Higher order corneal aberrations. Medical search. Frequent questions

Alhaji, H. Evaluation of Anterior and Posterior Corneal Higher Order Aberrations for the Detection of Keratoconus and Suspect Keratoconus. (preprints.org)
Aim: To investigate the application of anterior and posterior corneal higher order aberrations (HOAs) in detecting keratoconus (KC) and suspect keratoconus (SKC). (preprints.org)
Conclusion: Anterior and posterior corneal higher order aberrations can differentiate between keratoconus and normal eyes, with a high level of certainty. (preprints.org)
In suspect keratoconus disease however, only anterior corneal HOAs, and in particular coma-like aberrations, are of value. (preprints.org)
Corneal aberrometry may be of value in screening for keratoconus in populations with a high prevalence of the disease. (preprints.org)
Coma is common in patients with decentred corneal grafts, keratoconus, and decentred laser ablations. (wikipedia.org)
Keratoconus and related noninflammatory corneal thinning disorders. (medscape.com)
Keratoconus is a progressive, bilateral and often asymmetric corneal disorder characterized by thinning and steepening of the central and paracentral cornea that causes high myopia and irregular astigmatism [1-3] . (lww.com)
Rigid gas permeable contact lenses (RGP CLs) provide a tear layer between the irregular corneal surface and the contact lens and thus provide excellent vision for patients with keratoconus and improve patients' quality of life [1,5-7] . (lww.com)
Modern evaluations have broadened their scope beyond mere anterior corneal analysis to incorporate advanced techniques such as OCT-based epithelial mapping for early keratoconus detection. (crstoday.com)
Keratoconus causes a reduction in the optical quality of the eye as a result of corneal distortion, corneal scarring and higher-order aberrations. (college-optometrists.org)
Aims To characterise posterior corneal surface features in patients with Down syndrome (DS) and to compare them with healthy and mild keratoconus corneas. (bmj.com)
Only patients with no previous ocular surgery, no corneal scars and no active ocular disease other than keratoconus were included. (bmj.com)
The Sirius System topographer (CSO, Firenze, Italy) was used in order to analyse posterior corneal surface keratometry, shape and keratoconus screening indices, posterior corneal aberrations, corneal volume and pachymetry. (bmj.com)
Additionally, posterior corneal surface in patients with DS shows similar characteristics to those found in mild keratoconus. (bmj.com)
Keratoconus is a corneal ectasia characterised by progressive corneal thinning that results in gradual corneal protrusion, irregular astigmatism and decreased vision. (bmj.com)
9 In a recent work developed by our investigation team, 10 it was reported that patients with DS may present corneal morphological alterations similar to keratoconus in more than 70% of the cases, emphasising the importance of an early ophthalmic evaluation in this group of patients. (bmj.com)
Different studies report that posterior corneal surface data are useful in the diagnosis of keratoconus 11-13 and show a high discrimination capability in the early stages of the disease. (bmj.com)
14 Additionally, posterior corneal surface characteristics correlate well with the degree of visual impairment in patients with keratoconus and might be used to determine the severity of the disease. (bmj.com)
Three-Step Treatment of Keratoconus and Post-LASIK Ectasia: Implantation of ICRS, Corneal Cross-linking, and Implantation of Toric Posterior Chamber Phakic IOLs. (freevis.de)
Femtosecond laser-assisted small incision sutureless intrastromal lamellar keratoplasty (SILK) for corneal transplantation in keratoconus Journal of Refractive Surgery. (londonvisionclinic.com)
Izquierdo L, Henriquez MA, Dañin D. Corneal Elevation Values in Normal Eyes, forme fruste Keratoconus and Keratoconus at Different Stages Measured by Scheimpflug Imaging. (ijkecd.com)
To compare corneal elevation values in normal eyes, forme fruste keratoconus (FFKC) and different stages of keratoconus using Scheimpflug imaging. (ijkecd.com)
2000. Intrastromal inserts in keratoconus and ectatic corneal conditions 2000;95-163. (ijkecd.com)
Corneal higher order aberrations: a method to grade keratoconus. (ijkecd.com)
Keratoconus and corneal ectasia after LASIK. (ijkecd.com)
Reproducibility and repeatability of central corneal thickness measurement in keratoconus using the rotating Scheimpflug camera and ultrasound pachymetry. (ijkecd.com)
Sensitivity and specificity of posterior corneal elevation measured by Pentacam in discriminating keratoconus/ subclinical keratoconus. (ijkecd.com)
Corneal volume, pachymetry and correlation of anterior and posterior corneal shape in subclinical and different stages of clinical keratoconus. (ijkecd.com)
Estimation of the incidence and factors pre-dictive of corneal scarring in the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study. (ijkecd.com)
Longitudinal changes in corneal curvature in keratoconus. (ijkecd.com)
Correlation of Corneal Elevation With Severity of Keratoconus by Means of Anterior and Posterior Topographic Analysis. (ijkecd.com)
To compare the rate of fractional change for multiple corneal tomographic factors in progressive keratoconus (KC). (biomedcentral.com)
The indications for FLAK and conventional PKP are almost identical: previously failed PKP, corneal scarring or opacification, keratoconus or other types of ectasia and various corneal dystrophies. (reviewofophthalmology.com)
Marked reduction of alcohol dehydrogenase in keratoconus corneal fibroblasts. (utswmed.org)
Technological advancements in the design of soft and scleral contact lenses have led to the development of customised, aberration-controlling corrections for patients with keratoconus. (manchester.ac.uk)
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)
These are ultra-violet corneal crosslinking and intracorneal ring segments for mild to moderate keratoconus, and penetrating keratoplasty or deep anterior lamellar keratoplasty for the more advanced cases of keratoconus. (biomedcentral.com)
Thus, it aims at corneal stabilization in eyes with advanced keratoconus, and enabling continued contact lens wear for normal visual functionality. (biomedcentral.com)
The treatment seems to be a promising option in the management of advanced keratoconus in order to postpone or prevent a more invasive corneal surgery, while minimizing the risk of complications and allowing less stringent surveillance and less intensive medical therapy. (biomedcentral.com)
Clinical outcomes of Descemet membrane endothelial keratoplasty performed in eyes with keratoconus and corneal endothelial dysfunction. (niios.com)
It is indicated for use in corneal collagen cross-linking in combination with the KXL System for the treatment of progressive keratoconus. (medscape.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)
When evaluating patients for refractive surgery, two critical factors are age and corneal topography. (crstoday.com)
Corneal topography. (crstoday.com)
Ensure that the topography is regular and there is sufficient corneal thickness for laser correction. (crstoday.com)
Each step of SCTK entails the use of tomography, topography, and aberrometry followed by the execution of a corneal wavefront-guided customized ablation pattern and wet PTK (ie, smoothing) with a tomographic quality check at the end. (crstodayeurope.com)
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)
Slit-lamp microscopy, corneal topography, and optical coherence tomography were performed for the clinical examination of the patient's eye. (molvis.org)

