CRT inverts the pattern of peripheral refraction in spherical equivalent refraction, creating a treatment area of myopic reduction within the central 25 degrees of visual field, and a myopic shift beyond the 25 degrees. In peripheral refraction for 30 degrees and 35 degrees, the amount of myopia ind... | PMID: 20375751

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The amount of myopia reduction with orthokeratology occurred mostly within 1 week while the corneal biomechanical properties such as CH and CRF were decreased. However the corneal biomechanical properties are reversal to the original level thereafter and remain unchanged within the 6 months follow u... | PMID: 20450664

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The process of CL-related microbial keratitis and inflammation is thought to be preceded by the presence or transfer or both of microorganisms from the lens to the ocular surface. Thus, this detailed understanding of lens-related bioburden is important in the understanding of factors associated with... | PMID: 20168237

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Spherical ortho-k leads to significant changes in RJ0 and RJ45, but only 38% of the variance of the changes in all subjects could be explained by relationship between changes and the initial RJ0 or RJ45. No correlation between changes in refractive astigmatism and changes in corneal toricity was fou... | PMID: 19844190

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Subjects' awareness of the importance of lens cleanliness is high and can be improved by regular reinforcements. However, attitudes toward cleaning of accessories was far less satisfactory and while replacement and warnings resulted in significant improvements of contamination rates of tweezers and... | PMID: 19786928

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Overnight orthokeratology significantly reduced corneal sensation at both central and peripheral locations, and the reduction was not correlated with the amount of myopic correction. At present, the clinical significance of this sensory loss is not clear, but practitioners should take this effect in... | PMID: 19654526

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PMID: 19323673

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There was a statistically significant change from baseline in all variables at all visits in lens wearing eyes. Refraction changed after 1 h of lens wear, with greater effect after overnight wear. Para-central corneal flattening was apparent after 1 h of lens wear, with greater flattening after over... | PMID: 19225436

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Infectious keratitis is a significant, visual threatening complication of overnight orthokeratology. Eye care practitioners should be aware of this complication and educate their patients of the importance of lens hygiene and prompt medical care when symptoms or signs of keratitis appear.... | PMID: 19123161

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The prevalence and incidence of complications associated with OOK have not been determined. Complications, including more than 100 cases of infectious keratitis resulting from gram-positive and gram-negative bacteria and Acanthamoeba, have been described in case reports and case series representing... | PMID: 18804868

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The time course of refractive and corneal topographic changes in hyperopic OK is analogous to myopic OK. Most change in refractive and topographic variables occurs on day 1, with regression of effect during the day but greater retention of effect by day 7. Refractive outcomes were less predictable w... | PMID: 19050471

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Orthokeratology significantly reduced manifest refraction (p<0.0001, Dunnett test) and significantly improved uncorrected visual acuity (UCVA) at 12 months after commencement of the procedure (p<0.0001). Asymmetry and higher-order irregularity components increased significantly (p<0.0001, p = 0.0032... | PMID: 19019936

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CRTH lenses, designed to correct hyperopia, when worn overnight, caused an increase in CET. The amount of epithelial change seemed to differ with modified lens design.... | PMID: 18421075

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PMID: 18606565

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PURPOSE: A case of asymptomatic corneal foreign body injury during orthokeratology lens wear is reported. CASE REPORT: An 8-year-old Chinese female myopic child with 21 months of overnight orthokeratology lens wear experienced a corneal foreign body injury without symptoms. The foreign body was remo... | PMID: 18337157

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Short-term response of human cornea to corneal refractive therapy is correlated with the biomechanical properties of the cornea. Of the different theories supporting such involvement of corneal response to reverse geometry contact lenses, the most likely one seems to be the one assuming a faster res... | PMID: 18434845

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The primate cornea, particularly the corneal epithelium, responds rapidly to the application of reverse-geometry OK lenses with significant epithelial cell shape alterations with short-term OK lens wear. This finding suggests that the corneal epithelium is moldable in response to the physical forces... | PMID: 18434851

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The Jessen formula was found to underestimate the intended target of myopic reduction following ortho-k. The results suggested that the formula should be revised to BOZR = flattest K- (1.23 target reduction + 1.27). CONCLUSION: If the intention is to overcorrect the ortho-k patient by 0.75 D to allo... | PMID: 18426426

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Mesopic contrast sensitivity after overnight orthokeratology is deteriorated significantly as ocular higher-order aberrations increase, and these changes depend on the amount of myopic correction.... | PMID: 18241829

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We believe that the key to providing a safe orthokeratology practice is to continually update knowledge in the field, and to practice to the highest professional standards.... | PMID: 17714977

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The epithelium appears to play a major role in the changes induced by orthokeratology lenses. The epithelial effects were dependent on time and lens design. Further studies are needed to determine the mechanisms responsible for these changes.... | PMID: 17913568

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CRT lenses for myopia and hyperopia induce significant structural and optical changes in as little as 15 minutes. The cornea, particularly the epithelium, is remarkably malleable, with rapid steepening and flattening possible in little time.... | PMID: 18216565

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After 6 months of overnight orthokeratology wear, some optical aberrations showed regression during the day. Despite no significant change in UCVA during 10 to 12 hours, there was a significant increase in defocus (Z4) within the first 5 hours after removing the orthokeratology lens and a decrease i... | PMID: 18041257

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After overnight CRT lens wear, the central cornea flattened and the mid-periphery steepened (both p < 0.001). After 4 weeks of lens wear, the CFZ (+/-SE) increased from 3.41 +/- 0.09 mm on day 1 morning to 3.61 +/- 0.07 mm on day 28 morning and the diameter of the ASZ increased from 8.17 +/- 0.16 mm... | PMID: 17956362

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Acanthamoeba keratitis may be a vision-threatening complication associated with overnight orthokeratology lens wear. It is essential for eye care professionals to fully explain and warn parents of the potential downsides that may be associated with orthokeratology. Ophthalmologists should have a hig... | PMID: 17993830

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PMID: 17975415

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Although there has been an increasing number of reports of microbial keratitis associated with orthokeratology since 2001, most (85 [69%] of 123) of these cases occurred in East Asia, particularly in China and Taiwan, during a relatively short period, when regulation of this modality was limited. Th... | PMID: 17975424

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