May 2006
Volume 47, Issue 13
Free
ARVO Annual Meeting Abstract  |   May 2006
The Effect of Conventional and Silicone Hydrogel Contact Lenses Wear on the Tear Film
Author Affiliations & Notes
  • M.M. Lira
    University of Minho, Braga, Portugal
    Physics,
  • M.E. C. D. Real Oliveira
    University of Minho, Braga, Portugal
    Physics,
  • E.Y. Vilar
    Optics and Optometry, University of Santiago of Compostela, Santiago of Compostela, Spain
  • J. Azeredo
    University of Minho, Braga, Portugal
    Biological Engineering,
  • L. Santos
    University of Minho, Braga, Portugal
    Biological Engineering,
  • Footnotes
    Commercial Relationships  M.M. Lira, None; M.E.C.D. Real Oliveira, None; E.Y. Vilar, None; J. Azeredo, None; L. Santos, None.
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science May 2006, Vol.47, 116. doi:
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      M.M. Lira, M.E. C. D. Real Oliveira, E.Y. Vilar, J. Azeredo, L. Santos; The Effect of Conventional and Silicone Hydrogel Contact Lenses Wear on the Tear Film . Invest. Ophthalmol. Vis. Sci. 2006;47(13):116.

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      © ARVO (1962-2015); The Authors (2016-present)

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Abstract
 
Purpose:
 

The aim of this study was to evaluate the effect of one conventional hydrogel and four silicone hydrogel daily wear contact lenses on the volume and stability of the tear film. The tests were performed with a group of patients with no previous contact lens experience before and after 6 months of contact lenses wear.

 
Methods:
 

Tear film stability and volume were monitored on 49 eyes before and after contact lenses wear. The contact lenses tested were: 10 Galyfilcon A, 7 Balafilcon A, 10 Lotrafilcon A, 7 Lotrafilcon B and 15 Etalfilcon A. Each silicone hydrogel lens was used for 1 month and the conventional hydrogel for 15 days. Tests to assess the tear film stability: Break–up–time (BUT): – Time of lachrymal rupture: since the last blink until the appearance of the first dark zone; Non Invasive Break Up Time (NiBUT): – In a biomicroscope at 16x magnification, the Keeler Tearscope Plus, with the help of a grid insert, was used to observe the regularity of the image of the grid. Tests to assess the tear volume: Total Tear Meniscus Height: – Observed in a slit lamp with a milimetric eyepiece: Phenol Red Test: – It was measured the length of the thread which colour was modified from yellow to red because of the effect of the tear pH.

 
Results:
 

USAN: United States Adopted Name BUT (a): medium values for BUT in the first day, in secs BUT (b): medium values for BUT after 6 months, in secs NiBUT (a): medium values for NiBUT in the first day, in secs NiBUT (b): medium values for NiBUT after 6 months, in secs Red Phenol (a): value in the first day, in mm Red Phenol (b): value after 6 months, in mm Meniscus (a): value in the first day, in mm Meniscus (b): value after 6 months, in mm 

 
Conclusions:
 

– Apparently the tear film stability reduces whereas tear film quantity increases after contact lenses wear of all types . However on account of the limited number of patients involved in the study the difference are not statistically different.

 
Keywords: contact lens • cornea: tears/tear film/dry eye • clinical research methodology 
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