Assessment of the Tear Meniscus by Strip Meniscometry and Keratograph in Patients With Dry Eye Disease According to the Presence of Meibomian Gland Dysfunction

After-effect on tear film quality and quantity of reading on laptop computer screen versus hardcopy

CLINICAL RELEVANCE

Electronic displays, including laptops, tablets, and smartphones, have dramatically altered the way information is accessed and become significant factors in human daily life. They interfere with the blink rate and increase dry eye symptoms, which lead to more discomfort compared to hard copy while reading.

BACKGROUND

Digital eye strain occurs when an individual suffers from symptoms, or they are exacerbated, while performing a task requiring digital screen viewing. This study assessed the tear film status immediately following reading on a laptop computer screen versus an identical hard copy.

METHODS

Thirty young adults with normal ocular health and reporting no significant symptoms of dry eye (ocular surface disease index (OSDI) score < 13 and non-invasive tear break-up time (NITBUT) > 10 seconds) read a text as hard copy and on a laptop computer screen for 30 min on separate days in a random sequence in a controlled reading experimental condition. The texts were matched in size and contrast and presented at a viewing distance of 40 cm. The NITBUT and strip meniscometry tube tests were administered at baseline and after reading in both conditions.

RESULTS

The median baseline NITBUT decreased from 13.0 s to 10.0 s (P < 0.001) after hardcopy reading and to 7.0 (P < 0.001) after reading from a laptop computer screen, with a significant difference between the task medium (P = 0.001). The baseline strip meniscometry tube results decreased from 6.7 mm to 5.0 mm (P < 0.001) after hardcopy reading and to 5.0 mm (P < 0.001) after reading from a laptop computer screen, but there was no significant difference with the task medium (P = 0.085).

CONCLUSION

Reading in both conditions led to tear film instability in terms of the tear film quality and quantity. Additionally, the computer screen has a greater impact on the TBUT compared to hardcopy reading, while these two reading mediums had a similar effect on the tear volume.

Influential Signs of Dry Eye-Related Ocular Symptoms in Participants With Unstable Tear Film

PURPOSE

The aim of this study was to investigate the factors influencing dry eye disease (DED)-related ocular symptoms in participants with short fluorescein tear break-up time (FTBUT).

METHODS

This cross-sectional study included 82 participants with short FTBUT (<10 seconds). Examinations included Ocular Surface Disease Index (OSDI), FTBUT, average noninvasive tear break-up time (NIBUTave), lid wiper epitheliopathy, lipid layer thickness, blink rate, partial blink, tear meniscus height, and meibomian gland (MG) evaluation which included ratio of residual MG area (RMGA) and MG grade in tarsal plates. One-way analysis of variance was used to detect differences between symptomatic tear film instability group (FTBUT <5 s, OSDI ≥13), asymptomatic tear film instability group (FTBUT <5 s, OSDI <13), and control group (FTBUT ≥5 s, OSDI <13). A bivariate correlation, partial correlation, and multiple linear regression analyses were used to identify major factors. Only the right eye was included.

RESULTS

Among the participants with FTBUT <5 seconds, symptomatic group showed less upper RMGA ( P < 0.001) and NIBUTave ( P = 0.010). OSDI was negatively associated with upper RMGA ( r = -0.450, P < 0.001) and NIBUTave ( r = -0.414, P = 0.001), and positively associated with upper MG grade ( r = 0.277, P = 0.027). Linear regression analysis showed that the upper RMGA significantly affected OSDI (B = -41.895, P = 0.001), while not significantly correlated with age, upper MG grade, and NIBUTave.

CONCLUSIONS

The upper RMGA might be the main factor affecting DED-related discomfort in participants with unstable tear film, indicating an early ocular change in DED.

Evaluation of the Tear Meniscus Using Optical Coherence Tomography in Meibomian Gland Dysfunction

INTRODUCTION

This study aimed to evaluate tear meniscus parameters in meibomian gland dysfunction (MGD) using optical coherence tomography and ImageJ software.

METHODS

We enrolled 66 eyes of 66 participants and measured tear meniscus parameters, including height, depth, turbidity, and percentage area occupied by particles (PAOP) in the meniscus in the MGD and control groups.

RESULTS

Tear meniscus turbidity and PAOP were significantly higher in the MGD group, but tear meniscus height (TMH) and depth (TMD) did not differ significantly between groups. Tear meniscus turbidity and PAOP were positively correlated with each other and ocular surface parameters, including OSDI and ocular surface staining scores.

