Correlation between osmolarity measurements using the TearLab™ and I-Pen® systems in subjects with a high body mass index

• Published in: Advances in clinical and experimental medicine : official organ Wroclaw Medical University Vol. 31; no. 12; pp. 1413 - 1418
• Main Authors: Alanazi, Mana, El-Hiti, Gamal, Alhafy, Naif, Almutleb, Essam, Fagehi, Raied, Alanazi, Saud, Masmali, Ali
• Format: Journal Article
• Language: English
• Published: Poland 01.12.2022
• Subjects: Adult; Body Mass Index; Dry Eye Syndromes; Humans; Male; Osmolar Concentration; Tears; Young Adult; tear osmolarity; TearLab™ system; tear film; dry eye; high body mass index; I-Pen® system
• ISSN: 1899-5276
• DOI: 10.17219/acem/156645

Osmolarity is used to detect symptoms of dry eye disease (DED) and can be measured using TearLab™ and I-Pen® systems. To investigate the correlation between osmolarity measurements using the TearLab™ and I-Pen® systems in subjects with a high body mass index (BMI). Thirty male subjects with a high BMI (27-48 kg/m2; 23.3 ±2.1 years old) participated in this study. The control group consisting of 30 healthy males (24.9 kg/m2; 22.9 ±2.1 years old) was also enrolled. Osmolarity measurements were recorded from the right eye using the TearLab™ and I-Pen® systems, and interviews were conducted to determine ocular surface disease index (OSDI) scores. The OSDI (p = 0.042), TearLab™ (p < 0.001) and I-Pen® (p < 0.001) scores were significantly higher in the study group than in the control group. In the study group, OSDI scores ranged from 2 to 16 (median 8.0, interquartile range (IQR) 6.8), while it was from 0 to 10 (median 6.3, IQR 4.1) in the control group. The TearLab™ osmolarity scores were in the range of 278-309 mOsm/L in the study group, whereas the I-Pen® osmolarity measurements were in the range of 294-336 mOsm/L in the study group, compared with 263-304 mOsm/L and 278-317 mOsm/L in the control group, respectively. In the study group, there was a strong correlation between the TearLab™ and I-Pen® osmolarity scores (r = 0.934; p = 0.001). In addition, strong correlations were found between the BMI and both TearLab™ (r = 0.736; p = 0.001) and I-Pen® (r = 0.707; p = 0.001) scores, as well as between the OSDI scores and both TearLab™ (r = 0.731; p = 0.001) and I-Pen® measurements (r = 0.666; p = 0.001). Osmolarity measurements using the I-Pen® system were significantly higher than those recorded using the TearLab™ system in subjects with a high BMI. The I-Pen® measurements showed large variations in osmolarity scores and were highly unreliable in correctly identifying normal eyes compared to the TearLab™ system. Also, a strong correlation was found between the osmolarity scores obtained from the TearLab™ and I-Pen® systems.