A refractive error in which rays of light entering the eye parallel to the optic axis are brought to a focus behind the retina, as a result of the eyeball being too short from front to back. It is also called farsightedness because the near point is more distant than it is in emmetropia with an equal amplitude of accommodation. (Dorland, 27th ed)
A refractive error in which rays of light entering the EYE parallel to the optic axis are brought to a focus in front of the RETINA when accommodation (ACCOMMODATION, OCULAR) is relaxed. This results from an overly curved CORNEA or from the eyeball being too long from front to back. It is also called nearsightedness.
Refraction of LIGHT effected by the media of the EYE.
The only family of the order SCANDENTIA, variously included in the order Insectivora or in the order Primates, and often in the order Microscelidea, consisting of five genera. They are TUPAIA, Ananthana (Indian tree shrew), Dendrogale (small smooth-tailed tree shrew), Urogale (Mindanao tree shrew), and Ptilocercus (pen-tailed tree shrew). The tree shrews inhabit the forest areas of eastern Asia from India and southwestern China to Borneo and the Philippines.
The distance between the anterior and posterior poles of the eye, measured either by ULTRASONOGRAPHY or by partial coherence interferometry.
The condition of where images are correctly brought to a focus on the retina.
The absence or restriction of the usual external sensory stimuli to which the individual responds.
A pair of ophthalmic lenses in a frame or mounting which is supported by the nose and ears. The purpose is to aid or improve vision. It does not include goggles or nonprescription sun glasses for which EYE PROTECTIVE DEVICES is available.
An alternative to REFRACTIVE SURGICAL PROCEDURES. A therapeutic procedure for correcting REFRACTIVE ERRORS. It involves wearing CONTACT LENSES designed to force corrective changes to the curvature of the CORNEA that remain after the lenses are removed. The effect is temporary but is maintained by wearing the therapeutic lenses daily, usually during sleep.
The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.
Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.
A genus of tree shrews of the family TUPAIIDAE which consists of about 12 species. One of the most frequently encountered species is T. glis. Members of this genus inhabit rain forests and secondary growth areas in southeast Asia.
The dioptric adjustment of the EYE (to attain maximal sharpness of retinal imagery for an object of regard) referring to the ability, to the mechanism, or to the process. Ocular accommodation is the effecting of refractive changes by changes in the shape of the CRYSTALLINE LENS. Loosely, it refers to ocular adjustments for VISION, OCULAR at various distances. (Cline et al., Dictionary of Visual Science, 4th ed)
The segment of GASTROINTESTINAL TRACT that includes the small intestine below the DUODENUM, and the LARGE INTESTINE.
Absence of crystalline lens totally or partially from field of vision, from any cause except after cataract extraction. Aphakia is mainly congenital or as result of LENS DISLOCATION AND SUBLUXATION.
The use of statistical and mathematical methods to analyze biological observations and phenomena.
The white, opaque, fibrous, outer tunic of the eyeball, covering it entirely excepting the segment covered anteriorly by the cornea. It is essentially avascular but contains apertures for vessels, lymphatics, and nerves. It receives the tendons of insertion of the extraocular muscles and at the corneoscleral junction contains the canal of Schlemm. (From Cline et al., Dictionary of Visual Science, 4th ed)
Lenses designed to be worn on the front surface of the eyeball. (UMDNS, 1999)
Images seen by one eye.
Protein factors uniquely required during the elongation phase of protein synthesis.
Unequal curvature of the refractive surfaces of the eye. Thus a point source of light cannot be brought to a point focus on the retina but is spread over a more or less diffuse area. This results from the radius of curvature in one plane being longer or shorter than the radius at right angles to it. (Dorland, 27th ed)
The processes occurring in early development that direct morphogenesis. They specify the body plan ensuring that cells will proceed to differentiate, grow, and diversify in size and shape at the correct relative positions. Included are axial patterning, segmentation, compartment specification, limb position, organ boundary patterning, blood vessel patterning, etc.
An objective determination of the refractive state of the eye (NEARSIGHTEDNESS; FARSIGHTEDNESS; ASTIGMATISM). By using a RETINOSCOPE, the amount of correction and the power of lens needed can be determined.
Peptide elongation factor 1 is a multisubunit protein that is responsible for the GTP-dependent binding of aminoacyl-tRNAs to eukaryotic ribosomes. The alpha subunit (EF-1alpha) binds aminoacyl-tRNA and transfers it to the ribosome in a process linked to GTP hydrolysis. The beta and delta subunits (EF-1beta, EF-1delta) are involved in exchanging GDP for GTP. The gamma subunit (EF-1gamma) is a structural component.
A process of GENETIC TRANSLATION, when an amino acid is transferred from its cognate TRANSFER RNA to the lengthening chain of PEPTIDES.
A protein found in bacteria and eukaryotic mitochondria which delivers aminoacyl-tRNA's to the A site of the ribosome. The aminoacyl-tRNA is first bound to a complex of elongation factor Tu containing a molecule of bound GTP. The resulting complex is then bound to the 70S initiation complex. Simultaneously the GTP is hydrolyzed and a Tu-GDP complex is released from the 70S ribosome. The Tu-GTP complex is regenerated from the Tu-GDP complex by the Ts elongation factor and GTP.
Transcription factors whose primary function is to regulate the rate in which RNA is transcribed.
Peptide Elongation Factor 2 catalyzes the translocation of peptidyl-tRNA from the A site to the P site of eukaryotic ribosomes by a process linked to the hydrolysis of GTP to GDP.
A parasympatholytic anticholinergic used solely to obtain mydriasis or cycloplegia.
A condition of an inequality of refractive power of the two eyes.
A form of ocular misalignment characterized by an excessive convergence of the visual axes, resulting in a "cross-eye" appearance. An example of this condition occurs when paralysis of the lateral rectus muscle causes an abnormal inward deviation of one eye on attempted gaze.
Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.
A surgical procedure to correct MYOPIA by CORNEAL STROMA subtraction. It involves the use of a microkeratome to make a lamellar dissection of the CORNEA creating a flap with intact CORNEAL EPITHELIUM. After the flap is lifted, the underlying midstroma is reshaped with an EXCIMER LASER and the flap is returned to its original position.
Agents that dilate the pupil. They may be either sympathomimetics or parasympatholytics.
Measurement of the index of refraction (the ratio of the velocity of light or other radiation in the first of two media to its velocity in the second as it passes from one into the other).
A monomeric calcium-calmodulin-dependent protein kinase subtype that specifically phosphorylates PEPTIDE ELONGATION FACTOR 2. The enzyme lacks a phosphorylatable activation domain that can respond to CALCIUM-CALMODULIN-DEPENDENT PROTEIN KINASE KINASE, however it is regulated by phosphorylation by PROTEIN KINASE A and through intramolecular autophosphorylation.
Application of tests and examinations to identify visual defects or vision disorders occurring in specific populations, as in school children, the elderly, etc. It is differentiated from VISION TESTS, which are given to evaluate/measure individual visual performance not related to a specific population.
Pieces of glass or other transparent materials used for magnification or increased visual acuity.
Peptide Elongation Factor G catalyzes the translocation of peptidyl-tRNA from the A to the P site of bacterial ribosomes by a process linked to hydrolysis of GTP to GDP.
