Assessment of Tear Osmolarity in Smokers Using TearLab and I-Pen 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 (Spearman's 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.

Assessment of Tear Film Parameters in Smokers and Subjects with a High Body Mass Index.

SIGNIFICANCE: The current study compares the ocular tear film parameters in three different groups using a single noninvasive, practical, and easy-to-use tool. PURPOSE: This study aimed to assess the tear film in smokers, those with a high body mass index (BMI), and healthy subjects using the EASYTEAR view+. METHODS: Thirty men with a high BMI (>25 kg/m2; 24.4 ± 6.4 years), 30 smokers (25.1 ± 6.1 years), and 30 healthy subjects (22.2 ± 3.5 years) were recruited. Each subject completed the Ocular Surface Disease Index, followed by the assessment of noninvasive tear breakup time, tear meniscus height (TMH), and lipid layer patterns (LLPs). RESULTS: Significant differences were found in the median TMH scores between smokers and healthy subjects (P = .03) and between subjects with a high BMI and the healthy ones (P = .04). The median LLP score was significantly (P < .001) higher in normal subjects (4.0 [1.0]) than in smokers (2.4 [1.0]) and subjects with high BMI (2.0 [1.3]). For subjects with a high BMI, the noninvasive tear breakup time score was strongly correlated (Spearman rank correlation coefficient; r) with TMH (r = 0.552, P = .002) and LLP (r = 0.555, P = .001). The LLP showed that grade B (lipid layer thickness, 30 to 50 nm; more compact) was common in subjects with a high BMI, grade C (50 to 80 nm, gray waves) was predominant in smokers, and grade D (~80 nm, dense white-blue layer) represented the majority of normal eye subjects. CONCLUSIONS: Smokers and individuals with a high BMI showed significantly lower lipid layer grades and tear meniscus height scores compared with the control group. The assessment of tear film parameters using the EASYTEAR view+ supports the findings of previous studies that implicate smoking and high BMI as risk factors for dry eye.

Agreement Between Autorefraction and Subjective Refraction in Keraring-Implanted Keratoconic Eyes.

OBJECTIVES: To assess the agreement between subjective refraction and autorefraction and to explore the relationship between the magnitude of higher order aberration, and visual acuity and refraction, before and after keraring implantation. METHODS: This prospective, randomized, interventional study enrolled 27 subjects (mean age 28.1±6.5 years) with keratoconus. Noncycloplegic refraction was performed subjectively by one clinician and with an autorefractor by another clinician, before and 6 months after surgery. The limit of agreement (LoA) between methods was assessed, and the relationships between the corrected distance visual acuity, logMAR on the one hand and refraction measurements and higher-order aberrations on the other, were examined. RESULTS: The agreement in mean spherical equivalent refraction (MSER) between methods was good postoperatively but poor preoperatively. The autorefractor gave a more myopic refraction than subjective refraction preoperatively (-3.28±3.06 D; LoA -9.27 to +2.71 D, P<0.0001) and postoperatively (-0.63±1.64 D; LoA -3.85 to +2.58 D, P=0.055), and returned higher negative cylinders preoperatively (-1.10±1.17 D; LoA -3.40 to +1.19 D, P<0.0001) and postoperatively (-1.08±1.27 D; LoA -3.60 to +1.41 D, P<0.0001) in keratoconic eyes. The difference in MSER between methods was significantly related to the refractive error at both visits (P<0.05) and to the magnitude of higher-order aberrations in keratoconic eyes preoperatively (P<0.05). The logMAR visual acuity achieved subjectively worsened as the magnitude of higher-order aberrations increased preoperatively (P<0.001). CONCLUSIONS: The autorefractor returns values that are significantly more myopic in MSER and higher negative cylinders than subjective refraction, preoperatively, but the MSER was similar between devices postoperatively. The autorefactor seems a valid starting point for subjective refraction in keratoconic eyes treated with keraring, but the cylinder should be corrected by about +1 D. The instruments agree more in less myopic than high myopic eyes.