Evaluation of tear meniscus height and lipid layer patterns in the tear film in domestic cats: An observational study.

Background: Healthy vision in humans and animals requires a stable tear film. The environmental factor could affect the status of the tear film. Therefore, assessing the tear film in animals is essential to avoid visual system disturbance. Aim: The current research used a noninvasive device to evaluate the tear meniscus height (TMH) and lipid layer pattern (LLP) in domestic cats. In addition, the scores were compared with those of humans with healthy eyes. Methods: Fifty-four domestic cats (28 males and 26 females; mean ± SD = 13.9 ± 18.2 months) were randomly selected and included in the study. The cats were healthy, without any ocular disorders or diseases. Fifty-four healthy eye subjects (27 males and 27 females; mean ± SD = 25.6 ± 5.1 years) were randomly recruited and took part in the study for comparison. EASYTEAR View+ was used, for the first time, to assess the tear film parameters on the right eye of each subject. The examiner allowed a 5-minute gap between the tests. Each test was performed by the same examiner three times, followed by calculating the mean scores. Results: Significant differences (Mann-Whitney U test) were found in the median scores of LLP (p = 0.009) between cats and subjects with healthy eyes. The median TMH score was higher in cats (0.18 mm) than in humans (0.14). However, no significant difference (Mann-Whitney U Test, p = 0.210) exists in the TMH scores between cats and humans. The LLP analysis indicated that a dense white-blue lipid layer (grade 4 or D; lipid layer thickness, LLT, = approximately 80 nm) was predominant in both cats (N = 24, 44.4%) and humans (N = 29, 53.7%). In comparison, variable colors lipid layer (grade 5 or E; LLT = 90-140 nm) was a minority in cats (N = 5, 9.3%) and common in humans (N = 16, 29.6%). The statistical analysis indicated medium correlations between cats' TMH and LLP scores (r = 0.431, p < 0.01) and between age and TMH scores in humans (r = 0.440, p < 0.01). In addition, it indicated a weak correlation (r = 0.291, p < 0.05) between the LLP scores in cats and humans. Conclusion: Assessing animals' tear film is essential to avoid any ocular disorders. EASYTEAR View+ is efficiently used to evaluate domestic cats' TMH and LLP. Cats have thicker lipid layers and longer TMH comparable to those reported for humans with healthy eyes.

Assessment of lipid layer patterns in domestic dogs and rabbits: an observational study.

Background: Maintaining a stable tear film is crucial for having healthy human and animal vision. Animals are expected to have thicker lipid layers than humans due to living in high-temperature and humid environments. Aim: The study aimed to evaluate the lipid layer patterns (LLPs) in Arabian dogs and rabbits using a non-invasive, practical, and easy-to-use device and compare them to humans with healthy eyes. Methods: The study included 75 domestic Arabian dogs (42 males and 33 females; mean ± SD = 6.1 ± 12.7 months) and 75 rabbits (37 males and 38 females; mean ± SD = 3.1 ± 3.4 months). In addition, 75 individuals with healthy eyes (39 males and 36 females; mean ± SD = 25.7 ± 5.0 years) were included for comparison. EASYTEAR View+ assessed the LLP in each animal's and individual's right eye. Results: The median LLP grades significantly differed between dogs and humans (Mann-Whitney U test, p < 0.001). Similarly, the LLP grades differed significantly between rabbits and humans (Mann-Whitney U test, p < 0.001). No significant difference (Mann-Whitney U test) in the LLP grades between dogs and rabbits was found. The analysis indicated that most dogs had either an A (34.7%) or a B grade (37.3%). Similarly, rabbits had predominantly A or 1 (46.7%) and B (30.7%) grades. On the other hand, humans had predominantly D (53.3%) and E (30.7%) grades. Conclusion: The EASYTEAR View+ has been employed to assess LLP in dogs and rabbits, and the measurements were compared to those of humans with normal ocular health. Dogs and rabbits have thinner lipid layers than healthy humans.

Synergistic Effect of Nilavembu Choornam-Gold Nanoparticles on Antibiotic-Resistant Bacterial Susceptibility and Contact Lens Contamination-Associated Infectious Pathogenicity.

