Study of the Cell Response in the Tear Film After Overnight Contact Lens Wear

Polymorphonuclear Leukocyte Response During Overnight Lens Wear

The purpose of this study was to count and analyze the white blood cells in tear samples collected from study participants following sleep. The results from contact lens wearers were compared with the results from non-contact lens wearers.

The objective of the study was to determine and compare the relative oxidative response of polymorphonuclear neutrophils (PMNs), the relative cell adhesion response of PMNs, and the leukocyte population in tear samples collected from contact lens wearers and non-contact lens wearers. Tear samples were collected via a binocular eye-wash. The samples were processed, and a cell count was performed using a hemacytometer. Flow cytometry was used to determine the expression of different PMN cell markers before and after stimulation with bacterial lipopolysaccharide (LPS).

Inclusion Criteria:

• 17 years of age or older.

• Ocular examination in the last two years.

• Has up-to-date spectacles.

• Falls into one of the following three categories:

  • Adapted wearer of Lotrafilcon A contact lenses
  • Adapted wearer of Lotrafilcon B contact lenses
  • Does not wear contact lenses

• Other protocol-defined inclusion criteria may apply.

Exclusion Criteria:

• Ocular disease
• Systemic or topical medications that may affect ocular health.
• Known sensitivity to diagnostic pharmaceuticals used in study.
• Uses artificial tears and/or rewetting drops.
• Wears contact lenses on an overnight basis for more than one night per week.
• Other protocol-defined exclusion criteria may apply.