Dry eye symptoms are associated with refractive errors. We aimed to measure the tear evaporation rate (TER) in subjects with refractive errors (RE) using a portable evaporimeter. This nonrandomized, case–control, and observational study included 75 subjects, including 25 subjects aged 18–38 years (28.8 ± 6.8 years) with myopia (−0.75 to −3.75 D) and 25 subjects aged 18–39 years (27.7 ± 5.5 years) with hyperopia (+0.50 to +3.75 D). In addition, a control group of 25 subjects with emmetropic eyes aged 20–30 years (23.6 ± 2.6 years) was recruited. The ocular surface disease index (OSDI) was completed, followed by the TER measurements using a portable evaporimeter. The OSDI score and TER measurements showed dry eye symptoms in 36% and 48% of myopic subjects, respectively. For hyperopic participants, dry eye was observed in 24% and 56% of the subjects based on the OSDI and TER scores, respectively. Significant differences (Mann-Whitney U test; p < 0.001) were found among the OSDI and TER scores recorded within the study (myopic and hyperopic subjects) and control groups. Significant strong positive correlations were detected between the OSDI and TER scores in both myopic (p = 0.004; r = 0.559) and hyperopic (p = 0.001; r = 0.619) subjects. The TER scores were significantly higher in subjects with RE (myopic and hyperopic) as compared with individuals with normal eyes.

To evaluate the dry eye symptoms and ocular tear film in young female subjects with refractive errors (RE) using the ocular surface disease index (OSDI), phenol red thread (PRT) and tear ferning (TF) tests. Methods . A group of 50 young female subjects (mean ± standard division = 20.3 ± 1.1 years) with RE (−0.25 to −6.00D) completed the study. An age‐matched control group consisting of 50 healthy normal eye female subjects (22.2 ± 1.5 years) was recruited for comparison. The OSDI was completed first, followed by PRT and TF tests. Results . Median OSDI and TF scores were significantly higher (Mann–Whitney test; P < 0.001) among the study group subjects [median (interquartile range (IQR)) = 13.5 (15.3) and 1.6 (1.3), respectively] compared to the control group [6.0 (4.0) and 0.9 (0.8), respectively], whereas the median PRT score was significantly lower (Mann–Whitney test; P = 0.003) in the study group [(27.5 (6.3) mm] compared to the control group [29.5 (5.0) mm]. For subjects within the mild RE group ( N = 30), significant differences (Mann–Whitney test, P < 0.001 to 0.005) were found between the median OSDI, PRT, and TF scores and those recorded within the control group. For the subjects with moderate RE ( N = 20), significant differences (Mann–Whitney test, P < 0.001 to 0.002) were found between the median OSDI and TF scores, and those recorded within the control group. Conclusion . The presence of RE in young females has a negative effect on tear film in terms of dry eye symptoms, tear volume, and TF grades. Dry eye symptoms experienced by subjects with RE and the TF grades were significantly higher compared with the control group. In addition, the tear volume was significantly lower in the study group. Clearly, RE has a risk factor for dry eye.

Purpose. To assess the effect of wearing a face mask for a short time on the tear film parameters in normal eye subjects. Methods. Fifty-four normal eye subjects (14 female and 40 male) aged 18–40 years (23.8 ± 4.4 years) were recruited. A standardized patient evaluation of eye dryness was completed first, followed by noninvasive tear break-up time, phenol red thread, and tear ferning tests. A 5-minute gap was allowed between the tests. The subjects were asked to wear a surgical mask for one hour. The measurements were taken both before wearing a face mask and immediately after its removal. Results. Significant (Wilcoxon test) differences were found between the standardized patient evaluation of eye dryness ( ) and the noninvasive tear break-up time scores ( ) before and after wearing face masks. No significant differences (Wilcoxon test, ) were found between the phenol red thread scores and tear ferning grades before and after wearing face masks. Strong correlations (Spearman’s rank correlation coefficient, r) were found among the standardized patient evaluation of eye dryness score (r = 0.590; ), noninvasive tear break-up time measurements (r = 0.631; ), and the tear ferning grades (r = 0.517; ) before and after wearing the mask. A medium correlation (r = 0.377; ) was found between the noninvasive tear break-up time scores and tear ferning grades before wearing the mask. Conclusions. Wearing a surgical face mask for a short duration of one hour has an effect on ocular tear film in normal eye subjects. Dry eye symptoms and tear break-up increased after wearing a face mask compared with those experienced before wearing one.

