Comparison of Tear Meniscus Height Measurements Obtained With the Keratograph and Fourier Domain Optical Coherence Tomography in Dry Eye

Quantitative evaluation of morphological and functional changes in meibomian glands and lipid layer thickness in patients with and without keratoconus

PURPOSE

To quantitatively evaluate the morphological parameters of meibomian glands (MGs) and lipid layer thickness (LLT) in patients with keratoconus (KC).

METHODS

In this prospective, cross-sectional study, 164 eyes of 164 keratoconus patients and 64 eyes of 64 age-matched control subjects were included. An advanced automatic MG analyzer was used to quantitatively measure the morphological and functional parameters of MGs. Morphological and functional parameters of MGs, LLT, and other ocular surface parameters were compared between the control and KC groups.

RESULTS

The mean meibomian gland diameter, length, square, and gland area ratio (GA) were all significantly decreased in the KC group (all P < 0.05), while no significant difference was observed in the gland tortuosity index (TI) and gland signal index (SI) between the KC and control groups (all P > 0.05). There was no significant difference in the number of total and incomplete blinking among patients with different stages of keratoconus (all P > 0.05). The gland diameter, square, and TI were all negatively associated with KC severity (all P < 0.05), while no significant difference was observed among all stages of KC in gland length, GA, and SI (all P > 0.05). Moreover, the LLTs were positively correlated with the gland diameter, square, GA, and TI and negatively correlated with anterior corneal curvature or KC severity (all P < 0.05).

CONCLUSIONS

Atrophic morphological changes in the meibomian glands were closely correlated with the severity of keratoconus. Gland diameter may be a sensitive functional morphology metric of meibomian glands in patients with keratoconus.

Applications of Artificial Intelligence in Diagnosis of Dry Eye Disease: A Systematic Review and Meta-Analysis

PURPOSE

Clinical diagnosis of dry eye disease is based on a subjective Ocular Surface Disease Index questionnaire or various objective tests, however, these diagnostic methods have several limitations.

METHODS

We conducted a comprehensive review of articles discussing various applications of artificial intelligence (AI) models in the diagnosis of the dry eye disease by searching PubMed, Web of Science, Scopus, and Google Scholar databases up to December 2022. We initially extracted 2838 articles, and after removing duplicates and applying inclusion and exclusion criteria based on title and abstract, we selected 47 eligible full-text articles. We ultimately selected 17 articles for the meta-analysis after applying inclusion and exclusion criteria on the full-text articles. We used the Standards for Reporting of Diagnostic Accuracy Studies to evaluate the quality of the methodologies used in the included studies. The performance criteria for measuring the effectiveness of AI models included area under the receiver operating characteristic curve, sensitivity, specificity, and accuracy. We calculated the pooled estimate of accuracy using the random-effects model.

RESULTS

The meta-analysis showed that pooled estimate of accuracy was 91.91% (95% confidence interval: 87.46-95.49) for all studies. The mean (±SD) of area under the receiver operating characteristic curve, sensitivity, and specificity were 94.1 (±5.14), 89.58 (±6.13), and 92.62 (±6.61), respectively.

CONCLUSIONS

This study revealed that AI models are more accurate in diagnosing dry eye disease based on some imaging modalities and suggested that AI models are promising in augmenting dry eye clinics to assist physicians in diagnosis of this ocular surface condition.

Feasibility of Tear Meniscus Height Measurements Obtained with a Smartphone-Attachable Portable Device and Agreement of the Results with Standard Slit Lamp Examination

PURPOSE

We aimed to evaluate the feasibility of using a novel device, the Smart Eye Camera (SEC), for assessing tear meniscus height (TMH) after fluorescein staining and the agreement of the results with measurements obtained using standard slit lamp examination.

METHODS

TMH was assessed using both SEC and conventional slit lamp examination. The images were analyzed using the software ImageJ 1.53t (National Institutes of Health, Bethesda, MD, USA). A common measurement unit scale was established based on a paper strip, which was used as a calibration marker to convert pixels into metric scale. A color threshold was applied using uniform parameters for brightness, saturation, and hue. The images were then binarized to black and white to enhance the representation of the tear menisci. A 2 mm area around the upper and lower meniscus in the central eye lid zone was selected and magnified 3200 times to facilitate manual measurement. The values obtained using SEC were compared with those obtained with a slit lamp.

RESULTS

The upper and lower TMH values measured using the SEC were not statistically different from those obtained with a slit lamp (0.209 ± 0.073 mm vs. 0.235 ± 0.085, p = 0.073, and 0.297 ± 0.168 vs. 0.260 ± 0.173, p = 0.275, respectively). The results of Bland-Altman analysis demonstrated strong agreement between the two instruments, with a mean bias of -0.016 mm (agreement limits: -0.117 to 0.145 mm) for upper TMH and 0.031 mm (agreement limits: -0.306 to 0.368 mm) for lower TMH.

CONCLUSIONS

The SEC demonstrated sufficient validity and reliability for assessing TMH in healthy eyes in a clinical setting, demonstrating concordance with the conventional slit lamp examination.

Blinking and normal ocular surface in school-aged children and the effects of age and screen time

PURPOSE

Baseline ocular surface characteristics in children require investigation. This study characterised blinking and relationships with ocular symptoms, tear film and digital device use.

METHODS

45 children aged 6-15 years (56% female) participated in a cross-sectional study. Ocular surface symptoms (Instant Ocular Symptoms Survey, Dry Eye Questionnaire 5, Symptoms Assessment in Dry Eye, Ocular Surface Disease Index, Ocular Comfort Index and Numerical Rating Scale) and clinical indices (lipid layer thickness, tear secretion and stability, meibomian gland) were assessed. Blink rate and interblink interval were measured in situ using a wearable eye-tracking headset (Pupil Labs GmbH, Germany). Associations between blinking, ocular surface, age, and digital device use (bivariate and partial correlations) and between automated and manually counted blink rate (Bland & Altman) were examined.

RESULTS

Mean blink rate and interblink interval were 20.5±10.5 blinks/min and 2.9±1.9 s during conversation. There was no difference between automated and manual blink rate (p=0.78) and no relationship between blinking and digital device use, age or sex. Mean group symptoms were within normal range and not associated with clinical measurements including blinking. Greater tear volume was associated with a faster blink rate (r=0.46, p=0.001) and shorter interblink interval (r=-0.36, p=0.02). Older age was associated with improved tear volume (r=0.37, p=0.01) and stability (r=0.38, p=0.01).

