{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T08:00:27Z","timestamp":1774944027954,"version":"3.50.1"},"reference-count":31,"publisher":"Wiley","issue":"7","license":[{"start":{"date-parts":[[2011,7,1]],"date-time":"2011-07-01T00:00:00Z","timestamp":1309478400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2011,7,1]],"date-time":"2011-07-01T00:00:00Z","timestamp":1309478400000},"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":[[2011,7]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Purpose.<\/jats:title>\n                    <jats:p>To validate the clinical performance of point\u2010source corneal topography (PCT) in postpenetrating keratoplasty (PKP) eyes and to compare it with conventional Placido\u2010based topography.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods.<\/jats:title>\n                    <jats:p>Corneal elevation maps of the anterior corneal surface were obtained from 20 post\u2010PKP corneas using PCT (VU topographer, prototype; VU University Medical Center, Amsterdam, The Netherlands) and Placido\u2010based topography (Keratron, Optikon 2000, Rome, Italy). Corneal surface parameters are calculated in terms of radius and asphericity. Corneal aberrations were characterized using standard Zernike convention. An artificial surface with quadrafoil feature (SUMIPRO, Almelo, The Netherlands) was measured and used as a reference to assess instrument performance compared with the gold standard.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results.<\/jats:title>\n                    <jats:p>The differences (mean \u00b1 std of PCT \u2212 Placido) found between the two types of topographers in measurements of post\u2010PKP eyes are 0.02 \u00b1 0.21 mm (p = 0.64) for radius of curvature, 0.14 \u00b1 0.49 (p = 0.23) for asphericity, \u22120.19 \u00b1 1.67 \u03bcm (p = 0.61) for corneal astigmatism, \u22120.25 \u00b1 1.34 \u03bcm (p = 0.41) for corneal coma, 0.23 \u00b1 0.82 \u03bcm (p = 0.23) for corneal trefoil, and 0.15 \u00b1 0.28 \u03bcm (p = 0.02) for corneal quadrafoil. The PCT measured the artificial surface more accurate (rms error 0.16 \u03bcm; 0.12 eq. Dpt.) than the Placido\u2010based topographer (rms error 1.50 \u03bcm; 1.15 eq. Dpt.).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions.<\/jats:title>\n                    <jats:p>PCT is more accurate than Placido\u2010based topography in measuring quadrafoil aberration.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1097\/opx.0b013e31821bbd68","type":"journal-article","created":{"date-parts":[[2011,4,22]],"date-time":"2011-04-22T02:53:51Z","timestamp":1303440831000},"source":"Crossref","is-referenced-by-count":2,"title":["Clinical Validation of Point\u2010Source Corneal Topography in Keratoplasty"],"prefix":"10.1002","volume":"88","author":[{"given":"Anne C. L.","family":"Vrijling","sequence":"first","affiliation":[{"name":"Royal Dutch Visio Centre of Expertise for Blind and Partially Sighted People Huizen The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Boy","family":"Braaf","sequence":"additional","affiliation":[{"name":"Ophthalmic Imaging Group Rotterdam Ophthalmic Institute Rotterdam The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joris J.","family":"Snellenburg","sequence":"additional","affiliation":[{"name":"Department of Physics and Astronomy VU University Amsterdam The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fleur","family":"de Lange","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology VU University Medical Center Amsterdam The Netherlands"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michel J. 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