CONCLUSION

Tear meniscus turbidity and PAOP were higher in the MGD group than in the control group; therefore, they can be used as significant non-invasive parameters in the prediction of MGD. TMH and TMD did not differ significantly between groups.

Categorization of the Aqueous Deficient Dry Eye by a Cut-Off Criterion of TMH Measured with Tearscope

A decrease of the Tear Meniscus Height (TMH) has been proposed as a useful indicator for Aqueous Deficient Dry Eye (ADDE) categorization. The present study aimed to calculate a TMH cut-off criterion for the categorization or severity assessment of ADDE with the Tearscope. 200 participants with a previous Dry Eye Disease (DED) diagnosis according to TFOS DEWS-II criteria were recruited. TMH by slit-lamp illumination and Lipid Layer Pattern (LLP) with Tearscope were assessed to categorise the participants into the ADDE or the Evaporative Dry Eye (EDE) group. The ADDE group was also subdivided into Mild-moderate ADDE and Moderate-severe ADDE based on TMH with slit-lamp. Additionally, the TMH was measured by Tearscope (TMH-Tc). Receiver Operating Characteristics showed that the TMH-Tc have a diagnostic capability to differentiate between ADDE and EDE participants, and between Mild-moderate or Moderate-severe ADDE, with a cut-off value of 0.159 mm (AUC = 0.843 ± 0.035, p < 0.001; sensitivity: 86.4%; specificity: 75.4%) and 0.105 mm (AUC = 0.953 ± 0.025, p < 0.001; sensitivity: 98.1%; specificity: 80.0%), respectively. The present study proposed a cut-off criterion to differentiate between ADDE and EDE participants, or between ADDE severities through TMH assessed by Tearscope.

Tear Strip Meniscometry and Its Clinical Application: Analysis of More Than 2000 Cases

Purpose

To evaluate the association of strip meniscometry tear meniscus volume measurement with signs and symptoms related to dry eye.

Methods

This cross-sectional study enrolled 2234 consecutive outpatients and used dry eye symptomatology and related ocular surface examinations, including the Schirmer test, fluorescein tear film break-up time (BUT), corneal fluorescein vital staining and strip meniscometry. The strip meniscometry cut-off was estimated using a receiver operating characteristic analysis. The subjective symptoms consisted of six binarized items: dryness, fatigue, photophobia, pain, irritation, and blurring. The clinical signs were also binarized by the cut-off in each test. The presence of all signs and symptoms were then analyzed using Hayashi's quantification theory type III analysis.

Results

The mean age of the participants was 59.3 ± 17.3 years. The mean values for Schirmer test, BUT, corneal fluorescein staining, and strip meniscometry were 13.6 ± 9.6 mm, 3.1 ± 2.1 seconds, 0.40 ± 0.66, and 2.4 ± 2.7 mm, respectively. The Schirmer test was negatively correlated with age (r = -0.152; P < 0.01), whereas the BUT and strip meniscometry were not. All pairs of Schirmer test, BUT, and strip meniscometry had significant correlations, but the greatest correlation was found between BUT-strip meniscometry (r = 0.238; P < 0.01). An strip meniscometry cut-off length of 2.5 mm (area under the curve = 0.618) was calculated. Hayashi's analysis found high similarity among the presence of signs by strip meniscometry, BUT. and corneal fluorescein staining, and three nonvisual symptoms (pain, irritation, and dryness) had a distinct similarity.

Conclusions

Strip meniscometry results using the cut-off of 2.5 mm could be a useful clinical indicator for the initial screening of dry eye.

Translational Relevance

This large-scale case-control study further confirmed tear strip meniscometry with the new cut-off is a useful tear function examination for dry eye; it is a 5-second noninvasive procedure and associated with clinical symptoms and corneal parameters.

Strip Meniscometry Tube in the Assessment of Tear Lactoferrin in Non-Obese Diabetic (NOD) Mice

Purpose: To investigate the applicability of strip meniscometry tube (SMT) in the measurement of tear lactoferrin in non-obese diabetic mice (NOD). Methods: SMT (SMTube, Echo Electricity Co., Ltd., Tokyo, Japan) and fluorescein staining tests were performed on 7–14 week NOD- male mice (n = 4) and age and sex matched wild–type (Balbc, WT) mice (n = 5). Tears collected during SMT underwent lactoferrin concentration measurement by ELISA. Results: The mean SMT value was significantly lower in NOD mice compared to wild-type mice (p = 0.01). The mean corneal fluorescein staining score in the NOD mice was significantly lower compared with the wild-type mice (p = 0.03). The mean tear lactoferrin level also showed a significantly lower concentration in NOD mice (p = 0.02). Conclusions: SMT has been shown to be an effective tool in measuring tear volume in humans, cats, dogs, and mice. SMT may also serve as a useful tool for tear lactoferrin assessment in NOD and WT mice in experimental settings.

