Purchase this article with an account.
William H. Ridder, III; Do Contrast Thresholds Improve When Dry Eye Subjects are Treated With Artificial Tears?. Invest. Ophthalmol. Vis. Sci. 2011;52(14):3802.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Dry eye is frequently encountered and often treated with artificial tears (AT). Dry eye patients have poorer contrast thresholds (CT) than normal patients. The purpose of this investigation was to determine if there is a decrease in CT after dry eye patients are treated for 2 weeks with artificial tears.
Twenty-one dry eye subjects (age 47.4 ± 16.59) were examined. Their average acuity was -0.02 ± 0.079 logMAR. Subjects were characterized as having dry eye based on a comprehensive battery of non-invasive (e.g., tear meniscus height, white-light lipid interferometry) and invasive (e.g., fluorescein breakup time, meibomian gland expression) tests. To be included, the subjects had to pass two of the three following criteria: Schein symptom score ≥ 7, TBUT ≤ 7.0 seconds, and total corneal staining score ≥ 4.0 in either eye (0 - 20 scale). CT was measured for a 14 cpd sine wave grating (16 ms duration) using a temporal, 2-alternative, forced-choice technique. The stimulus was presented 1 sec after a blink was detected. Employing a staircase method, eleven reversals of stimulus contrast were obtained and the last 9 were averaged for the CT. Two CT measurements were made before daily artificial tear use and at 1 and 2 weeks after daily artificial tear use (minimum 2 times per day). The two measurements obtained at each visit were averaged for comparison across visits. The artificial tear used was Optive (Allergan, Inc).
The group averaged contrast thresholds (mean ± SD) for the dry eye subjects were: 17.3 ± 18.31, 18.8 ± 18.32, and 14.9 ± 15.40 for baseline, week 1, and week 2, respectively. A two-way ANOVA found a significant difference across visits for the dry eye subjects (p = 0.004, F = 6.21). A Tukey simultaneous test indicated that the contrast threshold for week 1 was significantly different from week 2 (p = 0.003, T = 3.49).
Treating dry eye subjects for 2 weeks with an artificial tear resulted in a decrease in the CT. This may be the result of the tear layer becoming more stable after a couple of weeks of artificial tear use.
Clinical Trial: :
This PDF is available to Subscribers Only