Objective: This study aimed to improve the tear ferning (TF) patterns in the sheep tears after the addition of various electrolyte solutions in different proportions.Animal Studied: Sheep were located at a small farm in the outskirts of Riyadh, Saudi Arabia. The sheep had no ocular disorders or diseases, and none of the female sheep were pregnant.Methods: Tear samples (20 μl) were collected from the right eyes of seven healthy sheep (five female sheep and two male sheep; age 7–36 months with an average of 17.0 ± 10.3 months). A tear sample (1 μl) from each sheep was dried on a microscopic glass slide at 22°C and <40% humidity. The TF patterns were graded based on the five-point grading scale in 0.1 increments. Homogenous mixtures were prepared by mixing tears from each sheep (0.5 μl) with various electrolyte solutions in different proportions (1:1, 1:2, 1:4, 1:6, 1:8, and 1:10). A sample of each mixture (1 μl) was dried on a glass slide, and the TF patterns for each mixture were observed, recorded, graded, and compared with those of the corresponding pure sheep tears. In addition, each sheep tear sample (0.5 μl) was diluted with pure water (0.5 μl) and the TF images were recorded and graded to test the dilution effect.Results: General improvement was noted in TF grades after the addition of electrolyte solutions, ranging from 1.7–1.4 to 1.3–0.3 regardless of the ratio between the electrolyte solutions and sheep tears within the mixture. TF grades of sheep tear samples improved significantly after adding different volumes of calcium chloride solution. Similar improvements in TF grades were observed when magnesium chloride hexahydrate and sodium dihydrogen phosphate solutions were used as the electrolytes. Some improvements in the TF grades occurred with the addition of potassium chloride to sheep tear samples. There was little improvement in TF grades after the addition of sodium chloride solution.Conclusion: Tear ferning grades of sheep tear samples improved when mixed with a number of electrolyte solutions at different volumes, in particular with calcium chloride or magnesium chloride solutions. Some improvements in TF grades were seen with sodium dihydrogen phosphate or potassium chloride solution added as the electrolyte. Clearly, divalent electrolytes lead to a greater improvement in TF grades of sheep tear samples as compared with sodium dihydrogen phosphate or monovalent electrolytes.

PURPOSE: To investigate the repeatability of tear osmolarity in healthy Saudi subjects using an I-PEN osmolarity device. MATERIALS AND METHODS: Thirty typical male subjects with healthy eyes (27.4 ± 4.9 years) participated in the study. Eye abnormalities were tested with a slit lamp, and eye comfort was determined with the surface disease index. Measurements of the tear break-up time and phenol red thread tests were used for as exclusion criteria. The tear osmolarity test, using an I-PEN osmolarity system, was performed three times in the right eye of each subject with a 5 min' gap between tests. RESULTS: The average osmolarity test score was 303.8 ± 4.8 mOsm/L. Tear osmolarity measurements showed tear osmolarity of 280–299 mOsm/L, 300–309 mOsm/L, and 310–329 mOsm/L in 14 (46.7%), three (10%), and 13 (43.3%) subjects, respectively. Correlations among the three I-PEN measurements were significant (Spearman's correlation coefficient; r = 0.036, 0.501, and 0.603; P = 0.050, 0.006, and 0.001, respectively). The mean coefficient of variance among the three measurements was 4.4%. CONCLUSION: The mean measurement of an I-PEN tear osmolarity was 303.8 ± 4.8 mOsm/L which is in agreement with the range of those reported for healthy subjects. The I-PEN is reliable and has the advantage of portability (hand-held) compared to the other osmolarity systems.

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.

SIGNIFICANCEThe current study is the first report to describe the improvement of ferning patterns of human tears using electrolyte solutions. The results can help in the production of new artificial tears to improve the quality of tears.PURPOSEThis study aimed to investigate the effect of the addition of different volumes of various electrolyte solutions on ferning patterns of human tears.METHODSTear samples (20 μL) were collected from the right eye of 13 subjects (5 men and 5 women) aged 19 to 36 years (27.1 ± 5.1 years) with normal eyes. Then, 1 μL of each tear sample was dried on a microscopic glass slide, and obtained ferns were observed using light microscopy and graded using the 5-point tear ferning (TF) grading scale. Homogenous mixtures of each tear sample (0.5 μL) and different volumes (0.5 to 5 μL) of each electrolyte were prepared. A sample (1 μL) of each mixture was dried, and the ferns obtained were graded and compared with those of the corresponding tears collected from subjects before the addition of electrolyte solutions.RESULTSAfter the addition of electrolyte solutions, the TF grades of tears collected from healthy humans were generally improved. Significant (Wilcoxon test) improvements have been seen in the TF grades of the tear samples after the addition of a solution of potassium chloride (P = .03), calcium chloride (P = .01), magnesium chloride hexahydrate (P = .002), and sodium dihydrogen phosphate (P = .002). No significant improvements in the TF grades were seen after the addition of sodium chloride solution (P = .33).CONCLUSIONSFerning grades of human tears improved with most of the electrolytes used.

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.