Assessment of lower tear meniscus measurements obtained with Keratograph and agreement with Fourier-domain optical-coherence tomography

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.

Reliability of Tear Meniscus Height Measurements in Contact Lens Wearers and Its Relationship With Discomfort Symptoms

OBJECTIVES

To evaluate the reliability and agreement of tear meniscus height (TMH) measurements performed with a corneal analyzer and optical coherence tomography (OCT) technology in contact lens (CL) wearers and its correlation with contact lens discomfort symptoms.

METHODS

Asymptomatic and symptomatic CL wearers classified through the Contact Lens Dry Eye Questionnaire-8 were evaluated with the Corneal Analyzer (Topcon CA-800) and OCT technology (Topcon 3D OCT-2000). The repeatability and intraclass correlation coefficient (ICC) were calculated. The agreement between devices was calculated using the Bland-Altman method. The relationship between TMH measurements and the Contact Lens Dry Eye Questionnaire-8 and Contact Lens Discomfort Index scores was assessed through the Spearman correlation coefficient.

RESULTS

Seventy-nine asymptomatic and 42 symptomatic CL wearers aged 34.24±12.50 years were enrolled. The repeatability values obtained for the CA-800 were 0.07 mm in all cases, and the ICC was 0.93 for the whole sample. The CA-800 provided significantly ( P <0.01) higher TMH values than the OCT for the whole sample (0.22±0.08 vs. 0.17±0.06 mm). A weak indirect correlation (ρ=-0.22) between the OCT TMH measurement and Contact Lens Discomfort Index scores was found ( P ≤0.04).

CONCLUSION

The CA-800 provides reliable TMH measurements during CL wear; however, they might not be interchangeable with OCT ones. Tear meniscus height measurements might be useful as a complementary sign to detect CL discomfort, but it cannot be used alone as a diagnostic tool.

Ocular surface parameters repeatability and agreement -A comparison between Keratograph 5M and IDRA

PURPOSE

To evaluate the repeatability and agreement in dry eye measurements using Oculus Keratograph 5M (K5M) and SBM Sistemi IDRA (IDRA).

METHODS

A total of 108 participants were enrolled and 108 eyes were evaluated. Tear meniscus height (TMH) and first and average non-invasive break-up time (NIBUT) were measured using the K5M and IDRA (order randomly assigned). TMH was measured using the built-in caliper tool while NIBUT was computed by the automatic algorithm of the instruments.

RESULTS

The Bland Altman plots analysis showed a good agreement between the two instruments for TMH (95 % Limits of Agreement (LoA), -0.17 to 0.16), but not the first NIBUT (95 % LoA, -8.13 to 14.79) and average NIBUT (95 % LoA, -7.89 to 10.32). The values of the first and average NIBUT measured using IDRA were significantly shorter than in K5M (difference = median (IQR) -2.75 (-6.48- -0.28)s, p < 0.001 and difference = median (IQR) -1.65 (-3.97-1.89)s, p = 0.008 respectively). The TMH (p = 0.037) and NIBUT average (p = 0.033) measured by K5M, as well as the TMH (p = 0.040) measured by IDRA, exhibited unstable measurements across the three measurement times. The remaining parameters exhibited stability with three repeated measurements.

CONCLUSION

The NIBUT measurements are not interchangeable between IDRA and K5M, while the TMH was little difference between the two instruments. It is important to exercise caution when using different ocular surface analyzers to minimize errors in comparing multiple measurements.

Association between dryness sensation and ocular surface temperature and conjunctival blood flow in soft contact lens wearers

PURPOSE

To investigate the association between dryness, ocular surface temperature (OST), and conjunctival blood flow (CBF) in soft contact lens (SCL) wearers after airflow stimulation.

METHODS

After recruiting 21 SCL wearers (mean age, 25.3 ± 4.2 years), subjects used two different daily disposable silicone hydrogel SCLs (narafilcon A and delefilcon A lenses). On three of four measurement days, excluding the first, OST, CBF, tear meniscus height (TMH), and non-invasive tear break-up time (NIBUT) were measured after airflow stimulation at a rate of 3 m/s for 10 min. The measurements were conducted without SCLs on the first and second days, and with different SCLs on the third and fourth days. Dryness was evaluated using the visual analogue scale (VAS). These parameters were compared between the two types of SCLs, and their association with the dryness sensation was then investigated.

RESULTS

Dryness was significantly weakly correlated with OST (r = -0.375, p < 0.05) and CBF (r = 0.339, p < 0.05). TMH, NIBUT, and VAS scores for dryness with the delefilcon A lens (0.15 ± 0.05 mm, 3.7 ± 01.7 s and 29.4 ± 16.9) were significantly higher, longer, and lower, respectively, than those with the narafilcon A lens (0.12 ± 0.05 mm, 2.3 ± 1.7 s and 35.9 ± 17.0; p < 0.05, p < 0.01 and p < 0.01). The changes in the OST and CBF between with and without the delefilcon A lens (-0.36 ± 0.35 °C and 0.99 ± 0.19) were significantly small compared to the narafilcon A lens (-0.60 ± 0.42 °C and 1.11 ± 0.21; p < 0.01 for both comparisons).

CONCLUSION

Dryness was correlated with OST and CBF, which indicates that when dryness was high, OST was low and CBF was high. These results suggest that OST and CBF assessments are effective for evaluating dryness sensation.

The Long-Term Effect on Dry Eye of Posterior Approach Ptosis Surgery Vs. Upper Eyelid Blepharoplasty

PURPOSE

To examine the long-term effect of combined blepharoplasty and Müller muscle-conjunctival resection (MMCR) compared to an upper blepharoplasty procedure on dry eye syndrome.

METHODS

This is a Prospective comparative case series. Two groups of patients participated in this study: the blepharoplasty group included adult patients that underwent blepharoplasty at least 3 years earlier and the ptosis group consisting of adult patients that underwent MMCR with blepharoplasty at least 3 years earlier. The parameters that were compared for all patients before the procedure, on postoperative day 90, and at the long-term follow-up were: Schirmer-test 2, tear break-up time (TBUT), fluorescein staining, and lissamine green (LG) staining.