Antibiotic-resistant bacterial colonies mitigate rapid biofilm formation and have complex cell wall fabrications, making it challenging to penetrate drugs across their biofilm barriers. The objective of this study was to investigate the antibacterial susceptibility of antibiotic-resistant bacteria and contact lens barrenness. Nilavembu Choornam-Gold Nanoparticles (NC-GNPs) were synthesized using NC polyherbal extract and characterized by UV-visible spectrophotometer, SEM-EDX, XRD, Zeta sizer, FTIR, and TEM analysis. Contact lenses with overnight cultures of antibiotic-resistant bacteria K. pneumoniae and S. aureus showed significant differences in growth, biofilm formation, and infection pathogenicity. The NC-GNPs were observed in terms of size (average size is 57.6 nm) and surface chemistry. A zone of inhibition was calculated for K. pneumoniae 18.8 ± 1.06, S. aureus 23.6 ± 1.15, P. aeruginosa 24.16 ± 0.87, and E. faecalis 24.5 ± 1.54 mm at 24 h of NC-GNPs alone treatment. In electron microscopy studies, NC-GNP-treated groups showed nuclear shrinkage, nuclear disintegration, degeneration of cell walls, and inhibited chromosomal division. In contrast, normal bacterial colonies had a higher number of cell divisions and routinely migrated toward cell multiplications. NC-GNPs exhibited antibacterial efficacy against antibiotic-resistant bacteria when compared to NC extract alone. We suggest that NC-GNPs are highly valuable to the population of hospitalized patients and other people to reduce the primary complications of contact lens contamination-oriented microbial infection and the therapeutic efficiency of antibiotic-resistant bacterial pathogenicity.

Effect of monovalent electrolyte solutions on the human tear ferning pattern.

PURPOSE: To investigate the effect of the addition of a low concentration of sodium chloride (NaCl) and potassium chloride (KCl) solutions on the tear ferning (TF) patterns of tears collected from humans. METHODS: A tear sample (20 µL) was collected from the right eye of 23 males and 7 females (25.4 ± 6.6 years). The tears were collected in one sitting for healthy subjects (N = 13). For dry eye participants (N = 17), the tear samples were collected in two separate settings with five minutes gap in between. A sample (1 µL) from each tear was dried on a glass slide, and the obtained ferns were observed using a microscope and graded using the five-point TF grading scale. Mixtures of tear samples (0.5 µL) and different volumes (0.5-2.5 µL) of each electrolyte (10-30 mg in 100 mL of water) solution were prepared, and their TF patterns were recorded and compared with those of the corresponding pure tears. RESULTS: Significant improvements (Wilcoxon test, P < 0.001) have been seen in the TF grades of the tear samples after the addition of NaCl and KCl solutions. A significant difference (Wilcoxon test, P = 0.016) was found between the TF grades when NaCl and KCl solutions were added to the tear samples. The TF grades of pure tears collected from dry-eye subjects ranged from 2.1 to 3.5, based on the five points grading scale, and decreased to be in the range of 0.4 to 1.6 after the addition of electrolyte solutions. While the TF grades of pure tears collected from normal-eye ranged from 1.2 to 1.9 and improved after the addition of electrolyte solution to be in the range of 0.4 to 1.5. CONCLUSIONS: The TF test was used in vitro to assess the impact of the addition of a low concentration of sodium and potassium chloride solutions on tears collected from humans. The TF grades of human tears significantly improved after the addition of either sodium or potassium chloride solution. The mechanism for the improvement in TF grades due to the addition of electrolyte solutions must be investigated.

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

BACKGROUND: Osmolarity is used to detect symptoms of dry eye disease (DED) and can be measured using TearLab™ and I-Pen® systems. OBJECTIVES: To investigate the correlation between osmolarity measurements using the TearLab™ and I-Pen® systems in subjects with a high body mass index (BMI). MATERIAL AND METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Assessment of the Effect of Wearing a Surgical Face Mask on Tear Film in Normal Eye Subjects.

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 (p=0.002) and the noninvasive tear break-up time scores (p < 0.001) before and after wearing face masks. No significant differences (Wilcoxon test, p > 0.05) 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; p < 0.001), noninvasive tear break-up time measurements (r = 0.631; p < 0.001), and the tear ferning grades (r = 0.517; p < 0.001) before and after wearing the mask. A medium correlation (r = 0.377; p=0.005) 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.