CONCLUSIONS

Blinking characterised in situ was not impacted by age or habitual digital device use. A faster blink rate was associated with greater tear volume but not symptoms. Improved tear function was found with age suggesting that the ocular surface continues to develop through childhood.

Evaluation of the Clinical Characteristics of Dry Eye Secondary to Different Types of Liver Diseases

INTRODUCTION

This study compares the clinical characteristics of dry eye secondary to primary biliary cholangitis (PBC), drug-induced liver injury (DILI), and viral hepatitis B(HBV) to evaluate the ocular surface damage caused by different types of liver diseases.

METHODS

Thirty healthy people were included as control group. Sixty patients with dry eye secondary to different types of liver disease were included, including 19 cases of PBC, 18 cases of DILI, and 23 cases of HBV. All patients were evaluated by the SPEED questionnaire, corneal fluorescein staining (CFS), noninvasive tear breakup time (NIBUT), Schirmer I test (SIt), tear meniscus height test (TMH), the area of meibomian glands dropout (MG dropout), partial blinking rate (PBR), lipid layer thickness (LLT), meibum expressibility, and meibum quality.

RESULTS

There are statistical differences in ophthalmic examination results between different types of liver diseases and normal people (P < 0.05). Compared with DILI and HBV groups, the CFS score of PBC group score was higher (P < 0.05), the PBR was higher (P < 0.05), and the SIt was lower (P < 0.01). The TMH of PBC and DILI groups were significantly lower than the HBV group, and the difference was statistically significant (P < 0.05). Compared with the PBC group, the LLT of the DILI group decreased (P < 0.01). The area of meibomian glands dropout of the three groups had mild-to-moderate defects, but there was no significant statistical difference between groups (P > 0.05).The Meibum quality score in the DILI group was significantly higher than the HBV group (P < 0.05).

CONCLUSIONS

The PBC group was more prone to aqueous-deficient dry eye. The DILI group was more prone to obstructive meibomian gland dysfunction (MGD).The HBV group was more prone to nonobstructive MGD. The symptoms of dry eye in the PBC group are mild-to-moderate discomfort, but the degree of corneal damage is higher, indicating that the corneal sensitivity is reduced, which may be related to the high rate of partial blinking.

Application of optical coherence tomography and keratograph in the measurements of lower lid margin thickness

PURPOSE

This study aims to investigate the applicability of lower lid margin thickness (LLMT) measurements in adults with and without meibomian gland dysfunction (MGD) by optical coherence tomography (OCT) and keratograph.

METHODS

This is a cross-sectional, observational study. A hundred and eight volunteers aged 20 to 79, including 68 MGD patients and 40 normal subjects, were recruited. Using OCT and keratograph to measure the LLMT from the posterior lash line to anterior edge or outer edge of the tear meniscus was separately performed two times by the same person.

RESULTS

The mean age of normal and MGD subjects was 50.5 ± 14.2 years and 55.8 ± 15.5 years, respectively. The LLMT with OCT and keratograph in MGD patients was significantly greater than that in normal subjects (1.06 ± 0.27 and 1.03 ± 0.25 mm vs. 0.90 ± 0.20 and 0.86 ± 0.16 mm, respectively). In both normal and MGD subjects, the tear meniscus height and LLMT with OCT were both greater than that with keratograph (P < 0.05), and intraclass correlation coefficient (ICC) demonstrated a good agreement in the LLMT measurements between two devices (ICC = 0.83 and 0.79, respectively). Additionally, the LLMT in MGD patients was appeared to be positively correlated with meiboscore (rs = 0.37, P = 0.002).

CONCLUSIONS

The OCT and keratograph were two reliable tools in the LLMT measurements, which may have potential applications for diagnosis and evaluation of MGD. Furthermore, we found that the LLMT measured by OCT was greater than that measured by keratograph.

Promising High-Tech Devices in Dry Eye Disease Diagnosis

BACKGROUND

Dry eye disease (DED) is a common and debilitating condition that affects millions of people worldwide. Despite its prevalence, the diagnosis and management of DED can be challenging, as the condition is multifactorial and symptoms can be nonspecific. In recent years, there have been significant advancements in diagnostic technology for DED, including the development of several new devices.

METHODS

A literature review of articles on the dry eye syndrome and innovative diagnostic devices was carried out to provide an overview of some of the current high-tech diagnostic tools for DED, specifically focusing on the TearLab Osmolarity System, DEvice Hygrometer, IDRA, Tearcheck, Keratograph 5M, Cornea Dome Lens Imaging System, I-PEN Osmolarity System, LipiView II interferometer, LacryDiag Ocular Surface Analyzer, Tearscope-Plus, and Cobra HD Camera.

CONCLUSIONS

Despite the fact that consistent use of these tools in clinical settings could facilitate diagnosis, no diagnostic device can replace the TFOS algorithm.

Blink Rate Measured In Situ Decreases While Reading From Printed Text or Digital Devices, Regardless of Task Duration, Difficulty, or Viewing Distance

Purpose

To compare blinking measured in situ during various tasks and examine relationships with ocular surface symptoms. The day-to-day repeatability of the blink rate and interblink interval was assessed.

Methods

Twenty-four students (28.6 ± 6.3 years; 8 male and 16 female) completed six reading tasks (printed text, laptop, TV, smartphone, smartphone at 50% brightness, smartphone with complex text), and two nonreading tasks (conversation, walking) in a randomized cross-over study. Ocular surface symptoms and clinical signs were assessed. The blink rate and interblink interval were measured using a wearable eye tracking headset. Blink parameters were compared across tasks and time (linear mixed model and post hoc comparisons with Bonferroni correction). Associations between blinking, symptoms, ocular surface, and clinical signs were assessed (Spearman's correlation). The smartphone reading task was completed twice to determine the coefficient of repeatability.

