Hyperopia: 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)Myopia: 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, Ocular: Refraction of LIGHT effected by the media of the EYE.Refractive Errors: Deviations from the average or standard indices of refraction of the eye through its dioptric or refractive apparatus.Myopia, Degenerative: Excessive axial myopia associated with complications (especially posterior staphyloma and CHOROIDAL NEOVASCULARIZATION) that can lead to BLINDNESS.Eyeglasses: 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.Astigmatism: 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)Retinoscopy: 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.Emmetropia: The condition of where images are correctly brought to a focus on the retina.Accommodation, Ocular: 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)Eye: 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.Tupaiidae: 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.Visual Acuity: 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.Sensory Deprivation: The absence or restriction of the usual external sensory stimuli to which the individual responds.Biometry: The use of statistical and mathematical methods to analyze biological observations and phenomena.Keratomileusis, Laser In Situ: 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.Axial Length, Eye: The distance between the anterior and posterior poles of the eye, measured either by ULTRASONOGRAPHY or by partial coherence interferometry.Anisometropia: A condition of an inequality of refractive power of the two eyes.Photorefractive Keratectomy: 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.Lasers, Excimer: 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)Lenses: Pieces of glass or other transparent materials used for magnification or increased visual acuity.Mydriatics: Agents that dilate the pupil. They may be either sympathomimetics or parasympatholytics.Cyclopentolate: A parasympatholytic anticholinergic used solely to obtain mydriasis or cycloplegia.Esotropia: 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.Refractometry: 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).Contact Lenses: Lenses designed to be worn on the front surface of the eyeball. (UMDNS, 1999)Keratotomy, Radial: A procedure to surgically correct REFRACTIVE ERRORS by cutting radial slits into the CORNEA to change its refractive properties.Vision Screening: 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.Cornea: 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)Refractive Surgical Procedures: 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.Corneal Topography: 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.Vitreous Body: 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.Anterior Chamber: 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)SingaporeSclera: 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)Barbados: 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)Ophthalmologic Surgical Procedures: Surgery performed on the eye or any of its parts.Microphthalmos: Congenital or developmental anomaly in which the eyeballs are abnormally small.Vision, Binocular: The blending of separate images seen by each eye into one composite image.Eye Diseases, Hereditary: 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.Strabismus: 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)Amblyopia: 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.Vision Tests: A series of tests used to assess various functions of the eyes.Holmium: Holmium. An element of the rare earth family of metals. It has the atomic symbol Ho, atomic number 67, and atomic weight 164.93.Lens DiseasesPresbyopia: The normal decreasing elasticity of the crystalline lens that leads to loss of accommodation.Tupaia: 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.Pupil: The aperture in the iris through which light passes.Lens, Crystalline: 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.Asian Continental Ancestry Group: Individuals whose ancestral origins are in the southeastern and eastern areas of the Asian continent.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Glaucoma, Angle-Closure: 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.Chickens: Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.Serine Proteases: Peptide hydrolases that contain at the active site a SERINE residue involved in catalysis.Cataract: Partial or complete opacity on or in the lens or capsule of one or both eyes, impairing vision or causing blindness. The many kinds of cataract are classified by their morphology (size, shape, location) or etiology (cause and time of occurrence). (Dorland, 27th ed)Age Distribution: The frequency of different ages or age groups in a given population. The distribution may refer to either how many or what proportion of the group. The population is usually patients with a specific disease but the concept is not restricted to humans and is not restricted to medicine.Los AngelesVision Disorders: Visual impairments limiting one or more of the basic functions of the eye: visual acuity, dark adaptation, color vision, or peripheral vision. These may result from EYE DISEASES; OPTIC NERVE DISEASES; VISUAL PATHWAY diseases; OCCIPITAL LOBE diseases; OCULAR MOTILITY DISORDERS; and other conditions (From Newell, Ophthalmology: Principles and Concepts, 7th ed, p132).Diagnostic Techniques, Ophthalmological: Methods and procedures for the diagnosis of diseases of the eye or of vision disorders.Lens Implantation, Intraocular: Insertion of an artificial lens to replace the natural CRYSTALLINE LENS after CATARACT EXTRACTION or to supplement the natural lens which is left in place.Exotropia: A form of ocular misalignment where the visual axes diverge inappropriately. For example, medial rectus muscle weakness may produce this condition as the affected eye will deviate laterally upon attempted forward gaze. An exotropia occurs due to the relatively unopposed force exerted on the eye by the lateral rectus muscle, which pulls the eye in an outward direction.BaltimoreOrthokeratologic Procedures: 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.