A type of refractive surgery of the CORNEA to correct MYOPIA and ASTIGMATISM. An EXCIMER LASER is used directly on the surface of the EYE to remove some of the CORNEAL EPITHELIUM thus reshaping the anterior curvature of the cornea.
Congenital or developmental anomaly in which the eyeballs are abnormally small.
Surgical procedures employed to correct REFRACTIVE ERRORS such as MYOPIA; HYPEROPIA; or ASTIGMATISM. These may involve altering the curvature of the CORNEA; removal or replacement of the CRYSTALLINE LENS; or modification of the SCLERA to change the axial length of the eye.
Surgery performed on the eye or any of its parts.
Gas lasers with excited dimers (i.e., excimers) as the active medium. The most commonly used are rare gas monohalides (e.g., argon fluoride, xenon chloride). Their principal emission wavelengths are in the ultraviolet range and depend on the monohalide used (e.g., 193 nm for ArF, 308 nm for Xe Cl). These lasers are operated in pulsed and Q-switched modes and used in photoablative decomposition involving actual removal of tissue. (UMDNS, 2005)
An island in the Lesser Antilles in the West Indies. It is chiefly of coral formation with no good harbors and only small streams. It was probably discovered by the Portuguese in the sixteenth century. The name was given by 16th-century Spanish explorers from barbados, the plural for "bearded", with reference to the beard-like leaves or trails of moss on the trees that grew there in abundance. (From Webster's New Geographical Dictionary, 1988, p116 & Room, Brewer's Dictionary of Names, 1992, p49)
The transparent anterior portion of the fibrous coat of the eye consisting of five layers: stratified squamous CORNEAL EPITHELIUM; BOWMAN MEMBRANE; CORNEAL STROMA; DESCEMET MEMBRANE; and mesenchymal CORNEAL ENDOTHELIUM. It serves as the first refracting medium of the eye. It is structurally continuous with the SCLERA, avascular, receiving its nourishment by permeation through spaces between the lamellae, and is innervated by the ophthalmic division of the TRIGEMINAL NERVE via the ciliary nerves and those of the surrounding conjunctiva which together form plexuses. (Cline et al., Dictionary of Visual Science, 4th ed)
Holmium. An element of the rare earth family of metals. It has the atomic symbol Ho, atomic number 67, and atomic weight 164.93.
A procedure to surgically correct REFRACTIVE ERRORS by cutting radial slits into the CORNEA to change its refractive properties.
A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure and transcribes DNA into RNA. It has different requirements for cations and salt than RNA polymerase I and is strongly inhibited by alpha-amanitin. EC 2.7.7.6.
Factors that utilize energy from the hydrolysis of GTP to GDP for peptide chain elongation. EC 3.6.1.-.
The blending of separate images seen by each eye into one composite image.
A transcriptional elongation factor complex that is comprised of a heterodimer of CYCLIN-DEPENDENT KINASE 9 and one of several CYCLINS including TYPE T CYCLINS and cyclin K. It functions by phosphorylating the carboxy-terminal domain of RNA POLYMERASE II.
A nonspecific term referring to impaired vision. Major subcategories include stimulus deprivation-induced amblyopia and toxic amblyopia. Stimulus deprivation-induced amblyopia is a developmental disorder of the visual cortex. A discrepancy between visual information received by the visual cortex from each eye results in abnormal cortical development. STRABISMUS and REFRACTIVE ERRORS may cause this condition. Toxic amblyopia is a disorder of the OPTIC NERVE which is associated with ALCOHOLISM, tobacco SMOKING, and other toxins and as an adverse effect of the use of some medications.
The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. (Cline et al., Dictionary of Visual Science, 4th ed, p109)
The normal decreasing elasticity of the crystalline lens that leads to loss of accommodation.
The transparent, semigelatinous substance that fills the cavity behind the CRYSTALLINE LENS of the EYE and in front of the RETINA. It is contained in a thin hyaloid membrane and forms about four fifths of the optic globe.
Transmission of gene defects or chromosomal aberrations/abnormalities which are expressed in extreme variation in the structure or function of the eye. These may be evident at birth, but may be manifested later with progression of the disorder.
Misalignment of the visual axes of the eyes. In comitant strabismus the degree of ocular misalignment does not vary with the direction of gaze. In noncomitant strabismus the degree of misalignment varies depending on direction of gaze or which eye is fixating on the target. (Miller, Walsh & Hoyt's Clinical Neuro-Ophthalmology, 4th ed, p641)
A series of tests used to assess various functions of the eyes.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
A transparent, biconvex structure of the EYE, enclosed in a capsule and situated behind the IRIS and in front of the vitreous humor (VITREOUS BODY). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the CILIARY BODY is crucial for OCULAR ACCOMMODATION.
The measurement of curvature and shape of the anterior surface of the cornea using techniques such as keratometry, keratoscopy, photokeratoscopy, profile photography, computer-assisted image processing and videokeratography. This measurement is often applied in the fitting of contact lenses and in diagnosing corneal diseases or corneal changes including keratoconus, which occur after keratotomy and keratoplasty.
A form of glaucoma in which the intraocular pressure increases because the angle of the anterior chamber is blocked and the aqueous humor cannot drain from the anterior chamber.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Medical professionals characterize refractive errors as consequences of the eye's shape and other basic anatomy, for which no ... This was mainly due to opacities in both corneas, complicated by hyperopia and astigmatism. He was able to read only if he wore ... Exceedingly small changes in axial length of the eyeball (18.6-19.2 μm) are caused by the action of the ciliary muscle during ... Science author John Grant writes that many animals, such as fishes, accommodate by elongation of the eyeball, "it's just that ...
Other types of refractive error are hyperopia, astigmatism, and presbyopia.[1] Types[edit]. Various forms of myopia have been ... Axial myopia is attributed to an increase in the eye's axial length.[50] ... where animals such as kittens and monkeys had their eyes sewn shut for long periods of time also show eyeball elongation, ... Refractive myopia is attributed to the condition of the refractive elements of the eye.[50] Borish further subclassified ...
... axial hyperopia) or by the cornea being too flat or the crystalline lens being to weak (refractive hyperopia). It has been ... Use of Multifocal Contact Lenses to Stimulate Axial Elongation in Axial Hyperopia. ... Hyperopia. Refractive Error. Ocular Biometrics. Axial Length. Contact Lenses. Bifocal Contact Lenses. ... be used to encourage axial growth in hyperopic children and adolescents with axial hyperopia in an effort to reduce hyperopia. ...
Purpose.: Peripheral hyperopia was hypothesized to stimulate axial elongation. This study describes peripheral refraction and ... Mutti DO Hayes JR Mitchell L . Refractive error, axial length, and relative peripheral refractive error before and after the ... Relative peripheral hyperopia in myopic eyes is reflective of a prolate ocular shape, 8 -11 in which the axial length exceeds ... Children with the highest quartile of axial length were myopic at the center (−3.76 D) and had relatively more hyperopia at the ...
Compared to the WL group, the eyes in the SL group demonstrated more hyperopia by 1.95 D and a shorter axial length by 0.26 mm ... accompanied by an elongation of the axial length from 7.57 mm to 8.40 mm. ... It is also expected that the density of cones changes with axial length and refractive state [19]. In guinea pigs with form ... Meanwhile, the eyes in the ML group showed a further reduction of hyperopic refractive error (0.75 D) and greater axial length ...