Dry eye signs and symptoms in patients on aromatase inhibitor therapy

PURPOSE

The study aimed to test whether symptomatic dry eye in aromatase inhibitor (AI) patients is associated with the clinical features of evaporative dry eye.

METHODS

A cross-sectional, observational study of postmenopausal women treated with AI was conducted. Clinical information was gathered from their treating clinician. Ocular and treatment symptoms were assessed using validated questionnaires. Clinical assessments were performed to assess for dry eye. The primary outcome measure for this study was dry eye symptoms measured via questionnaire. The secondary outcome measures were clinical signs of dry eye and hormone levels.

RESULTS

A total of 25 women on AI were recruited. 64% of women reported symptoms of dry eye (ocular surface disease index ≥ 13). Higher tear osmolarity (323 vs 307 mOsm/L, p = 0.002) and increased meibomian gland dropout (4 vs 1, p = 0.002) were observed in patients with symptomatic dry eye when compared to asymptomatic patients. Multivariate logistic regression identified that longer duration of AI use and higher tear osmolarity increased the likelihood of a patient experiencing dry eye symptoms.

CONCLUSION

Our study found increased tear osmolarity and meibomian gland drop out in women on AI with symptomatic dry eye. Longer duration of AI therapy and higher tear osmolarity may increase the risk of developing dry eye.

The Role of Different Tear Volume Detection Methods in the Evaluation and Diagnosis of Mild Dry Eye Disease

Purpose

To compare the diagnostic power of strip meniscometry (SM), Schirmer test (ST), and tear meniscus (TM) in mild dry eye disease (DED) and to evaluate the association with DED-related parameters.

Methods

Forty left eyes with mild DED and 40 left eyes of control participants were investigated. All participants underwent a comprehensive ocular surface examination, including the Ocular Surface Disease Index (OSDI), fluorescein tear film break-up time (FTBUT), ocular surface staining grades, meiboscores, and tear film volume examinations, including SM, ST, tear meniscus height (TMH), and tear meniscus cross-sectional area (TMA) measurements, respectively, by optical coherence tomography (OCT) and Keratograph 5M (K5M). The correlation between these parameters was evaluated, and the receiver operating characteristic (ROC) curve was used to verify the diagnostic power by the area under the curve (AUC).

Results

All tear film volume examinations significantly correlated with DED parameters. Among them, the most relevant factor to OSDI scores and FTBUT was SM. In addition, SM (AUC = 0.992), TMH-OCT (AUC = 0.978), and TMA-OCT (AUC = 0.960) showed better diagnostic power than ST (AUC = 0.650) in DED, in which the cutoff value of SM was 3.5 mm (sensitivity, 97.5%; specificity, 95.0%).

Conclusions

Compared with ST, SM and TM parameters obtained by OCT were more relevant to ocular surface parameters and can provide a more valuable approach to discriminate mild DED from control participants.

Translational Relevance

This study made a comprehensive comparison of the existing tear volume detection methods and provided a basis for the clinical selection of appropriate detection methods and the diagnosis of mild DED.

Application of Keratograph and Fourier-Domain Optical Coherence Tomography in Measurements of Tear Meniscus Height

To compare the interoperator repeatability of tear meniscus height (TMH) measurements obtained with a keratograph and Fourier-domain optical coherence tomography (FD-OCT) and to assess the agreement between the methods.Forty-seven eyes with DED and 41 healthy eyes were analyzed using the Schirmer test I and tear breakup time test (TBUT). The TMH was measured three times with each device. The repeatability of measurements was assessed by within-subject standard deviation (Sw), repeatability (2.77 Sw), coefficient of variation (CoV) and intraclass correlation coefficient (ICC). Efficacy in detecting DED was evaluated in terms of the area under the curve (AUC). The TMHs obtained with the keratograph were 0.03 mm lower than those obtained with FD-OCT in both groups (p < 0.001 for the DED group and p = 0.0143 for the control group, respectively). The intraexaminerICCs of the keratographic TMH were 0.789 and 0.817 for the DED and control groups, respectively, and those of the FD-OCT TMH were 0.859 and 0.845, respectively. Although a close correlation was found between the TMHs measured with the keratograph and FD-OCT by the Spearman analysis in both groups (both p < 0.001), poor agreement between the devices was shown in both groups using a Bland−Altman plot. The AUCs of the keratography and FD-OCT results were 0.971 (p < 0.001) and 0.923 (p < 0.001), respectively. Both devices had excellent diagnostic accuracy in differentiating normal patients from DED patients. FD-OCT TMH measurements were more reliable than the keratograph data in the DED group. Agreement between the devices was poor in both groups.