In a rabbit model of DMEK surgery, SF artificial endothelial graft restored the corneal transparency and thickness at 6 week of follow-up. (arvojournals.org)
Anterior segment optical coherence tomography revealed the SF graft as a fully integrated component in the corneal tissue, displaying a similar corneal thickness and endothelial cell count when compared with its healthy contralateral cornea. (arvojournals.org)
Corneal epithelial thickness mapping after photorefractive keratectomy for myopia Journal of Refractive Surgery. (londonvisionclinic.com)
According to a multiple generalised estimating equation model, the root mean square of total higher-order aberrations was related to age (ß = 0.081, p = 0.002), crystalline lens thickness (ß = 0.08, p (bvsalud.org)
The root mean square of total coma aberration was directly related to the female sex (ß = 0.02, p = 0.05), and crystalline lens thickness (ß = 0.06, p (bvsalud.org)
There was a direct relationship between the root mean square of third- and fourth-order higher-order aberrations and crystalline lens thickness (p (bvsalud.org)
Spherical aberration was directly related to the male sex (ß = -0.02, p = 0.004), axial length (ß = 0.05, p anterior chamber depth (ß = -0.07, p = 0.031) and crystalline lens thickness (ß = -0.25, p (bvsalud.org)
The most significant factor that determined VA improvement in eyes with LV using LEW was the corneal opacity grade, while the corneal topographic parameters, including keratometric refractive parameters (K max , K s , K f , and Cylinder), higher-order aberrations (HOAs), and central corneal thickness (CCT), showed no or limited impact on the VA improvement effect by LEW in LV. (fortunejournals.com)
Differing roles for TCF4 and COL8A2 in central corneal thickness and fuchs endothelial corneal dystrophy. (utswmed.org)
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)
Corneal thickness and posterior elevation before and after DMEK in left eyes (OS) with less than 50 μm (A) or more than 100 μm (B) of corneal edema. (jamanetwork.com)
Human corneal thickness and its impact on intraocular pressure measures: a review and meta-analysis approach. (jamanetwork.com)
The results of the procedure have been encouraging, with approximately 80-90% of treated eyes reaching topographic stability [ 3 ], but the procedure may only be indicated in corneas with minimum corneal thickness of 400 μm. (biomedcentral.com)
1. Corneal thickness - laser vision corrections on the cornea reduce the thickness of the cornea in order to flatten it. (laservue.com)
Pachymetry is a tool that measures the corneal thickness. (stonehengevisionsource.com)

