The Effect of a New Emulsion in Dry Eye Patients on Tear Layer Aberrometry, Contrast Sensitivity, and Reading Ability

Not Applicable

Completed

Conditions: Dry Eye Syndrome

Registration Number: NCT01013077

Lead Sponsor: Southern California College of Optometry at Marshall B. Ketchum University

Brief Summary: The purpose of this study is to investigate how the addition of a new emulsion artificial tear to the tear layer of dry eye and normal patients affects aberrometry, contrast sensitivity, and reading ability over time. Previous studies have indicated that daily use of artificial tears over a two week period decreases the short term affect of drop application on aberrometry and contrast sensitivity measurements. The present study will examine the effects of 4 weeks of artificial tear use to determine when the responses stabilize.

Detailed Description: Dry eye patients experience symptoms such as; irritation, dryness, a scratchy sensation, and blur. These symptoms are the result of an insufficient tear layer. Blur can occur in dry eye patients because of an irregular tear film surface.

Artificial tears are applied to the eye to treat a variety of eye conditions. These conditions typically are associated with dry eyes and include tear film deficiency due to ocular or systemic disease, lid resurfacing problems, and contact lens wear. The artificial tears are used to alleviate the dry eye symptoms.

Dry eye is a frequently encountered ocular condition. Recent studies estimate that 7.8% of women and 4.8% of men over the age of 50 suffer from dry eye. The administration of an artificial tear to the eye can disrupt the tear layer and this disruption could then result in a change in contrast sensitivity for a few moments. Aberrometry is a technique that is able to monitor tear layer disruption and its results may correlate with contrast sensitivity changes.

Tear layer disruption results in a decrease in the modulation transfer function (MTF) for the eye. Since the tear layer is the first refracting surface of the eye, its disruption can also result in a change in contrast sensitivity, visual acuity, and aberrometry. Previous work has demonstrated that higher order aberrations increase 1.44 fold after the tear film breaks up in normal subjects. Dry eye subjects demonstrate a significant increase in higher order aberrations (i.e., total S3+4+5, spherical-like S4, and coma-like S3+5) when compared to normal subjects. This has been interpreted to be the result of increased tear irregularities in the dry eye subjects.

When an artificial tear (i.e., Vismed) was applied to the tear layer of dry eye subjects, the optical aberrations decreased. This previous study only examined the short term affect (less than 10 minutes) of a single administration of an artificial tear. In this study, we propose to examine the short and long term effects of a new emulsion on contrast sensitivity, optical aberrations, and reading ability after administration into the tear layer of normal and dry eye subjects.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 20

Inclusion Criteria

mild, moderate, or severe symptoms of dry eye

Exclusion Criteria

uncontrolled systemic disease
contact lens wear
participation in another clinical trial
best corrected visual acuity poorer than 20/25

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Contrast Sensitivity	Baseline, 1 week, 2 weeks, 4 weeks	Change in contrast sensitivity with administration of the artificial tear. During a visit, contrast sensitivity is initially monitored for several minutes (i.e., pre-artificial tear application contrast sensitivity) and the artificial tear is then applied and the contrast sensitivity is continually measured for several more minutes (post-artificial tear application contrast sensitivity). The administration of the artificial tear decreases contrast sensitivity for approximately a minute. The data reported in the table is the change in contrast sensitivity from pre-artificial tear administration to the peak loss in contrast sensitivity after the artificial tear administration (negative values). This procedure is carried out before the subjects use artificial tears on a daily basis (i.e., baseline data) and for several weeks after using artificial tears on a daily basis (i.e., weeks 1, 2, and 4) to determine if there is an adaptation to the artificial tear.

Secondary Outcome Measures

Name	Time	Method

Trial Locations

Locations (1): Southern California College of Optometry
🇺🇸
Fullerton, California, United States
Southern California College of Optometry
🇺🇸Fullerton, California, United States