Advances in Dry Eye Disease Examination Techniques

Dry eye-related ocular surface examination is very important in the diagnosis and treatment of dry eye disease. With the recent advances in science and technology, dry eye examination techniques have progressed rapidly, which has greatly improved dry eye diagnoses and treatment. However, clinically, confusion remains about which examination to choose, how to ensure the repeatability of the examination, and how to accurately interpret the examination results. In this review, we systematically evaluate previous examinations of dry eye, analyze the latest views and research hotspots, and provide a reference for the diagnosis and management of dry eye.

Hypochlorous Acid Can Be the Novel Option for the Meibomian Gland Dysfunction Dry Eye through Ultrasonic Atomization

Background

Dry eye is a multifactor disease which needs comprehensive treatments to keep the homeostasis of ocular surface.

Objective

To explore the effect of hypochlorous acid on the meibomian gland dysfunction dry eye through ultrasonic atomization.

Methods

We set this study of 0.01% HOCL and 0.1% hyaluronate by ultrasonic atomization. All the data was recorded at the 1^st, 15^th, 30^th, and 55^th days. The patients' complains, the meibum analysis, conjunctive congestion, corneal staining, Schirmer's I test, and NIBUT were recorded by K5M, the MMP-9, and IL-2 of tear by inflammation kit; the Demodex was recorded by microscopy.

Results

53 patients have joined this study. There is no statistic difference between them on OSDI (day 15: p = 0.061, 30: p = 0.055, 55: p = 0.052); results show the 10.57 ± 0.13 and 12.54 ± 0.17 reduction on OSDI; the differences of both treatments are significant (^∗∗p < 0.01). Increased Schirmer's and TBUT are 3.27 ± 0.10 and 6.29 ± 0.10 (^∗∗p < 0.01) or 7.32 ± 1.72 s and 9.22 ± 1.41 s (^∗p < 0.05); the decreased conjunctive and corneal staining are 0.23 ± 0.07 and 0.45 ± 0.06 (^∗∗p < 0.01) or 0.42 ± 0.03 and 0.37 ± 0.02 (^∗p < 0.05) at both groups. The differences of MMP-9 and IL-2 negative rate are significant (Z = 0.896, ^∗∗p = 0.002 < 0.01; Z = 0.659, ^∗∗p = 0.001 < 0.01); the number of Demodex mites at first is 10 or 11, while the last is 2 or 6 (Z = −4.642, ^∗∗p < 0.01; Z = 2.742, p > 0.05). The Demodex count between them is significant (Z = −2.310, ^∗p = 0.032 < 0.05). The survival times (ST) of each stage at the HOCL are 110.75 (108.50 ± 24.50), 95.50 (90.25 ± 14.50), and 75.25 (73.48 ± 8.50) min which are shorter than those of control which are 155.50 (160.10 ± 21.50), 130.25 (128.25 ± 16.50), and 105.75 (102.50 ± 14.50) min (^∗∗p < 0.01). The Demodex eradication rate of HOCL is statistic significant (^∗p15^th vs. 1^stday = 0.028 < 0.05; ^∗∗p30^th vs. 1^stday = 0.002 < 0.01; ^∗∗p55^th vs. 1^stday = 0.0018 < 0.01).

Conclusions

0.01% HOCL improves the Demodex eradication by shortening the survival time; the HOCL acts on the ocular surface by reducing the inflammation. The ultrasonic atomization helps for the drug usage.