  • Birth History Birth Weight Full-term vs Premature What kind of delivery Complications ¾ During pregnancy ¾ During delivery Hypoxia Bleeding Family History Night blindness Color vision High myopia Nystagmus Cataracts CNS disorders Visual Acuity Does the baby fixate while eating? (spotidoc.com)
  • Instead, surveys show that ultraviolet radiation is the main cause of some eye diseases, such as keratitis, cataracts, retinal damage. (myblog.de)
  • approximately 66% of patients with myopia have less than 2 diopters (D) of myopia and 95% of myopic patients have less than 6 diopters . (eyewiki.org)
  • Methods: An observational descriptive longitudinal study was conducted of 43 children aged 3-15 years diagnosed with myopia equal to or greater than 6 diopters in one or both eyes (72 eyes) who attended the Pediatric Ophthalmology and Strabismus Service at Ramón Pando Ferrer Cuban Institute of Ophthalmology from January to December 2018. (bvsalud.org)
  • The underlying biological cause of myopia is unknown, and there is no widely accepted means of prevention or cure. (utah.edu)
  • Instead of myopia being caused by a defect in a structural protein, defects in the control of these structural proteins might be the actual cause of myopia. (wikipedia.org)
  • Understanding the underlying cause of myopia could help identify potential targets for therapeutic intervention and slow or prevent progression and myopic complications. (reviewofophthalmology.com)
  • While no strategy yet guarantees 100 per cent efficacy, if we can reduce myopia progression by 50 per cent - the general mean efficacy of treatments currently available - we will reduce the incidence of high myopia across the population by 90 per cent. (mieducation.com)
  • While traditional OCT has produced longitudinal cross-sectional images, advancements in data processing have led to the development of en-face OCT, which produces transverse images of retinal and choroidal layers at any specified depth. (ijo.in)
  • En-face OCT has also enabled high-resolution analysis and quantification of pathological structures such as reticular pseudodrusen (RPD) and choroidal neovascularization, which have the potential to become useful markers for disease monitoring. (ijo.in)
  • En-face Doppler OCT enables subtle changes in the choroidal vasculature to be detected in eyes with RPD and AMD, which has significantly advanced our understanding of their pathogenesis. (ijo.in)
  • Choroidal effusion as a mechanism for transient myopia induced by hydrochlorothiazide and triamterene. (scholarena.co)
  • However, the retinal degeneration models with low basal levels of DOPAC had increased susceptibility to form deprivation myopia. (molvis.org)
  • Furthermore, mouse studies revealed that lack of Aplp2 has a dose-dependent suppressive effect on susceptibility to form-deprivation myopia, providing a potential gene-specific target for therapeutic intervention to treat myopia. (plos.org)
  • The phenotype was significantly stronger than form-deprivation myopia. (nature.com)
  • A substantial amount of research has been done to determine the etiology of myopia, the risk factors associated with myopia, techniques to prevent myopia and ways to treat myopia. (eyewiki.org)
  • Instead of a simple one-gene locus controlling the onset of myopia, a complex interaction of many mutated proteins acting in concert may be the cause. (wikipedia.org)
  • 7,8 For these reasons, delaying the onset of myopia and/or slowing myopia progression has been the focus of significant study. (reviewofophthalmology.com)
  • Despite the global pandemic of myopia, the precise molecular mechanism of the onset of myopia remains largely unknown. (nature.com)
  • In light of these factors that question whether IOP causes myopia, we aimed to assess whether IOP is associated with refractive error or AL using data collected from a large sample of Singaporean Chinese schoolchildren. (bmj.com)
  • Founding and facilitating the popular 'Myopia Profile' Facebook group some two years ago has seen the author observe an interesting combination of practitioner attitudes to the evidence - from reticence to accept credible studies to equating anecdotal observations with research outcomes. (mieducation.com)
  • the last few decades and this progress has improved our post-op refractive outcomes. (coursera.org)
  • The increase in axial lengh of the ciliary body (CBAXL) was used as an indicator during accommodation. (escrs.org)