Kawasaki disease in an infant after administration of hexavalent vaccine.

Kawasaki disease is a vascular disorder of unknown etiology that affects children. Kawasaki disease mainly involves medium-sized blood vessels and may cause cardiovascular complications, particularly coronary artery aneurysms. Concern has been raised against various types of vaccines becoming potential risk factors for Kawasaki disease. Here, we describe a case of a 4-month-old Saudi infant who presented with incomplete Kawasaki disease a few hours after receiving his hexavalent vaccine and there was a significant dilatation of all coronary arteries. Although a relationship between vaccinations and Kawasaki disease has been suggested, there is no strong evidence of an increased risk or causal association. This possibility of adverse effects is rare but should be observed and further investigated.

Modifications of Polymers through the Addition of Ultraviolet Absorbers to Reduce the Aging Effect of Accelerated and Natural Irradiation.

The photooxidative degradation process of plastics caused by ultraviolet irradiation leads to bond breaking, crosslinking, the elimination of volatiles, formation of free radicals, and decreases in weight and molecular weight. Photodegradation deteriorates both the mechanical and physical properties of plastics and affects their predicted life use, in particular for applications in harsh environments. Plastics have many benefits, while on the other hand, they have numerous disadvantages, such as photodegradation and photooxidation in harsh environments and the release of toxic substances due to the leaching of some components, which have a negative effect on living organisms. Therefore, attention is paid to the design and use of safe, plastic, ultraviolet stabilizers that do not pose a danger to the environment if released. Plastic ultraviolet photostabilizers act as efficient light screeners (absorbers or pigments), excited-state deactivators (quenchers), hydroperoxide decomposers, and radical scavengers. Ultraviolet absorbers are cheap to produce, can be used in low concentrations, mix well with polymers to produce a homogenous matrix, and do not alter the color of polymers. Recently, polyphosphates, Schiff bases, and organometallic complexes were synthesized and used as potential ultraviolet absorbers for polymeric materials. They reduced the damage caused by accelerated and natural ultraviolet aging, which was confirmed by inspecting the surface morphology of irradiated polymeric films. For example, atomic force microscopy revealed that the roughness factor of polymers' irradiated surfaces was improved significantly in the presence of ultraviolet absorbers. In addition, the investigation of the surface of irradiated polymers using scanning electron microscopy showed a high degree of homogeneity and the appearance of pores that were different in size and shape. The current work surveys for the first time the use of newly synthesized, ultraviolet absorbers as additives to enhance the photostability of polymeric materials and, in particular, polyvinyl chloride and polystyrene, based mainly on our own recent work in the field.

2-[3-(4-Chloro-phen-yl)-5-(4-fluoro-phen-yl)-4,5-di-hydro-1H-pyrazol-1-yl]-5-[(4-fluoro-phen-yl)diazen-yl]-4-methyl-thia-zole.

The mol-ecule of the title compound, C25H18ClF2N5S, comprises almost co-planar fluoro-phenyl, methyl-thia-zolyl, pyrazolyl and chloro-phenyl rings with the second fluoro-phenyl ring almost perpendicular to this plane. One fluoro-phenyl group is disordered over two components of occupancy ratio 0.767 (10):0.233 (10) related by a 24.2 (8)° twist. In the crystal, two mol-ecules related by inversion symmetry are linked by a pair of C-H⋯F contacts in an R(8)2 2 geometry.

An assessment of the ocular tear film in patients with thyroid disorders.