Results

The blink rate was lower (mean 10.7 ± 9.7 blinks/min) and the interblink interval longer (mean 9.6 ± 8.7 seconds) during all reading tasks compared with conversation (mean 32.4 ± 12.4 blinks/min; 1.5 ± 0.6 seconds) and walking (mean 31.3 ± 15.5 blinks/min; 1.9 ± 1.3s) (P < 0.001). There were no significant differences in blink parameters between any of the reading tasks or between conversation and walking. Changes in blinking occurred within 1 minute of starting the task. No associations were evident between blink rate or interblink interval and ocular surface symptoms or signs. The coefficient of repeatability was ±12.4 blinks/min for blink rate and ±18.8 seconds for interblink interval.

Conclusions

Spontaneous blinking can be measured reliably in situ. The blink rate was decreased and the interblink interval increased during reading compared with conversation and walking. Changes in blinking were immediate, sustained, and not associated with ocular surface symptoms or signs.

The Incidence and Risk Factors for Dry Eye After Pediatric Strabismus Surgery

INTRODUCTION

This study aimed to investigate the incidence and risk factors for dry eye after pediatric strabismus surgery.

METHODS

Children aged 5-12 years who underwent strabismus surgery were included in this single-center, prospective, cohort study. The ocular surface assessments were conducted 1 day before and 1, 4, and 8 weeks after surgery. The main outcome measures were the incidence of dry eye after strabismus surgery and associated risk factors.

RESULTS

A total of 84 eyes (48 children) that underwent strabismus surgery were included in the study. The mean age at surgery was 7.21 years. The incidence of dry eye was 47.62% at 1 week, 10.71% at 4 weeks, 0% at 8 weeks after surgery. The preoperative tear breakup time (BUT) was lower in the dry eye group than that in the non-dry eye group (P ≤ 0.01). The univariate analysis showed that preoperative BUT was significantly associated with the incidence of dry eye after pediatric strabismus surgery (odds ratio [OR] 0.647, confidence interval [CI] 0.503-0.833, P ≤ 0.01).

CONCLUSIONS

Dry eye commonly occurs after pediatric strabismus surgery. Tear film instability is more common than deficient aqueous tear production in patients with dry eye after surgery. Children with a low preoperative BUT are more likely to develop dry eye after strabismus surgery.

Tear Proteomics Approach to Distinguishing Primary from Secondary Sjögren's Syndrome for Dry Eye Patients with Long-Term Instillation of Eyedrops

The diagnosis and monitoring of Sjögren syndrome (SS) is often difficult, requiring a multidisciplinary approach with invasive procedures. Our aim is to elucidate the tear protein alterations of dry eye disease (DED) with primary SS (pSS) and secondary SS (sSS) with the long-term instillation of eyedrops. We collected clinical demographics and tear fluid (TF) samples from DED patients with no autoimmune diseases (non-SS-DED), pSS-DED, and sSS-DED patients, followed by TF screening with tandem mass tagging-labeling gel-free proteomics assay. Bioinformatic analysis via Ingenuity Pathway Analysis was used to identify functional pathways and interacting networks. Validation of candidate proteins with enzyme-linked immunosorbent assay on the tear samples was done. The top functional pathways of the two comparisons (sSS-DED vs. pSS-DED and sSS-DED vs. non-SS-DED) were both associated with inflammation and stress-related signaling. After constructing an interaction network model with the selected candidate proteins, five proteins were identified. A Disintegrin and Metalloproteinase domain-containing protein 10 (ADAM10) was found to be an important candidate biomarker in all groups, followed by epidermal growth factor (EGF) in TF. This study revealed novel DED markers, ADAM10 and EGF, in differentiating between primary and secondary SS patients from tears by in-depth proteomic analysis.

Dry eye disease and tear film assessment through a novel non-invasive ocular surface analyzer: The OSA protocol

We describe the role of OSA as a new instrument in the study of dry eye, and we recommend a protocol for conducting the tests as well as describe the advantages and disadvantages compared with other instruments. A comparison with other ocular surface devices (Tearscope Plus, Keratograph 5M, anterior-segment ocular coherence tomography, Easy Tear View-Plus, LipiView, IDRA, and LacryDiag) were presented due to manual or automatic procedure and objective or subjective measurements. The purpose of this study was to describe the OSA as new non-invasive dry eye disease diagnostic device. The OSA is a device that can provide accurate, non-invasive and easy-to-use parameters to specifically interpret distinct functions of the tear film. This OSA protocol proposed a lesser to higher non-invasive ocular surface dry eye disease tear film diagnostic methodology. A complete and exhaustive OSA and OSA Plus examination protocol was presented within the subjective questionnaire (Dry Eye Questionnaire 5, DEQ5), limbal and bulbar redness classification (within the Efron grade Scale, interferometry lipid layer thickness (LLT) (according to Guillon pattern), tear meniscus height (manually or automatic), first and mean non-invasive break up time (objective and automatic) and meibomian gland (MG) dysfunction grade and percentage (objective and automatic). The OSA and OSA Plus devices are novel and relevant dry eye disease diagnostic tools; however, the automatization and objectivity of the measurements can be increased in future software or device updates. The new non-invasive devices supposed represent a renewal in the dry eye disease diagnosis and introduce a tendency to replace the classic invasive techniques that supposed less reliability and reproducibility.

Automation of dry eye disease quantitative assessment: A review

Dry eye disease (DED) is a common eye condition worldwide and a primary reason for visits to the ophthalmologist. DED diagnosis is performed through a combination of tests, some of which are unfortunately invasive, non‐reproducible and lack accuracy. The following review describes methods that diagnose and measure the extent of eye dryness, enabling clinicians to quantify its severity. Our aim with this paper is to review classical methods as well as those that incorporate automation. For only four ways of quantifying DED, we take a deeper look into what main elements can benefit from automation and the different ways studies have incorporated it. Like numerous medical fields, Artificial Intelligence (AI) appears to be the path towards quality DED diagnosis. This review categorises diagnostic methods into the following: classical, semi‐automated and promising AI‐based automated methods.

Reliability, repeatability, and accordance between three different corneal diagnostic imaging devices for evaluating the ocular surface

Purpose

To evaluate repeatability, reproducibility, and accordance between ocular surface measurements within three different imaging devices.