Extreme prematurity itself is associated with increased higher-order aberrations of the cornea. (aao.org)
Several studies have reported a compensation of the aberration of the cornea by the aberration of the crystalline lens. (wikipedia.org)
The spherical aberration of the cornea is usually positive whereas the young crystalline lens exhibits a negative spherical aberration. (wikipedia.org)
Besides, there is strong evidence of compensation for aberrations between the cornea and intraocular optics in cases of astigmatism (horizontal/vertical) and horizontal coma. (wikipedia.org)
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)
Pellucid marginal degeneration (PMD) is a bilateral, noninflammatory, peripheral corneal thinning disorder characterized by a peripheral band of thinning of the inferior cornea. (medscape.com)
If corneal HOAs are detected and correspond to alterations in the anterior corneal surface, they can be treated only by reshaping the cornea with customized excimer ablation (ie, SCTK) based on the corneal wavefront. (crstodayeurope.com)
An AcrySof PanOptix trifocal toric IOL sitting behind a cornea that was previously flattened by LASIK for what looks like a moderate to high myopic refraction is less likely to deliver optimal quality of vision. (crstodayeurope.com)
The technique consists of transplanting an isolated donor Bowman layer into a mid-stromal pocket of a keratoconic cornea resulting in corneal flattening and stabilization against further ectasia. (biomedcentral.com)
Vercammen H, Miron A, Oellerich S, Melles GRJ, Ni Dhubhghaill S, Koppen C, van den Bogerd B. Corneal endothelial wound healing: Understanding the regenerative capacity of the innermost layer of the cornea. (niios.com)
If your prescription is too high or the cornea is too thin, it is not safe to perform a laser vision correction. (laservue.com)
2. Initial corneal curvature - Since the cornea is being flattened, if your cornea starts off relatively flat and must be flattened further, the result could cause problems with aberrations or dryness. (laservue.com)
Ectatic corneal disease (ECD) comprises a group of disorders characterized by progressive thinning and protrusion of the cornea, leading to visual impairment. (contactlensupdate.com)
Corneal Cross-Linking: Current USA Status: Report From the Cornea Society. (snec.com.sg)