All lens treatments inhibited axial ocular elongation and induced hyperopia. There was no difference between the responses to ... Refractive errors and ocular axial dimensions were tracked using retinoscopy and high-resolution A-scan ultrasonography ... contrasting with the previous finding that MF lenses inhibited axial elongation more than SV lenses in normal eyes (Liu and ... Ablation of Peripheral Glucagonergic Amacrine Cells in the Chick Retina and its Effects on Axial Eye Growth and Refractive ...
Pachymeter, Myopia, Hyperopia, Emmetropia. Introduction. Cornea is the major refractive element of the eye where it contributes ... This work also revealed that axial length elongation or shortening does not influence CCT. Similarly CCT did not show any ... Relationship between central corneal thickness, refractive error, corneal curvature, anterior chamber depth and axial length. J ... All the known possible changes in most of the refractive errors are located in the posterior segment like staphyloma, myopic ...
Before the surgery, the mean manifest refractive spherical equivalent (MRSE) of amblyopic eyes was +3.90 ± 1.60 diopters (D) ( ... in children with hyperopia and unilateral anisome-tropic amblyopia.METHODS:The study included 24 patients (24 eyes) aged 5 to ... Journal of Refractive Surgery , PURPOSE:To analyze clinical and functional results of femtosecond laser-assisted laser in situ ... In planning pediatric refractive treatment, possible future axial elongation should be considered. Refractive development after ...
... axial elongation). As reported in previous studies, myopia was also associated with increased curvature of the lens. But the ... The study also found noticeable differences related to refractive error: eyes with myopia were significantly larger, especially ... hyperopia). The various measures of eye structure were analyzed for association with age, refraction (vision prescription), and ... which in turn may cause the eye to undergo excessive elongation. ... larger than for a 60-year-old person with hyperopia. That has ...
... or at least result in an eye that is not nearly so myopic as its abnormal axial elongation would suggest). This would provide ... Human adults show a non-Gaussian distribution of refractive errors with a predominance of refractions around emmetropia. Other ... While nanophthalmos with a steep cornea and small eye results in high hyperopia. ... and an increase in axial length (especially vitreous length), often asymmetrically. The myopia due to increased axial length is ...
Pathological myopia is characterized by rapid, extreme axial elongation of the globe, leading to a high refractive error ( ... but affixing a positive lens over the eye causes inhibition of axial elongation, and far-sightedness (hyperopia) (Fig. 6). The ... refractive error progression: PAL: −1.28 ± 0.06 D vs. SVL: −1.48 ± 0.06 D, p = 0.004; axial length elongation: PAL: 0.64 ± 0.02 ... significantly inhibited changes in refractive error and axial elongation (Fig. 23). These studies are appealing, because the ...
... thereby increasing axial elongation. To examine signaling early in this cascade, we measured gene expression in the retina and ... Hyperopic refractive error is detected by retinal neurons, which generate GO signals through a direct emmetropization signaling ... RPE after short exposure to hyperopia produced by minus-lens wear. Gene expression in each tissue was compared with gene ...
Refractive error, axial length, and relative peripheral refractive error before and after the onset of myopia. Invest ... It can be difficult to understand how a percentage reduction in axial elongation relates to the individual patient in your ... Decrease in rate of myopia progression with a contact lens designed to reduce relative peripheral hyperopia: one-year results. ... Long-term effect of overnight orthokeratology on axial length elongation in childhood myopia: a 5-year follow-up study. Invest ...
... axial elongation). As reported in previous studies, myopia was also associated with increased curvature of the lens. ... Article: The Effect of Age, Accommodation, and Refractive Error on the Adult Human Eye (doi: 10.1097/OPX.0000000000000757) ... muscle ring for a 40-year-old person with myopia would be substantially larger than for a 60-year-old person with hyperopia. ... Click here to read The Effect of Age, Accommodation, and Refractive Error on the Adult Human Eye. ...
Refractive error (cycloplegic autorefraction) and axial length were measured at 6-month intervals. Differences between groups ... A) Mean and SEM of myopia progression (spherical equivalent refractions) and (B) mean and SEM of axial length elongation for ... et al. Decrease in rate of myopia progression with a contact lens designed to reduce relative peripheral hyperopia: one-year ... The present study showed children wearing DISC lenses had 25% less myopia progression and 31% less axial elongation than those ...
The increased axial length of the eye is the underlying cause of both the refractive error, which needs correction, and longer- ... This dissertation went on to discuss what we know about axial elongation of the eye, and its role in the development of myopia. ... Inducing myopia, hyperopia, and astigmatism in chicks. Optom Vis Sci 1991;68:364-8. 31. IrvingEL,SivakJG,CallenderMG. ... Myopia in humans results from an imbalance between the refractive power of the cornea and lens and the axial length of the eye ...
... blurry images associated with hyperopia stimulate axial elongation and the "function of emmetropization is to minimize blur."47 ... For example, for the patients reported by Patterson et al.,18 the standard deviation (SD) for refractive error was more than 5 ... The activity of the ON bipolar cells, which we suggest is the signal for axial elongation, is controlled by the ... We suggest that the idea that "contrast" is the driver for axial elongation deserves consideration as an alternative to the " ...
Our findings link gene expression with the morphological characteristics of refractive error, and suggest that physiological ... was used to identify gene sets correlated with ocular axial length and refraction across lens groups. Like previous studies, we ... Our findings link gene expression with the morphological characteristics of refractive error, and suggest that physiological ... was used to identify gene sets correlated with ocular axial length and refraction across lens groups. Like previous studies, we ...
Effect of Refractive Error on RNFL Thickness. The spherical equivalent (SE) ranged from −5.25 to +7.5 D with a mean refractive ... concluded that children with high hyperopia had thicker average in total and inferior RNFL compared to those with low hyperopia ... In addition, we did not measure the axial length of the eyes examined; therefore we could not verify the optical magnification ... The thinner RNFL thickness in myopic eyes may be a result of mechanical eye globe elongation associated with myopia and ...
Kakita T, Hiraoka T, Oshika T. Influence of Overnight Orthokeratology on Axial Elongation in Childhood Myopia. Invest. ... Smith EL 3rd, Hung LF, Huang J. Relative peripheral hyperopic defocus alters central refractive development in infant monkeys. ... Decrease in rate of myopia progression with a contact lens designed to reduce relative peripheral hyperopia: one-year results. ... 2011a). Accommodative lag and juvenile-onset myopia progression in children wearing refractive correction. Vision Res 51(9): ...
It is characterized by blurring of objects viewed at a distance, and is commonly the result of abnormal elongation of the ... eyeball - which causes the refractive image formed by the cornea and the lens to fall in front of the photoreceptors of the ... is the most common refractive vision disorder in children. ... inhibited changes in refractive error and axial elongation ( ... but affixing a positive lens over the eye causes inhibition of axial elongation, and far-sightedness (hyperopia) (Figure 6). ...
The elongation of the eye is whats at issue; the greater the myopia, the longer the axial length of the eye and thus greater ... However, myopia is different from other refractive errors like hyperopia or astigmatism. Myopia typically starts in childhood ... "refractive error", along with other conditions of the eye such as hyperopia (farsightedness) and astigmatism (an eye that isnt ... So, myopia is an abnormal elongation of the eye.. Myopia and the Risks. Myopia matters because it is proven that higher myopia ...