Objective: To investigate the ocular tear film in patients with thyroid disorders using various tests. Methods: The study involved the assessment of the ocular tear film in 20 patients with thyroid disorders (6 men and 14 women) aged 18-43 years (mean±standard deviation=34.3±3.2 years). An age-matched control group consisting of 20 subjects (8 males and 12 females) ranging in age from 18 to 43 years (31.3±2.9 years) was also examined under similar conditions. All patients completed the Ocular Surface Disease Index questionnaire, followed by the tear ferning test within the right eye. A phenol red thread test was carried out 10 mins later followed by the fluorescein tear break-up test with a 10-min gap between the tests being implemented. Results: The median score for the Ocular Surface Disease Index (P<0.05) showed the condition of mild dry eyes [median (IQR)=15.5 (21.9)] in patients with thyroid disorders compared to the control group [5.6 (3.6)]. The mean score for the phenol red thread test within both the right and left eyes showed acceptable tear volumes of 11.7±8.1 and 10.5±7.4 mm, respectively, but this was much lower (P<0.05) compared to those recorded within the control group (22.2±6.5 and 20.7±5.2 mm, respectively). In addition, the mean for the tear break-up time (P<0.05) scores in both eyes within the patients with thyroid disorders revealed a certain degree of eye dryness (4.9±1.6 and 4.2±1.9 s), while the control group showed normal eye scores (13.2±2.6 and 12.3±2.2 s). The median score for tear ferning grades showed eye dryness [2.0 (2.2)] within the study group and normal eyes [1.2 (0.9)] within the control group. Conclusions: Patients with thyroid disorders have a significant level of eye dryness compared to normal eye subjects.

Assessment of tear film in subjects with a high body mass index.

PURPOSE: The aim of the study was to assess the tear film in subjects with a high body mass index (BMI). METHODS: Twenty male subjects aged 23-42 years (mean ± standard deviation =31.3±5.7 years) with a high BMI [median (interquartile range) =31.8 (5.2) kg/m2] were recruited. An age-matched control group of twenty male subjects aged 22-38 years with a normal BMI [20.5 (2.8) kg/m2] also participated in the study. RESULTS: There were significant (Kolmogorov-Smirnov test; P<0.05) differences in the BMI, non-invasive tear break-up time (NITBUT), and tear ferning (TF) scores between the study and control groups. There were some differences in the ocular surface disease index (OSDI), tear meniscus height (TMH), and phenol red thread (PRT) scores between the study and control groups, but these differences were not significant (Kolmogorov-Smirnov test; P>0.05). For the study group, the NITBUT and TF tests mean scores showed a dry eye condition (8.5±2.8 s and 2.0±1.1, respectively). However, these two tests showed a normal eye condition within the control group (14.7±2.8 s and 0.7±0.6, respectively). The TMH score had strong correlations with the NITBUT (r=0.711; P=0.001) and PRT scores (r=0.566; P=0.009) and strong negative correlations with age (r=-0.503; P=0.024) and the OSDI scores (r=-0.520; P=0.018). The TF score had a strong correlation with age (r=0.579; P=0.007) and strong negtive correlations with the scores from the NITBUT (r=-0.525; P=0.018), TMH (r=-0.575; P=0.008), and PRT (r=-0.773; P=0.001) tests. CONCLUSION: The acquired data suggest a high BMI has an effect on the quality of tears. The quality of tears seems to be lower in subjects with a high BMI compared with normal subjects. On the other hand, the tear volume in subjects with a high BMI was just as high and adequate as for normal eye subjects.

A comparative study of the quality of non-stimulated and stimulated tears in normal eye male subjects using the tear ferning test.

PURPOSE: To evaluate and compare the tear ferning patterns of non-stimulated and stimulated tears in normal eye male subjects using the tear ferning test. METHODS: Thirty-five male subjects aged 20-38 years with normal eyes were enrolled in the study. Subjects with dry eye or with a risk factor for eye dryness (eg, recent ocular surgery, contact-lens wearers, smokers, anemic, diabetes, and thyroid gland problems) were excluded from the study. Dry eye subjects were excluded based on the ocular surface diseases index scores, non-invasive tear break-up time, and tear meniscus height measurements from the right and left eyes. A tear sample was collected from both eyes in each subject to perform the tear ferning test for non-stimulated tears. After 10 mins, the tears were stimulated using a Schirmer strip, a tear sample was collected from both eyes in each participant, the tear ferning test was performed, and the ferns were graded based on the five-point tear ferning grading scale. RESULTS: The average tear ferning grade [median (interquartile range)] for non-stimulated tears from the right and left eyes was 0.60 (1.25) and 0.50 (1.31), respectively. For stimulated tears, the average tear ferning grade from the right and left eyes was 0.50 (1.05) and 0.75 (1.25), respectively. There was no significant difference in the tear ferning grades obtained from non-stimulated and stimulated tears (Wilcoxon test, P>0.05). CONCLUSION: This study found no significant difference in the tear ferning patterns obtained from non-stimulated and stimulated tears, or between the tear ferning patterns in the tears collected from the right and left eyes before and after stimulating tears. It seems that there were no changes in the chemical composition of tears before and after stimulation, possibly due to the steady concentration of electrolytes and lipids within the tear film for both non-stimulated and stimulated tears.