Methods

We performed an observational study on 66 healthy eyes. Tear meniscus height, non-invasive tear break-up time (NITBUT) and meibography were measured using three corneal imaging devices: Keratograph 5M (Oculus, Wetzlar, Germany), Antares (Lumenis, Sidney, Australia), and LacryDiag (Quantel Medical, Cournon d'Auvergne, France). One-way ANOVAs with post hoc analyses were used to calculate accordance between the tear meniscus and NITBUT. Reproducibility was assessed through coefficients of variation and repeatability with intraclass correlation coefficients (ICC). Reliability of meibography classification was analyzed by calculating Fleiss' Kappa Index and presented in Venn diagrams.

Results

Coefficients of variation were high and differed greatly depending on the device and measurement. ICCs showed moderate reliability of NITBUT and tear meniscus height measurements. We observed discordance between measurements of tear meniscus height between the three devices, F2, 195 = 15.24, p < 0.01. Measurements performed with Antares were higher; 0.365 ± 0.0851, than those with Keratograph 5M and LacryDiag; 0.293 ± 0.0790 and 0.306 ± 0.0731. NITBUT also showed discordance between devices, F2, 111 = 13.152, p < 0.01. Measurements performed with LacryDiag were lower (10.4 ± 1.82) compared to those of Keratograph 5M (12.6 ± 4.01) and Antares (12.6 ± 4.21). Fleiss' Kappa showed a value of -0.00487 for upper lid and 0.128 for inferior lid Meibography classification, suggesting discrete to poor agreement between measurements.

Conclusion

Depending on the device used and parameter analyzed, measurements varied between each other, showing a difference in image processing.

Smartphone gaming induces dry eye symptoms and reduces blinking in school-aged children

Purpose

Smartphone use by children is rising rapidly, but its ocular surface impact is unknown. This study examined the effect of smartphone use on blinking, symptoms, and tear function in children.

Methods

Prospective intervention study where 36 children aged 6–15years (14 M:22 F) played games on a smartphone continuously for one hour. Symptoms (SANDE, IOSS, NRS) and tear film (lipid layer thickness, tear secretion, stability) were assessed before and after gaming. Blink rate and interblink interval were measured in situ using an eye tracking headset, before (during conversation) and continuously throughout gaming. Symptoms and tear film changes were examined using paired t-tests. Changes in blinking throughout one hour were examined using repeated measures ANOVA, post-hoc comparisons with Bonferroni correction. Associations examined using Pearson bivariate correlation. Significance level was 0.05.

Results

Symptoms worsened following one hour smartphone gaming (SANDE + 8.2units, p = 0.01; IOSS + 1.3units, p < 0.001; NRS-average +6.3units, p = 0.03; NRS-comfort +7.6units, p = 0.04; NRS-tiredness +10.1units, p = 0.01), but tear film remained unchanged. Blink rate reduced from 20.8 blinks/min to 8.9 blinks/min (p < 0.001) and interblink interval increased from 2.9 s to 8.7 s (p = 0.002) within the first minute of gaming relative to baseline conversation, and this effect remained unchanged throughout one hour of gaming.

Conclusions

Smartphone use in children results in dry eye symptoms and immediate and sustained slowing of blinking, with no change in tear function evident up to one hour. Given the ubiquitous use of smartphones by children, future work should examine whether effects reported herein persist or get worse over a longer term causing cumulative damage to the ocular surface.

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.

Alterations in meibomian glands in patients treated with intensity-modulated radiotherapy for head and neck cancer

Patients undergoing intensity-modulated radiotherapy (IMRT) for head and neck cancer may have increased incidence of dry eye disease and the exact mechanism is unclear. The present study aims to assess tear film and meibomian gland (MG) features in patients who received IMRT for head and neck cancer not involving the orbital area. Twenty-seven patients (64.7 ± 9.8 years) and 30 age-matched controls (61.4 ± 11.0 years) underwent a comprehensive dry eye work-up. Compared to the control group, the patients had more lid margin abnormalities, and worse meibum quality. The MG loss, calculated as (tarsal area-MG area)/tarsal area, was higher in the patient group in both the upper (53.0 ± 12.0% vs. 35.1 ± 10.3%, p < 0.001) and lower lids (69.5 ± 12.6% vs. 48.5 ± 12.5%, p < 0.001). In the patient group, more MG loss in the lower lids correlated with worse meibum quality (r = 0.445, p = 0.029). In contrast, there was no significant difference in aqueous tear production level, measured with Schirmer test. Patients treated with IMRT for head and neck cancer seemed to have comparable lacrimal gland function to the controls despite more dry eye symptoms. However, the patients had MG functional and morphological changes, which may present a higher risk for developing dry eye disease.

Measurement of the Lower Lid Margin Thickness by Oculus Keratograph

OBJECTIVES

To investigate the lower lid margin thickness (LLMT) from the posterior lash line to the anterior edge of tear meniscus with Oculus Keratograph 4 (K4).

METHODS

This was a prospective, single-center, observational study. A total of 90 volunteers aged 18 to 79 years with no ocular diseases were included in this study. The LLMT of 90 subjects was measured twice by the same person with K4. To determine the reliability of K4, measuring the LLMT of 30 normal subjects was separately performed by two operators.

RESULTS

The LLMT measurements with K4 between two operators demonstrated a good reproducibility (0.94±0.18 vs. 0.96±0.16 mm; intraclass correlation coefficient=0.88; P=0.18). The mean age of 90 volunteers (42 men and 48 women) was 45.5±14.1 years. The LLMT was 0.95±0.17 mm, which was a significant positive correlation with age (rs=0.57; P<0.001). In addition, there was no significant difference in the LLMT between genders (0.97±0.16 vs. 0.93±0.18 mm; P=0.32).

CONCLUSIONS

We found that K4 was a reliable tool in the LLMT measurements, and the LLMT seemed to be closely related to age but not to gender.

Tear Proteomics Study of Dry Eye Disease: Which Eye Do You Adopt as the Representative Eye for the Study?

