Application of visante optical coherence tomography tear meniscus height measurement in the diagnosis of dry eye disease

Diagnostic utility of tear meniscus height measurement using anterior segment optical coherence tomography for lacrimal passage disorder before cataract surgery

To evaluate diagnostic utility of tear meniscus height (TMH) measurement using anterior segment optical coherence tomography (AS-OCT) for lacrimal passage disorder (LPD) in patients scheduled for cataract surgery. Patients with cataracts were enrolled. Lacrimal irrigation test was used to diagnose LPD. TMH measurement was performed using prior to cataract surgery. A receiver operating characteristic curve analysis was performed to calculate the cutoff value of TMH to detect LPD. Correlation between TMH and age, sex, LPD, use of glaucoma eyedrops, and use of dry eye drops in patients with and without LPD was evaluated. Sixty-six patients (127 eyes) were included, of which 12 (9.4%) eyes had LPD. The mean TMH was significantly higher in the LPD group than in the non-LPD group (P = 0.007). Multiple regression analysis revealed a significant association of TMH with LPD (P = 0.000). With an area under the curve of 0.740, the optimal cut-off TMH value was 401.0 μm. The sensitivity and specificity of this cutoff value were 58.3% and 83.0%, respectively. These findings demonstrate the diagnostic utility of TMH, measured using AS-OCT, for LPD. This suggests that AS-OCT is useful for preoperative exclusion of LPD.

Does the palpebral morphology influence the tear meniscus height between Caucasian and Asian eyes?

PURPOSE

The central lower TMH is used as a clinical measure of tear volume in the assessment of contact lens candidates and patients with dry eyes. Ethnic differences in eyelid morphology may influence the measurement of the TMH. Furthermore, with the advent of larger contact lenses, such as scleral lenses, it would be of clinical value to assess the TMH centrally and peripherally. The purpose of this study was to evaluate and compare the TMH at different positions along the palpebral margin between Caucasian and Asian eyes.

METHODS

This prospective study evaluated the lower TMH in five positions (central, temporal and nasal limbus and temporal and nasal periphery) of the right eye using the Keratograph 5M (Oculus) instrument in Caucasian and Asian participants between 10 am and 12 pm . The TMH at each position was taken three times and averaged and analyzed using a 5 × 2 repeated-measures analysis of variance.

RESULTS

Central TMH did not differ significantly ( F = 0.02, p=0.88) in Caucasians (n = 20, aged 24.45 [2.30] years, TMH 0.320 [0.052] mm) and Asians (n = 20, aged 22.25 [3.43] years, TMH 0.325 [0.048] mm). A difference was noted with respect to TMH positions along the lid margin ( F = 64.17, p<0.001), independent of ethnicity ( F = 2.15, p=0.15). A post hoc analysis revealed a significantly higher TMH temporally when compared with centrally or nasally (p<0.001).

CONCLUSIONS

This study demonstrated the similarity of the central TMH and the differences in the peripheral TMH within Caucasian and Asian eyes. This may be clinically relevant when using the Tear Film & Ocular Surface Society Dry Eye Workshop II diagnostic algorithm for dry eyes and when fitting scleral contact lenses. Future studies need to consider that ethnic differences may exist for certain tests in order to personalize the care and management of each patient.

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.

Immediate and Delayed Effects of Punctal Plug Insertion on Tear Meniscus Height in Severe Aqueous-Deficient Dry Eye

PURPOSE

The aim of this study was to assess the immediate and delayed effects of tear punctal occlusion with punctal plugs on tear meniscus height (TMH) in severe aqueous-deficient dry eye (ADDE) disease.

METHODS

Consecutive patients with severe ADDE related to Sjögren syndrome or ocular graft-versus-host disease underwent inferior and superior occlusion with punctal plugs. TMH was measured using the LacryDiag ocular surface analyzer platform before, 10 minutes, and at least 1 month after punctal occlusion. The corneal fluorescein staining (CFS) score was graded with the Oxford scale (from 0 to 5). Ocular symptoms were graded with a visual analog scale (from 1 to 10).

RESULTS

We included 24 eyes of 24 patients (mean age 61 ± 9 years; mean follow-up 7 ± 5 months). The mean TMH was 0.19 ± 0.06 mm at baseline and increased significantly to 0.41 ± 0.13 mm ( P < 0.001) and 0.46 ± 0.17 mm ( P < 0.001) at 10 minutes after punctal plug insertion and at the end of follow-up, respectively. The median CFS score decreased from 3 ± 1 before plug insertion to 1 ± 2 at the end of follow-up ( P < 0.001). Many patients (67%; n = 16) reported subjective improvement of symptoms. TMH was negatively correlated with the CFS score and visual analog scale score assessing symptoms.