Effect of Refresh Plus® preservative-free lubricant eyedrops on tear ferning patterns in dry eye and normal eye subjects.

PURPOSE: To evaluate the tear ferning patterns in dry eye and normal eye subjects in the 3 hours following application of Refresh Plus® preservative-free lubricant eyedrops. METHODS: Thirty men with dry eye (mean age 22.14±2.34 years) and 30 age-matched men with normal eyes (mean age 23.91±3.24 years) were enrolled. Eyes were classified as normal or dry based on their Ocular Surface Disease Index score, tear meniscus height, and noninvasive tear breakup time. The tear ferning test was performed before and 30, 60, 120, and 180 minutes after application of a Refresh Plus eyedrop into the right eye in each subject. RESULTS: There was a significant change in tear ferning grade after application of Refresh Plus eyedrops (P=0.02, Wilcoxon test) in the group with dry eye, but not in the normal eye group (P=0.19, Wilcoxon test). The correlation of tear ferning grade was moderate (r=0.484, P=0.049) at 60 minutes after application of the eyedrops and strong at 120 minutes (r=0.560, P=0.019) and 180 minutes (r=0.726, P=0.001). There was also a strong correlation (r=0.865, P=0.001) between tear ferning grades obtained 120 and 180 minutes after application. In the normal eye group, there was a moderate (r=0.407, P=0.029) correlation between tear ferning grades obtained before and 60 minutes after application of the eyedrops. There was also a strong correlation (r=0.532, P=0.003) between tear ferning grades obtained 120 and 180 minutes after application. CONCLUSION: Tear ferning patterns improved significantly after application of Refresh Plus preservative-free lubricant eyedrops in subjects with dry eye. Artificial tears containing sodium carboxymethylcellulose, such as Refresh Plus, can be used to improve tear ferning patterns in dry eye for at least 3 hours.

Assessment of the tear film in normal eye subjects after consumption of a single dose of hot peppermint drink.

Objective: To test the effect of a single dose of hot peppermint consumption on the tear film in normal eye subjects. Methods: Thirty healthy male subjects aged 18-39 years (23.20±2.17 years) were enrolled. Also, an age-matched control group of 30 male subjects (19-39 years, 23.50±0.70 years) was enrolled to test the effect of the hot water. Tear meniscus height (TMH), noninvasive tear breakup time (NITBUT), and tear ferning (TF) tests were performed for each patient 30 mins before and 60 mins after they drank hot peppermint. Results: Mean TMH measurements were higher postintervention (0.32±0.07) than preintervention (0.27±0.04 mm). Similarly, mean TF grades were significantly higher (2.07±1.20) postintervention than preintervention (0.84±0.71). By contrast, mean NITBUT was lower postintervention than preintervention (11.57±3.17 and 15.84±3.36, respectively). TMH measurements increased in 90% of the subjects. Conversely, NITBUT decreased in 96.7% of the subjects. For the control group that tests the effect of drinking hot water, the scores did not differ significantly in the three tests pre- and postintervention (P˂0.05). TF grades increased in 93.3% of the subjects, postintervention. Conclusion: Tear film quality decreases significantly after peppermint beverage consumption. A similar observation has been made on the consumption of hot green tea drink.

Effects of short-term oral vitamin A supplementation on the ocular tear film in patients with dry eye.