RESULTS

The participants included 25 post-MMCR patients with a mean follow-up of 4.94 ± 0.64 years and 15 post-blepharoplasty patients with a mean follow-up of 4.22 ± 0.32 years. There was a significant increase in the postoperative LG and fluorescein staining scores compared to the preoperative scores in the ptosis group (p < .01 and p < .01, respectively) as well as a decrease in postoperative TBUT compared to the preoperative values (p = .044). Those parameters were not significant in the blepharoplasty group.

CONCLUSIONS

Patients who underwent MMCR, but not those following upper blepharoplasty, showed signs of dry eye compared to the preoperative status after long-term follow-up. Dry eye signs should be examined before MMCR surgery, and patients should be aware of the high risk of developing dry eye and the need for long-term treatment. Surgeons should carefully consider performing MMCR for patients with severe dry eye.

Improvement of objective ocular redness measured with Keratograph 5M in glaucoma patients after instilling brimonidine drops

OBJECTIVE

To compare objective ocular redness measured using OCULUS Keratograph 5 M before and after 0.2% brimonidine instillation in glaucoma patients under topical hypotensive treatment.

METHODS

60 eyes from 60 subjects diagnosed with glaucoma or ocular hypertension under hypotensive ocular topical treatment were analyzed. Basal Ophthalmological examination was performed.Outcome variables were OCULUS Keratograph 5 M redness scores (RS) before and after 0.2% brimonidine instillation; overall, bulbar temporal (BT), bulbar nasal (BN), limbar temporal (LT), and limbar nasal (LN); non-invasive average tear film breakup time (Nia-BUT), non-invasive first tear film breakup time (Nif-BUT) and meibography. In addition, the following clinical data were collected: intraocular pressure, type, duration, amount, and preservatives/or not of hypotensive treatment, fluorescein corneal staining score and lower tear meniscus height.

RESULTS

All eyes were under topical medication. All redness scores were reduced after brimonidine instillation, mean RS differences were BT 0.82 ± 0.62, BN hyperemia 1.03 ± 0.55, LN hyperemia 0.84 ± 0.49, LT hyperemia 0.71 ± 0.50 and total hyperemia 0.91 ± 0.52 (all p < 0.001). 30 min after brimonidine instillation mean overall RS reduction was 47.97 ± 12.39% (p < 0.001) and after 1 h there was a persistent reduction of overall RS of 45.92 ± 14.27% (p < 0.001). Hyperemia reduction was significant and comparable between preservative and preservative-free group 0.12 ± 0.14 (p > 0.392) and between patient with combination therapy and monotherapy 0.16 ± 0.14 (p > 0.258).

CONCLUSION

A significant reduction of conjunctival hyperemia was objectively found in glaucoma patients under topical hypotensive treatment before and after brimonidine instillation. Its fast and long-lasting effect may be useful preoperatively in glaucoma patients to reduce intraoperative bleeding and associated complications.

New advances in medical management of dry eye: optimizing treatment strategies for enhanced relief

PURPOSE

Dry eye disease (DED) is a prevalent ocular surface disease that is conventionally characterized by tear film hyperosmolarity and instability. This review presents a summarized classification of DED, followed by a comprehensive discussion of the most recent topical and systemic medications and clinical recommendations for selecting the most appropriate option for each patient.

METHODS

An extensive literature search was conducted on electronic databases, such as PubMed, Scopus, and Web of Science, using keywords including "dry eye syndrome," "ocular surface disease," "medical management," "artificial tears," "topical immunomodulators," and "meibomian gland dysfunction."

RESULTS

The underlying reasons for DED can range from insufficient aqueous tear production to increased tear evaporation. Recent literature has provided a more in-depth understanding of the pathophysiology of DED by examining the tear film's lipid, aqueous, and mucin layers. However, despite these advancements, medical management of patients with symptomatic DED has not fully reflected this modernized knowledge of its pathophysiology.

CONCLUSION

To develop a rationalized strategy for treating DED, it is crucial to have updated knowledge of therapeutic options, their mechanisms of actions, and indications based on the DED type and underlying causes.

Lower tear meniscus height measured by optical coherence tomography in children

INTRODUCTION

While optical coherence tomography (OCT) measurements of the lower tear meniscus height (LTMH) have been reported in adults, here we obtained LTMH measurements through Fourier Domain OCT in healthy children and compared these with values obtained in healthy adults.

METHODS

Participants were children 7-17 years of age and a control group of adults 20-40 years of age. Inclusion criteria were no abnormal eye conditions or the use of contact lenses. Candidates who fulfilled the TFOS DEWS II criteria for dry eye disease (DED) were excluded. All subjects underwent LTMH measurement (OCT Spectralis) and tests for non-invasive tear break-up time and ocular surface staining. Participants also completed the ocular surface disease index questionnaire.

RESULTS

A total of 86 children and 27 adults were included. Mean LTMH values in the children and adult groups were 217.40 ± 71.40 μm and 225.0 ± 54.86 μm, respectively; p = 0.53. However, 59.3% of the children had an LTMH ≤210 μm suggestive of DED, compared with only 33.3% of adults (p = 0.02). For the children, no significant differences in LTMH were observed with sex or for those more or less than 12 years of age.

CONCLUSIONS

Optical coherence tomography-derived LTMH measurements were obtained in healthy children. While values were similar in children and adults, a greater proportion of children had an LTMH compatible with a diagnosis of DED. More studies in different paediatric populations are required to establish a complete set of normative LTMH measurements.

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.

Repeatability, reproducibility and agreement between three different diagnostic imaging platforms for tear film evaluation of normal and dry eye disease

PURPOSE

To assess the repeatability and reliability of different commercially available diagnostic platforms in the objective assessment of tear film parameters and if there exists any agreement between them.

METHODS

Thirty healthy individuals (N = 60 eyes) and fifteen DED patients (N = 30 eyes) had their tear film parameters (Lipid layer thickness (LLT), Tear meniscus height (TMH), Non-invasive tear break up time (NIBUT)) assessed using three instruments - LipiView® II, IDRA ocular surface analyser (IDRA-OSA) and Oculus keratograph 5 M (K5M). Bland-Altman analysis and linear mixed effects modelling & Generalized Linear Hypothesis Test were used for analysis and coefficient of variation (CoV).