Most studies about dry eye disease (DED) chose unilateral eye for investigation and drew conclusions based on monocular results, whereas most studies involving tear proteomics were based on the results of pooling tears from a group of DED patients. Patients with DED were consecutively enrolled for binocular clinical tests, tear biochemical markers of DED, and tear proteome. We found that bilateral eyes of DED patients may have similar but different ocular surface performance and tear proteome. Most ocular surface homeostatic markers and tear biomarkers were not significantly different in the bilateral eyes of DED subjects, and most clinical parameters and tear biomarkers were correlated significantly between bilateral eyes. However, discrepant binocular presentation in the markers of ocular surface homeostasis and the associations with tear proteins suggested that one eye’s performance cannot represent that of the other eye or both eyes. Therefore, in studies for elucidating tear film homeostasis of DED, we may lose some important messages hidden in the fellow eye if we collected clinical and proteomic data only from a unilateral eye. For mechanistic studies, it is recommended that researchers collect tear samples from the eye with more severe DED under sensitive criteria for identifying the more severe eye and evaluating the tear biochemical and proteomic markers with binocular concordance drawn in prior binocular studies.

Analysis of tear film spatial instability for pediatric myopia under treatment

In Taiwan, the prevalence of myopia in children between 6 and 18 years old is over 80%, and high myopia accounts for over 20%, which turned out to be in the leading place worldwide. Orthokeratology and low-dose atropine are proven treatments to reduce myopia progression, though the potential corneal disturbances remain an issue in young populations. The alteration of the tear film is widely discussed but there is no consensus to date, so we aim to investigate the tear film spatial instability in children with myopia control using atropine or orthokeratology. Thirty-eight treatment-naïve participants and 126 myopic children under treatments were enrolled. The ocular surface homeostasis, spatial distribution of tear break-up, and high-order aberrations (HOAs) of the corneal surface were assessed. We found out that myopic children treated with either atropine or orthokeratology showed ocular surface homeostasis similar to that in treatment-naïve children. Nevertheless, children treated with orthokeratology presented higher HOAs (p < 0.00001) and a tendency of the first tear break-up zone at the inner half of the cornea (p = 0.04). This unique spatial instability of the tear film associated with myopia treatment might provide a more focused way of monitoring the pediatric tear film instability.

Comparison of the therapeutic effect of Meibomian Thermal Pulsation LipiFlow® on obstructive and hyposecretory meibomian gland dysfunction patients

PURPOSE

To explore the effect of Meibomian Thermal Pulsation LipiFlow® on obstructive and hyposecretory meibomian gland dysfunction.

METHODS

Twenty-five subjects diagnosed with obstructive meibomian gland dysfunction (OMGD) and another 25 hyposecretory meibomian gland dysfunction (HMGD) patients were collected receiving the unilateral treatment with LipiFlow®. We evaluated the parameters variables including Standard Patient Evaluation of Eye Dryness (SPEED), Ocular Surface Disease Index (OSDI), Schirmer I test (SIT), noninvasive keratographic breakup time (NIKBUT), tear meniscus height (TMH), and lipid layer thickness (LLT), partial blink rate (PBR), meibomian gland loss, meibomian gland morphology with LipiView®. Meibomian gland expressibility and secretion quality were evaluated for OMGD subjects. All the results were recorded pre-therapy and 4 weeks, 8 weeks, 12 weeks post-therapy.

RESULTS

SPEED, OSDI, and PB decreased, meanwhile, NIKBUT, TMH, SIT, and LLT increased compared with baseline in both groups after treatment (P < 0.001), whereas the magnitude of the improvement in the OMGD group was greater than that in the HMGD group (P < 0.001). There was no significant posttreatment structural meibomian gland change in both groups. The meibomian gland expressibility and secretion quality score increased after treatment in the OMGD group (P < 0.001).

CONCLUSIONS

The Meibomian Thermal Pulsation LipiFlow® is effective for both obstructive and hyposecretory meibomian gland dysfunction and the therapeutic effect on obstructive meibomian gland dysfunction is greater than that on hyposecretory meibomian gland dysfunction.

Improved Tear Film Stability in Patients with Dry Eye After Hyaluronic Acid and Galactoxyloglucan Use

Purpose

Artificial tears only provide transient relief for dry eye. To the best of our knowledge, this is the first study to objectively compare treatment with artificial tears with Keratograph 5M, which allows accurate and objective investigation of dry eye and artificial tear treatment. We aimed to evaluate whether a preservative-free combination of 0.4% hyaluronic acid and 0.2% galactoxyloglucan can improve dry eye using the new topographer, Keratograph 5M.

Patients and Methods

This prospective longitudinal, single-arm interventional cohort study was performed at a tertiary referral center and involved 20 patients with dry eye (40 eyes). Preservative-free artificial tears were administered every 3 h. The participants underwent clinical and instrumental evaluations at baseline, 15, 30, 60, 90 and 120 min after instillation and 1 week and 1 month after treatment. Baseline values were considered as the controls. All patients were assessed with Keratograph 5M for non-invasive Keratograph first break-up time and non-invasive Keratograph average break-up time, conjunctival hyperemia, and tear meniscus height. Ocular surface staining with fluorescein was evaluated using the slit-lamp and fluorescein break-up time examinations, and the Ocular Surface Disease Index score was recorded for each patient.

Results

The signs and symptoms improved after 1 month of preservative-free 0.4% hyaluronic acid and 0.2% galactoxyloglucan treatment. There was a significant increase in the non-invasive Keratograph first break-up time and non-invasive Keratograph average break-up time at 15, 30, 60, and 90 min, and 1 week and 1 month (P < 0.05) and a decrease in hyperemia, corneal staining, and Ocular Surface Disease Index scores after 1 week and 1 month (P < 0.05). No treatment-related adverse event was observed.

Conclusion

A combination of 0.4% hyaluronic acid and 0.2% galactoxyloglucan artificial tears seems effective for treating dry eye. Keratograph 5M can objectively detect these changes during the follow-up period.

TMIS: a new image-based software application for the measurement of tear meniscus height

PURPOSE

To present a new automated image recognition software for the measurement of tear meniscus height (TMH) and investigate its correlation and efficacy compared with an open-source software (NIH ImageJ) and manual evaluation.

METHODS

A total of 520 slit lamp photographs, among which 276 were in ×16 magnification and 244 were ×40 magnified, captured from 138 eyes of 69 healthy subjects were assessed for TMH by the new automated Tear Meniscus Identification Software (TMIS), ImageJ and human graders. Images processing of TMIS included filtration, recognition and measurement of slit lamp photographs under certain algorithm, which output two measurement patterns, TMIS_{M ax} and TMIS_{M ean} . TMH measured by ImageJ software, considered as the reference value, was conducted by a masked observer while four masked ophthalmologists performed the manual evaluation.