  • There was a dose-dependent relationship between the peripheral treatment zone area and the treatment-induced changes in eye growth and refractive state. (nih.gov)
  • It also demonstrates an important role for APLP2 in refractive development in mice and humans, suggesting a high level of evolutionary conservation of the signaling pathways underlying refractive eye development. (plos.org)
  • In cases of high myopia, a staphyloma can sometimes be seen on fundoscopic examination. (wikipedia.org)
  • While one might think that the inhibitory effect of outside activity on myopia is due to the longer viewing distances, and the lack of 'near work', our recent experiments in chickens show that the development of deprivation myopia (induced by frosted diffusers in front of the eye) is inhibited by high light levels. (vision-research.eu)
  • It could be that temporary exposure to high light may represent a simple way to interfere with myopia also in children - monkey expriments are planned. (vision-research.eu)
  • Mutations in the membrane-type frizzled-related protein ( MFRP ) gene have been identified in patients with pathologic high hyperopia associated with nanophthalmos or microphthalmia. (molvis.org)
  • This study is to test if a mutation in MFRP is responsible for physiologic high hyperopia. (molvis.org)
  • Our results imply that MFRP is less likely to play a major role in physiologic high hyperopia. (molvis.org)
  • Most cases of high hyperopia are physiologic high hyperopia that is not associated with other ocular or systemic anomalies. (molvis.org)
  • RLE should not be indicated in high myopia where patients are under 35, useful residual accommodation remains greater or equal to 2 D, or where refractive ambylopia associated to hyperopia is greater than or equal to 9 D. (ophthalmologytimes.com)
  • SE⩽−0.5D) and high myopia (SE⩽−3.0D). (bmj.com)
  • 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)
  • Children who exhibit myopia by age six to seven years are over six times more likely to progress to high myopia (over 5D) compared to older age of onset of 11-12 years of age, independent of ethnicity and gender. (aop.org.uk)
  • Greene believed that this tensile weakening, plus the increase of IOP caused by the EOM's - anywhere from 5 to 14 mm. of pressure increase during convergence - were the proximal causes of the myopic staphyloma formation seen in high myopia. (simplybrainy.com)
  • Notice the nanophthalmic eyes all have very high hyperopia which in fact is one of the diagnostic indices. (blogspot.com)
  • Sequence variants of the MFRP gene do not appear to be associated with either the less severe forms of hyperopia, extreme forms of limited eye growth and development, or high myopia. (cdc.gov)
  • Note the 5 high-amplitude spikes and the steeply rising retinal spike, as well as the good resolution of the separate retinal and scleral spikes. (medscape.com)
  • Pathologic myopia is generally classified as a high myopic refractive error that is progressive and generally presents very early in childhood. (eyewiki.org)
  • Patients with high axial myopia are at a greater risk of developing progressive retinal degeneration and other vision threatening pathology. (eyewiki.org)
  • It is well documented that pathological non-syndromic high myopia and associated syndromic high myopia show evidence of familial inheritance. (eyewiki.org)
  • High myopia is also a symptom of several multi-system complex diseases. (eyewiki.org)
  • The prevalence rates of myopia in the United States have been reported as 20-50% and as high as 80-90% in some parts of Asia . (eyewiki.org)
  • In terms of safe and effective treatment, orthokeratology is now known to be successful in controlling myopia and has even been shown to slow down progression in individuals with high myopia. (pointsdevue.com)
  • Practitioners are more and more concerned with regard to the increased incidence of patients moving into the category of high myopia. (pointsdevue.com)
  • The ocular health consequences of sequelae related to high myopia can be devastating in later life. (pointsdevue.com)
  • 2.Laser eye surgery.Excimer laser corneal refractive surgery one of the fastest developed medical high-techs, is approaching perfect, Adolescents, who are growing up, should be given much caution on the operation. (myblog.de)