RESULTS

There is poor repeatability but good reproducibility of LLT values measured with Lipiview, or IDRA. NIBUT using K5M & IDRA-OSA shows good repeatability and reproducibility in control group but poor repeatability in DED patients. TMH values obtained with K5M or IDRA-OSA had poor repeatability with high CoV. Between two observers, good reproducibility is observed for TMH and NIBUT values using both K5M & IDRA-OSA but not for LLT values. Between instruments, all the measurements (LLT, NIBUT and TMH) were significantly different on Bland Altman analysis.

CONCLUSION

No two dry eye diagnostic platforms can be used interchangeably and non-invasive tear film values should be interpreted keeping in mind the individual machine's variability. The high coefficient of variation in DED patients compared to normal reflects inherent variability in tear film irrespective of the device used.

Development of a novel protocol to evaluate contact-lens related ocular surface health on marmosets (Callithrix jacchus)

Contact lens wear affects the ocular surface and can cause contact lens-induced dry eye (CLIDE). The purpose of this study was bifold: (1) to develop a novel protocol to assess the ocular surface in a non-human primate (NHP) model, the common marmoset (Callithrix jacchus), and (2) to characterize central corneal thickness (CCT), tear osmolarity, blink rate and tear meniscus height (TMH) longitudinally, in untreated marmosets (controls) compared to animals treated with contact lenses (CL). Longitudinal changes in CCT (N = 10 control; N = 10 treated with contact lenses, CL-treated), osmolarity (N = 4 control; N = 6 CL-treated), blink rate (N = 8 control; N = 10 CL-treated) and TMH (N = 8 control; N = 6 CL-treated) were assessed using high frequency A-scan ultrasound, the I-PEN Vet Tear Osmolarity System, a video recording system (745 frames/minute) and Image J respectively, from 70 days to 224 days (5 months) at approx. 9am, and again after 9hrs of CL wear (methafilcon A, 55% water content; Capricornia, Australia) after every 4 weeks of contact lens wear for a total of 22 weeks of treatment. Repeated measures ANOVA was used to compare eyes over time and student t-test was used to compare treated to control eyes at each time point. At baseline, untreated marmosets had a CCT (mean ± SD) of 0.31 ± 0.01 mm, tear osmolarity (mean ± SD) 311.67 ± 11.48 mOsms/L, blink rate (mean ± SD) 1.83 ± 1.79 blinks per minute (bpm) and TMH (mean ± SD) 0.07 ± 0.02 arbitrary units (au), all of which remained stable over 5 months, except blink rate that increased to 5.32 ± 1.58 bpm (p < 0.01) after 5 months. In CL-treated marmosets, however, CCT progressively increased with CL wear (baseline: 0.30 ± 0.01 mm; 5 months: 0.31 ± 0.02 mm, p < 0.05), while osmolarity decreased after 2 and 3 months of CL wear (baseline: 316.11 ± 13.63; 2 months: 302.63 ± 11.27, p < 0.05; 3 months: 302.92 ± 14.58, p < 0.05). The decrease in osmolarity occurred in parallel to an increase in blink rate (baseline: 0.98 ± 1.18 bpm; 2 months: 3.46 ± 3.04 bpm, p < 0.05; 3 months: 3.73 ± 1.50 bpm, p < 0.001). TMH decreased during the third month of CL wear (baseline: 0.06 ± 0.00 au; 3 months: 0.05 ± 0.01 au, p < 0.05), and increased after 4 months (0.08 ± 0.01 au, p < 0.05). As TMH decreased, tear osmolarity increased in both control (R = -0.66, p < 0.05) and CL-treated marmosets (R = -0.64, p < 0.05). The results suggest that marmosets treated with CL for 5 months experienced an increase in blink rate, CCT and TMH, along with a decrease in osmolarity within the first few months of CL treatment that differed from the unaffected stable ocular surface findings observed untreated animals. We hypothesize that CL wear in marmosets might induce mild corneal edema, an increased blink rate and TMH, in turn delaying the development of hyperosmolarity. These findings confirm that the marmoset is a good novel animal model for ocular surface research for the assessment of novel contact lens materials aimed to alleviate CLIDE.

Measurement method of tear meniscus height based on deep learning

Tear meniscus height (TMH) is an important reference parameter in the diagnosis of dry eye disease. However, most traditional methods of measuring TMH are manual or semi-automatic, which causes the measurement of TMH to be prone to the influence of subjective factors, time consuming, and laborious. To solve these problems, a segmentation algorithm based on deep learning and image processing was proposed to realize the automatic measurement of TMH. To accurately segment the tear meniscus region, the segmentation algorithm designed in this study is based on the DeepLabv3 architecture and combines the partial structure of the ResNet50, GoogleNet, and FCN networks for further improvements. A total of 305 ocular surface images were used in this study, which were divided into training and testing sets. The training set was used to train the network model, and the testing set was used to evaluate the model performance. In the experiment, for tear meniscus segmentation, the average intersection over union was 0.896, the dice coefficient was 0.884, and the sensitivity was 0.877. For the central ring of corneal projection ring segmentation, the average intersection over union was 0.932, the dice coefficient was 0.926, and the sensitivity was 0.947. According to the evaluation index comparison, the segmentation model used in this study was superior to the existing model. Finally, the measurement outcome of TMH of the testing set using the proposed method was compared with manual measurement results. All measurement results were directly compared via linear regression; the regression line was y0.98x-0.02, and the overall correlation coefficient was r ²0.94. Thus, the proposed method for measuring TMH in this paper is highly consistent with manual measurement and can realize the automatic measurement of TMH and assist clinicians in the diagnosis of dry eye disease.

Changes in Tear Meniscus Analysis of Children Who Have Type 1 Diabetes Mellitus, With and Without Vitamin D Deficiency

PURPOSE

The aim of this study was to quantitatively evaluate dry eye test parameters of pediatric patients with and without vitamin D deficiency (VDD) in type 1 diabetes mellitus.