The Sirius Scheimpfug (CSO, Italy) analyzer was used to measure HOAs of the anterior and posterior corneal surfaces. (preprints.org)
Based on the iTrace (Tracey Technologies) data, his corneal higher-order aberrations (HOAs)-including coma and trefoil-are elevated. (crstoday.com)
SCTK is a transepithelial, customized, multistepped approach that addresses corneal higher-order aberrations (HOAs). (crstodayeurope.com)
HOAs such as spherical aberration and secondary astigmatism, however, can reduce contrast sensitivity, and coma and trefoil can reduce visual resolution. (crstodayeurope.com)
The main advantage of SCTK is that it treats corneal HOAs while removing a minimal amount of tissue. (crstodayeurope.com)
The procedure reshapes the corneal surface, and it prioritizes the elimination of HOAs over the correction of ametropia. (crstodayeurope.com)
Corneal HOAs caused by alterations in the posterior corneal surface are rare and cannot be corrected with SCTK or cataract surgery. (crstodayeurope.com)
If corneal HOAs are still present or the surgeon is not satisfied with the outcome, a new corneal wavefront-guided customized ablation pattern, derived from the intraoperative corneal wavefront measurement, can be executed immediately, followed by wet PTK. (crstodayeurope.com)

Then I'll discuss some of the challenges of bringing this technology to more widespread use in corneal transplantation. (reviewofophthalmology.com)
As with any emerging medical technology, some clinicians met the use of the femtosecond laser in corneal transplantation with trepidation. (reviewofophthalmology.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)
Corneal transplantation. (niios.com)
The side effects of an experimental 'gene-silencing' treatment that is currently being investigated for a variety of diseases could be useful in corneal transplantation, where growth of new blood and lymph vessels is believed to be a major cause of graft failure. (ophthalmologytimes.com)
In fact, the formation of lymphatic vessels after corneal transplantation is purported to be a major mechanism through which transplant rejection occurs. (ophthalmologytimes.com)
Her areas of subspecialty include cataract surgery with intraocular lens implantation, management of corneal and external eye diseases, corneal transplantation surgeries, refractive surgeries including LASIK and medical contact lenses. (snec.com.sg)
She has mentored and trained both local and international ophthalmologists in cataract, refractive and corneal transplantation surgeries. (snec.com.sg)

Low order aberrations include Myopia (positive defocus), hyperopia (negative defocus), and regular astigmatism. (wikipedia.org)
Spherical aberration is the cause of night myopia and is commonly increased after myopic LASIK and surface ablation. (wikipedia.org)
Spherical aberration exacerbates myopia in low light (night myopia). (wikipedia.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)
For that reason, refractive errors-myopia, hyperopia, and astigmatism-can increase after SCTK, but cataract surgery with IOL implantation following SCTK can eliminate these remaining lower-order aberrations (LOAs). (crstodayeurope.com)
Preoperative refraction, age and optical zone as predictors of optical and visual quality after advanced surface ablation in patients with high myopia: a cross-sectional study. (freevis.de)
Three-Year Stability of Posterior Corneal Elevation After Small Incision Lenticule Extraction (SMILE) for Moderate and High Myopia. (freevis.de)
Figure 1 shows that the patient has high myopia (evidenced by long axial length) and flat (oblate) corneas with residual oblique astigmatism (astigmatism measured by total keratometry was 2.35 D @ 43º). (crstodayeurope.com)
Can Lasik Surgery Help High Myopia? (laservue.com)

Conclusions Posterior corneal surface of patients with DS is steeper, more irregular and shows more higher order aberrations, as well as reduced volume and thinner pachymetry than patients with healthy corneas. (bmj.com)
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)

Treatment of Corneal Ectasia by Implantation of an Allogenic Corneal Lenticule. (freevis.de)
Risk factors and prognosis for corneal ectasia after LASIK. (ijkecd.com)
Cases with previous history of ocular surgery, poor scans, corneal scars, severe dry eyes, post-excimer ectasia, pellucid marginal degeneration were excluded. (biomedcentral.com)