RESULTS

In both magnifications, TMH measured by TMIS_{M ean} showed similar values with ImageJ while manual evaluation demonstrated underestimated results, and a strong correlation was detected between TMIS and ImageJ. In ×16 magnified photographs, manually obtained TMH revealed a higher correlation with ImageJ, whereas a notably stronger correlation of TMIS with ImageJ was observed in ×40 photographs. Correspondingly, the accuracy for both TMIS_{M ax} and TMIS_{M ean} appeared to be lower than most doctors in ×16 slit lamp images, in contrast to a better precision of TMIS_{M ean} in ×40 ones.

CONCLUSION

The new software displayed high accuracy and efficacy in ×40 magnification and TMIS_{M ean} pattern, suggesting the possibility of this automated TMH measurement platform to be a valid tool in dry eye screening and follow-up practice.

Automated Measurement of Tear Meniscus Height with the Kowa DR-1α Tear Interferometer in Both Healthy Subjects and Dry Eye Patients

Purpose

To develop and assess a method for quantitation of lower tear meniscus height (TMH) with the Kowa DR-1α tear interferometer.

Methods

Sixty-nine eyes of 49 men and 20 women (36 healthy volunteers, 33 patients with aqueous-deficient dry eye [ADDE]; mean age ± SD, 50.0 ± 14.0 years) were enrolled. TMH of each subject was measured by two observers both with DR-1α and newly developed software and with anterior-segment swept-source optical coherence tomography (SS-OCT). Intraoperator repeatability and interoperator and intersession reproducibility of measurements were assessed based on the within-subject SD (Sw), coefficient of variation (CV), and intraclass correlation coefficient (ICC). Agreement between the two devices was assessed by regression and Bland-Altman analysis.

Results

The CV for system repeatability of DR-1α was <2.0%. The CV for intraoperator repeatability and interoperator and intersession reproducibility for DR-1α measurements was ≤9.6%, ≤4.5%, and ≤4.4% in healthy subjects, respectively, and ≤16.8%, ≤9.8%, and ≤10.3% in ADDE patients. All corresponding ICC values were ≥0.87 in healthy subjects and ≥0.48 in ADDE patients. Bland-Altman plots indicated a high level of agreement between the two devices. Schirmer test value was significantly correlated with interferometric TMH in both healthy subjects (β = 0.59, P < 0.001) and ADDE patients (β = 0.47, P = 0.017).

Conclusions

Tear interferometry allows measurement of TMH as reliably as does SS-OCT. DR-1α may inform not only the diagnosis of dry eye disease but also identification of disease subtype.

Dry Eye Disease: Emerging Approaches to Disease Analysis and Therapy

Dry eye disease (DED) is among the most common ocular disorders affecting tens of millions of individuals worldwide; however, the condition remains incompletely understood and treated. Valuable insights have emerged from multidisciplinary approaches, including immunometabolic analyses, microbiome analyses, and bioengineering. Furthermore, we have seen new developments in clinical assessment approaches and treatment strategies in the recent past. Here, we review the emerging frontiers in the pathobiology and clinical management of DED.

Lower Tear Meniscus Height Measurements Using Keratography and Swept-Source Optical Coherence Tomography and Effect of Fluorescein Instillation Methods

Purpose: The first aim of this study was to compare inferior tear meniscus height (TMH) measured by keratography and swept-source optical coherence tomography (OCT). Effect of locations of fluorescein instillation and subjects' subjective sensation, and the TMH results were also investigated.Methods: Forty-one eyes from 41 healthy adults had TMH randomly measured by keratography (K5M, Oculus, Germany) and swept-source OCT (Casia SS-1000, Tomey Corp, Japan) at baseline, followed by touching either the inferior bulbar or inferior palpebral conjunctiva, randomly assigned, with a moistened fluorescein strip. Two-way analysis of variance (ANOVA) was used to compare TMH obtained from the two devices and three measurement conditions. Subjective sensation of conjunctival touch was obtained through a 4-point scale with zero representing no sensation, and one to three representing ocular sensation in an ascending order.Results: Two-way ANOVA revealed no significant difference in TMH between keratography and swept-source OCT (Factor (devices): F = 0.579, p = .451) while there was a significant difference among fluorescein instillations (Factor (conditions): F = 10.146, p < .001). Baseline TMH was around 0.25 mm, and increased to around 0.28 mm after instillation of fluorescein sodium. Ocular sensation was similar between the two conjunctival touch, and TMH was not significantly associated with ocular sensation.Conclusions: Keratography and swept-source OCT provided similar TMH results. Applying fluorescein sodium through moistened fluorescein strip could over-estimate TMH by around 0.03 mm. Applying moistened fluorescein strip at bulbar or palpebral conjunctival led to similar subjective sensations and did not affect TMH measurement.

Tear Proteomics Approach to Monitoring Sjögren Syndrome or Dry Eye Disease

Sjögren syndrome (SS) or dry eye disease (DED) is one of the most complicated ocular surface diseases. The goal of this study is to elucidate the relationship of the changes in clinical indices of tear film (TF) homeostasis with respect to tear components to allow for SS-DED monitoring and avoid stably controlled SS-DED patients from re-entering a vicious cycle. This prospective case-control study compared stable SS-DED patients with non-SS-DED control from several aspects, including clinical indices for TF homeostasis, 2 DED diagnostic biomarkers (MMP-9 and lactoferrin), and the proteome of flush tears. Compared with non-SS-DED controls, stably controlled SS-DED subjects had less tear secretion and higher ocular surface inflammation, a higher concentration ratio of tear MMP-9/lactoferrin, a more diverse tear proteome, and lower spectral intensities of lipocalin-1, lacritin, and prolactin-inducible protein among the abundant tear proteins. For stable SS-DED patients, the concentration ratio of tear MMP-9/lactoferrin and the corrected lipocalin-1 signal was positively correlated with ocular inflammation and TF stability, respectively. MMP-9 released from stressed ocular surface epithelium and lipocalin-1 secreted from the energetic lacrimal gland are two tear biomarkers responding well to TF homeostasis. The tear proteomics approach through flush tears is a promising method for monitoring SS-DED patients with a standardized sampling procedure and lactoferrin-corrected analysis.