METHODS

In this prospective cross-sectional study, the Ocular Surface Disease Index, Schirmer test, tear film breakup time, corneal staining score, and anterior segment optical coherence tomography were used to determine the dry eye test parameters of pediatric patients with type 1 diabetes mellitus (T1-DMPs) (group 1) and a healthy pediatric control group (group 2). Group 1 was divided into 2 subgroups based on their vitamin D status: group 1a, who had a VDD, and group 1b, who had vitamin D levels that were within the normal range.

RESULTS

This study compared 90 eyes of 90 pediatric T1-DMPs with 80 eyes of 80 healthy controls. The demographic characteristics of the groups were similar ( P > 0.05). The tear film breakup time, Schirmer test, corneal staining score, and values of the tear meniscus height and area were observed to have been lower in the patients in group 1a than the healthy pediatric control group, at P < 0.001. The same parameters were statistically significantly lower in the patients in group 1a when compared with group 1b ( P < 0.05 for both).

CONCLUSIONS

The tear measurements of the pediatric T1-DMPs were lower than those in the healthy pediatric control group. The accompanying VDD made this situation more pronounced.

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.

Agreement of Tear Break-up Time and Meniscus Height between Medmont E300 and Visionix VX120+

The goal of this study was to analyze the agreement between the Medmont E300 and the Visionix VX120+ systems in terms of non-invasive tear break-up time (NIBUT) and tear meniscus height (TMH) measurements. A total of 60 eyes (30 healthy subjects) were enrolled. NIBUT and TMH were evaluated with Medmont E300; first NIBUT, NIBUT50%, and TMH were evaluated with Visionix VX120+. Both evaluations were performed in a random order by the same clinician for right, left, and both eyes. The Medmont E300 provided significantly higher NIBUT than Visionix VX120+ for first NIBUT in right, left, and both eyes (p ≤ 0.003) and NIBUT50% in left and both eyes (p ≤ 0.042). The TMH measured with VX120+ was significantly higher than with Medmont E300 considering both eyes (p = 0.037). No significant correlations were found between both devices for either NIBUT (p ≥ 0.11) or TMH (p ≥ 0.09). Passing–Bablok regression analyses revealed poor agreement between devices for NIBUT and TMH outcomes. VX120+ is expected to provide substantial lower first NIBUT values than the NIBUT measured by Medmont E300. Clinicians should consider not using both instruments as interchangeable for dry eye diagnosis.

Changes in Tear Meniscus Analysis After Ptosis Procedure and Upper Blepharoplasty

INTRODUCTION

To quantitatively evaluate dry eye test and tear measurements following oculoplastic surgery.

METHODS

This comparative prospective clinical study comprised three groups of adult patients: the 1) blepharoplasty group: those with dermatochalasis; and 2) the blepharoplasty + Muller's muscle-conjunctival resection and 3) blepharoplasty + anterior levator resection groups: those with dermatochalasis and ptosis showing significant improvement after 10% phenylephrine administration. Ocular Surface Disease Index, tear film break-up time, corneal staining, and Schirmer test values were recorded. Tear meniscus area and height were measured using anterior segment-optical coherence tomography.

RESULTS

This study comprised 56 patients (18 males, 38 females). The blepharoplasty group included 40 eyes of 20 patients. The blepharoplasty + MMCR group included 21 eyes of 16 patients. The blepharoplasty + ALR group included 30 eyes of 20 patients. No significant differences resulted between the preoperative and postoperative dry eye test and tear measurements in the blepharoplasty group (P> 0.005/for all). Significant increases were seen in the corneal staining, TMH, TMA, and Schirmer test values were significantly decreased compared to those postoperatively in the blepharoplasty + MMCR group (P= 0.018, P< 0.001, P= 0.033 and P= 0.030, respectively). In the blepharoplasty + ALR group, the TMH and TMA were significantly decreased (P= 0.031, P= 0.036).

CONCLUSION

No changes resulted in dry eye tests following blepharoplasty in patients without dry eye symptoms. Changes were more pronounced following ptosis surgery, especially MMCR. Patients should be carefully examined for dry eye and treated during follow-up.

LEVEL OF EVIDENCE IV

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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.

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.

Thin-Flap Laser In Situ Keratomileusis-Associated Dry Eye: A Comparative Study Between Femtosecond Laser and Mechanical Microkeratome-Assisted Laser In Situ Keratomileusis

OBJECTIVE

To assess and compare postlaser in situ keratomileusis (LASIK) dry eye after LASIK with planned thin flaps created by a femtosecond laser (FS) and mechanical microkeratome (MK).

METHODS

Patients were stratified according to the flap creation technique into FS and MK groups with planned 100 μm flap thickness in all eyes. Dry eye parameters including tear film break-up time (TBUT), Schirmer I test, ocular surface disease index (OSDI), and lower tear meniscus height and area (tear meniscus height [TMH] and tear meniscus area [TMA]) were assessed before surgery and at 3 and 6 months after surgery.

RESULTS

The study included 102 eyes of 55 patients (52 eyes underwent FS-LASIK/50 eyes underwent MK-LASIK). The preoperative characteristics including age, gender, and spherical equivalents were similar in both groups (P>0.05). The difference in postoperative flap thickness was statistically significant (P<0.05). In each group, dry eye parameters showed a statistically significant worsening (P value<0.001) at 3 months with later significant improvement at 6 months but did not return to baseline. The mean TBUT, Schirmer I, and lower TMH and TMA were statistically higher, and the mean OSDI was statistically lower in FS-LASIK than the MK-LASIK group at both 3 and 6 months (P value<0.001). The depth of ablation had a statistically significant correlation with Schirmer I at 6 months and OSDI at both 3 and 6 months post-LASIK (P<0.05).

CONCLUSION

The use of femtosecond laser technology in performing thin-Flap LASIK eye surgeries has improved the outcome of post-LASIK dry eye when compared with the mechanical microkeratome.

