{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T07:21:15Z","timestamp":1774941675661,"version":"3.50.1"},"reference-count":25,"publisher":"Wiley","issue":"12","license":[{"start":{"date-parts":[[2009,12,1]],"date-time":"2009-12-01T00:00:00Z","timestamp":1259625600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2009,12,1]],"date-time":"2009-12-01T00:00:00Z","timestamp":1259625600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["OVS"],"published-print":{"date-parts":[[2009,12]]},"abstract":"ABSTRACT<\/jats:title>\n \n Purpose.<\/jats:title>\n To investigate and compare changes in refractive astigmatism and corneal toricity in orthokeratology (ortho\u2010k) using the Thibos vector analysis.<\/jats:p>\n <\/jats:sec>\n \n Methods.<\/jats:title>\n \n Consecutive records of 74 patients (aged 7 to 16 years) who were fitted with spherical ortho\u2010k lenses at the Optometry Clinic of The Hong Kong Polytechnic University between April 2000 and November 2003 and who had been on the treatment for at least 6 months were reviewed. Manifest refractive error and topographic data were retrieved from the right eye for data analysis. Changes in refractive astigmatism and corneal toricity were evaluated using the Thibos vectors (refractive vectors, RJ\n 0<\/jats:sub>\n and RJ\n 45<\/jats:sub>\n ; corneal vectors, CJ\n 0<\/jats:sub>\n and CJ\n 45<\/jats:sub>\n ) among the astigmats (refractive astigmatism 0.75 diopters cylinder (DC) or above) and the non\u2010astigmats (refractive astigmatism 0.50 DC or less).\n <\/jats:p>\n <\/jats:sec>\n \n Results.<\/jats:title>\n \n The mean changes in refractive astigmatism, RJ\n 0<\/jats:sub>\n and RJ\n 45<\/jats:sub>\n were 0.51 \u00b1 0.51 diopter (D), \u22120.31 \u00b1 0.35 D, and 0.09 \u00b1 0.16 D, respectively, among the astigmats; and 0.01 \u00b1 0.36 D, 0.00 \u00b1 0.17 D, and 0.03 \u00b1 0.13 D, respectively, among the non\u2010astigmats. RJ\n 0<\/jats:sub>\n was significantly reduced, and RJ\n 45<\/jats:sub>\n was significantly increased only in the astigmats (one sample t tests, astigmats: p < 0.01; non\u2010astigmats: p > 0.10). Although there were significant correlations between the initial RJ\n 0<\/jats:sub>\n and RJ\n 45<\/jats:sub>\n with their changes in all subjects and in the astigmats, only 21 to 55% of the variability could be explained by the regression equations (Pearson r: all subjects \u22120.63 < r < \u22120.62; astigmats \u22120.74 < r < \u22120.46, p < 0.001). No significant changes in corneal toricity and no correlations between the changes in refractive astigmatism and changes in corneal toricity were found (p > 0.13).\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions.<\/jats:title>\n \n Spherical ortho\u2010k leads to significant changes in RJ\n 0<\/jats:sub>\n and RJ\n 45,<\/jats:sub>\n but only 38% of the variance of the changes in all subjects could be explained by relationship between changes and the initial RJ\n 0<\/jats:sub>\n or RJ\n 45<\/jats:sub>\n . No correlation between changes in refractive astigmatism and changes in corneal toricity was found, and ortho\u2010k treatment did not induce astigmatism in our non\u2010astigmatic subjects.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.1097\/opx.0b013e3181be06ff","type":"journal-article","created":{"date-parts":[[2009,11,25]],"date-time":"2009-11-25T06:24:54Z","timestamp":1259130294000},"page":"1352-1358","source":"Crossref","is-referenced-by-count":24,"title":["Astigmatic Changes in Orthokeratology"],"prefix":"10.1002","volume":"86","author":[{"given":"Sin Wan","family":"Cheung","sequence":"first","affiliation":[{"name":"School of Optometry The Hong Kong Polytechnic University Hong Kong SAR China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pauline","family":"Cho","sequence":"additional","affiliation":[{"name":"School of Optometry The Hong Kong Polytechnic University Hong Kong SAR China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ben","family":"Chan","sequence":"additional","affiliation":[{"name":"School