Comparative of meibomian gland morphology in patients with evaporative dry eye disease versus non-dry eye disease

Many recent studies have showed that morphological changes are one of the key signs of meibomian gland disease (MGD). These changes can be seen even before symptom onset, potentially underestimating the prevalence of MGD; however, until now, there is no conclusive information about the impact of meibomian gland (MG) morphology in tear film physiology and disease. This study aimed to investigate the prevalence of anatomical and morphological MG alterations between patients with evaporative dry eye disease (DED) and healthy controls. Retrospective chart review of seventy-five patients with evaporative DED and healthy individuals who had dry eye assessments included Ocular Surface Disease Index questionnaire, meibum quality, meibum expressibility, lid margin abnormality, ocular staining, non-invasive tear film break-up time, and meibography. We did not find significant differences in MG alterations in the upper lid between healthy and DED subjects. Patients with evaporative DED presented MG alterations in the lower lid more frequently than healthy subjects (54.8 vs. 30.3%; p = 0.03). The presence of shortened glands was the only MG alteration that was more prevalent in the lower lid in dry-eye patients than in healthy subjects (p < 0.05). Subjects with evaporative DED presented more alterations in the lower lid than healthy subjects.

Repeatability and Reproducibility of SMTube Measurement in Dry Eye Disease Patients

Purpose

To evaluate the intraobserver repeatability and interobserver reproducibility of Strip Meniscometry Tube (SMTube) and determine the correlations among the SMTube measurements and other ocular examinations in dry eye disease (DED) patients.

Methods

The study recruited 73 eyes of 49 DED patients. Every subject was subjected to the following five measurements sequentially: the Ocular Surface Disease Index (OSDI) questionnaire, Tear Meniscus Height (TMH) assessment, SMTube measurements, tear film breakup time (BUT) examination, and Schirmer I test (SIT). The repeatability and reproducibility of the measurements were assessed by the intraclass correlation coefficient (ICC) and the Bland–Altman analysis, and the correlations were evaluated by the Spearman rank-order correlation.

Results

The repeatability and reproducibility of the SMTube measurements were good in DED patients. The ICCs between the repeatability and reproducibility of the SMTube measurements were 0.789 and 0.741, respectively, and the Bland–Altman 95% limits of the repeatability and the reproducibility were −1.726 to 1.658 and −0.967 to 1.474, respectively (all P < 0.01). The SMTube measurements had correlations with TMH, BUT, and SIT. The Spearman rank correlation coefficients between SMTube and TMH; SMTube and Schirmer I test; and SMTube and BUT were 0.632, 0.617, and 0.653, respectively (all P < 0.01).

Conclusions

The measurements of the SMTube may provide a novel, swift, noninvasive, and convenient approach to screen and diagnose DED with acceptable repeatability and reproducibility and specific correlations with TMH, BUT, and SIT.

[Schirmer's test and strip meniscometry : Comparative consideration in the diagnostics of dry eye]

BACKGROUND

As one alternative to the Schirmer test, strip meniscometry has been presented as a methodology which also seems to be suitable for quantifying a lack of tear volume.

METHODS

In a randomized prospective clinical study 391 eyes from 201 subjects were assigned to 3 groups according to the severity of eye surface deficiency (group 0: 225 healthy eyes, f/m = 1.25, mean age = 50.1 ± 17.6 years; group 1: 112 eyes with mild keratoconjunctivitis sicca (KCS), f/m = 1.38, mean age = 58.7 ± 13.9 years; group 2: 54 eyes with manifest KCS, f/m = 2.375, mean age = 52.6 ± 14.1 years). Objective test parameters used were strip meniscometry, Schirmer's 1 test and the Jones-test. In order to determine the condition of the ocular surface and tear film more precisely, slit-lamp examination, the detection of lid-parallel conjunctival folds (LIPCOF) and optical coherence tomography (OCT) meniscometry were also performed. Subjective discomfort was objectified by using the Ocular Surface Disease Index questionnaire (OSDI).

RESULTS

The results of strip meniscometry, Schirmer's 1 test, the Jones test and OCT meniscometry were significantly lower in KCS subjects than in healthy subjects (p < 0.001), whereas the OSDI score was significantly higher (p < 0.001). The parameters strip meniscometry, Schirmer's 1 test, the Jones test and OCT meniscometry scores correlated with each other. Sensitivity and specificity of strip meniscometry ranged from 0.79 to 0.89 and from 0.42 to 0.5.

CONCLUSION

Strip meniscometry is suitable to detect a lack of tear volume. Advantageous is the rapid performance of the procedure (5 s per eye) and a good agreement with established tests (e.g. Schirmer's test). To improve the specificity, strip meniscometry must be combined with other examination methods.

Factors associated with ocular surface epithelial damage in patients with primary Sjögren's syndrome

BACKGROUND

The aim of this study was to evaluate the effects of systemic parameters, laboratory findings, oral parameters, and other ocular surface parameters on ocular surface epithelial damage in patients with primary Sjögren's syndrome (pSS).