... to produce remodeling of the sclera that results in accelerated axial elongation in response to hyperopia and reduced axial ... Refractive errors occur when there is a mismatch between the axial length of an eye and its refractive power, which is produced ... signals produce a slowed elongation rate [18,20]. The axial elongation rate of the eye is primarily determined by the rate of ... The creep rate changes occur in parallel with the rise and decline of the axial elongation rate. This change in the sclera may ...
Low-addition soft CLs with decentered optical design can reduce the degree of axial elongation in myopic children.. Change of ... OK eyes showed a signi﫿cantly (P‹0.05) more stable myopic refractive prescription than control eyes over all of the 2-year ... Contact lenses that is designed to reduce relative peripheral hyperopia can slow the rate of progression of myopia in children. ... The daily wearing of DISC lens significantly slowed myopia progression and axial elongation in Hong Kong schoolchildren. Myopia ...
Hyperopia typically develops because the axial length of the eye is too short compared with the focal length of the optical ... As noted, myopia typically occurs due to excessive axial growth or elongation of the eye. It is now generally accepted, ... As refractive error (both positive and negative) is introduced into the optical system, the image quality starts to drop. A ... the terms myopia and hyperopia are used to include simple myopia or myopic astigmatism and hyperopia and hyperopic astigmatism ...
Spherical equivalent/refractive error and axial elongation were reduced significantly in eyes wearing the novel design compared ... Interestingly, several studies have reported that the human myopic eye experiences relative peripheral hyperopia25-27. These ... On the other hand, Phillips21 showed that use of monovision in a group of children slowed axial elongation and significantly ... The prescription of spectacles and/or contact lenses for vision correction is unable to prevent axial elongation of the eye, ...
8. Kakita T, Hiraoka T, Oshika T. Influence of overnight orthokeratology on axial elongation in childhood myopia. Invest ... Decrease in rate of myopia progression with a contact lens designed to reduce relative peripheral hyperopia: one-year results. ... Success of monovision in presbyopes: review of the literature and potential applications to refractive surgery. Surv Ophthalmol ... Long-term effect of overnight orthokeratology on axial length elongation in childhood myopia: a 5-year follow-up study. Invest ...
Differences in refractive error were also well correlated with changes in axial elongation over the course of the study. ... 6.9 D relative hyperopia, while +6 and +9.5 D lens wear did not induce hyperopia. Lens-induced defocus changes in refractive ... treated eyes demonstrated relative hyperopia and slowing of axial ocular growth in contrast to the normal decrease in hyperopia ... Positive lens treatment caused a reduced mean rate of axial elongation (ANOVA, p , 0.0001, Figure 3B) compared to plano-lens- ...
... of vision diseases.1 2 For children and young adults myopia hyperopia and astigmatism represent the categories of refractive ... Myopia reflects the mismatch between the refracting power of the eye and its optical axial length. Most myopia is usually ... caused by excessive ocular elongation with refracting power being near normal (Fig. 1).3 Myopia carries an increased risk of a ... Myopia is the most common type of refractive errors and one. Myopia is the most common type of refractive errors and one of the ...
Causes of nearsightedness and hyperopia How to improve eyesight with proper eye use habits How to improve vision at home How to ... This form is called refractive myopia . In the case of the axial form, the retina is stretched. The higher the degree of myopia ... What is hyperopia The need for treatment of hyperopia ( hypermetropia ) occurs when a loss of ability to clearly see objects ... One of the reasons for this kind of deterioration vision - the elongation of the eyeball forward and to the brain, because of ...
Lau JK, Vincent SJ, Cheung SW, Cho P. Higher order aberrations and axial elongation in myopic children treated with ... A plano over-refraction may be ideal, in the case that too much over-correction (manifest hyperopia) could potentially reduce ... findings have been reported indicating that the increased compression factor of 1D achieved around 0.30D additional refractive ... that have been suggested to play a part in reduction of axial elongation.5 However, increased HOAs may lead to poor low-light ...
2014). Associations between hyperopia and other vision and refractive error characteristics. Optometry and Vision Science, 91 ( ... warrants further research as animal models show a significant effect of the temporal modulation of light in axial elongation ... Relationships between refractive error (spherical equivalent, averaged across the two eyes), axial length, and the two ... refractive error (spherical equivalent, SE) between +0.75 hyperopia and −8.00DS myopia with ≤1.50DC of astigmatism or ≤1.00D ...
  • Hyperopia or farsightedness may cause distance vision and near vision to be blurred. (clinicaltrials.gov)
  • The participants --all free of cataracts or other eye diseases-- had vision prescriptions ranging from nearsightedness (myopia) to farsightedness (hyperopia). (medindia.net)
  • Historically, eye doctors like myself have been trained to equate myopia as synonymous with nearsightedness and treat them as a "refractive error", along with other conditions of the eye such as hyperopia (farsightedness) and astigmatism (an eye that isn't perfectly round). (treehouseeyes.com)
  • The opposite defect of myopia is hyperopia or farsightedness or long-sightedness -this is where the cornea is too flat or the eye is too short. (icce2007.info)
  • And while farsightedness is almost always present at birth, infantile hyperopia decreases in magnitude for most by age 4, while by age 15, almost 15 percent of children have developed some degree of myopia. (2020mag.com)
  • It can be enjoyed by people of all ages and those who have nearsightedness (myopia), farsightedness (hyperopia), astigmatism and the need for bifocals (presbyopia). (mypremiereyecare.com)
  • Pathological myopia is a type of farsightedness in which it causes elongation of the eyeball size resulting in high myopic refractive power. (myhealth.gov.my)
  • Hyperopia, also termed hypermetropia or farsightedness, is a refractive error in which parallel rays of light entering the eye reach a focal point behind the plane of the retina, while accommodation is maintained in a state of relaxation. (davision.co.za)
  • However, myopia is different from other refractive errors like hyperopia or astigmatism. (treehouseeyes.com)
  • Exclusion criteria: -Astigmatism of ≥1.25 D -Anisometropia ≥ 1.00 D -Strabismus at distance or near -Ocular or systemic pathology likely to affect refractive development or successful contact lens wear or a birth weight of 1250 g. (bestbets.org)
  • Information derived from computerized corneal mapping can now be used with software programs to design unique reverse geometry vision retainers that can rapidly and safely correct myopia, hyperopia and astigmatism. (drzhangeyecare.com)
  • While Ortho-K can help most individuals, including those with moderately high myopia, and mild to moderate astigmatism and hyperopia, the procedure is often most effective for those prescriptions falling within a specific range. (drzhangeyecare.com)
  • FS-LASIK was an effective method of hyperopia correction in this cohort of children with amblyopia, resulting in reduction in anisometropia, restoration of refractive balance, and functional improvement in the amblyopic eye when traditional methods failed. (healio.com)
  • This explains why ophthalmologists are so interested in searching for alternative methods of refractive error correction in hyperopic children, including refractive surgery. (healio.com)
  • It is therefore clear that preventive approaches need to concentrate on measures that prevent or reduce axial elongation , since this would result in a reduction in both the need for refractive correction and the long-term pathological outcomes. (endmyopia.org)
  • Accommodative lag and juvenile-onset myopia progression in children wearing refractive correction. (clspectrum.com)
