A healthy tear film is very important for many major functions of the ocular surface. Dry eye disease is a significant clinical problem that needs to be solved but the poor correlation between clinical signs and reported symptoms makes it difficult for the clinician to apply a scientific basis to his clinical management. The problem is compounded by the difficulties of evaluating the tear film due to its transparency, small volume and complex composition. Practical insight into tear film composition would be very useful to the clinician for patient diagnosis and treatment but detailed analysis is restricted to expensive, laboratory‐based systems. There is a pressing need for a simple test. The tear ferning test is a laboratory test but it has the potential to be applied in the clinic setting to investigate the tear film in a simple way. Drying a small sample of tear fluid onto a clean, glass microscope slide produces a characteristic crystallisation pattern, described as a ‘tear fern’. This test is currently not widely used because of some limitations that need to be overcome but several studies have demonstrated its potential. Such limitations need to be resolved so that tear ferning could be used in the clinic setting to assess the tear film.

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.

This paper reports on the development of a new tear ferning (TF) subjective grading scale, and compares it with the Rolando scale. TF patterns obtained from tear film samples collected from normal and dry eye subjects in previous studies were collated into a large image library. From this library, 60 images were selected to represent the full range of possible TF patterns, and a further sub-set of 15 images was chosen for analysis. Twenty-five optometrists were asked to rank the images in increasing order between extreme anchors on a scale of TF patterns. Interim statistical analysis of this ranking found 7 homogeneous sub-sets, where the image rankings overlapped for a group of images. A representative image (typically the mean) from each group was then adopted as the grade standard. Using this new 7-point grading scale, 25 optometrists were asked to grade the entire 60 image library at two sessions: once using the 4-point Rolando scale and once using the new 7-point scale, applying 0.25 grade unit interpolation. Statistical analysis found that for the larger image set, the Rolando scale produced 3 homogeneous sub-sets, and the 7-point scale produced 5 homogeneous sub-sets. With this refinement, a new 5-point TF scale (Grades 0-4) was obtained. The Rolando grading scale lacks discrimination between its Type I and II grades, reducing its reliability. The new 5-point grading scale is able to differentiate between TF patterns, and may provide additional support for the use of TF for both researcher and clinician.

To investigate the repeatability of the phenol red thread (PRT) and Schirmer tests in healthy Saudi adults. Additionally, we compared the PRT mean value with those reported previously because of significant differences between Hong Kong-Chinese, Japanese, and US subjects. Thirty healthy young Saudi adults (7 men and 23 women; 60 eyes) with a mean age of 22.37±2.31 years were recruited. Participants provided consent and completed a McMonnies questionnaire. Dry eye subjects were excluded based on this questionnaire and slit-lamp examination. Both eyes of each subject were examined using the PRT and Schirmer tests. Each test was repeated three times for each eye, five minutes apart. The PRT test was applied first, followed by the Schirmer test 15 minutes later under anesthesia to avoid any inconsistency of the measurements due to reflex tears. The PRT and Schirmer tests both demonstrated good repeatability with no statistically significant differences. There was a poor correlation between the 2 tests (r=0.286). There was no statistically significant difference between OD and OS in the two tests. The mean PRT values in normal Saudi subjects were higher than those reported previously for Hong Kong-Chinese, Japanese, and US subjects. Both the PRT and Schirmer tests displayed good repeatability; however, there was a poor correlation between the tests, as reported previously. The mean PRT value in normal Saudis was higher, when compared with those reported previously for other ethnic groups.

Objectives: To investigate the repeatability and average tear osmolarity using the new lab-on-chip TearLab technology device in normal subjects living in Saudi Arabia, a hot climate country, and to compare the average readings with data from previous studies. Methods: Thirty healthy young adults (13 males and 17 females) who ranged in age from 20 to 40 years (mean±SD: 28.57±5.58 years) with no symptoms of dry eyes or ocular disease, who did not wear contact lenses, and were not pregnant or breastfeeding were enrolled in the study. For inclusion criteria, all subjects were examined under a slit-lamp to verify the absence of ocular surface disorders. Moreover, phenol red thread, tear breakup time (TBUT) tests, and McMonnies questionnaire were used to exclude dry eyes. Three measurements of tear osmolarity were performed in 1 eye (at 5-min intervals) using the TearLab osmometer. Results: The mean score on the McMonnies questionnaire was 6±2.9. The mean values obtained from the phenol red thread and TBUT tests were 22±7.7 mm (OD), 21.5±6.6 mm (OS) and 12±1.7 s (OD), 12.5±1.6 s (OS), respectively. There were no statistically significant differences between the osmolarity readings (Wilks' lambda; P=0.945). Tear osmolarity results confirmed that 50% of subjects had readings of 299 to 312 mOsm/L, 40% had readings of 288 to 299 mOsm/L, and 10% had readings of 277 to 288 mOsm/L. The overall mean osmolarity was 299.06±7.65 mOsm/L. There was a medium correlation between osmolarity and the McMonnies questionnaire and a strong negative correlation between osmolarity and TBUT values. Conclusions: We found that the average osmolarity for subjects living in Saudi Arabia was 299.06±7.65 mOsm/L, which falls within the reference range and is in agreement with published results (298.0–301.9±7.2–16.0 mOsm/L). Osmolarity was positively correlated with McMonnies questionnaire and negatively correlated with TBUT values. The TearLab osmolarity system test showed good precision in repeated measurements. This is the first report of use of the TearLab osmolarity system to assess tear film in normal Saudi adults.

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±5.22and0.96±0.54, resp.) compared to nonsmokers (mean ± SD =5.96±3.06and0.41±0.38, resp.). The mean values obtained from PRT and TBUT tests were22.23±6.35 mm and12.17±3.81 sfor smokers and22.16±5.63 mm and14.13±2.62 sfor 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.