Influence of Sodium Hyaluronate Concentration in Tear Meniscus Height: 10-min Dynamic Profile After Single Instillation

PURPOSE

To assess the height, area, and density of tear meniscus throughout 10 min after instillation of sodium hyaluronate (SH) of equal molecular weight at two different concentrations.

METHODS

Thirty-four eyes from 17 patients were enrolled in this longitudinal, nonrandomized, interventional and contralateral eye study. Tear meniscus height (TMH), corneal meniscus junction (CMJ), lower-lid meniscus junction (LLMJ), and tear meniscus area (TMA) images were obtained with the anterior segment module of the deep range imaging ocular coherence tomography ([DRI-OCT] Triton Swept-Source). Tear meniscus density (TMD) was calculated using the image processing and analysis software by Java (ImageJ program). Sodium hyaluronate artificial tears at 0.1% and 0.2% concentrations were instilled into all right and left eyes, respectively.

RESULTS

Patients' mean age was 61.05±11.43 years. Tear meniscus height, CMJ, LLMJ, and TMA measured at 1-, 5-, 7- and 10-min postinstillation of 0.1% SH proved significant differences among them (P<0.05). Sodium hyaluronate 0.2% instillation obtained similar findings, although no significant differences were found between 1- and 3-min postinstillation measurements (P>0.05). Fewer differences were found in TMD 0.2% SH group due to a lower baseline densitometry compared to the 0.1% group.

CONCLUSION

0.2% sodium hyaluronate achieved better TMH and TMA in 1 and 3 min after instillation than 0.1% concentration. However, there were no statistically significant differences between 0.1% and 0.2% sodium hyaluronate throughout a ten-minute longitudinal profile measurement using DRI-OCT.

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.

Prospective trial of a 2940 nm Er:YAG laser for the treatment of meibomian gland dysfunction

PURPOSE

The primary objective was to evaluate the efficacy and safety of Er:YAG laser treatment for meibomian gland dysfunction (MGD) in a prospective study.

METHODS

A total of 128 eyes from 64 patients with MGD were enrolled to receive either three Er:YAG laser treatments with meibomian gland expression (MGX) or MGX-alone treatment sessions at 3-week intervals. The Standard Patient Evaluation of Eye Dryness (SPEED) validated questionnaire; fluorescein breakup time of the tear film (FBUT); corneal fluorescein staining (CFS); lid margin abnormalities; meibomian gland morphology (meiboscore); lower tear meniscus height (TMH); and assessment of 15 meibomian glands in the lower eyelids, including total meibomian gland secretion quality (TMGS), the number of glands secreting any liquid (GSAL), and the number of glands yielding optimal clear liquid secretion (GYCL), were assessed at day (D)0, D21, D42, and D63 for the Er:YAG-MGX group and D0 and D63 for the MGX group.

RESULTS

At D63, significant decreases in SPEED scores and lid margin abnormalities as well as significant increases in FBUT, TMGS, and GSAL were observed in both groups (all p < 0.05). The Er:YAG-MGX group showed a significantly better improvement in SPEED scores, TMGS, and GYCL than the MGX group (all p < 0.05).

CONCLUSION

Although preliminary, the study results of Er:YAG laser treatment for dry eye syndrome caused by MGD are promising. Er:YAG laser treatment may be a new direction for managing MGD.

TRIAL REGISTRATION

The study was registered at www.chictr.org.cn : ChiCTR1900026004.

Repeatability of Non-invasive Keratograph Break-Up Time measurements obtained using Oculus Keratograph 5M

PURPOSE

The aim of this study is to assess the intraexaminer repeatability of Non-invasive Keratograph Break-Up Time (NIKBUT) obtained using the Oculus Keratograph 5M (K5M), given its relevance as a homeostasis marker in Dry Eye Disease (DED).

METHODS

In total, 80 healthy volunteers aged between 30 and 89 years participated. Measurements were classified according to age, sex and the presence or not of DED. Repeatability was evaluated by the calculation of within-subject standard deviation (S_w), coefficient of repeatability (CoR) and coefficient of variation (CoV). Moreover, the Passing-Bablok regression method was applied.

RESULTS

S_w, CoR and CoV coefficients showed low repeatability in all groups with values between 3.57 and 7.14; 9.90 and 19.79; and 51.90 and 65.49, for each coefficient, respectively. No statistically significant differences were found in the NIKBUT measurements between healthy and DED patients (p = 0.188). Groups with more DED risk had better repeatability. Passing-Bablok regression also confirmed a lack of agreement between the maximum and minimum NIKBUT measurement.

CONCLUSION

NIKBUT measurement has low intraexaminer repeatability even when considering sex, age and DED diagnosis. Nevertheless, not only is this low repeatability due to the device, but also it is largely due to the intrinsic variability of the tear film.

A Review of Imaging Biomarkers of the Ocular Surface

A biomarker is a "characteristic that is measured as an indicator of normal biological processes, pathogenic processes, or responses to an exposure or intervention, including therapeutic interventions." Recently, calls for biomarkers for ocular surface diseases have increased, and advancements in imaging technologies have aided in allowing imaging biomarkers to serve as a potential solution for this need. This review focuses on the state of imaging biomarkers for ocular surface diseases, specifically non-invasive tear break-up time (NIBUT), tear meniscus measurement and corneal epithelial thickness with anterior segment optical coherence tomography (OCT), meibomian gland morphology with infrared meibography and in vivo confocal microscopy (IVCM), ocular redness with grading scales, and cellular corneal immune cells and nerve assessment by IVCM. Extensive literature review was performed for analytical and clinical validation that currently exists for potential imaging biomarkers. Our summary suggests that the reported analytical and clinical validation state for potential imaging biomarkers is broad, with some having good to excellent intra- and intergrader agreement to date. Examples of these include NIBUT for dry eye disease, ocular redness grading scales, and detection of corneal immune cells by IVCM for grading and monitoring inflammation. Further examples are nerve assessment by IVCM for monitoring severity of diabetes mellitus and neurotrophic keratitis, and corneal epithelial thickness assessment with anterior segment OCT for the diagnosis of early keratoconus. However, additional analytical validation for these biomarkers is required before clinical application as a biomarker.

