Effect of Refresh Plus(®) preservative-free lubricant eyedrops on tear ferning patterns in dry eye and normal eye subjects

PURPOSE: To evaluate the tear ferning patterns in dry eye and normal eye subjects in the 3 hours following application of Refresh Plus(®) preservative-free lubricant eyedrops. METHODS: Thirty men with dry eye (mean age 22.14±2.34 years) and 30 age-matched men with normal eyes (mean age 23.91±3.24 years) were enrolled. Eyes were classified as normal or dry based on their Ocular Surface Disease Index score, tear meniscus height, and noninvasive tear breakup time. The tear ferning test was performed before and 30, 60, 120, and 180 minutes after application of a Refresh Plus eyedrop into the right eye in each subject. RESULTS: There was a significant change in tear ferning grade after application of Refresh Plus eyedrops (P=0.02, Wilcoxon test) in the group with dry eye, but not in the normal eye group (P=0.19, Wilcoxon test). The correlation of tear ferning grade was moderate (r=0.484, P=0.049) at 60 minutes after application of the eyedrops and strong at 120 minutes (r=0.560, P=0.019) and 180 minutes (r=0.726, P=0.001). There was also a strong correlation (r=0.865, P=0.001) between tear ferning grades obtained 120 and 180 minutes after application. In the normal eye group, there was a moderate (r=0.407, P=0.029) correlation between tear ferning grades obtained before and 60 minutes after application of the eyedrops. There was also a strong correlation (r=0.532, P=0.003) between tear ferning grades obtained 120 and 180 minutes after application. CONCLUSION: Tear ferning patterns improved significantly after application of Refresh Plus preservative-free lubricant eyedrops in subjects with dry eye. Artificial tears containing sodium carboxymethylcellulose, such as Refresh Plus, can be used to improve tear ferning patterns in dry eye for at least 3 hours.