METHODS

A total of 82 dry eye disease (DED) patients with pSS were enrolled in this study. Ocular surface epithelial damage was measured by ocular staining score (OSS). Systemic parameters, laboratory findings including serologic markers, oral parameters, and other ocular surface parameters were collected. Other ocular surface parameter assessments such as the Schirmer's test, fluorescein tear breakup time, meibomian gland examinations, noninvasive keratographic tear film break-up time measurements using the Keratograph® 5 M were performed, and the Ocular Surface Disease Index was determined.

RESULTS

In a multivariate analysis, decreased age and increased duration of pSS were significantly related to increased logarithm-transformed OSS (β = -0.011, P = 0.043 and β = 0.003, P = 0.008). Among the ocular surface parameters, decreased fluorescein tear breakup time and increased MGD grade were significantly associated with increased logarithm-transformed OSS (β = -0.183, P < 0.001 and β = 0.192, P = 0.049).

CONCLUSIONS

Ocular surface epithelial damage in patients with pSS was associated with young age, long duration of disease, unstable tear film, and decreased meibomian gland function.

Dust exposure: a novel environmental risk factor for conjunctivochalasis?

OBJECTIVE

This study aimed to determine the relationship between clinical symptoms and findings of patients diagnosed with conjunctivochalasis in our clinic and the risk factors reported in the literature, to determine new possible etiological factors, and to compare routine tear assessment methods with novel strip meniscometry in these patients.

MATERIALS AND METHODS

The study included patients who presented to our clinic between March 2019 and June 2019 and were diagnosed with conjunctivochalasis. The Ocular Surface Disease Index was used to assess ocular surface symptoms. Anterior segment examination included tear break-up time, corneal staining, localization of conjunctivochalasis, and the presence of pinguecula or pterygium. For each patient, tears were measured using both Schirmer and strip meniscometry. Patients with conjunctivochalasis were evaluated as lid-parallel conjunctival folds grade 1, 2, or 3.

RESULTS

There was a total of 57 participants, including 31 women (54.4%) and 26 men (45.6%). Lid-parallel conjunctival folds grade was found to be statistically significantly associated with dust exposure (p = 0.034). Multiple regression analysis revealed that dust exposure was an independent predictor of being diagnosed with lid-parallel conjunctival folds grade 2 versus lid-parallel conjunctival folds grade 1 (odds ratio = 3.515, p = 0.029). Moreover, Schirmer's test and strip meniscometry results were positively correlated in patients with conjunctivochalasis (r = 0.302 and p = 0.022).

CONCLUSION

We conclude that external factors are prominent in patients with conjunctivochalasis, especially dust exposure. In addition, strip meniscometry may be preferred as a more practical and noninvasive alternative to investigate dry eye symptoms in patients with conjunctivochalasis.

Strip Meniscometry Correlates With Ocular Surface Tests and Symptoms

Purpose

The aim of this study was to investigate the association of dry eye disease (DED)-related signs and symptoms with two tear function tests.

Methods

This was a clinic-based, cross-sectional study with recruitment of consecutive participants. Schirmer test (ST), tear strip meniscometry (SM), and fluorescein tear breakup time were measured and corneal staining score was examined in outpatients at three clinics. Seven subjective symptoms were assessed by interview, including dryness, irritation, pain, lacrimation, fatigue, blurring, and photophobia. Statistical analyses included regression analysis and comparison tests.

Results

The mean age of the 210 participants was 61.2 ± 15.2 years (range, 12-91 years), with 135 women (64.3%) in the cohort. The mean ST value was 12.9 ± 9.3 (0-35) mm, and SM was 2.5 ± 1.6 (0-10) mm, with no difference between women and men. SM values were lower in the presence of irritation (P = 0.046) and photophobia (P = 0.011). Regression analysis revealed ST and SM values were strongly correlated (β = 0.255, P < 0.001). SM was significantly correlated with breakup time (β = 0.149, P = 0.032), whereas there was no correlation between ST and DED-related signs and symptoms.

Conclusions

SM was correlated with DED-related symptoms and breakup time, whereas ST was not. A low SM value could be an alternative clinical parameter to determine tear film-oriented therapy.

Translational Relevance

Tear strip meniscometry could be a useful tear function examination on a routine clinical basis since it is a 5-second noninvasive procedure and associated with subjective symptoms and the value of the conventional Schirmer test.