Comparison of Hasner valvulotomy outcomes in pediatric and adult patients: does age matter?

BACKGROUND

Hasner valve incision has been recently introduced as a new treatment for ophthalmic patients with epiphora symptoms. The aim of this study was to examine whether surgical outcomes of Hasner valve incision for inferior nasolacrimal duct obstruction were different between pediatric and adult patients.

METHODS

A total of 53 eyes of 52 patients who underwent Hasner valve incision in the Beijing Tongren Hospital from October 2016 to November 2019 were retrospectively observed. Patients were divided into two groups, including pediatric group (23 eyes of 22 patients, <18 years old) and adult group (30 eyes of 30 patients, ≥18 years old). Success rate of surgery was determined by both subjective measure (complete resolution of epiphora) and objective measure (lacrimal passage irrigation and tear meniscus height). Fisher exact test was conducted.

RESULTS

By conducting Fisher exact test and comparing complete resolution of epiphora (P = 0.627), lacrimal passage irrigation (P = 0.663), measurement of Tear Meniscus Height (P = 0.561), and appearance of complication (P = 0.339), there was no statistically significant difference of surgical outcomes between pediatric and adult patients (P > 0.05).

CONCLUSION

Hasner valve incision was effective for both adult and children with inferior nasolacrimal duct obstruction, with no difference in surgical outcomes between the two groups.

Repeatability of non-invasive break-up time measures with a new automated dry eye platform in healthy eyes

PURPOSE

To evaluate the intrasession repeatability for non-invasive break-up time (NIBUT) and tear meniscus height (TMH) measurements provided by a new multi-diagnostic platform, and to assess the interobserver reproducibility of TMH measures.

METHODS

Twenty-one healthy eyes of 21 patients (age, 23-65 years) were enrolled. A complete eye examination was performed in all cases with the VX120+ device (Visionix-Luneau Technologies), including an analysis with the new Dry Eye module, performing three consecutive measurements. The within-subject standard deviation (S_w) and Bland-Altman plots were used to assess intersession repeatability. Differences between examiners for TMH were also analysed.

RESULTS

No statistically significant differences were found between repeated measures of NIBUT (time associated with the first break) and TMH (p > 0.05). However, significant differences were found for NIBUT50% (time associated with half of breaks of the tear film) (p < 0.05). Mean S_w was 0.9 s, 1.4 s and 0.05 mm for NIBUT, NIBUT50% and TMH, respectively. Ranges of agreement between consecutive measures were below 3.5 s and 4.5 s for NIBUT and NIBUT50%, respectively, and below 0.16 mm for TMH. Furthermore, no significant differences were found between examiners in TMH measure, with an inter-examiner range of agreement of 0.12 mm.

CONCLUSIONS

The new dry eye platform of the VX120+ platform evaluated provides objective automated measures of NIBUT and TMH, with acceptable level of intrasession repeatability for clinical screening purposes.

New Technologies in Clinical Trials in Corneal Diseases and Limbal Stem Cell Deficiency: Review from the European Vision Institute Special Interest Focus Group Meeting

To discuss and evaluate new technologies for a better diagnosis of corneal diseases and limbal stem cell deficiency, the outcomes of a consensus process within the European Vision Institute (and of a workshop at the University of Cologne) are outlined. Various technologies are presented and analyzed for their potential clinical use also in defining new end points in clinical trials. The disease areas which are discussed comprise dry eye and ocular surface inflammation, imaging, and corneal neovascularization and corneal grafting/stem cell and cell transplantation. The unmet needs in the abovementioned disease areas are discussed, and realistically achievable new technologies for better diagnosis and use in clinical trials are outlined. To sum up, it can be said that there are several new technologies that can improve current diagnostics in the field of ophthalmology in the near future and will have impact on clinical trial end point design.

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.

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.

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 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.

Intraocular light scatter in patients on topical intraocular pressure-lowering medication

PURPOSE:

To quantify ocular light scattering in patients under treatment with intraocular pressure-lowering eye-drops.

METHODS:

In this prospective, observational, cross-sectional case series study, 160 eyes of 160 patients with primary open angle glaucoma or primary ocular hypertension were consecutively recruited from our Glaucoma Department over 7 months. In total, 46 eyes of 46 healthy volunteers matched for age and sex served as the control group. The variables recorded in a single visit were as follows: drug and number of drops per day, treatment duration, OXFORD corneal staining grade, lower tear meniscus height as measured by spectral domain optical coherence tomography, ocular redness and non-invasive tear breakup time measured with the Oculus Keratograph 5M, ocular surface disease index questionnaire score and objective scatter index through a double-pass technique (Optical Analysis System II).

RESULTS:

Objective scatter index was higher in the patient group (3.1, interquartile range = 1.8-5.47) than in the control group (1.95; interquartile range = 0.7-5; p = 0.017). In a multiple linear regression model, non-invasive tear breakup time was identified as the most influential variable on light scatter (mean ratio = -1.015; p = 0.003; 95% confidence interval = -1.025 to -1.005). No correlation with objective scatter index was observed for number of daily eye-drops, preservative concentration or treatment duration.

CONCLUSION:

Participants on anti-glaucoma medication showed a significantly higher objective scatter index than control group individuals. In the treated patient group, a lower non-invasive tear breakup time was associated with a higher objective scatter index. This suggests that lubricating eye-drops to improve tear breakup time could also improve vision quality in these patients by diminishing light scattering.

Assessments of tear meniscus height, tear film thickness, and corneal epithelial thickness after deep anterior lamellar keratoplasty

OBJECTIVE

To assess the lower tear meniscus height (LTMH), central tear film thickness (CTFT), and central corneal epithelial thickness (CCET) after deep anterior lamellar keratoplasty (DALK).

METHODS

This was a retrospective cross-sectional study of 20 patients who had DALK in one eye over a three-month period. LTMH, CTFT, and CCET of the operated eyes and the unoperated fellow eyes were measured using high-definition optical coherence tomography (HD-OCT). Correlations between three OCT assessments and age, time following surgery, graft size, bed size, and the number of residual sutures were analyzed.

