Abstract
Purpose: :
The purpose of this study was to evaluate functional visual acuity as determined by the interblink interval visual acuity decay (IVAD) test with two marketed artificial tear products.
Methods: :
This was a controlled, randomized, double masked, two-period crossover study comparing a PEG/PG based (SYSTANE® Ultra, Alcon) and a CMC/Glycerin based tear (OptiveTM, Allergan). 48 dry eye patients received both products in a randomized fashion with a 7-day washout between periods. Baseline measurements of IVAD, recorded as time (sec) that the patient could maintain best corrected visual acuity (BCVA) within an interblink period were performed. Following a single drop, IVAD measurements were repeated at 15, 45 and 90 min. Data was evaluated using a right-censored survival analysis with significance determined by Wilcoxon (p < 0.05).
Results: :
In dry eye patients, the PEG/PG based tear showed a statistically significant increase in the length of time at best corrected visual acuity within an interblink period at 90 minutes post instillation when compared to the CMC/Glycerin based tear (p=.0365). Baseline values were similar for both arms with median times at BCVA of 5.78 and 5.77 for the PEG/PG and CMC/Glycerin tears, respectively. The median times of BCVA measured at 15 (7.75 sec and 6.42 sec) and 45 (6.46 sec and 5.41 sec) minutes post instillation for PEG/PG and CMC/Glycerin, respectively, were not statistically different between groups. 90 minutes post-instillation, the PEG/PG tear showed significant improvement of time at BCVA with a median time of 9.17 sec compared to 6.85 sec for the CMC/Glycerin tear.
Conclusions: :
This study measured visual decay within the interblink period simulating routine visual tasking under focused conditions like reading, working on a computer or driving a car. The tear containing PEG/PG demonstrated a significant improvement in quality of vision in dry eye patients 90 minutes following a single drop. This tear allowed a 58% increase in time at BCVA within the interblink period compared to baseline and was significantly longer (33%) than the CMC/Glycerin product at the 90 minute timepoint.
Clinical Trial: :
www.clinicaltrials.gov NCT00673764
Keywords: cornea: tears/tear film/dry eye • cornea: clinical science • visual acuity