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Measurement errors related to contact angle analysis of hydrogel and silicone hydrogel contact lenses.
Read, Michael L; Morgan, Philip B; Maldonado-Codina, Carole.
Afiliação
  • Read ML; Eurolens Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom.
  • Morgan PB; Eurolens Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom.
  • Maldonado-Codina C; Eurolens Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom.
J Biomed Mater Res B Appl Biomater ; 91(2): 662-668, 2009 Nov.
Article em En | MEDLINE | ID: mdl-19582861
This work sought to undertake a comprehensive investigation of the measurement errors associated with contact angle assessment of curved hydrogel contact lens surfaces. The contact angle coefficient of repeatability (COR) associated with three measurement conditions (image analysis COR, intralens COR, and interlens COR) was determined by measuring the contact angles (using both sessile drop and captive bubble methods) for three silicone hydrogel lenses (senofilcon A, balafilcon A, lotrafilcon A) and one conventional hydrogel lens (etafilcon A). Image analysis COR values were about 2 degrees , whereas intralens COR values (95% confidence intervals) ranged from 4.0 degrees (3.3 degrees , 4.7 degrees ) (lotrafilcon A, captive bubble) to 10.2 degrees (8.4 degrees , 12.1 degrees ) (senofilcon A, sessile drop). Interlens COR values ranged from 4.5 degrees (3.7 degrees , 5.2 degrees ) (lotrafilcon A, captive bubble) to 16.5 degrees (13.6 degrees , 19.4 degrees ) (senofilcon A, sessile drop). Measurement error associated with image analysis was shown to be small as an absolute measure, although proportionally more significant for lenses with low contact angle. Sessile drop contact angles were typically less repeatable than captive bubble contact angles. For sessile drop measures, repeatability was poorer with the silicone hydrogel lenses when compared with the conventional hydrogel lens; this phenomenon was not observed for the captive bubble method, suggesting that methodological factors related to the sessile drop technique (such as surface dehydration and blotting) may play a role in the increased variability of contact angle measurements observed with silicone hydrogel contact lenses.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Silicones / Lentes de Contato Hidrofílicas / Hidrogéis Idioma: En Revista: J Biomed Mater Res B Appl Biomater Assunto da revista: ENGENHARIA BIOMEDICA Ano de publicação: 2009 Tipo de documento: Article País de afiliação: Reino Unido

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Silicones / Lentes de Contato Hidrofílicas / Hidrogéis Idioma: En Revista: J Biomed Mater Res B Appl Biomater Assunto da revista: ENGENHARIA BIOMEDICA Ano de publicação: 2009 Tipo de documento: Article País de afiliação: Reino Unido