RESULTS

Compared to patients with keratoconus, patients with other corneal conditions had significantly higher CCET in the fellow eye (P=0.024). For all patients, CCET in the operated eye was significantly negatively correlated with the number of residual sutures (R=-0.579, P=0.008), and was significantly positively correlated with time following surgery (R=0.636, P=0.003). In the fellow eye, a significant positive correlation was found between age and CCET (R=0.551, P=0.012), and a significant negative correlation between age and CTFT (R=-0.491, P=0.028). LTMH was found to be significantly correlated between operated and fellow eyes (R=0.554, P=0.011). There was no significant correlation between LTMH and age, bed/graft size, time following surgery, or residual sutures (all possible correlations, P>0.05).

CONCLUSIONS

Patients with keratoconus tend to have a thinner central corneal epithelium. Corneal epithelium keeps regenerating over time after DALK. DALK did not induce a significant change in tear volume compared with the fellow eye. Postoperative tear function might depend on an individual's general condition, rather than on age, gender, bed/graft size, time following surgery, or residual sutures.

Ocular Surface Disease in Patients under Topical Treatment for Glaucoma

Purpose

To examine the relationship between ocular surface disease (OSD) and topical antiglaucoma therapy.

Methods

A total of 211 eyes of 211 patients with open-angle glaucoma or ocular hypertension on topical medication were recruited over 10 months. Controls were 51 eyes of 51 healthy age- and sex-matched volunteers. In each patient, we recorded the intraocular pressure-lowering eyedrops used, the number of medications used, and daily and cumulative preservative concentrations (PC). Main outcome measures were fluorescein corneal staining score (Oxford scale), lower tear meniscus height (LTMH) (spectral-domain optical coherence tomography), noninvasive tear film breakup time (NI-TBUT) (Oculus Keratograph 5M), and OSD symptom questionnaire index (OSDI).

Results

Compared to controls, significantly higher OSDI (median [interquartile range] 10.24 [4.54-18.94] vs 2.5 [0-12.5]; p<0.001) and corneal staining (≥1: 64.93% vs 32.61%; p<0.001) scores were recorded in the medication group. The NI-TBUT and LTMH failed to vary between the groups (p>0.05). A higher daily PC was associated with a lower LTMH (R −0.142; p = 0.043). In the medication group, multivariate analysis identified correlations between benzalkonium chloride (BAK) (odds ratio [OR] 1.56) and BAK plus polyquaternium-containing drops (OR 5.09) or higher OSDI (OR 1.06) and abnormal corneal staining test results and between older age (mean ratio [MR] 1.05), longer treatment duration (MR 1.02), or corneal staining presence (MR 1.22) and a higher OSDI score.

Conclusions

Ocular surface disease was more prevalent in the medication group. The main factors impacting OSD were drops with preservatives, longer treatment duration, and older age.

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

PURPOSE

We aimed to compare the tear meniscus measurements using strip meniscometry (SM) and Keratograph5M (K5M) between 3 subtypes of dry eye disease patient groups, classified according to the presence of meibomian gland dysfunction (MGD), and normal subjects.

METHODS

We enrolled 145 eyes from 145 subjects and measured the tear meniscus using SM and K5M, tear film breakup time, ocular surface staining, and ocular surface disease index; the Schirmer test; and examined lid margins and meibomian glands. Correlation of tear meniscus parameters with other parameters and efficacy of the 2 measurements were evaluated.

RESULTS

The SM and K5M results were significantly lower in the non-Sjögren syndrome aqueous-deficient dry eye (non-SS ADDE) with and without MGD groups than in the MGD-only group and normal subjects. The SM or K5M results correlated with each other and with other ocular surface parameters. The area under the curve (AUC) of the SM and K5M results was 0.637 (P = 0.012) and 0.610 (P = 0.042), respectively. Except for the MGD group, the AUC of the SM and K5M results were 0.721 (P < 0.001) and 0.694 (P = 0.001), respectively. The AUC of SM and K5M were 0.947 (P < 0.001) and 0.784 (P = 0.002), differentiating non-SS ADDE-only patients from those with normal eyes.

CONCLUSIONS

Tear meniscus measurements using SM and K5M can compensate for detection of aqueous-deficient components of dry eye. These results should be interpreted according to the presence or absence of MGD.

Automated Measurement of Tear Film Dynamics and Lipid Layer Thickness for Assessment of Non-Sjögren Dry Eye Syndrome With Meibomian Gland Dysfunction

PURPOSE

To investigate automated values from an advanced corneal topographer with a built-in real keratometer, color camera, and ocular surface interferometer for the evaluation of non-Sjögren dry eye syndrome (NSDES) with meibomian gland dysfunction (MGD).

METHODS

Sixty-four patients (64 eyes) diagnosed with NSDES with MGD were enrolled. All eyes were evaluated using the Ocular Surface Disease Index (OSDI), fluorescence staining score, tear film breakup time (TBUT), Schirmer test, and MGD grade. Noninvasive Keratograph average tear film breakup time (NIKBUTav), tear meniscus height (TMHk), meibomian gland (MG) dropout grade, and lipid layer thickness (LLT) using interferometry were measured.

RESULTS

Among automated indexes, NIKBUTav (mean 7.68 ± 4.07 s) and the MG dropout grade (mean 1.0 ± 0.5) significantly correlated with the OSDI (mean 40.6 ± 22.9) (r = -0.337, P = 0.006; and r = 0.201, P = 0.023, respectively), as did all conventional indicators, except the Schirmer score (mean 9.1 ± 5.9 mm). TMHk (mean 0.21 ± 0.18 mm) had significant correlation with the Schirmer score, the staining score (mean 1.2 ± 0.7), TBUT (mean 3.8 ± 1.8 s), and NIKBUTav (r = 0.298, P = 0.007; r = -0.268, P = 0.016; r = 0.459, P < 0.001; and r = 0.439, P < 0.001, respectively), but not any MGD indicator, even the MG dropout grade. NIKBUTav showed significant correlations with all clinical parameters and other automated values, except the Schirmer score and LLT (mean 83.94 ± 20.82 nm) (all (Equation is included in full-text article.)≥ 0.25 and P < 0.01). The MG dropout grade highly correlated with all indexes except TMHk (all (Equation is included in full-text article.)≥ 0.25 and P < 0.05). LLT was significantly associated with TBUT, MGD grade (mean 2.0 ± 0.7), and MG dropout grade (r = 0.219, P = 0.047; r = -0.221, P = 0.039; and r = 0.433, P < 0.001, respectively), although it was not related to patient symptoms.