The distance in micrometers between the actual wavefront and the ideal wavefront is the wavefront aberration, which is the standard method of showing the aberrations of the eye. (wikipedia.org)
The accommodative response of the eye results in changes to the lens shape and substantially affects the wavefront aberration pattern. (wikipedia.org)

Other lower-order aberrations are non- visually significant aberrations known as first order aberrations, such as prisms and zero-order aberrations (piston). (wikipedia.org)
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)

Someone with no vision disturbances or refractive errors will show a normal, uninterrupted corneal curvature. (neovisioneyecenters.com)
A formula that takes postrefractive corneal curvature into account, such as the Barrett True-K, would be used for the IOL power calculation. (crstodayeurope.com)

Wang L, Koch DD " Age-related changes in corneal and ocular higher-order aberrations. . (bcm.edu)
To determine the distribution of ocular residual astigmatism (ORA) in astigmatic eyes and the influence on the anterior corneal (ACA) and refractive astigmatism (RA). (nature.com)
Twenty three years ago, based on the term residual astigmatism, Alpins 2 proposed the parameter ocular residual astigmatism (ORA) to express the discrepancy between corneal and refractive astigmatism (RA). (nature.com)
The association between ocular biometric components and corneal aberrations. (bvsalud.org)
To determine the relationship between ocular biometric components and corneal higher-order aberrations in an elderly population . (bvsalud.org)
Ocular biometric components are related to corneal aberrations in the elderly . (bvsalud.org)
The danger presented by these wavelengths is amplified due to the fact that ocular focus is possible, and collimated light within this range is focused by the eye on a very small spot on the retina, concentrating its power to a high density. (microscopyu.com)

0.9 for all except RMS spherical aberrations (AUC = 0.846). (preprints.org)
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)

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)

Many techniques for measuring the eye's aberrations have been described, The most common technique is Shack-Hartmann aberrometry. (wikipedia.org)
Anterior segment imaging and corneal aberrometry were performed using Pentacam AXL. (bvsalud.org)
iZon Wavefront Aberrometry helps our doctors detect higher order aberrations which are irregularities that affect vision. (stonehengevisionsource.com)

Evaluation of femtosecond laser-assisted and manual clear corneal incisions and their effect on surgically induced astigmatism and higher-order aberrations. (freevis.de)
Clear lens extraction is approached from the refractive surgery standpoint: management of astigmatism and higher order aberrations. (ucas.com)

In normal population the dominant aberrations are the ordinary second-order spherocylindrical focus errors, which are called refractive errors. (wikipedia.org)
This technology measures the unique shape of each of your corneas, while also analyzing any other corneal irregularities and refractive errors. (neovisioneyecenters.com)

2 Corneal Dystrophy Research Institute, Severance Biomedical Science Institute, and Brain Korea 21 Project for Medical Science, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea. (ekjo.org)
A study in the American Journal Ophthalmology (2010;149:785-93) compared visual acuity and corneal higher order aberrations after LASIK surgery with flaps made by a femtosecond (Intralase) laser to one created using a mechanical microkeratome. (rochestereyecare.us)

These consist of higher-order aberrations, treatment centration and also difficulty in estimating corneal power. (xtgem.com)
These consist of higher-order aberrations, therapy centration as well as problem in estimating corneal power. (xtgem.com)

Fleck corneal dystrophy (FCD, Online Mendelian Inheritance in Man (OMIM) #121850) was first reported in 1957 by Francois and Neetens [ 9 ], and is one of the hereditary corneal dystrophies in which the causative genes have already been identified. (molvis.org)
These include LV owing to corneal diseases, such as keratokonus, corneal dystrophies, opacities caused by infections, or corneal epithelial stem cell deficiency. (fortunejournals.com)

A small increase in postoperative corneal higher order aberration may be associated with increase in coma and trefoil. (ekjo.org)
SCTK can also be used to treat certain complications of refractive surgery, including a decentered treatment, postoperative corneal scars, an overly small optical zone, and interface problems during LASIK. (crstodayeurope.com)