Location and pattern of non-invasive keratographic tear film break-up according to dry eye disease subtypes

PURPOSE

To compare the non-invasive keratographic tear film break-up time (NIKBUT) and the location and pattern of non-invasive keratographic tear film break-up between normal group and each group of three dry eye disease (DED) subtypes.

METHODS

We enrolled 55 normal subjects and 250 patients with DED, who underwent tear meniscus height and NIKBUT measurements using the Keratograph^® 5M. Ocular surface parameter assessments such as the fluorescein tear break-up time, ocular surface staining, Schirmer's test, and lid margin and meibomian gland examinations were performed, and the ocular surface disease index was determined. These parameters, including the proportion of the first tear film break-up location and simultaneous multiple tear film break-up pattern, were compared amongst the normal and DED subtypes.

RESULTS

Aqueous-deficient dry eye disease (ADDE) and ADDE/meibomian gland dysfunction (MGD) subtypes showed lower NIKBUTs than those of the normal group, whilst NIKBUTs of the MGD subtype did not differ from those of the normal group. The NIKBUTs showed a good diagnostic ability in diagnosing dry eye except MGD only. The occurrence of the first tear film break-up in the central location was significantly higher in both the ADDE and ADDE/MGD subtypes, comprising approximately 40% in both subtypes (p < 0.001). The proportion of a simultaneous multiple tear film break-up pattern was higher in the ADDE and ADDE/MGD subtypes, at 60.9% and 45.5%, respectively (p < 0.001).

CONCLUSION

The NIKBUTs and the location and pattern of non-invasive tear film break-up were different between normal group and each group of three DED subtypes.

Diurnal variation of human tear meniscus volume measured with tear strip meniscometry self-examination

PURPOSE

Tear secretion is critical for maintenance of healthy ocular surface and vision. Most of normal subjects and dry eye patients feel worsening of ocular dryness in the afternoon, however, diurnal variation of tear meniscus volume has not been directly measured because there was no appropriate method. We used a simple, non-invasive technique, tear strip meniscometry (SM) by self-examination. Previous investigations indicated the values of SM correlated strongly with those of the Schirmer test, tests of tear break up time, and tear meniscus height measurement by anterior optical coherence tomography. The purpose of this study was to capture diurnal variation of aqueous availability at the tear meniscus by measuring wetted length using SM through self-examination.

METHODS

Thirty-six medical personnel (mean age; 35.7 years) participated and SM self-examination was performed using a mirror seven times a day. The strip is applied for 5 seconds to the lateral side of the lower lid tear meniscus without touching the ocular surface.

RESULTS

The measured SM value was the highest upon awakening (4.44 ± 3.14 mm) and gradually decreased in the evening; 3.81 ± 3.12 at 9:00, 3.31 ± 2.72* at 12:00, 2.89 ± 1.88* at 15:00, 2.92 ± 1.87* at 18:00, 2.78 ± 1.85* at 21:00, and 2.89 ± 1.75* at bedtime with statistical significance compared to the value upon awakening (*P < 0.05, Dunnett's multiple comparison test). Proportion of number of subjects with low SM value (< 4 mm) to total number of subjects was 52.8% upon awakening and 83.3% at 21:00, and gradually increased toward evening.

CONCLUSION

Our results could identify diurnal variation of tear meniscus volume in the general population.

Tear instability importance, mechanisms, validity and reliability of assessment

PURPOSE

To examine the factors which contribute to tear stability and the validity and reliability of methods used for assessing tear break up time which is a core part of an examination of tear stability in dry eye patients.

METHODS

A review of publications which are relevant to tear stability and its assessment.

RESULTS

Tear break up time may be more invasive than intended if difficulty avoiding blinking during assessment results in reflex tearing. Notwithstanding control of instilled volume and concentration of fluorescein, on-eye dilution is highly variable according to resident tear volume. Blinking to evenly distribute fluorescein may improve tear and lipid layer thickness so habitual tear function is not assessed. Emphasis on a role for Meibomian gland dysfunction as a cause of tear instability may be appropriate in many cases but ignores the roles for other sources of tear lipid and other non-lipid contributions to tear instability such as aqueous or mucus deficiency, desiccated epitheliopathy or anomalous blinking. Objective less-invasive methods eliminate problems of inter-observer variability and can reliably 'maintain vigilance' over wide areas of the tear layer. However less-invasive results to date include mean tear break up findings which are both shorter and longer than expected for normal controls.

CONCLUSIONS

Fluorescein tear break up time assessments cannot be standardised and less-invasive methods are not yet standardised. Objective less-invasive and subjective fluorescein break up time tests do not appear to be measuring the same tear phenomena although both should be performed before other invasive procedures.

