The orbscan acoustic (correction) factor for central corneal thickness measures of normal human corneas

Eye & Contact Lens
M J Doughty, Sven Jonuscheit

Abstract

Orbscan scanning-slit optical pachymetry was introduced over a decade ago and yielded higher central corneal thickness (CCT) values to the "gold standard" of contact ultrasound pachymetry (U/S). An acoustic correction factor (AF) was introduced later to compensate for this difference. The goal of this review was to assess the magnitude and consistency of the difference, as well as to assess how useful the AF had been. Using PubMed (Medline)-sourced citations, published articles were identified that included data on CCT from U/S and Orbscan, with the latter data checked to see whether an AF had been applied. Main comparisons were made between (1) Orbscan data without AF and U/S, and (2) Orbscan data with a 0.92 AF applied and the U/S data. From 46 studies involving a total of 6136 eyes (average number per study of 133, range 6-1214), the average CCT values by U/S ranged from 0.520 to 0.580, for a group mean of 0.545 mm. For Orbscan without AF, the average CCT values ranged from 0.557 to 0.624 mm, for a mean of 0.582 mm, a net difference of 0.037 mm from U/S, with all Orbscan data (average values from any particular study) being higher than U/S. With a 0.92 AF applied, the net difference was -0.009 mm. The calculated limits of ag...Continue Reading

References

Nov 1, 1991·Statistics in Medicine·A Whitehead, J Whitehead
Jan 10, 1998·Journal of Cataract and Refractive Surgery·V YaylaliH W Thompson
Jul 13, 2000·Journal of Cataract and Refractive Surgery·S A Naroo, W N Charman
Nov 30, 2000·Cornea·M W Marsich, M A Bullimore
Feb 1, 2002·Journal of Cataract and Refractive Surgery·Mohamed A FakhryJorge L Alió
Feb 1, 2002·Journal of Cataract and Refractive Surgery·Francesco BosciaCarlo Sborgia
Jan 29, 2003·Journal of Cataract and Refractive Surgery·Jose Manuel González-MéijomeManuel A Parafita
Mar 8, 2003·Ophthalmology·Olivier PrisantThanh Hoang-Xuan
Jun 5, 2004·Journal of Cataract and Refractive Surgery·D GherghelS Shah
Jun 9, 2004·American Journal of Ophthalmology·Jay W McLarenWilliam M Bourne
Apr 13, 2005·Arquivos brasileiros de oftalmologia·Adamo Lui NettoMilton Ruiz Alves
May 19, 2005·Journal of Cataract and Refractive Surgery·Gary R FishmanRobert Ritch
Nov 9, 2005·Optometry and Vision Science : Official Publication of the American Academy of Optometry·Birgit LacknerChristian Skorpik
Dec 19, 2006·Cornea·Arthur C K ChengDennis S C Lam
Jan 16, 2007·Optometry and Vision Science : Official Publication of the American Academy of Optometry·Sven Jonuscheit, Michael J Doughty
Feb 28, 2007·Ophthalmic & Physiological Optics : the Journal of the British College of Ophthalmic Opticians (Optometrists)·Sven JonuscheitNorman F Button
Mar 8, 2007·Graefe's Archive for Clinical and Experimental Ophthalmology = Albrecht Von Graefes Archiv Für Klinische Und Experimentelle Ophthalmologie·Ivan Goldberg, Robert Ritch
Apr 3, 2007·Optometry : Journal of the American Optometric Association·Michael J Doughty, Sven Jonuscheit
May 16, 2007·Eye & Contact Lens·Elliott H MyrowitzRoy S Chuck
May 25, 2007·Graefe's Archive for Clinical and Experimental Ophthalmology = Albrecht Von Graefes Archiv Für Klinische Und Experimentelle Ophthalmologie·Michael J Doughty, Sven Jonuscheit
Jun 23, 2007·Graefe's Archive for Clinical and Experimental Ophthalmology = Albrecht Von Graefes Archiv Für Klinische Und Experimentelle Ophthalmologie·Rana Altan-YayciogluYonca Aydin Akova
Sep 25, 2007·Journal of Cataract and Refractive Surgery·Hassan HashemiKamran Yazdani
Mar 26, 2008·Journal of Cataract and Refractive Surgery·Mohammad-Reza NilforoushanRobert Latkany
Nov 14, 2008·Journal of Cataract and Refractive Surgery·Tania PaulRonald H Silverman
Jan 7, 2009·Eye & Contact Lens·Sven Jonuscheit, Michael J Doughty
Feb 20, 2009·Optometry and Vision Science : Official Publication of the American Academy of Optometry·Raul MartinSofia Martin

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Citations

Oct 25, 2011·Surgical and Radiologic Anatomy : SRA·Juan A Sanchis-GimenoFrancisco Martinez-Soriano
Dec 18, 2013·Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft·A G M JünemannR Rejdak
Nov 23, 2012·Cornea·Juan A Sanchis-GimenoAlejandro Cerviño
Sep 17, 2014·Survey of Ophthalmology·Ana Rio-Cristobal, Raul Martin
Jan 7, 2014·The Kaohsiung Journal of Medical Sciences·Yi-Chun ChenSzu-Yuan Lin
Feb 18, 2011·Clinical & Experimental Optometry : Journal of the Australian Optometrical Association·Raul MartinGuadalupe Rodriguez
Jul 23, 2011·Clinical & Experimental Optometry : Journal of the Australian Optometrical Association·Michael J DoughtyNorman F Button
Aug 17, 2014·American Journal of Ophthalmology·Jos J RozemaMarie-José Tassignon
Nov 2, 2014·Optometry and Vision Science : Official Publication of the American Academy of Optometry·Pablo Fernandez-GarciaJuan A Sanchis-Gimeno
Jan 29, 2020·Cornea·Hesham Mohamed GhariebRania Serag Elkitkat
Mar 30, 2020·International Ophthalmology·Hesham Mohamed GhariebIhab Saad Othman
Apr 26, 2018·BioMed Research International·Marcelino Perez-BermejoJuan A Sanchis-Gimeno

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