  • The prescription of spectacles and/or contact lenses for vision correction is unable to prevent axial elongation of the eye, and thus myopia progression, particularly relevant during childhood, is not halted with traditional vision correction. (contactlensupdate.com)
  • Pilot studies in children wearing orthokeratology lenses found that the change in axial length was significantly smaller than that measured in children wearing regular vision correction strategies, such as single-vision spectacles and soft contact lenses 28,29 . (contactlensupdate.com)
  • A plano over-refraction may be ideal, in the case that too much over-correction (manifest hyperopia) could potentially reduce the relative peripheral myopia desired from OrthoK treatment. (myopiaprofile.com)
  • Lau et al 4 hypothesised that a higher amount of over-correction (study was up to 1.75D) may actually potentially improve the myopia control effect due to increased amounts of high order aberrations (HOAs) that have been suggested to play a part in reduction of axial elongation. (myopiaprofile.com)
  • So far, preliminary findings have been reported indicating that the increased compression factor of 1D achieved around 0.30D additional refractive correction on average, after one month of wear, but unaided VA results were not significantly different between the groups. (myopiaprofile.com)
  • This includes good vision at near, which could potentially be influenced by too much over-correction (manifest hyperopia). (myopiaprofile.com)
  • Although spectacle correction can improve vision, uncorrected refractive error is the most common cause of distance vision impairment and the second most common cause of blindness globally. (reviewofophthalmology.com)
  • Affected individuals benefit from correction of refractive error, use of low-vision aids when possible, and optimal access to educational and work-related opportunities. (nih.gov)
  • Periodic ophthalmic evaluation for assessment of vision, trials of correction for refractive error, and, in those with residual vision, assessment of the presence of amblyopia, glaucoma, or cataract. (nih.gov)
  • The most common barrier for refractive correction was lack of perceived need for refraction and its correction. (bvsalud.org)
  • Inaccurate refractive correction, which inevitably occurs during periods of emmetropisation, should also be checked for. (alpfmedical.info)
  • Studies by Earl Smith, O.D., Ph.D. have suggested that multi-zonal contact lenses that provide proper axial focus while manipulating peripheral defocus can either discourage or encourage axial growth to treat myopia or hyperopia respectively. (clinicaltrials.gov)
  • Refractive error can be modified using lenses: In an emmetropic eye, positive lenses impose myopic defocus (d), and negative lenses impose hyperopic defocus (e). (utah.edu)
  • Using GSEA, however, we are the first to show that more subtle shifts in structural, metabolic, and immune pathway expression are correlated with the eye size and refractive changes induced by lens defocus. (frontiersin.org)
  • It has been speculated that the presence of peripheral defocus (light focussing behind the peripheral retina) may act as an optical signal, triggering eye elongation and subsequent myopia. (contactlensupdate.com)
  • It has been further postulated that changing the retinal image shell by shifting the peripheral defocus in front of the retina may result in slowed axial elongation. (contactlensupdate.com)
  • Conversely, results from a 10-month study using concentric dual focus contact lenses that induced simultaneous myopic defocus reported a significant reduction in myopia progression and axial length in the test eyes compared to the control eyes 31 . (contactlensupdate.com)
  • Induced negative lens defocus results in accelerated ocular elongation and myopia. (arvojournals.org)
  • Lens-induced defocus changes in refractive state were significantly correlated with vitreous chamber depth changes. (arvojournals.org)
  • In the most frequently studied model of ocular growth and refractive development, the chick, it has been demonstrated that the rate of ocular growth can be manipulated to bring about compensation for a wide range of lens-induced defocus (−10 D to +15 D), predominantly brought about by altered axial ocular dimensions. (arvojournals.org)
  • The same myopia control theory can be said to occur in OK as well - the flatter central base curve compressing the central cornea during sleep also displaces the anterior corneal layers outward into the mid-peripheral annular steeper radius to create an artificially more myopic peripheral retina, correcting the hyperopic peripheral defocus and eliminating the stimulus for axial growth. (envisionmagazine.ca)
  • Of the commercially available spectacle lenses currently on the market, the Defocus Incorporated Multiple Segments (DIMS) lenses, manufactured by Hoya, with a 52% reduction in myopia progression and 62% less axial elongation compared to SV spectacle lenses over 2 years, 7 show the highest reported efficacy in retarding myopia progression. (contactlensupdate.com)
  • We know that correcting the refractive error with traditional single vision spectacle lenses or regular soft/rigid contact lenses will inherently cause more peripheral hyperopic defocus, encouraging axial elongation and an increase in myopia. (pointsdevue.com)
  • Axial hyperopia results when the length of the eye is too short for the eye to properly focus distance objects on the retina while the focusing system is relaxed. (clinicaltrials.gov)
  • If an abnormally short eye has resulted in hyperopia, exposing such an eye to retinal images partially located behind the retina might encourage axial elongation, thus reducing the hyperopia. (clinicaltrials.gov)
  • All the known possible changes in most of the refractive errors are located in the posterior segment like staphyloma, myopic conus, choroidal atrophy, thinning of the retina and sclera [ 1 ]. (alliedacademies.org)
  • It is characterized by blurring of objects viewed at a distance, and is commonly the result of abnormal elongation of the eyeball - which causes the refractive image formed by the cornea and the lens to fall in front of the photoreceptors of the retina (Fig. 1). (utah.edu)
  • Pathological myopia is characterized by rapid, extreme axial elongation of the globe, leading to a high refractive error (typically far more negative than -6.00D). This extreme stretching puts stress on the ocular structures (retina, choroid, and sclera), which can then result in degenerative changes in the eye (Fig. 3), and irreversible vision loss. (utah.edu)
  • Myopia in humans results from an imbalance between the refractive power of the cornea and lens and the axial length of the eye, such that the image of an object at infinity falls in front of the retina, with the lens at rest. (endmyopia.org)
  • Emmetropisation is a process describing how an eye is growing to the refractive state where distant objects are focused on the retina without accommodation. (bmj.com)
  • In the present study, we used RNA sequencing to examine gene expression in the retina/RPE/choroid across 3 days of optically-induced myopia and hyperopia induction in chick. (frontiersin.org)
  • More recently, interest has emerged in the role of the peripheral retina in emmetropization and/or refractive error development, based on experimental work in animal models 22-24 . (contactlensupdate.com)
  • In the case of the axial form, the retina is stretched. (womanoftrend.com)
  • BACKGROUND: Refractive errors (conditions in which the eye fails to focus objects accurately on the retina due to defects in the refractive system), are the most common cause of visual impairment. (bvsalud.org)
  • Myopia (Greek: μυωπία, muōpia, nearsightedness ), also called nearsightedness or shortsightedness, is a refractive defect of the eye in which collimated light produces image focus in front of the retina when accommodation is relaxed. (icce2007.info)
  • According to the World Health Organization, whose global health initiative currently places particular emphasis on correcting refractive conditions early, children whose myopia progresses beyond 5 diopters can become adults who are more predisposed to developing glaucoma, cataracts, macular degeneration, retinal holes and tears, as well as detachments of vitreous and retina. (2020mag.com)