CONCLUSIONS

Upper and lower punctal occlusion increased TMH in patients with severe ADDE as soon as 10 minutes after plug insertion. TMH remained stable over time, which led to the relief of symptoms and reduced corneal staining.

Tear Fluid Progranulin as a Noninvasive Biomarker for the Monitoring of Corneal Innervation Changes in Patients With Type 2 Diabetes Mellitus

Purpose

This study aimed to investigate the expression levels of progranulin (PGRN) in the tears of patients with diabetic retinopathy (DR) versus healthy controls. Additionally, we sought to explore the correlation between PGRN levels and the severity of ocular surface complications in patients with diabetes.

Methods

In this prospective, single-visit, cross-sectional study, patients with DR (n = 48) and age-matched healthy controls (n = 22) were included and underwent dry eye examinations. Tear fluid was collected, and its components were analyzed using the Luminex assay. The subbasal nerve plexus of all participants was evaluated by in vivo confocal microscopy.

Results

Patients with DR exhibited more severe dry eye symptoms, along with a reduction in nerve fiber density, length, and branch density within the subbasal nerve plexus, accompanied by an increase in the number of dendritic cells. Tear PGRN levels were also significantly lower in patients with diabetes than in normal controls, and the levels of some inflammatory factors (TNF-α, IL-6, and MMP-9) were higher in patients with DR. Remarkably, the PGRN level significantly correlated with nerve fiber density (R = 0.48, P < 0.001), nerve fiber length (R = 0.65, P < 0.001), and nerve branch density (R = 0.69, P < 0.001).

Conclusions

Tear PGRN levels might reflect morphological changes in the corneal nerve plexus under diabetic conditions, suggesting that PGRN itself is a reliable indicator for predicting the advancement of neurotrophic keratopathy in patients with diabetes.

Translational Relevance

PGRN insufficiency on the ocular surface under diabetic conditions was found to be closely associated with nerve impairment, providing a novel perspective to discover the pathogenesis of diabetic complications, which could help in developing innovative therapeutic strategies.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Dry Eye Disease: An Update on Changing Perspectives on Causes, Diagnosis, and Management

Dry eye disease is a common clinical problem encountered by ophthalmologists worldwide. Interest in this entity has increased in recent years due to the consequences it has on the ocular surface after any surface procedure. With changing times, several new factors have come to light that can influence this disease. The effect of the COVID-19 pandemic has also been greatly felt, with a range of causes, starting from increased screen work to inflammatory processes, exacerbating the condition in many. With changes in the concepts of the etiopathogenesis of the disease, a paradigm shift has taken place in the approaches to treatment. More researchers are in favor of a new tear film-oriented approach that tries to localize the disease to a single component in the tear film. Innovation of newer techniques for the treatment of meibomian gland disease has also made its foray into clinical ophthalmology. Newer drug formulations and molecules are underway to better treat the inflammatory component of the disease. Many other receptors and targets for the treatment of dry eyes are being researched. This review hopes to provide a succinct, narrative summary of the relevant research on dry eye disease to date to increase awareness about the nature and future course of this disease and its management.

Comparative study of surgical outcomes regarding tear meniscus area and high-order aberrations between two different interventional methods for primary acquired nasolacrimal duct obstruction

PURPOSE

To compare endonasal dacryocystorhinostomy (EN-DCR) with sheath-guided dacryoendoscopic probing and bicanalicular intubation (SG-BCI) by evaluating tear meniscus area (TMA) and total high-order aberrations (HOAs) for primary acquired nasolacrimal duct obstruction (PANDO).

METHOD

We retrospectively reviewed 56 eyes of 42 patients (7 men, 35 women; age, 72.7±13.1 years) who underwent EN-DCR or SG-BCI for PANDO in Toyama University Hospital from February 2020 to June 2022. In the EN-DCR and SG-BCI groups, we measured the patency of the lacrimal passage, preoperative and postoperative TMA, and HOAs of the central 4 mm of the cornea using optical coherence tomography (AS-OCT), six months postoperatively.