Diabetes is a very common disease and is considered a risk factor for many diseases such as dry eye. The aim of the current work was to evaluate the tear evaporation rate (TER) in patients with diabetes using a hand-held evaporimeter. This observational, case–control and non-randomized study included 30 male patients with diabetes (17 controlled and 13 uncontrolled) with a mean ± standard deviation (SD) of 33.1 ± 7.9 years. An age-matched (18–43 years; 32.2 ± 6.5 years) control group consisting of 30 male subjects was also enrolled for comparison. Subjects with thyroid gland disorder, a high body mass index, high blood cholesterol, or thalassemia, contact lens wearers, and smokers were excluded. The TER was measured after the completion of the ocular surface disease index (OSDI) by each participant. The OSDI and TER median scores were significantly (Wilcoxon test, p < 0.05) higher in patients with diabetes (median (interquartile range; IQR) = 12.0 (8.3) and 46.4 (36.7) g/m²h, respectively) compared to the subjects within the control group (5.6 (7.0) and 15.1 (11.9) g/m²h, respectively). The median scores for the OSDI and TER measurements were significantly (Wilcoxon test, p < 0.05) higher among uncontrolled diabetes patients (13.0 (11.5) and 53.4 (14.2) g/m²h, respectively) compared to those obtained for patients with controlled diabetes (11.0 (8.0) and 27.3 (32.6) g/m²h, respectively). The tear evaporation rate in patients with diabetes was significantly higher compared to those obtained in subjects without diabetes. Uncontrolled diabetes patients have a higher tear evaporation rate compared to controlled diabetes patients. Therefore, diabetes can lead to eye dryness, since these patients possibly suffer excessive tear evaporation.

Background. Osmolarity is used to detect symptoms of dry eye disease (DED) and can be measured using TearLab (TM) and I-Pen (R) systems. Objectives. To investigate the correlation between osmolarity measurements using the TearLab (TM) and I-Pen (R) systems in subjects with a high body mass index (BMI). Materials and methods. Thirty male subjects with a high BMI (27-48 kg/m(2); 23.3 +/- 2.1 years old) participated in this study. The control group consisting of 30 healthy males (24.9 kg/m(2); 22.9 +/- 2.1 years old) was also enrolled. Osmolarity measurements were recorded from the right eye using the TearLab (TM) and I-Pen (R) systems, and interviews were conducted to determine ocular surface disease index (OSDI) scores. Results. The OSDI (p = 0.042), TearLab (TM) (p < 0.001) and I-Pen (R) (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 (TM) osmolarity scores were in the range of 278-309 mOsm/L in the study group, whereas the I-Pen (R) 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 (TM) and I-Pen (R) osmolarity scores (r = 0.934; p = 0.001). In addition, strong correlations were found between the BMI and both TearLabT (r = 0.736; p = 0.001) and I-Pen (R) (r = 0.707; p = 0.001) scores, as well as between the OSDI scores and both TearLab (TM) (r = 0.731; p = 0.001) and I-Pen (R) measurements (r = 0.666; p = 0.001). Conclusions. Osmolarity measurements using the I- Pen (R) system were significantly higher than those recorded using the TearLab (TM) system in subjects with a high BMI. The I-Pen (R) measurements showed large variations in osmolarity scores and were highly unreliable in correctly identifying normal eyes compared to the TearLab (TM) system. Also, a strong correlation was found between the osmolarity scores obtained from the TearLab (TM) and I-Pen (R) systems.

Purpose. Smoking has a negative effect on health and ocular tear film. The purpose of the current study is to investigate the correlation between the TearLab and I-Pen osmolarity scores in smokers and compare them with those of non-smoking healthy males. Methods. Thirty male smokers (25.3±2.2 years) participated in the study. An age-matched (22.9±2.0 years) control group of non-smoking healthy males (N=30) was also recruited for comparison purposes. The ocular surface disease index (OSDI) was completed first, followed by the TearLab and I-Pen osmolarity measurements. Results. The median TearLab osmolarity score was lower (P<0.001) than that obtained using the I-Pen in both the study and the control groups. The OSDI scores and osmolality measurements were higher (P<0.001) in smokers than in the control subjects. In the smoker group, there were moderate correlations between the OSDI scores and the measurements obtained using the TearLab (Spearmans correlation coefficient, r=0.463; P=0.010) and I-Pen (r=0.449; P=0.013) systems. In addition, there was a strong correlation between the osmolarity scores obtained from the TearLab and I-Pen systems in smokers (r=0.911; P<0.001). Conclusion. The I-Pen scores in smokers were significantly higher than those obtained using TearLab. The TearLab scores showed small variations compared with those obtained using I-Pen. A strong correlation was found between the TearLab and I-Pen scores in smokers. The osmolarity TearLab and I-Pen scores were significantly higher in smokers compared with normal eye subjects.