  • Because the most significant cause of myopia is the increase in axial length of the eye, the retina must stretch out to cover the increased surface area. (wikipedia.org)
  • Glasses cause light to be in focus solely in the central retina and behind the retina in the periphery (which encourages axial elongation, or eye growth). (mypremiereyecare.com)
  • Staphyloma is a bump that forms at the back of the eyeball when the layers of the retina and sclera becomes thin due to the continued elongation of the eyeball. (myhealth.gov.my)
  • This elongation of the eye causes visual input (what your child sees) to focus in the front of the retina rather than on the retina proper. (ladavichoptical.com)
  • Myopia is the refractive anomaly of the eye in which the conjugate focus of the retina is at some finite point in front of the eye when the eye is not accommodating. (davision.co.za)
  • It can also be described as the refractive condition in which parallel light rays from an object at optical infinity are focused by the eye in front or short of the retina, in a relaxed state of accommodation. (davision.co.za)
  • This study describes peripheral refraction and its associations with central refractive error in young Singapore Chinese children. (arvojournals.org)
  • Two hundred fifty children aged 40 months or older recruited from the Strabismus, Amblyopia, and Refractive Error in Young Singapore Children study were included in this analysis. (arvojournals.org)
  • On-axis refraction (central refractive error) is typically regarded as the primary determinant of visual acuity and is the research topic of most studies on refractive errors. (arvojournals.org)
  • However, recent interest into understanding the influence of peripheral refraction on central refractive error has increased, and studies suggest that peripheral refractive error may play a key role in refractive eye development. (arvojournals.org)
  • The study also found noticeable differences related to refractive error: eyes with myopia were significantly larger, especially front to back (axial elongation). (medindia.net)
  • Refractive error (cycloplegic autorefraction) and axial length were measured at 6-month intervals. (bmj.com)
  • The average refractive error (SE) was +1.7 D (range −5.25 to +7.25 D). The mean total RNFL thickness was 105 μ m ± 10.3, the mean superior RNFL thickness was 112.7 μ m ± 16.5, and the mean inferior RNFL thickness was 132.6 μ m ± 18.3. (hindawi.com)
  • Our findings link gene expression with the morphological characteristics of refractive error, and suggest that physiological stress arising from metabolic and inflammatory pathway activation could increase the vulnerability of myopic eyes to secondary pathologies. (frontiersin.org)
  • 24 showed that a functioning fovea is not critical for emmetropisation or refractive error development in infant monkeys. (contactlensupdate.com)
  • Spherical equivalent/refractive error and axial elongation were reduced significantly in eyes wearing the novel design compared to that measured in a group of children wearing single-vision spectacles. (contactlensupdate.com)
  • Refractive error and ocular dimensions were measured at the start of treatment and every week thereafter. (arvojournals.org)
  • In particular, previous researchers have examined the effect of exposure to monochromatic light of different wavelengths upon longitudinal chromatic aberration (LCA), which refers to a wavelength-dependent refractive error (Liu et al. (arvojournals.org)
  • Consequently, myopia in the 21st century is not only treated as a refractive error but an ocular disorder with potential negative consequences. (avehjournal.org)
  • 5 These risks increase with high myopia (greater than -6 D). 6 Also, it's estimated that the global economic burden associated with uncorrected distance refractive error is $202 to 268 billion per year. (reviewofophthalmology.com)
  • Myopia, or nearsightedness, the most prevalent form of refractive error, is caused by excessive axial elongation of the eye as a major mechanism in children 1 . (nature.com)
  • Pathologic myopia is generally classified as a high myopic refractive error that is progressive and generally presents very early in childhood. (eyewiki.org)
  • It is the most common refractive error among children and young adults. (carolinaforesteyecare.com)
  • She started working on the Orinda Longitudinal Study of Myopia, which evolved into the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error, looking at nearsightedness and school-aged children. (osu.edu)
  • The Contributions of Near Work and Outdoor Activity to the Correlation Between Siblings in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study. (osu.edu)
  • Early Childhood Refractive Error and Parental History of Myopia as Predictors of Myopia. (osu.edu)
  • [1] [6] It is a type of refractive error . (wikipedia.org)
  • In recent years, reports from population-based prevalence studies carried out in various geographical areas now give a clear picture of the current distribution of refractive error. (cdc.gov)
  • These studies have confirmed the previous data indicating that prevalence of refractive error varies according to ethnicity and geographic regions, and also point to an increase in myopia prevalence over the past half-century. (cdc.gov)
  • The past decade has seen a greater understanding of the molecular biological mechanisms that determine refractive error, giving further support to the belief that myopia is the result of a complex interaction between genetic predisposition and environmental exposures. (cdc.gov)
  • We conducted a genome-wide association study for refractive error in 4,270 individuals from the TwinsUK cohort. (cdc.gov)
  • We identified SNPs on 15q25 associated with refractive error (rs8027411, P = 7.91 × 10⁻⁸). (cdc.gov)
  • The identification of a susceptibility locus for refractive error on 15q25 will be important in characterizing the molecular mechanism responsible for the most common cause of visual impairment. (cdc.gov)
  • Reasons for poor candidacy include: excessive amounts of refractive error, unpredictable sleep hours, irregular corneal curvature, unrealistic expectations, etc. (mypremiereyecare.com)
  • For several decades, environmental factors have been believed to play an important role in the determination of refractive error [ 6 , 7 ]. (biomedcentral.com)
  • The average spherical equivalent refractive error (SER) was (−2.74 ± 1.15)D, with examinations performed 1, 7, 30, and 90 days and 12 months after the patients started wearing ortho-k lenses. (biomedcentral.com)
  • Hyperopia is a common refractive error in children and adults. (davision.co.za)
  • Refraction and axial length were measured before and after 10-week illumination. (hindawi.com)
  • Cornea is the major refractive element of the eye where it contributes approximately two-thirds of optical refraction [ 1 ]. (alliedacademies.org)
  • 9-11 A key research finding in large-scale studies is that the fastest change in refraction occurs in the year just prior to myopia onset, 10 so it is crucial to watch these at-risk future myopes closely for shifts in their risk profile and especially in their manifest hyperopia. (aop.org.uk)
  • Data were analyzed for differential expression of single genes, and Gene Set Enrichment Analysis (GSEA) was used to identify gene sets correlated with ocular axial length and refraction across lens groups. (frontiersin.org)
  • We presented the protocol for precise evaluations of the state of myopia, including refraction, corneal curvature and axial length using up-to-date devices. (nature.com)
  • Definition of refractive groups using change in spherical equivalent refraction (SER) between timepoints. (journalofoptometry.org)
  • Height, spherical equivalent refraction (SER), axial length (AL) and anterior chamber depth (ACD) significantly differed by refractive group. (journalofoptometry.org)
  • Myopia and hyperopia are at opposite ends of the continuum of refraction, the measure of the eye's ability to focus light, which is an important cause of visual impairment (when aberrant) and is a highly heritable trait. (cdc.gov)
  • Partial reduction ortho-k has been shown to slow axial elongation in high myopic children, however, the main disadvantage is that the children have to wear spectacles in the daytime to correct residual refraction. (clinicaltrials.gov)