of Optometry The Hong Kong Polytechnic University Hong Kong SAR China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2009,12,1]]},"reference":[{"key":"e_1_2_7_2_2","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1097\/00006324-200005000-00012","article-title":"Overnight orthokeratology","volume":"77","author":"Nichols JJ","year":"2000","journal-title":"Optom Vis Sci"},{"key":"e_1_2_7_3_2","doi-asserted-by":"crossref","first-page":"598","DOI":"10.1097\/00006324-200209000-00011","article-title":"Overnight orthokeratology: preliminary results of the Lenses and Overnight Orthokeratology (LOOK) study","volume":"79","author":"Rah MJ","year":"2002","journal-title":"Optom Vis Sci"},{"key":"e_1_2_7_4_2","doi-asserted-by":"crossref","first-page":"796","DOI":"10.1097\/00006324-200312000-00009","article-title":"Comparison of reverse\u2010geometry lens designs for overnight orthokeratology","volume":"80","author":"Tahhan N","year":"2003","journal-title":"Optom Vis Sci"},{"key":"e_1_2_7_5_2","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1097\/01.ICL.0000133242.49355.BB","article-title":"Corneal topography in corneal refractive therapy (CRT): a 1\u2010month follow\u2010up","volume":"30","author":"Potapova N","year":"2004","journal-title":"Eye Contact Lens"},{"key":"e_1_2_7_6_2","doi-asserted-by":"crossref","first-page":"407","DOI":"10.1097\/01.opx.0000135093.77007.18","article-title":"The children's overnight orthokeratology investigation (COOKI) pilot study","volume":"81","author":"Walline JJ","year":"2004","journal-title":"Optom Vis Sci"},{"key":"e_1_2_7_7_2","doi-asserted-by":"crossref","first-page":"512","DOI":"10.1097\/01.opx.0000166772.68413.0e","article-title":"Reduction of myopia from corneal refractive therapy","volume":"82","author":"Sorbara L","year":"2005","journal-title":"Optom Vis Sci"},{"key":"e_1_2_7_8_2","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1111\/j.1444-0938.2006.00044.x","article-title":"Orthokeratology review and update","volume":"89","author":"Swarbrick HA","year":"2006","journal-title":"Clin Exp Optom"},{"key":"e_1_2_7_9_2","doi-asserted-by":"crossref","first-page":"410","DOI":"10.1097\/OPX.0b013e31804f5acc","article-title":"Refractive error and visual acuity changes in orthokeratology patients","volume":"84","author":"Cheung SW","year":"2007","journal-title":"Optom Vis Sci"},{"key":"e_1_2_7_10_2","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1111\/j.1444-0938.2002.tb03084.x","article-title":"An analysis of the astigmatic changes induced by accelerated orthokeratology","volume":"85","author":"Mountford J","year":"2002","journal-title":"Clin Exp Optom"},{"key":"e_1_2_7_11_2","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1076\/ceyr.28.2.121.26236","article-title":"Subjective and objective assessments of the effect of orthokeratology\u2014a cross\u2010sectional study","volume":"28","author":"Cheung SW","year":"2004","journal-title":"Curr Eye Res"},{"key":"e_1_2_7_12_2","doi-asserted-by":"crossref","first-page":"1425","DOI":"10.1016\/j.jcrs.2004.02.049","article-title":"Quantitative evaluation of regular and irregular corneal astigmatism in patients having overnight orthokeratology","volume":"30","author":"Hiraoka T","year":"2004","journal-title":"J Cataract Refract Surg"},{"key":"e_1_2_7_13_2","doi-asserted-by":"crossref","first-page":"367","DOI":"10.1097\/00006324-199706000-00019","article-title":"Power vectors: an application of Fourier analysis to the description and statistical analysis of refractive error","volume":"74","author":"Thibos LN","year":"1997","journal-title":"Optom Vis Sci"},{"key":"e_1_2_7_14_2","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1016\/S0886-3350(00)00797-5","article-title":"Power vector analysis of the optical outcome of refractive surgery","volume":"27","author":"Thibos LN","year":"2001","journal-title":"J Cataract Refract