[Tear film analysis and evaluation of optical quality: A review of the literature (French translation of the article)]

Dry eye is a complex multifactorial disease of the ocular surface and tears. It is associated with ocular surface symptoms and is one of the most common causes for ophthalmologic consultation. Despite their frequent use in clinical practice, the usual tests to evaluate dry eye and ocular surface disease-history of symptoms, tear break-up time (TBUT), Meibomian gland evaluation, corneal fluorescein staining, Schirmer test-have shown low reproducibility and reliability. In addition, subjective symptoms are often weakly or poorly correlated with objective signs. Since the tear film is the first system through which light must pass, the optical quality of the eye is highly dependent on the homogeneity of the tear film. Various investigative methods have been developed to evaluate both the structural and functional quality of the tear film, such as corneal topography, interferometry, tear meniscus measurement, evaporation rate, tear osmolarity and even aberrometry. Some are easily accessible to clinicians, while others remain in the field of clinical research. All of these tests provide a better understanding of the pathophysiology of the tear film. This review hopes to provide an overview of the existing tests and their role in evaluating the significance of the tear film in visual function.

Tear film analysis and evaluation of optical quality: A review of the literature

Dry eye is a complex multifactorial disease of the ocular surface and tears. It is associated with ocular surface symptoms and is one of the most common causes for ophthalmologic consultation. Despite their frequent use in clinical practice, the usual tests to evaluate dry eye and ocular surface disease-history of symptoms, tear break-up time (TBUT), Meibomian gland evaluation, corneal fluorescein staining, Schirmer test-have shown low reproducibility and reliability. In addition, subjective symptoms are often weakly or poorly correlated with objective signs. Since the tear film is the first system through which light must pass, the optical quality of the eye is highly dependent on the homogeneity of the tear film. Various investigative methods have been developed to evaluate both the structural and functional quality of the tear film, such as corneal topography, interferometry, tear meniscus measurement, evaporation rate, tear osmolarity and even aberrometry. Some are easily accessible to clinicians, while others remain in the field of clinical research. All of these tests provide a better understanding of the pathophysiology of the tear film. This review hopes to provide an overview of the existing tests and their role in evaluating the significance of the tear film in visual function.

The influences of smartphone use on the status of the tear film and ocular surface

PURPOSE

To investigate the influences of smartphone use on ocular symptoms, status of the tear film, and oxidative stress indices in the tears and at the ocular surface.

METHODS

Eighty healthy volunteers were enrolled in the study. Subjective symptoms and asthenopia were evaluated using the ocular surface disease index (OSDI), visual analogue scale (VAS), and computer vision syndrome (CVS) score before and after smartphone or computer display (control) use. The status of the tear film was evaluated using fluorescein film break-up time (FBUT), non-invasive keratograph break up time (NIKBUT), Schirmer score, keratoepitheliopathy (KEP), and tear meniscus height (TMH). Oxidative stress markers in the tear film including hexanoyl lysine (HEL), 4-hydroxy-2-nonenal (4-HNE), malondialdehyde (MDA), and 8-oxo-2'-deoxyguanosine (8-OHdG) in the tear film were measured using ELISA. Reactive oxygen species (ROS) at the ocular surface were measured through 2',7'-dichloro-dihydrofluorescein diacetate. All measurements were conducted at baseline, and after use for 1 and 4 h.

RESULTS

All parameters showed no significant group-wise differences at baseline. Scores of OSDI, VAS, fatigue, burning sensation, and dryness showed significant increases after 1 and 4 h of smartphone use compared with those at baseline (all P < 0.05). The smartphone group showed higher OSDI, fatigue, burning, and dryness scores than the control group at 4 h. Smartphone use showed significantly decreased FBUT and NIBUT at 4 h than those at baseline (P < 0.01). In the smartphone group, the concentration of HEL significantly increased at 4 h compared with that at baseline and 1 h (P < 0.01). Both groups showed increased ROS with higher value in the smartphone group versus the control group at 4 h (P < 0.01).

CONCLUSIONS

Smartphone use could not only aggravate subjective symptom indices such as the OSDI, VAS, and CVS but also induce tear film instability and oxidative stress indices in the tears and at the ocular surface.

Meibomian gland features in a Norwegian cohort of patients with primary Sjögren´s syndrome

Purpose

To assess the tear film and meibomian gland (MG) features in a Norwegian cohort of patients with primary Sjögren´s syndrome (pSS) and in age- and gender-matched control subjects.

Methods

Thirty-four female patients with pSS (age 52.9±11.9 years) and 32 female control subjects (age 49.0±11.5 years) were recruited. After completion of Ocular Surface Disease Index (OSDI) questionnaire and McMonnies Dry Eye Questionaire, participants underwent measurements of tear osmolarity, tear break-up time (TBUT), ocular surface and corneal staining, Schirmer I test, corneal sensitivity, MG expressibility evaluations, and lid margin morphology examination using slitlamp microscopy. Non-contact infrared meibography images were assessed by computer-assisted analysis. The MG loss, calculated as (tarsal area-MG area)/tarsal area, was evaluated in both upper (UL) and lower lids (LL).

Results

Compared to the control group, pSS patients demonstrated higher MG loss in both UL (33.8±13.2% vs. 24.4±8.5%, p< 0.01) and LL (52.5±15.7% vs. 43.0±9.6%, p<0.05), as well as higher lid abnormality score (0.8±0.8 vs. 0.2±0.6, p< 0.01). Furthermore, pSS patients showed higher OSDI and McMonnies questionnaire scores, elevated osmolarity, shorter TBUT, shorter blink interval, less wetting in Schirmer I test, more ocular surface staining and more corneal staining. MG loss in UL correlated negatively with TBUT (r = -0.386, p = 0.029) in the pSS group, whereas MG loss in LL correlated negatively with TBUT (r = -0.380, p = 0.035) in the control group.

Conclusions

Significantly elevated dry eye symptoms and signs were found in the pSS group compared with the control group, which might be attributed to both decreased aqueous tear production and increased tear evaporation.

Effectiveness of Combined Tear Film Therapy in Patients with Evaporative Dry Eye with Short Tear Film Breakup Time

PURPOSE

The aim of this study was to evaluate the effectiveness of combined tear film therapy targeted to aqueous, mucin, and lipid layers in patients with refractory evaporative dry eye (EDE) with short tear film breakup time (TBUT).