OBJECTIVE: To investigate the effects of short-term oral vitamin A supplementation on the ocular tear film in patients with dry eye. METHODS: In total, 30 male patients with dry eye (age range, 18-38 years; mean age, 25.2±2.8 years) who did not wear contact lenses or exhibit any ocular (other than dry eye) or systemic diseases were included, along with 30 age-matched men (control group; mean age, 24.5±2.3 years) with healthy eyes. Subject exclusion was based on the findings of the McMonnies questionnaire (cutoff score for dry eye: 14.5) and slit-lamp biomicroscopy. All subjects received an oral vitamin A supplement at a daily dose of 1,500 mg for 3 consecutive days. The phenol red thread (PRT) test was performed along with assessments of tear ferning (TF), tear osmolarity, and the tear break-up time (TBUT) before and 24 hours after the third dose of the vitamin A supplement. A 10-minute interval was observed between different tests. RESULTS: In the dry eye group, the TF grade (Wilcoxon test, P=0.01) exhibited a significant decrease, while the tear osmolarity value (t-test, P=0.01) exhibited a significant increase after vitamin A supplementation. The PRT test findings (P=0.17) and TBUT (P=0.49) showed no significant differences before and after vitamin A supplementation. In the control group, vitamin A supplementation showed no significant effects on TF (P=0.74), tear osmolarity (P=0.55), the TBUT (P=0.19), and the PRT test scores (P=0.48). CONCLUSION: Our findings suggest that short-term oral vitamin A supplementation improves the quality, but not quantity, of tears in patients with dry eye. Future studies should involve larger patient samples and longer periods of vitamin A supplementation.

The acute effect of a single dose of green tea on the quality and quantity of tears in normal eye subjects.

OBJECTIVE: The study aimed to investigate the acute effect of a single dose of green tea on the quality and quantity of tears in normal eye subjects. METHODS: Forty normal eye subjects (22 men and 18 women) aged 19-39 years were enrolled in the study. Also, an age matching control group (20 males and 20 females) was enrolled for comparison. McMonnies dry eye symptoms questionnaire and slit lamp were used for the exclusion criteria determination. Phenol red thread (PRT) test was performed on both eyes of each subject. A tear sample was collected from the lower tear meniscus of the right eye of each subject for the tear ferning (TF) test, which was performed before (30 minutes) and after (60 minutes) drinking green tea. RESULTS: The median PRT measurement after green tea consumption was lower (median [IQR]=23.50 [8.00] mm) compared to that before consumption (median [IQR]=27.00 [8.75] mm). In contrast, the median TF grade was significantly higher following green tea consumption than that before consumption (median [IQR]=2.65 [1.23] vs 1.50 [0.88] mm, respectively). The results show that TF grades increased in 97.5%, and the red phenol thread scores decreased in 80% of the subjects after green tea consumption compared to those before consumption. The PRT readings and TF grades were significantly different (P<0.05) before and after green tea consumption. CONCLUSION: Drinking green tea could have a significant effect on the eye tear film quality. Tear quality appeared to decrease after green tea consumption.

Assessment of tear-evaporation rate in thyroid-gland patients.

OBJECTIVE: To assess the tear-evaporation rate in thyroid-gland patients using a VapoMeter. METHODS: Twenty thyroid gland patients aged 18-43 years (mean 34.3±6.3 years) completed the study. Additionally, an age-matched control group of 20 patients aged 18-43 years (32.2±5.1 years) was enrolled in the study for comparison purposes. An Ocular Surface Disease Index dry-eye questionnaire was completed, followed by a test to determine the tear-evaporation rate using the VapoMeter. The test was performed three times per subject by the same examiner. Two readings were obtained each time. RESULTS: Significant differences (P<0.05) were found between mean Ocular Surface Disease Index and tear-evaporation-rate scores within the study and control groups. The average tear-evaporation rate was much higher in the study group (median 41.2 [IQR 41.4] g/m2⋅h) than the control group (15.7 [13.7] g/m2⋅h). Moreover, the average Ocular Surface Disease Index score for thyroid-gland patients was much higher (15.6 [23.4]) compared to the control group (5.5 [7.50]). CONCLUSION: The tear-evaporation rate in thyroid-gland patients was found to be much higher than normal-eye subjects.

Analysis of basal and reflex human tear osmolarity in normal subjects: assessment of tear osmolarity.

PURPOSE: The aim of this study is to evaluate the difference between reflex and basal tear osmolarity among healthy normal subjects. METHOD: The right eyes of 20 healthy normal male subjects aged 20 to 40 years were recruited for this study. The inclusion criteria for the subjects were the Ocular Surface Disease Index questionnaire score of less than 12 and wetting length of the phenol red thread of more than 10 mm. Tear film osmolarity was assessed using TearLab osmometer. Basic tear osmolarity was measured normally without inducing any irritation to the eye. In order to stimulate reflex tear, subjects were asked to open their eye as long as they can till they feel ocular surface irritation (minimum 20 s). RESULTS: The mean score on the Ocular Surface Disease Index questionnaire was 5.5 ± 3. The mean value obtained from the phenol red thread was 21 ± 4.5 mm. There were no statistically significant differences between the osmolarity readings of basal and reflex tear osmolarity (p > 0.05). The mean value was 308 ± 12 and 306 ± 9 mOsm/l for basic and reflex tear osmolarity, respectively. CONCLUSION: This study found that the osmolarity of the basal and reflex tears fell within the same range. The values found in this study are in agreement with published results for normal subjects.