Femtosecond laser systems have been used during cataract surgery for performing anterior capsulotomy, lens fragmentation, and clear corneal incisions. (dovepress.com)
1 - 5 Moreover, clear corneal incisions performed by femtosecond laser were superior to conventional corneal incisions in terms of tunnel morphology and tissue damage, and they did not significantly increase high-order aberrations postoperatively. (dovepress.com)

a disorder characterized by an irregular corneal surface (cone-shaped) resulting in blurred and distorted images. (eyeclinicofwestpoint.com)

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)
Refractive surgery, such as photorefractive keratectomy (PRK), can cause severe corneal haze, and results with laser-assisted in situ keratomileusis (LASIK) are unpredictable. (medscape.com)
Patients can have regular or irregular astigmatism after LASIK, and many have altered spherical aberration profiles. (crstoday.com)
Finally, some motorists who have undergone laser vision correction such as LASIK may experience increased glare from oncoming headlights due to corneal higher-order aberrations caused by their surgery. (allaboutvision.com)
When compared to traditional LASIK, your chances of achieving 20/20 vision are higher with custom WaveFront analysis. (neovisioneyecenters.com)
Conventional LASIK surgery is limited to treating low-order optical distortions only. (neovisioneyecenters.com)
With Custom WaveFront LASIK technology, our surgeons are able to address both low and higher-order optical distortions. (neovisioneyecenters.com)
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)
Review of Laser Vision Correction (LASIK, PRK and SMILE) with Simultaneous Accelerated Corneal Crosslinking - Long-term Results. (snec.com.sg)

Comparison of Color Light-Emitting Diode Corneal Topographer and Dual Rotating Scheimpflug-Placido Topographer. (freevis.de)
Corneal tomography and wavefront data were acquired using Scheimpflug tomography (Pentacam, Oculus, Wetzlar, Germany). (biomedcentral.com)
Corneal power measurement with a rotating Scheimpflug imaging system after Descemet-stripping automated endothelial keratoplasty. (utswmed.org)
Determining subclinical edema in Fuchs endothelial corneal dystrophy: revised classification using Scheimpflug tomography for preoperative assessment. (jamanetwork.com)
Voncken Santana S, Vasiliauskaitė I, van Dijk K, van Tilborg M, Melles GRJ, Kocaba V, Oellerich S. Impact of Fuchs endothelial corneal dystrophy severity on Scheimpflug-derived parameters after DMEK. (niios.com)

Given the irregular astigmatism and greatly increased spherical aberration, it is surprising that the patient's uncorrected distance visual acuity is 20/25 OS. (crstodayeurope.com)
Corneal densitometry as a predictive diagnostic tool for visual acuity results after Descemet membrane endothelial keratoplasty. (jamanetwork.com)

Several mechanisms may explain the increase in the amount of higher-order aberrations with conventional eximer laser refractive procedures: a change in corneal shape toward oblateness or prolateness (after myopic and hyperopic ablations respectively), insufficient optical zone size and imperfect centration. (wikipedia.org)

High-impact activities such as boxing or martial arts may sway you to consider alternatives to flap-based procedures such as PRK, SMILE, or intraocular methods. (crstoday.com)
This technique provides the highest quality measurements and treatment plans for all types of optical distortions that were previously unavailable with older methods. (neovisioneyecenters.com)

The correction of these optical aberrations would significantly improve the visual performance of keratoconic eyes. (college-optometrists.org)
Often a surgeon will recommend a phakic intraocular lens , such as Visian or Verisyse, for this high prescription but there are certainly many people who have had laser vision correction with a -11 Rx and are very happy. (laservue.com)