RESULTS

There was a positive correlation between preoperative TMA and preoperative HOAs in all cases. Postoperative patency of lacrimal passage was 100% in the EN-DCR and 80.8% in the SG-BCI group. There was a significant difference in the number of passages between the two groups (p = 0.01). Preoperative TMA and HOAs showed a significant postoperative decrease in both groups (EN-DCR group: p<0.01, p<0.01, SG-BCI group: p<0.01, p=0.03, respectively). We then calculated the rate of change of preoperative and postoperative TMA and HOAs and compared them between the two groups. The rate of change was significantly higher in the EN-DCR group than that in the SG-BCI group (TMA, p=0.03; HOAs, p=0.02).

CONCLUSION

Although both EN-DCR and SG-BCI are effective for PANDO, our results suggest that EN-DCR is more effective in improving TMA and HOAs.

Evaluation of the relationship between tear meniscus changes and quality of life outcomes after external dacryocystorhinostomy

PURPOSE

This study aims to investigate the effects of external dacryocystorhinostomy (DCR) surgery on tear meniscus parameters and assess its relationship with improvements in quality of life (QoL) in patients with nasolacrimal duct obstruction (NLDO).

METHODS

This prospective study included 30 patients diagnosed with NLDO who underwent external DCR surgery. Tear meniscus (TM) parameters, including height, depth and area, were measured using anterior segment optical coherence tomography. Lacrimal symptom questionnaire (LacQ), Munk scores and Glasgow benefit inventories (GBI) were collected. Statistical analysis was performed to evaluate the correlation between tear meniscus changes and improvements in QoL.

RESULTS

TM height, depth and area decreased from preoperative median measurements (0.09 mm2, 0.37 mm, 0.56 mm) to postoperative median measurements (0.03 mm2, 0.21 mm, 0.30 mm) (p < 0.001). Lacrimal symptom scores and Munk scores showed a significant improvement at 3-month postoperatively (p < 0.001). The GBI scores also demonstrated a significant improvement, indicating a positive impact on the patients' QoL. (p < 0.001). A statistically significant correlation was found between the change in TM parameters and LacQ lacrimal symptom scores.

CONCLUSION

External DCR surgery leads to significant improvements in tear meniscus parameters and quality of life outcomes in patients with NLDO. The decreased in TM height and TM area indicates improved tear film dynamics and decreased tear volume, which positively impact the patients' ocular comfort and overall well-being. This study highlights the importance of tear meniscus evaluation as a potential market for assessing the success of DCR surgery and its impact on patients' QoL.

Surgical outcomes of endoscopic dacryocystorhinostomy for eyes with nasolacrimal duct obstruction via tear meniscus height evaluation

PURPOSE

To evaluate the association of tear meniscus height (TMH) with clinical outcomes of patients who underwent endonasal dacryocystorhinostomy.

METHODS

We recruited 304 patients from two institutes. The TMH was measured using anterior segment optical coherence tomography before surgery. All patients underwent endoscopic DCR with lacrimal intubation stent insertion. The lacrimal stent was removed 2 months after surgery. The TMH was measured at 2 months and 12 months after surgery. Improvements in epiphora were assessed using a visual analogue scale (range, 0-2). Recurrence was determined based on lacrimal irrigation and endoscopic evaluation results.

RESULTS

All patients experienced improvements in subjective symptoms 2 months after surgery. The mean TMH also decreased significantly compared with that before surgery. During the follow-up period, four patients experienced recurrence. The mean TMH 12 months after surgery was significantly lower than that before surgery. The rate of change in the TMH was significantly associated with the use of a dacryoendoscope during sheath-guided lacrimal stent intubation at all time points. Of the 251 patients who were followed up at 12 months after surgery, three reported recurrences, and 17 reported mild improvement of epiphora. The rate of change in the TMH was significantly associated with epiphora improvement. Height was also associated with epiphora improvement.

CONCLUSIONS

Endoscopic DCR is an acceptable surgical procedure for managing nasolacrimal duct obstruction. Sheath-guided lacrimal stent intubation using a dacryoendoscope resulted in a greater reduction in postoperative TMH compared to the blind insertion technique, which may lead to favorable clinical outcomes.

Assessment of Tear Meniscus Dimensions Using Anterior Segment Optical Coherence Tomography in Vitamin D Deficiency in a Pediatric Population

BACKGROUND

To investigate of the effect of vitamin D (Vit-D) deficiency on the tear film in children and compare it with that of healthy subjects.

METHODS

This prospective and cross-sectional study comprised 75 eyes of children who had Vit-D deficiency (Group 1) and 85 eyes of age- and gender-matched healthy children (Group 2). The tear-film break-up time (TF-BUT) and Schirmer test values, as well as the Ocular Surface Disease Index (OSDI) scores, were recorded for the participants in all groups. Measurement of the tear meniscus area (TMA) and tear meniscus height (TMH) was performed 2 times in the same day via the use of anterior segment-optical coherence tomography (AS-OCT).