  • moreover, high incidence of retinal changes is reported as a result of prematurity. (ac.ir)
  • High incidence of myopia in premature infants could be related to preterm birth, ROP, or disease treatment (13). (ac.ir)
  • The survey shows that positive effect can be seen after children with myopia wearing the no line bifocal . (myblog.de)
  • Concave lenses that diverge light rays (for myopia) and convex lenses that converge light rays (for hyperopia) are used to focus the object's image on the appropriate retinal point. (healio.com)
  • When we found in 1987 that young chickens, treated with spectacle lenses (Figure 1), change their eye axial growth exactly so that they reach again normal refractions - with the lenses still in front of the eye -, we (with my co-authors Adrian Glasser and Howard Howland) believed that we had found 'the mechanism' that also drives myopia development in humans (Schaeffel et al, Vision Research 28, 639-657, 1988). (vision-research.eu)
  • Orthokeratology (OK) lenses can reduce the rate of progression of childhood myopia over the long term. (bestbets.org)
  • Moreover, it was shown that the amount of retinal glucagon mRNA increased during treatment with positive lenses. (cambridge.org)
  • This study examines the influence of photoreceptor degeneration on refractive development by testing two mouse models of retinitis pigmentosa under normal and form deprivation visual conditions. (molvis.org)
  • Refractive development under normal visual conditions was disrupted toward greater hyperopia from 4 to 12 weeks of age in these photoreceptor degeneration models, despite significantly lower DOPAC levels. (molvis.org)
  • These results indicate that photoreceptor degeneration may alter dopamine metabolism, leading to increased susceptibility to myopia with an environmental visual challenge. (molvis.org)
  • Two L / M cone opsin interchange mutants, designated LIAVA and LVAVA , are associated with clinical diagnoses, including red-green color vision deficiency, blue cone monochromacy, cone degeneration, myopia, and Bornholm Eye Disease. (arvojournals.org)
  • Retinitis pigmentosa (RP), the most common type of inherited retinal degeneration causing blindness, initially manifests as severely impaired rod function followed by deteriorating cone function. (bioscirep.org)
  • Retinitis pigmentosa (RP, OMIM 268000) is the most common type of inherited, blindness-causing retinal degeneration. (bioscirep.org)
  • Patients who have had LASIK or other refractive surgeries are especially difficult to measure precisely. (deserteyedoc.com)
  • When using a Z-haptic IOL, aiming for slight residual hyperopia (+0.50 D) is suggested in patients having phacovitrectomy. (dovepress.com)
  • The retinal changes found after LASIK in this series of patients, appear to reflect the predisposition of myopes. (scielo.br)
  • While AO cameras have been shown to capture images successfully from the same retinal area over follow-up visits to follow progression of lesions with excellent accuracy in patients with stable foveal fixation, 1 there often are a number of retinal lesions in several retinal areas that should be tracked over time, and fixation locus may drift due to foveal involvement by the lesion. (arvojournals.org)
  • However, there is a wealth of scientific evidence for engaging products and management processes today, in your practice, to slow down the race of your paediatric patients towards ever increasing myopia, and the associated escalating risks of ocular pathology. (aop.org.uk)
  • Table I. Refractive error of patients and volunteers (5 eyes/group). (blogspot.com)
  • It highlights the need to balance the available evidence with emerging knowledge when discussing options for myopia control with patients and their carers. (mieducation.com)
  • An understanding of the difference between the evidence base and anecdotal observations in myopia control efficacy, to ensure appropriate informed consent for parents and young myopic patients. (mieducation.com)
  • Many clinicians are implementing a systematic approach to establish a control protocol for their patients with rapidly progressing myopia. (pointsdevue.com)
  • ABSTRACT Objective: Identify the characteristics of pediatric patients with greater than 6 diopter myopia. (bvsalud.org)
  • Patients that have had previous refractive surgery frequently show additional loss of contrast with a reduction in visual quality 6). (ophtec.com)