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D.L. Meadows, M.T. Christensen, M. Tudor, J.M. Stein, M. Abelson, G. Ousler, III; Use of a Controlled Adverse Environmental (CAE) Chamber to Evaluate Artificial Tears . Invest. Ophthalmol. Vis. Sci. 2003;44(13):2487.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose: To evaluate the efficacy of an artificial tear formulation in a Controlled Adverse Environmental (CAE) Chamber. Methods: 60 dry eye subjects were enrolled in this randomized, parallel, double masked, vehicle controlled clinical study. To be eligible, patients had to demonstrate at least a one-grade increase in inferior corneal staining in either eye within 90 minutes after entering the CAE Chamber. The test product was a Polyquad® (Polyquaterium-1) preserved solution containing demulcents, essential ions and a novel polymer system, HP-Guar, that forms a soft protective gel over the eye upon instillation. On Day 0, LogMAR VA, corneal staining (5 regions), conjunctival injection and tear break up time (TBUT) were determined prior to entering the chamber and after 90 minutes in the chamber. Discomfort measurements were taken every 5 minutes while in the chamber. TBUT was taken immediately after 5 µ l instillation of NaFl and corneal staining was determined 5 minutes later. After establishing eligibility on Day 0, patients were assigned per randomization either the test or control solution and were required to instill 1-2 drops a minimum of 2 times/day for 7 days. On Day 7 the above tests were repeated prior to entering the chamber then after 30 minutes, one drop per eye of the assigned tear solution was instilled and the subject entered the chamber for another 90 minutes session. Based on the clinical signs, study subjects were classified as Aqueous Deficient, Meibomian Gland Dysfunctional (MGD), Mucin Deficient and/or Mechanical Deficient. Results: On Day 7 prior to entering the chamber, the test product had less average inferior staining (0.604) that was statistically significant (p = 0.008). Post exposure to the chamber, staining for the test product was 0.556 units lower with a trend toward significance (p=0.08) . Tear breakup time of the active treatment was statistically significantly longer prechamber than that of the vehicle control (p = 0.036). There were no differences pre or post chamber for superior, nasal, temporal and central cornea or injection. On average, approximately 3 drops were used per day for each group. Conclusions: This study demonstrated that a CAE chamber can be used to evaluate palliative dry eye treatments. Using this approach, it was demonstrated that novel artificial tear based on HP-Guar can reduce clinical signs over a 7 day period.
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