RESULTS

The mean age of the participants in Group 1 was 12.42 ± 3.40 years, while in Group 2, it was 12.59 ± 2.32 years (p = 0.758). Group 1 comprised 43 females and 32 males, while Group 2 comprised 44 females and 41 males (p = 0.250). The mean TMH, TMA, and Schirmer test values were found to be significantly lower in children with Vit-D deficiency (Group 1) than in healthy children (Group 2), with p < 0.05 for all the values. It was concluded that there was no significant difference in the values for the mean TF-BUT and OSDI scores (p = 0.029 and p = 0.596, respectively).

CONCLUSION

The children with Vit-D deficiency exhibited lower TMH, TMA, and Schirmer test values. The alterations that were observed in these parameters were more prominent in the participants who had lower Vit-D levels.

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.

Unilateral Herpetik Keratitli Hastalarda Kuru Göz Parametrelerinin Değerlendirilmesi

Amaç: Çalışmamızın amacı tek taraflı herpes simpleks virüs (HSV) keratiti olan hastalarda etkilenen ve etkilenmeyen gözler arasındaki gözyaşı parametrelerinin özellikle meibomian bezlerinin durumunun değerlendirilmesidir. Yöntem: Kliniğimizde tek taraflı HSV endoteliti ve HSV stromal keratiti tanılarıyla tedavi uygulanmış ve 3 aydan uzun süredir sakin dönemde seyreden hastaların muayeneleri ve gözyaşı filmi menisküsü yüksekliği (GFMY), alanı (GFMA), non-invazif gözyaşı kırılma zamanı (NIGKZ), schirmer testi, meibomian bezleri ekspressibilite gradeleri, drop-out dereceleri ve mikroyapısının değerlendirilmesini içeren gözyaşı parametreleri retrospektif olarak değerlendirildi. Bulgular: Hastalarımızın yaş ortalaması 58,0 (55,25-72,25) yıldı. Medyan NIGKZ etkilenen gözde 6,85 (4,62-17,0) sn. ve etkilenmemiş gözde 15,85 (10,47-17,15) sn. idi. Gruplar arasındaki değişim istatistiksel olarak anlamlı olmasa da, etkilenen gözde NIGKZ değerlerinin belirgin şekilde daha düşük olduğu gözlendi. Schirmer test değerleri, GFMY ve GFMA, etkilenen ve etkilenmeyen gözler arasında benzerdi. Etkilenen ve etkilenmeyen gözlerin meibomian bezi değerlendirmeleri, meibomian ekspresyonu ve bırakma dereceleri benzer dağılım gösterdi. Sonuç: Her iki gözde meibom bezlerinin hem morfolojik hem de mikroyapısal özelliklerinde benzer etkiler gözlemledik. Bu durum bize her iki gözde gelişen kuru göz hastalığının sadece nörosensoriyel anomalilerden değil meibomian bezlerdeki değişikliklerden de kaynaklanabileceğini düşündürmektedir.

Association between tear meniscus dimensions and higher-order aberrations in patients with surgically treated lacrimal passage obstruction

PURPOSE

To analyze the relationship between tear meniscus dimensions and higher-order aberrations (HOAs) in patients with lacrimal passage obstruction using anterior segment optical coherence tomography (AS-OCT).

METHODS

This study was a retrospective observational study of 71 eyes of 49 patients with lacrimal passage obstruction. These patients received sheath-guided dacryoendoscopic probing and bicanalicular intubation (SG-BCI) at Toyama University Hospital between August 2020 and October 2021. Using AS-OCT, tear meniscus height (TMH), tear meniscus area (TMA), and total corneal HOAs values were measured before and after surgery.

RESULTS

Surgical success was achieved in 69 eyes (97.1%). At the final observation, 62 eyes showed lacrimal patency (89.8%). The preoperative TMH, TMA, and HOAs values were 1.55 ± 0.96 mm, 0.11 ± 0.14 mm², and 0.37 ± 0.27 µm, respectively, and the final postoperative TMH, TMA, and HOAs values were 0.97 ± 0.74 mm (p < 0.0001), 0.06 ± 0.11 mm² (p = 0.02), and 0.29 ± 0.16 µm (p = 0.001), respectively. The results showed a significant improvement. The changes in HOAs before and after surgery were positively correlated with the changes in TMH (r = 0.3476, p = 0.0241) and TMA (r = 0.3653, p = 0.0174).