Evaluation of lacrimal production, osmolarity, crystallization, proteomic profile, and biochemistry of capuchin monkeys' tear film

BACKGROUND

To evaluate the composition and characteristics of capuchin monkey (CM) tear film.

METHODS

Eleven CM (Sapajus sp.) was evaluated. Strip meniscometry test (SMT), osmolarity, and tear ferning test (TFT) (by Rolando and Masmali scales) were assessed. Tear protein profile (SDS-PAGE), and total protein, albumin, urea, glucose, and cholesterol levels in tear film and blood serum were screened.

RESULTS

Median ± semi-interquatil range for SMT and osmolarity values were 8.0 ± 1.625 and 303.0 ± 9.875, respectively. TFT for Rolando was 2.0 ± 0.5, and Masmali was 2.0 ± 0.0. Monkeys's tear obtained type II and III for Rolando, and 1 and 2 for Masmali. Tear components showed protein bands among 23-217 kDa, and presence of albumin, urea, glucose, and cholesterol.

CONCLUSIONS

The results of SMT, osmolarity, TFT, SDS-PAGE, and tear biochemistry may serve as a reference baseline for CM, and the data may serve as a basis for future experimental model evaluations.

Sjogren's syndrome from the perspective of ophthalmology

Sjogren's syndrome (SS) is an autoimmune disease affecting the lacrimal glands resulting in dry eye disease (DED). Ophthalmologists may be the first line of detection of Sjogren's syndrome given the frequency of DED in SS and that dry eye is often the presenting symptom. Numerous symptom questionnaires and tests have been developed to help diagnose DED, but as of yet, there is no "gold standard." Minimally invasive objective metrics are needed for a reliable diagnosis of DED. Currently there is no single test to diagnose SS-associated DED. Although there are several approaches to treatment, none are specific for DED in SS, and, generally, several methods need to be tried to find what works best for a specific patient. Treatment for DED continues to be an unmet medical need, especially given that DED in SS is typically on the severe end of the spectrum.

The Growing Need for Validated Biomarkers and Endpoints for Dry Eye Clinical Research

Purpose

Biomarkers with minimally invasive and reproducible objective metrics provide the key to future paradigm shifts in understanding of the underlying causes of dry eye disease (DED) and approaches to treatment of DED. We review biomarkers and their validity in providing objective metrics for DED clinical research and patient care.

Methods

The English-language literature in PubMed primarily over the last decade was surveyed for studies related to identification of biomarkers of DED: (1) inflammation, (2) point-of-care, (3) ocular imaging, and (4) genetics. Relevant studies in each group were individually evaluated for (1) methodological and analytical details, (2) data and concordance with other similar studies, and (3) potential to serve as validated biomarkers with objective metrics.

Results

Significant work has been done to identify biomarkers for DED clinical trials and for patient care. Interstudy variation among studies dealing with the same biomarker type was high. This could be attributed to biologic variations and/or differences in processing, and data analysis. Correlation with other signs and symptoms of DED was not always clear or present.

Conclusions

Many of the biomarkers reviewed show the potential to serve as validated and objective metrics for clinical research and patient care in DED. Interstudy variation for a given biomarker emphasizes the need for detailed reporting of study methodology, including information on subject characteristics, quality control, processing, and analysis methods to optimize development of nonsubjective metrics. Biomarker development offers a rich opportunity to significantly move forward clinical research and patient care in DED.

Overview

DED is an unmet medical need - a chronic pain syndrome associated with variable vision that affects quality of life, is common with advancing age, interferes with the comfortable use of contact lenses, and can diminish results of eye surgeries, such as cataract extraction, LASIK, and glaucoma procedures. It is a worldwide medical challenge with a prevalence rate ranging from 8% to 50%. Many clinicians and researchers across the globe are searching for better answers to understand the mechanisms related to the development and chronicity of DED. Though there have been many clinical trials for DED, few new treatments have emerged over the last decade. Biomarkers may provide the needed breakthrough to propel our understanding of DED to the next level and the potential to realize our goal of truly personalized medicine based on scientific evidence. Clinical trials and research on DED have suffered from the lack of validated biomarkers and less than objective and reproducible endpoints. Current work on biomarkers has provided the groundwork to move forward. This review highlights primarily ocular biomarkers that have been investigated for use in DED, discusses the methodologic outcomes in providing objective metrics for clinical research, and suggests recommendations for further work.