Surg"},{"key":"e_1_2_7_15_2","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1097\/00006324-197010000-00001","article-title":"Analyzing contact lens induced changes of the corneal curvature","volume":"47","author":"Bailey IL","year":"1970","journal-title":"Am J Optom Arch Am Acad Optom"},{"key":"e_1_2_7_16_2","doi-asserted-by":"crossref","first-page":"524","DOI":"10.1016\/S0886-3350(13)80617-7","article-title":"A new method of analyzing vectors for changes in astigmatism","volume":"19","author":"Alpins NA","year":"1993","journal-title":"J Cataract Refract Surg"},{"key":"e_1_2_7_17_2","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/S0886-3350(00)00798-7","article-title":"Astigmatism analysis by the Alpins method","volume":"27","author":"Alpins N","year":"2001","journal-title":"J Cataract Refract Surg"},{"key":"e_1_2_7_18_2","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1111\/j.1475-1313.2008.00545.x","article-title":"The validity of the Jessen formula in overnight orthokeratology: a retrospective study","volume":"28","author":"Chan B","year":"2008","journal-title":"Ophthalmic Physiol Opt"},{"key":"e_1_2_7_19_2","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1167\/iovs.06-0914","article-title":"Contrast sensitivity function and ocular higher\u2010order aberrations following overnight orthokeratology","volume":"48","author":"Hiraoka T","year":"2007","journal-title":"Invest Ophthalmol Vis Sci"},{"key":"e_1_2_7_20_2","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1046\/j.1475-1313.1995.9592795.x","article-title":"Corneal optics from video keratographs","volume":"15","author":"Hemenger RP","year":"1995","journal-title":"Ophthal Physiol Opt"},{"key":"e_1_2_7_21_2","doi-asserted-by":"crossref","first-page":"657","DOI":"10.1364\/JOSAA.19.000657","article-title":"Videokeratoscope\u2010line\u2010of\u2010sight misalignment and its effect on measurements of corneal and internal ocular aberrations","volume":"19","author":"Salmon TO","year":"2002","journal-title":"J Opt Soc Am (A)"},{"key":"e_1_2_7_22_2","doi-asserted-by":"crossref","first-page":"1499","DOI":"10.1136\/bmj.308.6942.1499","article-title":"Regression towards the mean","volume":"308","author":"Bland JM","year":"1994","journal-title":"BMJ"},{"key":"e_1_2_7_23_2","doi-asserted-by":"crossref","first-page":"780","DOI":"10.1136\/bmj.309.6957.780","article-title":"Some examples of regression towards the mean","volume":"309","author":"Bland JM","year":"1994","journal-title":"BMJ"},{"key":"e_1_2_7_24_2","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/B978-0-7506-4007-7.50007-6","volume-title":"Orthokeratology: Principles and Practice","author":"Ruston D","year":"2004"},{"key":"e_1_2_7_25_2","unstructured":"BaertschiM.Short and long term success with correction of high astigmatism in OK. Poster presented at the Global Orthokeratology Symposium Chicago July 2005 Illinois USA."},{"key":"e_1_2_7_26_2","unstructured":"BeertenR ChristieC SpraterN LudwigF.Improving orthokeratology results in astigmatism.Poster presented at the Global Orthokeratology Symposium Chicago July 2005 Illinois USA."}],"container-title":["Optometry and Vision Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1097\/OPX.0b013e3181be06ff","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1097\/OPX.0b013e3181be06ff","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1097\/OPX.0b013e3181be06ff","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T05:49:01Z","timestamp":1774936141000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1097\/OPX.0b013e3181be06ff"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,12]]},"references-count":25,"journal-issue":{"issue":"12","published-print":{"date-parts":[[2009,12]]}},"alternative-id":["10.1097\/OPX.0b013e3181be06ff"],"URL":"https:\/\/doi.org\/10.1097\/opx.0b013e3181be06ff","archive":["Portico"],"relation":{},"ISSN":["1040-5488","1538-9235"],"issn-type":[{"value":"1040-5488","type":"print"},{"value":"1538-9235","type":"electronic"}],"subject":[],"published":{"date-parts":[[2009,12]]}}}