The Effect Of Soft Contact Lens Materials On Tear Film Stability-Invasive And Non-Invasive Break-Up Time In Young Adult Population
Background: This study sets out to investigate the effect of soft contact lens materials [polymacon (Bescon), hioxifilcon A (Extreme H2O®), lotrafilcon B (O2Optix)] on the non-invasive tear break-up time (NIBUT) and fluorescein-instillation break-up time (FBUT).
Materials and Methods: A total of forty-five subjects within age range 18-30years with mean age 22.4 ± 3.2 years consisting of males (n=11) and females (n=34) were used for this study. The NIBUT was assessed with the Bausch & Lomb Keratometer, stopwatch and FBUT assessed using BIO GLO sterile strips (1 mg fluorescein sodium ophthalmic strip, U.S.P) with Burton lamp.
Results: The mean NIBUT was profoundly affected by wear of contact lenses made from polymacon (p=0.018) and Hioxifilcon A (p=0.006) materials though they belong to different FDA classes. However, the NIBUT was not affected by wear of contact lens made of lotrafilcon B. The FBUT was not affected by wear of contact lenses made from the three materials.
Conclusion: The change in NIBUT caused by polymacon and hioxifilcon A was due to disruption of the tear film by the wear of lenses made of such materials. Destabilization of the tear film by instilled fluorescein during assessment masked the possible effect of lens wear hence no change in FBUT was noticed with lenses made of Polymacon, Hioxifilcon A and Lotrafilcon B.
Keywords: soft contact lens materials, tear film stability, non-invasive tear break-up
time, fluorescein-instillation tear break-up time.