ABSTRACT

Soft Contact lenses have been used by millions of patients for the correction of various vision disorders and cosmetics.The purpose of this study was to determine the short term effect of soft contact lens materials on the tear film stability and pH of healthy eyes. This experimental study was carried out on 30 healthy human eyes. These participants were divided into 3 groups with each group having 10 participants. Group “A” participants were fitted with Polymacon contact lenses, Group “B” with Omafilcon A contact lenses and Group “C” with Lotrafilcon B contact lenses. The tear film stability was measured before and after 6 hours of wear using the non invasive tear break up time (NIBUT) method by a keratometer, also tears was collected before and after 6 hours of wear using a sterile micro capillary tube and stored for analysis of pH. Data obtained was analyzed using paired t-test and descriptive statistics. Omafilcon A, polymacon and lotrafilcon B reduced TBUT by 3.37 ± 5.16s, 3.25 ± 7.98s and 3.96 ± 8.13s respectively. An analysis of variance showed that there was no significant difference among the effects of the three contact lens materials (p = 0.972). Omafilcon A led to a reduction of 0.15 ± 0.78 on average, while polymacon resulted in an increase of 0.15 ± 0.53 on average. Lotrafilcon B also increased the PH by 0.10 ± 0.32 on average.An analysis of variance showed that there was no significant difference among the effects of the three contact lens materials (p = 0.469).

Keywords: Tear film stability, Soft contact lenses, pH , Keratometer.