METHODS

The patients who had EDE with short TBUT and severe symptoms refractory to artificial tears were treated with hyaluronic acid (HA) 0.15% and diquafosol tetrasodium (DQS) 3% (Group 1), HA and carbomer-based lipid-containing eyedrops (Liposic EDO Gel, LPO) (Group 2), or HA, DQS, and LPO (Group 3). Ocular Surface Disease Index (OSDI) score, visual analog scale (VAS) symptom score, TBUT, Schirmer score, and corneal and conjunctival staining scores were evaluated, and noninvasive tear film breakup time (NIBUT) and tear meniscus height were measured using Keratograph^® 5 M before and 1 and 3 months after treatment.

RESULTS

OSDI scores, VAS scores, TBUT, and NIBUT were improved at 1 and 3 months after treatment in all groups (all P < 0.05). At each follow-up visit, the total OSDI, OSDI symptom, and all VAS scores were significantly lower in group 3 compared with groups 1 and 2 (all P < 0.05). In addition, TBUT and NIBUT were significantly higher in group 3 compared with groups 1 and 2 (all P < 0.05). No significant adverse effects were noted in the groups during treatment.

CONCLUSIONS

Mucin or lipid-targeting agents combined with aqueous supplements in patients with refractory EDE with short TBUT might improve subjective symptoms and TBUT. Of this, targeting whole tear film layers was most effective in improving ocular symptoms and tear film quality.

Assessment of Lower Tear Meniscus

PURPOSE

To evaluate the applicability of the fourth-generation OCULUS keratograph in measuring lower tear meniscus height.

METHODS

Seventy cases (140 eyes) with dry eye disease and 37 controls (74 eyes) were enrolled. Tear breakup time (TBUT), Schirmer test I, and corneal fluorescein staining were examined. The images of lower tear meniscus were obtained by OCULUS keratograph. The tear meniscus height was measured and its correlation with traditional tear film diagnostic tests were analyzed.

RESULTS

Using the hyper-reflective lines, the height of the tear meniscus was measured using the images of the OCULUS keratograph. For the inter-individual variation, the intraclass correlation coefficients and coefficient of variation values were 0.914 and 16.4%, respectively. For the intra-individual variation, the intraclass correlation coefficients and coefficient of variation values were 0.939 and 15.9%, respectively. The interobserver reproducibility and the intraobserver repeatability were for the control only. The average tear meniscus height value in dry eye disease group was 0.22 (0.19-0.24) mm, being significantly lower compared with 0.29 (0.26-0.34) mm in the control group (p<0.001). Tear meniscus height value had significantly correlation with TBUT and Schirmer test I (r=0.619 and 0.626, both p<0.001). The measurement of lower tear meniscus by OCULUS had lower individual variability and better repeatability.

CONCLUSIONS

OCULUS keratograph is a quick, noninvasive, and reliable method to measure lower tear meniscus, whose value has a significant correlation with traditional dry eye disease diagnostic tests.

Manifestation of meibomian gland dysfunction in patients with Sjögren's syndrome, non-Sjögren's dry eye, and non-dry eye controls

PURPOSE

To evaluate the manifestation of meibomian gland dysfunction in patients with Sjögren's syndrome (SS), non-Sjögren's syndrome dry eye (non-SS) patients, and non-dry eye controls.

METHODS

We recruited 31 participants with SS dry eye, 30 participants with non-SS dry eye, and 35 healthy controls without dry eye symptoms. Noninvasive tear breakup time (NITBUT) and meibomian gland dropout score (meiboscore) were measured using the Oculus Keratograph 5 M. Meibomian gland expressibility and secretion quality were evaluated via slit lamp biomicroscopy. The correlation between measurements was analyzed.

RESULTS

NITBUT was lower, and the meiboscore, meibomian gland expressibility, and secretion quality scores were significantly higher in the SS and non-SS groups than in the control group (p < 0.001). NITBUT was lower, and the meiboscore and meibomian gland expressibility were higher in the SS group than in the non-SS group. NITBUT correlated negatively with the meiboscore in both SS and non-SS groups and with meibomian gland expressibility in the SS group. A positive correlation was obtained between meiboscore and meibomian gland expressibility in both the SS and the non-SS groups.

CONCLUSION

Patients in both SS and non-SS groups exhibited greater impairment in meibomian gland function than the non-dry eye controls. SS patients had more severe meibomian gland dysfunction with poorer mean meiboscore and meibomian gland expressibility than non-SS patients.

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.

The relief of dry eye signs and symptoms using a combination of lubricants, lid hygiene and ocular nutraceuticals

PURPOSE

To determine the combined effect of TheraTears^® Lubricant Eye Drops, TheraTears^® SteriLid Eyelid Cleanser, and TheraTears^® Nutrition on dry eye signs and symptoms.

METHODS

This prospective study enrolled 28 dry eye participants. Participants were instructed to use the Lubricant Eye Drops at least 2-4× a day, SteriLid 1-2× a day, and Nutrition 3 gel caps once a day. Participants were followed up at baseline, 1 month and 3 months. Outcome variables were the Ocular Surface Disease Index (OSDI), Symptom Assessment iN Dry Eye (SANDE) questionnaire, non-invasive tear break-up time (NIBUT), osmolarity, number of meibomian glands blocked (#MG blocked), meibum quality, eyelid margin features, Schirmer's test, tear film lipid layer thickness (LLT), meniscus height, corneal and conjunctival staining.

RESULTS

Twenty participants (mean age=43, from 23 to 66, 17F, 3M) completed the study. Participants reported having used, on average, the Lubricant Eye Drop 2.4×/day, the SteriLid 1.1×/day, and the Nutrition 3 gel caps 1×/day. There was a significant change over time (p<0.05) for OSDI (-21.2 points), SANDE (-32.4 points), NIBUT (+0.43s), eyelid margin features (-1.1 grade), meibum quality (-1.0 grade), and #MG blocked (-4.0 glands).

CONCLUSION

By using a combination of TheraTears^® Lubricant Eye Drop, SteriLid, and Nutrition, patients experience significant relief in both dry eye symptoms and signs.