CONCLUSION

SG-BCI for lacrimal passage obstruction resulted in a significant decrease in measured HOAs. The decrease in HOAs was correlated with decreases in tear meniscus dimensions.

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.

AS-OCT and Ocular Hygrometer as Innovative Tools in Dry Eye Disease Diagnosis

Dry eye disease (DED) is one of the conditions that most commonly leads patients to visit an ophthalmologist. Fast and accurate diagnosis relieves patient discomfort and spares them from long-term effects on the ocular surface. Many tests used in the diagnosis of DED may be considered subjective as they rely on an experienced observer for image interpretation, resulting in variations in diagnosis. On one hand, the non-contact nature of the anterior segment optical coherence tomography (AS-OCT) device and its rapid image acquisition enable the measurement of the tear meniscus parameter without reflex tearing. On the other hand, an ocular hygrometer allows a rapid, safe, but also efficient, analysis and is associated with low costs and the repeatability of the procedure.

Objective assessment of eyelid position and tear meniscus in facial nerve palsy

PURPOSE

To evaluate lower lid position and tear meniscus in peripheral idiopathic facial nerve palsy (FNP).

METHODS

A prospective study enrolled patients with peripheral idiopathic FNP and epiphora. Data were collected on patient demographics, House-Brackmann (HB) scale, digital photographs of the face, and tear meniscus at the 1st, 30, and 90 day after onset of FNP. Marginal reflex distance to the upper (MRD1) and lower eyelid (MRD2) were evaluated using ImageJ software. Anterior segment optical coherence tomography (OCT) was performed to measure the tear menis- cus. P< .05 was considered statistically significant.

RESULTS

Sixteen patients were evaluated. The HB scale at presentation was grade III in six patients (37.5%). At 90 day, nine patients (56.25%) were grade I-normal. Three (18.7%) had upper lid retraction, three (18.7%) upper eyelid asymmetry and 7 (43.75%), lower eyelid retraction. The difference between MRD2-FNP with MRD2-healthy side was 0.51 ± 1.9 mm at the 1st visit, decreasing to 0.09 ± 1.47 mm at 90 days (P= .877). Tear meniscus measurements were significantly higher in FNP at the 1st visit (P= .001). The decrease in MRD2 was statistically correlated with the reduction of the tear meniscus area (TMA) (r = 0.67; P= .007) at 90 days. No correlation was found between HB and TMA. There is a difference in TMA between age groups at the 1st day(p= .009). Eldest group had higher HB scales.

CONCLUSION

Quantitative evaluation of eyelid position and tear meniscus are effective to document the evolution of FNP and can serve as a clue of orbicularis recovery.

Stimulating Tear Production: Spotlight on Neurostimulation

Dry eye disease (DED) affects up to one-third of the global population. Traditional therapies, including topical lubricants, have been employed with variable success in the treatment of DED. Recently, neurostimulation of the lacrimal functional unit (LFU) has emerged as a promising alternative therapy for DED. In this review, we describe the neuroanatomical and pathophysiological considerations of DED and the LFU that make neurostimulation a viable therapeutic alternative. We further detail the various neurostimulatory approaches taken thus far-from implanted stimulators to external devices to chemical neurostimulation. Existing studies reveal the strengths of the neurostimulatory approach in increasing tear volume and improving dry eye symptoms, but further studies are needed to elucidate its true potential in treatment of DED.

Anterior Segment Optical Coherence Tomography of Tear Film and Cornea in Systemic Lupus Erythematosus Patients

Purpose

To study tear film and corneal thickness measurements in systemic lupus erythematosus (SLE) patients compared to age-matched controls using anterior segment optical coherence tomography (AS-OCT).

Methods

This was a cross-sectional study. Study participants were divided into 3 groups: Group A: SLE patients with clinical dry eye, Group B: SLE patients without clinical dry eye and Group C: healthy controls. The lower tear meniscus parameters measured using AS-OCT were tear meniscus height (TMH), tear meniscus depth (TMD) and tear meniscus area (TMA). The central corneal and corneal epithelial thickness were automatically calculated.