The phosphoinositide kinase, FYVE finger containing ( PIKFYVE ) gene has been identified as a gene responsible for fleck corneal dystrophy (FCD). (molvis.org)
The purpose of this study is to report a novel mutation of the PIKFYVE gene in a Japanese patient with fleck corneal dystrophy. (molvis.org)
To the best of our knowledge, this is the first study to show that a novel mutation (p.Glu1389AspfsX16) causing the truncation of the PIKFYVE protein causes fleck corneal dystrophy in the Japanese population. (molvis.org)
This corneal dystrophy is a rare autosomal dominant disease characterized by numerous tiny, dot-like white flecks scattered in all layers of the corneal stroma. (molvis.org)
The patient had no obvious vision loss or any complaints related to this corneal dystrophy, and the appropriateness of our identified mutation as a causative one for FCD is theoretically discussed. (molvis.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)
Morphological and optical determinants of visual disability in Fuchs endothelial corneal dystrophy. (jamanetwork.com)
Corneal high-order aberrations and backscatter in Fuchs' endothelial corneal dystrophy. (jamanetwork.com)
Descemet stripping endothelial keratoplasty for Fuchs' endothelial corneal dystrophy: five-year results of a prospective study. (jamanetwork.com)
Five-year DMEK graft survival in eyes with Fuchs endothelial corneal dystrophy is negatively affected by low 6-month endothelial cell density. (niios.com)
Bowman layer onlay graft for recurrent corneal erosions in map-dot-fingerprint dystrophy. (niios.com)

Corneal scars lack the tensile strength of native tissue and tend to heal more slowly with age. (reviewofophthalmology.com)
However, we've found that previous corneal lacerations, penetrating injuries or paracentral trephination scars do not seem to impair laser trephination and are sturdy enough to withstand significant transient applanation forces during laser trephination. (reviewofophthalmology.com)

In brighter conditions, the pupil constricts, blocking the more peripheral rays and minimizing the effect of spherical aberration. (wikipedia.org)
The effect of spherical aberration increases as the fourth power of the pupil diameter. (wikipedia.org)
To compare the effect of spherical aberration on optical quality in eyes with two different aspherical intraocular lenses. (hindawi.com)

In this phase of SCTK, corneal imaging is performed, and corneal wavefront-guided customized transepithelial ablation is executed with a pattern derived from the immediate preoperative corneal wavefront measurement. (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)

What makes the femtosecond laser appealing in keratoplasty is its ability to incise corneal tissue with greater precision and accuracy than hand trephination and to achieve interlocking edges in the graft-host interface that are not possible by hand. (reviewofophthalmology.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 investigate clinical outcomes of small incision lenticule extraction (SMILE) including vector parameters and corneal aberrations in myopic patients. (ekjo.org)
Intraocular pressure changes and corneal biomechanics after hyperopic small-incision lenticule extraction. (freevis.de)

Figure 2 shows a relatively regular bow tie appearance to the astigmatism within the visual axis and high positive spherical aberration in each eye, likely a result of the myopic ablation with a small optical zone. (crstodayeurope.com)

Most eyes show positive spherical aberration when unaccommodated with a trend toward negative spherical aberration on accommodation. (wikipedia.org)
We would recommend exchanging the IOL for one with negative spherical aberration to offset the positive corneal spherical aberration. (crstodayeurope.com)

an ultraviolet laser used in refractive surgery to remove corneal tissue. (eyeclinicofwestpoint.com)

Histologic analysis showed that the SF artificial endothelial graft was attached and integrated on the surface of the corneal stroma without a significant inflammatory reaction, and rabbit CECs consisted in a monolayer that showed their characteristic markers ZO-1 and Na + /K + ATPase, suggesting proper intercellular junctions and cellular pump function. (arvojournals.org)
Both eyes exhibited small, dot-like, white flecks scattered throughout all layers of the corneal stroma, which corresponds to the typical FCD phenotype. (molvis.org)

There are numerous higher-order aberrations, of which only spherical aberration, coma and trefoil are of clinical interest. (wikipedia.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)

Many corneal surgeons were concerned about the elevated intraocular pressure the device applies to the eye during trephination. (reviewofophthalmology.com)

