor that measures distortion as the light scatters off the retina and exits the eye, a wavefront corrector (adaptive mirror) that compensates for this distortion, and a control system to measure the distortion from the sensor and adjust the mirror shape for optimal correction. (universityofgalway.ie)
- Your eye doctor uses Wavefront Custom Vue technology to achieve the most precise correction possible. (spectrumeye.com)
- Eye&U also offers Wavefront assisted vision correction technology which scores over other procedures for vision correction in several ways. (eyenu.com)
- Wavefront assisted customized LASIK is a cutting edge laser vision correction technique where a spot laser also removes tiny aberrations in the eye, that may occur after conventional (or Plano) LASIK, thus improving the outcome of the surgery. (eyenu.com)
Ectasia1
- These include dry eyes, halos or glare around lights at night, overcorrection or undercorrection of vision, and rare complications such as infection or corneal ectasia. (internationalvisioncenters.com)
Irregularities1
- [ 5 ] If corneal aberrations and irregularities could be reduced after LASIK, then halo, glare, and monocular diplopia also should be reduced. (medscape.com)
Procedure1
- This type of aberration currently cannot be corrected by any procedure. (medscape.com)
Positively correlated1
- Spherical aberration was positively correlated with corrected diopter (D), but x-Tetrafoil and y-Trefoil remained stable. (bvsalud.org)
LASIK Surgery1
- Surgeons can achieve more precise corneal reshaping during LASIK surgery, providing outstanding visual outcomes and lowering the chance of post-operative visual problems including glare and halos. (rub-md.com)
Incision1
- Most procedures create a corneoscleral or corneal incision and require the placement of an IOL on the iris following some intracameral manipulations. (karger.com)
Hartmann-Shack1
- Wavefront measurements were performed with a Hartmann-Shack sensor in maximum mydriasis preoperatively and 12 months after LASIK. (lasiksucks4u.com)
Minimizes1
- Minimizes post-operative symptoms like corneal haze and scarring. (ater-medical.com)
Placido1
- The workhorse of my evaluation is the OPD-Scan III (Nidek) to assess corneal aberration profiles and Placido disc mires. (crstodayeurope.com)
Scheimpflug1
- Corneal tomography and wavefront data were acquired using Scheimpflug tomography (Pentacam, Oculus, Wetzlar, Germany). (biomedcentral.com)
Surgery7
- After surgery, contrast sensitivity and wavefront measurements as well as tilt and decentration measurements were performed. (hindawi.com)
- We analyzed the safety, efficacy, vector parameters, and corneal aberrations at 3 months after surgery. (ekjo.org)
- Surface ablation laser surgery is another type of corneal refractive surgery. (ekjo.org)
- Technological advancements have allowed incorporation of wavefront technology to laser refractive surgery. (ekjo.org)
- Secondary ectasias, on the other hand, refer to corneal shape changes caused by external factors, such as corneal surgery or trauma, with no underlying ectatic propensity existing, and would be considered "thinning disorders" as opposed to a primary ECD. (contactlensupdate.com)
- He then received advanced training in treating corneal and external eye disease and performing keratorefractive surgery through a fellowship at UT Southwestern Medical Center. (utswmed.org)
- Over the years, a number of innovations such as eye trackers, iris registration, wavefront technology and the introduction of ultra-precise lasers have improved safety and outcomes of refractive surgery. (seegreat.net)
Fibroblasts1
- 1. TGF-β regulate TGFBIp expression through coordination between miR-21 and miR-181a, and Smad signaling in corneal fibroblasts. (eyereum.com)
Defocus1
- The magnitude of this shift provides data to estimate the first-order parameters such as radius of curvature and hence error due to defocus and spherical aberration. (wikipedia.org)
Lasers1
- While older lasers only correct the spherical and cylindrical power, the aberrometer can measure many more types of aberrations and correct them. (eyenu.com)
Slit-lamp1
- Slit-lamp, confocal, and light microscopic findings of corneal siderosis. (utswmed.org)
Cannot be corrected1
- These aberrations cannot be corrected by spectacles. (defeatkeratoconus.com)
Precise1
- A wavefront technology will be used to send light waves through your eyes to create a more precise map of aberrations which affect your vision. (findhealthtips.com)
Characterize1
- Shack-Hartmann sensors are used in astronomy to measure telescopes and in medicine to characterize eyes for corneal treatment of complex refractive errors. (wikipedia.org)