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

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).

• Lotrafilcon A contact lens (Device), also known as AIR OPTIX NIGHT & DAY AQUA: Commercially marketed, silicone hydrogel, single-vision contact lens FDA-approved for daily and extended (overnight) wear for up to 30 nights.
• Lotrafilcon B contact lens (Device), also known as NIGHT & DAY®: Commercially marketed, silicone hydrogel, single-vision contact lens FDA-approved for daily or extended (overnight) wear up to 6 nights.
• Clear Care Cleaning and Disinfection Solution (Device), also known as Clear Care®: Hydrogen peroxide-based contact lens care system for nightly cleaning and disinfection of study lenses

Primary outcomes

• Leukocyte Population [Week 5]: A tear sample was collected after 8 hours of sleep using an ocular surface cell collection apparatus (OSCCA). Different types of white blood cells (leukocytes) were identified, which included neutrophils, monocytes, and lymphocytes. The total amount of leukocytes for contact lens wearers and non-lens wearers is presented. Potential differences in leukocyte count between lens wearers and non-lens wearers may indicate a different immune response.
• Relative Cell Adhesion Response of Polymorphonuclear Leukocytes (PMNs) [Week 5]: A tear sample was collected after 8 hours of sleep using an ocular surface cell collection apparatus (OSCCA) and analyzed on a flow cytometer. CD54 is a protein typically found in the cell membrane of leukocytes, which up-regulates during inflammation and promotes cell adhesion. Cell adhesion response is reported as a ratio of stimulated to non-stimulated samples.
• Relative Oxidative Response of Polymorphonuclear Leukocytes (PMNs) [Week 5]: A tear sample was collected after 8 hours of sleep using an ocular surface cell collection apparatus (OSCCA) and analyzed on a flow cytometer. Oxidative response is reported as a ratio of activated to non-activated samples. DCF (dichlorofluorescein diacetate) is a molecular probe that measures the oxidative burst. Upon stimulation, the PMNs synthesize reactive oxygen species, such as superoxide or hydrogen peroxide, which is detected by the probe. Differences in the oxidative response between contact lens wearers and non-lens wearers is indicated by a shift in the ratio (stimulated/unstimulated).
• Change From Week 1 in Leukocyte Population at Week 5 [Week 1, Week 5]: A tear sample was collected after 8 hours of sleep using an ocular surface cell collection apparatus (OSCCA). Different types of white blood cells (leukocytes) were identified, which included neutrophils, monocytes, and lymphocytes. The difference between total leukocytes for contact lens wearers and non-lens wearers (Week 5 minus Week 1) is presented.
• Change From 1 Week in Relative Cell Adhesion Response of PMNs at Week 5 [Week 1, Week 5]: A tear sample was collected after 8 hours of sleep using an ocular surface cell collection apparatus (OSCCA) and analyzed on a flow cytometer. Cell adhesion response is reported as a ratio of activated to non-activated samples. The difference between the ratio data for contact lens wearers and non-lens wearers (Week 5 minus Week 1) is presented.
• Change From Week 1 in Relative Oxidative Response of PMNs at Week 5 [Week 1, Week 5]: A tear sample was collected after 8 hours of sleep using an ocular surface cell collection apparatus (OSCCA) and analyzed on a flow cytometer. Oxidative response is reported as a ratio of activated to non-activated samples. The difference between the ratio data for contact lens wearers and non-lens wearers (Week 5 minus Week 1) is presented.

Sex: All, ages: 17 Years to any, accepts healthy volunteers

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.

Participant flow

Outcome results

• Leukocyte Population (Primary), Mean, Leukocytes: Lotrafilcon A 583187 +/- 832636; Lotrafilcon B 420345 +/- 355940; No Lens Wear 738140 +/- 609853
• Relative Cell Adhesion Response of Polymorphonuclear Leukocytes (PMNs) (Primary), Mean, Ratio: Lotrafilcon A 1.1 +/- 0.2; Lotrafilcon B 1.2 +/- 0.2; No Lens Wear 1.1 +/- 0.1
• Relative Oxidative Response of Polymorphonuclear Leukocytes (PMNs) (Primary), Mean, Ratio: Lotrafilcon A 1.2 +/- 0.5; Lotrafilcon B 1.7 +/- 1.1; No Lens Wear 1.3 +/- 0.6
• Change From Week 1 in Leukocyte Population at Week 5 (Primary), Mean, Leukocytes: Lotrafilcon A -1377 +/- 453,119; Lotrafilcon B -95301 +/- 632752; No Lens Wear 122316 +/- 519976
• Change From 1 Week in Relative Cell Adhesion Response of PMNs at Week 5 (Primary), Mean, Ratio: Lotrafilcon A -0.01 +/- 0.23; Lotrafilcon B 0.00 +/- 0.24; No Lens Wear -0.01 +/- 0.20
• Change From Week 1 in Relative Oxidative Response of PMNs at Week 5 (Primary), Mean, Ratio: Lotrafilcon A 0.05 +/- 0.94; Lotrafilcon B 0.24 +/- 1.20; No Lens Wear -0.19 +/- 0.58

Adverse events

Time frame: Adverse events were collected for the duration of the study.

• Lyndon Jones, PhD FCOptom FAAO, Director, Principal investigator, Centre for Contact Lens Research, School of Optometry, University of Waterloo