  • Current refraction - the most significant risk factor of this lot for future myopia is if a child exhibits 0.50D or less of manifest hyperopia at age 6-7. (myopiaprofile.com)
  • Myopia (nearsightedness) is an ocular disorder in which the optical power of the eye is too strong for the corresponding axial length. (eyewiki.org)
  • Hyperopia can be caused by the eye being too short (axial hyperopia) or by the cornea being too flat or the crystalline lens being to weak (refractive hyperopia). (clinicaltrials.gov)
  • Refractive errors occur when there is a mismatch between the axial length of an eye and its refractive power, which is produced by the cornea, lens and anterior chamber depth. (molvis.org)
  • Unlike refractive surgery, OK is not permanent and discontinuing lens wear will cause the cornea to revert to its original shape. (envisionmagazine.ca)
  • AKS: Refractive Therapy or cornea brace in some practice) utilizes unique designed contact lens retainers to gently mold the cornea to a new desired shape usually in a matter of hours, days, or weeks. (drzhangeyecare.com)
  • [1] Refractive surgery permanently changes the shape of the cornea . (wikipedia.org)
  • One of the reasons for this kind of deterioration vision - the elongation of the eyeball forward and to the brain, because of what is clearly visible only when looking at nearby objects. (womanoftrend.com)
  • Inherited are the physical parameters of the eyeball and the refractive properties of its lens. (womanoftrend.com)
  • Science author John Grant writes that many animals, such as fishes, accommodate by elongation of the eyeball, "it's just that humans aren't one of those animals. (wikipedia.org)
  • Exceedingly small changes in axial length of the eyeball (18.6-19.2 μm) are caused by the action of the ciliary muscle during accommodation. (wikipedia.org)
  • If OK can, in fact, control and decrease the progression of axial length growth and stop the eyes from becoming more nearsighted, then children fitted in early childhood will have their eyes return to the way they were before treatment - when their myopia levels were low - not to where their eyeball lengths would otherwise have been years later when they stop lens wear. (envisionmagazine.ca)
  • The average axial length of human eyeball is 24.0mm. (myhealth.gov.my)
  • The continued elongation of the eyeball will cause cracks in the retinal layer, especially along the peripheral lining. (myhealth.gov.my)
  • Treatment of pathological myopia is limited because of the elongation of the eyeball cannot be controlled. (myhealth.gov.my)
  • The elongation of the eyeball is associated with retinal thinning and tears, which may lead to retinal detachments. (eyedocsottawa.com)
  • Peripheral hyperopia was hypothesized to stimulate axial elongation. (arvojournals.org)
  • It has been established by the PI that axial growth can be dramatically lessened in children and adolescents with myopia through the use of bifocal contact lenses prescribed in a particular way (The CONTROL Study). (clinicaltrials.gov)
  • In the present study, simultaneous vision bifocal soft contact lenses will be used to encourage axial growth in hyperopic children and adolescents with axial hyperopia in an effort to reduce hyperopia. (clinicaltrials.gov)
  • There was no difference between the responses to SV and MF lenses in colchicine-treated eyes, contrasting with the previous finding that MF lenses inhibited axial elongation more than SV lenses in normal eyes (Liu and Wildsoet 2011). (arvojournals.org)
  • 12 Orthokeratology has showed certain effect on retarding axial elongation, 13 , 14 but children need to sleep with lenses overnight to maintain appropriate corneal curvature and clear vision. (bmj.com)
  • Myopia progression and eye elongation were reduced significantly in eyes wearing Dual-Focus soft contact lenses. (bestbets.org)
  • 5. Santodomingo-Rubido J, Villa-Collar C, Gilmartin B, Gutiérrez-Ortega R. Myopia Control with Orthokeratology Contact Lenses in Spain: refractive and biometric changes. (clspectrum.com)
  • 4 Interventions, which have shown clinically significant efficacy for reducing refractive and axial progression of myopia, include progressive and bifocal spectacles, orthokeratology (ortho-K), dual focus and multifocal soft contact lenses (MFSCL), and atropine in various concentrations. (mieducation.com)
  • Recent myopia studies have revealed that gas permeable (GP) lenses offer a beneficial influence in helping retard axial elongation (growth) of the eye during the growth years. (drzhangeyecare.com)
  • Progressive multi-focal lenses defer the development of myopia by changing brightness so as to block the vicious cycle caused by regulation of axial elongation and alleviate eye fatigue. (myblog.de)
  • Regular glasses or contact lenses adjust for the poor focus, but do nothing to address the elongation of the eye itself and don't slow the progression. (ladavichoptical.com)
  • In short, by slightly altering how your child focuses in near and center vision, soft multifocal lenses are used to halt the elongation responsible for the myopia. (ladavichoptical.com)
  • Clear distance vision is usually restored with minus power (concave) spectacle or contact lenses or corneal modification procedures in which corneal refractive power is decreased. (davision.co.za)
  • Young myopic Singapore Chinese children had relative hyperopia in the periphery. (arvojournals.org)
  • After 10-week illumination, the guinea pigs developed relative hyperopia in the SL group and relative myopia in the ML group. (hindawi.com)
  • 0.01) compared to the plano lens group (+10.9 ± 1.8 D vs +5.3 ± 0.5 D). Constant +4 D lens wear produced +6.9 D relative hyperopia, while +6 and +9.5 D lens wear did not induce hyperopia. (arvojournals.org)
  • Knowing how to improve vision, you can use them not only to treat myopia or hyperopia, but to further increase the visual acuity. (womanoftrend.com)
  • Corneal Molding (CM) is a non-surgical alternative to refractive surgery, yet has many advantages over refractive surgery (PRK, LASIK, LASEK, RK). (mypremiereyecare.com)
  • All lens treatments inhibited axial ocular elongation and induced hyperopia. (arvojournals.org)
  • Conclusions The daily wearing of DISC lens significantly slowed myopia progression and axial elongation in Hong Kong schoolchildren. (bmj.com)
  • Decrease in rate of myopia progression with a contact lens designed to reduce relative peripheral hyperopia: one-year results. (clspectrum.com)
  • The different patterns of differential mRNA expression during minus lens compensation (hyperopia) and recovery (myopia) show that scleral fibroblasts distinguish between "go" and "stop" conditions. (molvis.org)
  • SCLs don't increase axial length, corneal curvature or myopia when compared to spectacle lens wear in children, nor do they decrease myopic progression. (reviewofophthalmology.com)
  • This graph shows cross-sectional data for mean axial length (AL) and mean LOCS nuclear opacity (NO) lens grade in a Chinese Singaporean population aged 40-82 years. (cdc.gov)
  • 9 ] concluded that the following induced abnormal axial growth of the eye: near accommodation lag, mechanical tension created by the crystalline lens or ciliary body, and peripheral retinal signal domination. (biomedcentral.com)
  • Refractive Surgery Screening Instructions Refractive Surgery Screening Instructions CONTACT LENS HOLIDAY. (eye.com.ph)
  • Participants had refractive errors ranging from high myopia to low hyperopia. (bvsalud.org)
  • OBJECTIVES: The primary objective was to compare effectiveness and safety of wavefront procedures, laser-assisted in-situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) or laser epithelial keratomileusis (LASEK) versus corresponding conventional procedures, for correcting refractive errors in adults for postoperative uncorrected visual acuity, residual refractive errors, and residual HOAs. (bvsalud.org)
  • Partial reduction ortho-k is target for 4.00-5.00D reduction and the residual refractive errors will be corrected with single vision spectacles to allow good visual acuity in the daytime. (clinicaltrials.gov)