CONCLUSIONS

Automated noninvasive measurements using an advanced corneal topographer and LLT measured with an ocular surface interferometer can be alternatives to conventional methods to evaluate tear conditions on the ocular surface; the former device can provide information about conformational MG changes in NSDES with MGD.

Lower Tear Meniscus Measurements Using a New Anterior Segment Swept-Source Optical Coherence Tomography and Agreement With Fourier-Domain Optical Coherence Tomography

PURPOSE

To assess intraobserver repeatability and interobserver and intersession reproducibility of lower tear meniscus height (LTMH) measurements obtained using a new anterior segment swept-source optical coherence tomography (SS-OCT) device. Agreement with Fourier-domain (FD) OCT (Spectralis) was also examined.

METHODS

In an observational cross-sectional study, one eye of 29 healthy subjects was randomly imaged with both devices at our center. Two examiners then randomly measured the LTMH using the software's calipers. To assess intraobserver repeatability and interobserver and intersession reproducibility, within-subject standard deviation (Sw), test-retest repeatability, coefficients of variation (CoV), and intraclass correlation coefficients (ICCs) were calculated. Agreement between both devices was also determined in Bland-Altman plots.

RESULTS

Mean LTMHs for SS-OCT and FD-OCT were 276.6 ± 87.6 and 280.3 ± 80 μm, respectively. Using the SS-OCT device, intraobserver CoV, interobserver CoV, and intersession CoV were found to be ≥16.9%, ≤7.2%, and ≤11.5%, respectively. ICCs for these parameters were ≤88%, ≥97%, and ≥94%, respectively. Bland-Altman analysis indicated poor agreement between SS-OCT and FD-OCT, and the correlation was low (CoV 34.5%, ICC 0.36).

CONCLUSIONS

SS-OCT LTMH measurements showed excellent interobserver and intersession repeatability along with good intraobserver reproducibility. Agreement between the devices was poor.

Hydroxypropyl methylcellulose 2% for dry eye prevention during phacoemulsification in senile and diabetic patients

PURPOSE

To assess the effect of hydroxypropyl methylcellulose (HPMC) 2% to prevent dry eye during phacoemulsification in senile and diabetic patients.

METHODS

This prospective interventional case series comprised 60 eyes (44 patients) with age-related cataract scheduled for standardized phacoemulsification surgery. The patients were assigned to receive either balanced saline solution (BSS, 30 eyes) or HPMC 2% (30 eyes) during surgery. Preoperative and postoperative examinations (1, 3, 7 and 30 days) included measurements of automatic noninvasive tear film breakup time (NITBUT), fluorescein staining, Schirmer I test, tear meniscus height, depth and area and subjective symptoms. Intraoperative application frequency was also assessed.

RESULTS

The mean age of patients was 68.7 ± 2.3 years. The application frequency of BSS during surgery was significantly reduced in HPMC group (P = 0.001). The incidence of dry eye syndrome (DES) was significantly reduced in HPMC group in both senile and diabetic patients. Scores of subjective symptoms were significantly higher in the BSS group in 1 day (P = 0.003) and 3 days (P = 0.043) postoperatively. The first and average NITBUT were significantly higher in HPMC group in 1 day and 3 days after surgery, respectively (P = 0.012 and P = 0.024, respectively). NITBUT values did not significantly change postoperatively in the HPMC group (P > 0.05), while they were significantly lower postoperatively in the BSS group.

CONCLUSIONS

Application of HPMC 2% during phacoemulsification reduced the incidence of DES and improved patients' satisfaction in both senile and diabetic cataract patients. It was also effective in maintaining corneal hydration and was able to significantly reduce the application frequency intraoperatively.

Assessment of meibomian glands and tear film in post-refractive surgery patients

IMPORTANCE

Corneal refractive surgery may impact meibomian gland and tear film in post-refractive surgery patients.

BACKGROUND

To compare ocular surface parameters between post-refractive surgery patients and normal controls.

DESIGN

Cross-sectional single centre study.

PARTICIPANTS

A total of 120 eyes of 120 subjects were divided into three groups: (i) 60 controls and 60 patients underwent corneal refractive surgery at least 12 months ago; (ii) 30 post-laser in-situ keratomileusis (LASIK) patients and (iii) 30 post-laser epithelial keratomileusis (LASEK)/photo-refractive keratectomy (PRK) patients.

METHODS

Tear meniscus height, non-invasive keratographic tear film break-up time and meibography were measured using the Keratograph^® 5M. Fluorescein break-up time, ocular surface staining, examination of lid margins and meibomian glands, Schirmer's test and Ocular Surface Disease Index questionnaire were performed.

MAIN OUTCOME MEASURES

Ordinary logistic regression was performed to evaluate the impact of clinical variables including refractive surgery on the meiboscores.

RESULTS

In post-LASIK patients, ocular surface parameters including Ocular Surface Disease Index scores, fluorescein break-up time and staining scores, except Schirmer's scores, were significantly worse than those in controls (P < 0.050). Ocular surface staining scores in post-LASEK/PRK patients was higher than that in the controls (P = 0.001). In post-refractive surgery patients, grade of meibomian gland parameters and meiboscores were worse than those of controls (all P < 0.050). Histories of refractive surgery were associated with high meiboscore (β = 1.100, P = 0.043 for LASIK and β = 1.039, P = 0.042 for LASEK/PRK).

CONCLUSIONS AND RELEVANCE

Corneal refractive surgery may adversely affect the ocular surface, and a reduction of functional meibomian glands can contribute to chronic tear film dysfunction after corneal refractive surgery.