The eye, like any other optical system, suffers from a number of specific optical aberrations. (wikipedia.org)
The optical quality of the eye is limited by optical aberrations, diffraction and scatter. (wikipedia.org)
The appearance of visual complaints such as halos, glare and monocular diplopia after corneal refractive surgery has long been correlated with the induction of optical aberrations. (wikipedia.org)
The balance of corneal and internal aberrations is a typical example of creating two coupling optical systems. (wikipedia.org)
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)
Correcting the optical aberrations typically found in keratoconic eyes using soft contact lenses. (college-optometrists.org)
This paper will attempt to explain the optical aberrations typically found in keratoconic eyes, and will also review the progress made in attempting to correct them using soft contact lenses. (college-optometrists.org)
Many people's eyes have optical imperfections called higher-order aberrations that can't be corrected with eyeglasses or contact lenses . (allaboutvision.com)
Likewise, this optical coherence tomograph also illustrates the excellent corneal contours post-FLAK. (reviewofophthalmology.com)

Recently, femtosecond laser application in cataract surgery has been gaining increasing interest, given that use of premium intraocular lenses and higher patient expectations amplify the necessity for more predictable and accurate refractive outcomes, as well as maximum safety. (dovepress.com)

8 The incidence of this corneal disorder in the general population is about 4-6 of 1000 but can vary between studies depending on two aspects: the ethnic group evaluated, in fact the pathogenesis of the disease is a combination of genetic and environmental factors, and the criteria used to establish the diagnosis. (bmj.com)

Management of pellucid marginal corneal degeneration with rigid gas permeable contact lenses. (medscape.com)
Even over-wearing your contact lenses can sometimes lead to significant corneal swelling. (stonehengevisionsource.com)

corneal opacity grade was observed using slit lamp examination. (fortunejournals.com)

Refractive and Corneal Aberrometric Changes After Crescentic Lamellar Wedge Resection in Pellucid Marginal Degeneration. (medscape.com)
Bhandari V, Ganesh S. Corneal Hydrops in Pellucid Marginal Degeneration: A Case Series. (medscape.com)

Surface ablation laser surgery is another type of corneal refractive surgery. (ekjo.org)

Screening for corneal topographic abnormalities before refractive surgery. (ijkecd.com)

We analyzed the safety, efficacy, vector parameters, and corneal aberrations at 3 months after surgery. (ekjo.org)
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)
The aim of this study was to compare the rate of change in pachymetric, keratometric, and corneal wavefront-related parameters over a standardized change in time and base values (defined as the fractional rate of change later) in cases with progressive KC. (biomedcentral.com)

Spontaneous corneal clearance after graft detachment in DMEK. (niios.com)

Anatomy8

Diseases15

Chemicals and Drugs1

Analytical, Diagnostic and Therapeutic Techniques and Equipment18

Phenomena and Processes17

Disciplines and Occupations2

Technology, Industry, Agriculture1

Keratoconus42

Topography7

Thickness15

Cornea14

HOAs8

Transplantation8

Myopia9

Pachymetry2

Ectasia3

Wavefront aberration2

Lower-order aberrations2

Curvature2

Ocular7

Spherical aberrations3

Laser in situ keratomileusis2

Aberrometry3

Astigmatism and higher-order aberrations2

Refractive errors2

Ophthalmology2

Consist of higher-order aberrations2

Dystrophies2

Postoperative corneal2

Clear corneal incisions2

Irregular corneal surface1

LASIK9

Scheimpflug5

Visual acuity2

Change in corneal1

Methods2

Correction2

Dystrophy12

Scars2

Effect of spherical aberration3

Measurement1

Total corneal1

Keratoplasty2

Incision lenticule extraction2

Myopic1

Negative spherical aberration2

Remove corneal1

Stroma2

Coma and trefoil1

Surgically induced1

Intraocular pressure1

Optical12

Cataract surgery1

Disorder1

Contact lenses2

Slit-lamp examination1

Pellucid Marginal Deg2

Ablation1

Topographic1

Parameters3

Graft1