  • Before the surgery, the mean manifest refractive spherical equivalent (MRSE) of amblyopic eyes was +3.90 ± 1.60 diopters (D) (range: +1.50 to +6.80 D) and the mean refractive anisometropia was 3.06 ± 1.64 D (range: 0.87 to 7.50 D). Every patient had at least 1 year of ineffective traditional amblyopia treatment before surgery. (healio.com)
  • According to the optical structure of mouse eyes, myopic refractive change of 1 diopter (D) is equivalent to only 5.4-6.5 μm elongation of the AL in mice 30 . (nature.com)
  • Axial length increased with spherical equivalent. (bvsalud.org)
  • Children aged from 3 to 7 years with refractive amblyopia (Landolt C equivalent (bvsalud.org)
  • PURPOSE: To determine the correlation between higher-order aberrations (HOAs) and best-corrected visual acuity (BCVA) recovery speed after spectacles treatment using iDesign measurements in refractive amblyopic children. (bvsalud.org)
  • Kröger & Wagner, 1996 ) indicate that early visual experience plays an important role in refractive development of the eye. (arvojournals.org)
  • SELECTION CRITERIA: We included randomized controlled trials (RCTs) comparing either wavefront modified with conventional refractive surgery or wavefront-optimized with wavefront-guided refractive surgery in participants aged ⪰ 18 years with refractive errors. (bvsalud.org)
  • In recent years, multiple studies have provided strong evidence that OK can effectively reduce myopia progression in children and slow axial elongation. (envisionmagazine.ca)
  • Depending on the severity of the condition and the age of the patient and the status of the binocular vision system, hyperopia can also cause fatigue, asthenopia, headaches, double vision, and amblyopia. (clinicaltrials.gov)
  • To analyze clinical and functional results of femtosecond laser-assisted laser in situ keratomileusis (FSLASIK) in children with hyperopia and unilateral anisome-tropic amblyopia. (healio.com)
  • Amblyopia, along with refractive errors, is one of the leading reasons for visual disability in children and adults and poses a serious medical and social problem on a global scale. (healio.com)
  • The aim of this study was to analyze the long-term clinical and functional results of unilateral femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK) in children with hyperopia and uni-lateral anisometropic amblyopia. (healio.com)
  • The current study results may aid in further investigation for diagnosis and treatment of refractory refractive and idiopathic amblyopia. (bvsalud.org)
  • Altered retinal cones/opsins induced by monochromatic lights might be involved in the refractive development in guinea pigs. (hindawi.com)
  • It is associated with a greater risk for sight-threatening complications such as cataract, glaucoma and retinal detachment, especially in axial myopia. (envisionmagazine.ca)
  • F or many people, their world seems to be getting smaller: The prevalence of myopia, commonly due to an increase in axial length of the eye causing a distant image to be projected anterior to the retinal plane, 1 is increasing. (reviewofophthalmology.com)
  • Patients with high axial myopia are at a greater risk of developing progressive retinal degeneration and other vision threatening pathology. (eyewiki.org)
  • On the other hand, Phillips 21 showed that use of monovision in a group of children slowed axial elongation and significantly reduced myopia progression in the near-corrected eye. (contactlensupdate.com)
  • In addition to this, the fastest rate of refractive change in myopic children occurs in the year prior to onset, 7 so the child who is less hyperopic than age normal should be closely monitored, especially if concurrent risk factors are evident. (myopiaprofile.com)
  • 7 who observed that pilots who became myopic during their training had relative peripheral hyperopia before the onset of myopia. (arvojournals.org)
  • 1 Baseline measurements of axial length can help detect rapid eye growth that is known to precede the imminent onset of myopia. (contactlensupdate.com)
  • 4. Cho P, Cheung SW, Edwards M. The longitudinal orthokeratology research in children (LORIC) in Hong Kong: a pilot study on refractive changes and myopic control. (clspectrum.com)
  • The prevalence of refractive errors among adults in the United States, Western Europe, and Australia. (scholarena.co)
  • Exaggerated representation of simple refractive errors caused by abnormal eye growth. (utah.edu)
  • Experimental designs that concurrently compare myopia and hyperopia induction enable identification of genes with expression profiles that are discriminatory for different ocular growth trajectories. (frontiersin.org)
  • However, this delay in progression was linked to a steepened corneal curvature, as opposed to a significant difference in axial growth, and therefore doesn't indicate viability for myopia control. (reviewofophthalmology.com)
  • There is no consensus regarding the association between body growth and AL during refractive development. (journalofoptometry.org)
  • Increasing outdoor activities prevented myopia onset and development, as well as axial growth and elevated IOP in children. (biomedcentral.com)
  • While numerous studies have shown that orthokeratology is an effective clinical treatment to slow axial eye growth in children, the exact mechanism underlying this reduction in myopia progression associated with orthokeratology remains unclear. (clinicaltrials.gov)
  • TIME Soft Contacts With Positive Spherical Aberration Slow Axial Elongation, Study Shows. (southwestvision.org)
  • Refractive errors and ocular axial dimensions were tracked using retinoscopy and high-resolution A-scan ultrasonography respectively. (arvojournals.org)
  • Theoretically, the problem could lie with excessively power optics, or excessive axial length, but population studies show that it is almost always excessive axial length that causes the problem. (endmyopia.org)
  • The nurture theory on myopia development indicates excessive reading and near work activities during childhood as risk factors of abnormal axial length (AL) elongation, yet its onset and development is not clearly understood. (avehjournal.org)
  • Body height and axial length (AL) increase during childhood with excessive axial elongation resulting in myopia. (journalofoptometry.org)
  • Myopia (near-sightedness) is the most common refractive vision disorder in children. (utah.edu)
  • The included group of children was referred to the Ophthalmology Department due to failed school or primary care visual screening, visual behaviour/abnormalities noticed by parents, or possible family history of refractive errors. (hindawi.com)
  • The CLEERE study found that less than +0.75D of hyperopia in first grade children was a reliable risk factor for predicting future myopia. (contactlensupdate.com)
  • This study explored the association between change in body height, AL and refractive status over 4-years in children and young adults. (journalofoptometry.org)
  • Las variables del estudio fueron la edad, el sexo, el color de la piel, la miopía (isometrópica y anisometrópica), la longitud axial, la agudeza visual con corrección, el tipo de corrección óptica, la presencia y el grado de estereopsia. (bvsalud.org)
  • La longitud axial aumentó junto con el equivalente esférico de los pacientes. (bvsalud.org)
  • CONCLUSIONS: trefoil and tetrafoil measured with iDesign negatively correlates with the BCVA recovery speed of refractive amblyopic eyes after spectacles treatment in this pilot study. (bvsalud.org)
  • The role of CCT in refractive errors was studied intensely over the years. (alliedacademies.org)
  • Changes in the anterior segment associated with refractive errors are still debatable. (alliedacademies.org)
  • some of these stories claimed that such methods had cured glaucoma and cataracts as well as refractive errors. (wikipedia.org)
  • Medical professionals characterize refractive errors as consequences of the eye's shape and other basic anatomy, for which no evidence shows that any exercise can alter. (wikipedia.org)
  • BACKGROUND: Uncorrected refractive errors contribute enormously to the burden of avoidable visual impairment worldwide. (bvsalud.org)
  • Effective myopia control results in less severe myopia and less vitreous chamber elongation than would otherwise have occurred. (davision.co.za)
  • The need for treatment of hyperopia ( hypermetropia ) occurs when a loss of ability to clearly see objects located near. (womanoftrend.com)