Research Article
Volume 12 Issue 2 - 2021
Correlation between Tear Osmolarity Measurements Using TearLab and I-Pen Osmolarity Systems in Normal Young Saudi Subjects
Raied Fagehi1*, Mana A Alanazi1, Wael A Abdualkarim1, Nawaf F Alsubaie1, Gamal A El-Hiti2, Ali M Masmali2 and Turki Almubrad2
1Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
2Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
*Corresponding Author: Raied Fagehi, Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
Received: December 09, 2020; Published: January 30, 2021


Background: Increases in tear osmolarity and instability of the tear film are core mechanisms of dry eye regardless of its etiology. Techniques for measuring tear osmolarity and detecting instability of the tear film should be reliable and accurate. TearLab and I-Pen are the most commonly used new techniques for measuring tear osmolarity. The purpose of this study was to determine the correlation between tear osmolarity measured using TearLab and I-Pen in normal young Saudi subjects.

Methods: Thirty-seven men aged from 20 to 28 years (mean, 23.0 ± 2.2 years) completed the study. The subjects were healthy with no symptoms of dry eye or ocular disease and did not wear contact lenses. The exclusion criteria were thyroid gland disorder, high cholesterol level (above 4 mmol/L), high body mass index (above 24.9 kg/m2), vitamin A or D deficiency, hypertension, anemia, diabetes and smoking. The ocular surface disease index (OSDI) was completed first, followed by measurements of tear osmolarity in the right eye using TearLab and I-Pen.

Results: The average (mean ± SD) OSDI values and osmolarity readings from TearLab and I-Pen were normally distributed (P > 0.05, Kolmogorov-Smirnov test). The OSDI scores ranged from 0 to 10.4 and confirmed that none of the subjects had dry eye symptoms. The TearLab and I-Pen scores ranged from 263 to 304 mOsm/L and from 278 to 317 mOsm/L, respectively. I-Pen scores were higher than TearLab scores (300.5 ± 10.0 vs. 287.4 ± 10.7 mOsm/L). The TearLab and I-Pen scores were strongly correlated (Pearson correlation coefficient r = 0.968; P < 0.001).

Conclusion: Tear osmolarity scores with I-Pen were higher than those with TearLab in normal young Saudi subjects. The TearLab and I-Pen osmolarity scores were strongly correlated.

Keywords: Tear Osmolarity; Normal Eye Subjects; Strong Correlation; Tear Film Stability; Dry Eye


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Citation: Raied Fagehi., et al. “Correlation between Tear Osmolarity Measurements Using TearLab and I-Pen Osmolarity Systems in Normal Young Saudi Subjects”. EC Ophthalmology 12.2 (2021): 40-46.

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