The two artificial tears had similar results from objective measurements of improvement, but Blink Tears produced less blur and performed better in several other subjective evaluations, said Mohamed A. Guenena, MD, of the Magill Research Center for Vision Correction, Storm Eye Institute, Medical University of South Carolina, Charleston.
The prospective, randomized, double-masked, multicenter pilot study included 50 eyes of 25 patients aged 18 or more years in whom with chronic dry eye had been diagnosed and who had been using topical cyclosporine for at least 3 months before joining the study. Inclusion criteria were up to grade 3 conjunctival staining and a score of no more than 4 on the Subjective Evaluation of Symptoms of Dryness at screening. Patients were excluded if they had any confounding factors that might affect the results of the study, such as contact lens use or ocular allergy, infection, or disease.
After being randomly assigned to either one of the artificial tears (Blink Tears: 28 eyes of 14 patients; Systane: 22 eyes of 11 patients), the subjects were instructed to use the drops at least twice a day. The patients were matched closely in demographic characteristics such as age, race, and gender; most patients were female and Caucasian, and the mean age was in the mid-60s. There was no difference in best-corrected visual acuity (BCVA) between the Blink and Systane groups.
Patients were evaluated at baseline and at months 1 and 3. In a poster presented at the annual meeting of the American Academy, Dr. Mohamed and co-authors reported 3-month results. Assessments included BCVA, tear break-up time (TBUT), Schirmer's test with anesthesia, and lissamine conjunctival staining. Subjective evaluation measures included the Ocular Surface Disease Index questionnaire, a patient satisfaction evaluation, a patient acute comfort and vision questionnaire, and a patient compliance questionnaire.
"For the objective measurements, we didn't see much difference between the drops," Dr. Guenena said. "This was expected, because both groups of patients had been [using] cyclosporine for 3 months, which has proved to be very beneficial. Improvement in staining, tear break-up time, and Schirmer's scores would be expected."
At month 3, the mean staining scores were 1.6 and 1.9 for Blink Tears and Systane, respectively; mean TBUT scores were 4.8 and 5.1 sec, and mean Schirmer's scores were 8.6 and 8.1 mm.
The subjective results revealed several differences between the two products. Blink Tears produced significantly less blur than Systane at month 3 (p < 0.018). On a scale of zero to 10, the mean scores at month 3 were 1.4 for the Blink Tears/cyclosporine group and 3 for the Systane/cyclosporine group.
There also was a statistically significant difference in the percentage of patients who reported that the eye drops adequately controlled their symptoms (Blink Tears, 100%; Systane, 73%; p < 0.044). A higher percentage of patients in the Blink Tears group said the drops had improved stinging compared with the Systane group (60% versus 50%), and more patients in the Blink Tears group than in the Systane group reported improvement in ocular burning (73% versus 44%).
It is unclear why the Blink Tears resulted in greater improvement in symptoms, Dr. Guenena said, explaining that the two artificial tears would have to be studied without the concomitant use of cyclosporine to answer this question.
However, differences in the inactive ingredients of the two artificial tears may be associated with the change in symptoms seen in this study. Another hypothesis is that the artificial tears may have different forms of interaction with cyclosporine that affect improvement in symptoms.
Co-authors of the study were Helga P. Sandoval, MD, MSCR; Luis E. Fernandez de Castro, MD; and Kerry D. Solomon, MD, who all are affiliated with the Magill Research Center for Vision Correction.