Assessment of Tear Film Quality among Smokers Using Tear Ferning Patterns.

Purpose. To investigate the effect of cigarette smoking on the ocular tear film. Methods. Thirty healthy young male cigarette smokers (20-38 years old) and 30 healthy age matched nonsmokers were enrolled in the study. McMonnies questionnaire, slit lamp, and PRT test were used to screen the subjects. Tear samples were collected from the right eyes and tear ferning patterns were observed and graded. Results. The mean MacMonnies scores and TF grades were significantly higher in the smoker subjects (mean ± SD = 9.83 ± 5.22 and 0.96 ± 0.54, resp.) compared to nonsmokers (mean ± SD = 5.96 ± 3.06 and 0.41 ± 0.38, resp.). The mean values obtained from PRT and TBUT tests were 22.23 ± 6.35 mm and 12.17 ± 3.81 s for smokers and 22.16 ± 5.63 mm and 14.13 ± 2.62 s for nonsmokers, respectively. Strong correlations were found between MacMonnies scores and both PRT (r = 0.596) and TF (r = 0.516). There was statistically significant difference in TF grades (p = 0.00), TBUT (p = 0.036) and McMonnies (p = 0.02) between smokers and nonsmokers. Conclusion. Cigarette smoking could have a significant effect on the tear film quality of the eye.

Evaluation of visual stress symptoms in age-matched dyslexic, Meares-Irlen syndrome and normal adults.

AIM: To examine the prevalence of dyslexia and Meares-Irlen syndrome (MIS) among female students and determine their level of visual stress in comparison with normal subjects. METHODS: A random sample of 450 female medical students of King Saud University Riyadh (age range, 18-30y) responded to a wide range of questions designed to accomplish the aims of this study. The detailed questionnaire consisted of 54 questions with 12 questions enquiring on ocular history and demography of participants while 42 questions were on visual symptoms. Items were categorized into critical and non-critical questions (CQ and NCQ) and were rated on four point Likert scale. Based on the responses obtained, the subjects were grouped into normal (control), dyslexic with or without MIS (Group 1) and subjects with MIS only (Group 2). Responses were analysed as averages and mean scores were calculated and compared between groups using one way analysis of variance to evaluate total visual stress score (TVSS=NCQ+CQ), critical and non-critical visual stress scores. The relationship between categorical variables such as age, handedness and condition were assessed with Chi-square test. RESULTS: The completion rate was 97.6% and majority of the respondents (92%) were normal readers, 2% dyslexic and 6% had MIS. They were age-matched. More than half of the participants had visited an eye care practitioner in the last 2y. About 13% were recommended eye exercises and one participant experienced pattern glare. Hand preference was not associated with any condition but Group 1 subjects (3/9, 33%) were significantly more likely to be diagnosed of lazy eye than Group 2 (2/27, 7%) and control (27/414, 7%) subjects. The mean±SD of TVSS responses were 63±14 and it was 44±9 for CQ and 19±5 for NCQ. Responses from all three variables were normally distributed but the CQ responses were on the average more positive (82%) in Group 2 and less positive (46%) in Group 1 than control. With NCQ, the responses were equally less positive in Group 1 and 2 than control. Group 2 subjects showed significantly higher TVSS (P=0.002), NCQ (P=0.006) and CQ (P=0.008) visual stress scores than control but no difference between Group 1 and control subjects, was observed for all scores (P>0.05, for all comparisons). CONCLUSION: The prevalence of dyslexia and MIS among Saudi female students was 2% and 6%, respectively. Critical questions performed best for assessing visual stress symptoms in dyslexic and MIS subjects. Generally, students with MIS were more sensitive to visual stress than normal students but dyslexics were more likely to present with a lazy eye than MIS and normal readers.