Results

The study included 40 eyes in Group A, 60 in Group B, and 100 in Group C. Mean age was 26.9±6.6 years for Group A, 27.6±7.3 years for Group B and 35.7±9.2 years for Group C (p= 0.06). All subjects were females except for 1 male patient in Group A. Mean TMH, TMA and TMD in Group C were 487.7±185.6 µm, 0.068±0.040 mm², and 341.2±99.1 µm, respectively, which was significantly higher compared to Group A (225.5±27.9 µm, 0.018±0.004 mm² and 171.9±26.0 µm, respectively, all p < 0.001) and Group B (395.4±118.8 µm, p < 0.001; 0.05±0.04 mm², p=0.016 and 280.6±93.4 µm, p < 0.001, respectively). Group B eyes also had significantly higher parameters compared to Group A (all p < 0.001). Mean corneal and epithelial thickness in Group C were 501.6±37.5 µm and 53.3±4.5 µm, respectively, which was significantly higher compared to Group A (496.1±24.1 µm, p=0.044 and 49.5±3.5 µm, p < 0.001, respectively) and Group B (504.2±22.03 µm, p=0.046 and 47.5±5.6 µm, p < 0.001, respectively). Group B eyes also had a significantly higher corneal thickness (p=0.031) and epithelial thickness (p=0.011) compared to Group A.

Conclusion

We demonstrated significant reduction of tear meniscus dimensions, central corneal thickness and epithelial thickness in SLE patients compared to age-matched controls using AS-OCT.

Management of ocular surface squamous neoplasia: Bowman Club Lecture 2021

The gold-standard treatment for ocular surface squamous neoplasia (OSSN) has traditionally been surgical excision with wide margins and a no-touch technique. However, surgery may be associated with several unfavourable sequelae, as well as significant recurrence rates if margins are positive. In recent years, topical chemotherapy with 5-fluorouracil, interferon α-2b and mitomycin C have emerged as valuable agents capable of effectively treating OSSN with varying adverse effects. These medical treatment options usually present additional costs to the patient but can allow patients to avoid surgery with fewer long-term effects. Anterior segment high-resolution optical coherence tomography is an excellent tool for diagnosing and monitoring OSSN and can be a useful aid for both surgical and medical treatments of OSSN.

Evaluation of dry eye subtypes and characteristics using conventional assessments and dynamic tear interferometry

BACKGROUND/AIMS

To evaluate subtypes and characteristics of dry eye (DE) using conventional tests and dynamic tear interferometry, and to investigate determinants of disease severity in each DE subtype.

METHODS

309 patients diagnosed with DE and 69 healthy controls were prospectively enrolled. All eyes were evaluated using Ocular Surface Disease Index (OSDI), Schirmer's test I (ST1) and Meibomian gland dysfunction (MGD) grade were analysed. The tear interferometric pattern and lipid layer thickness were determined using DR-1α and LipiView II, respectively.

RESULTS

Dynamic interferometric analysis revealed 56.6% of patients with DE exhibited Jupiter patterns, indicative of aqueous-deficiency, while 43.4% exhibited crystal patterns, indicative of lipid deficiency. These findings were in accordance with classification based on ST1 scores and MGD grade. Conventional assessment indicated 286 patients exhibited evidence of evaporative DE (EDE) due to MGD, while only 11 exhibited signs of pure aqueous-deficient DE (pure ADDE, only ST1 ≤5 mm). Interestingly, of 286 patients with EDE, 144 were categorised into the mixed-ADDE/EDE group, in which ST1 was identified as a strong negative determinant of OSDI. In contrast, 72.2% of patients with mixed-ADDE/EDE exhibited Jupiter patterns (Jupiter mixed), while 27.8% exhibited crystal patterns (crystal mixed). OSDI values were significantly higher in the crystal-mixed group than in the Jupiter mixed, in which OSDI scores were independently associated with ST1 values only.

CONCLUSIONS

Our findings indicate that majority of EDE patients also exhibit aqueous deficiency, which can aggravate symptoms even in patients with lipid-deficient mixed-ADDE/EDE. Conventional assessments should be combined with interferometric tear analysis to determine the most appropriate treatment for each DE patient.

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.

Update on imaging modalities for ocular surface pathologies

Purpose of review

To discuss recent studies of imaging modalities for ocular surface pathologies.

Recent findings

Novel micro-ocular coherence tomography technology can produce high-resolution images of corneal cellular and nervous structures. Ocular coherence tomography angiography can aid in detecting early stage limbal stem cell deficiency. Several studies used in vivo confocal microscopy to evaluate corneal nerve metrics and morphology.

Summary

The applications of anterior segment optical coherence tomography, anterior segment optical coherence tomography angiography, ultrasound biomicroscopy, and in vivo confocal microscopy are useful technologies for imaging the ocular surface. Several studies have used artificial intelligence in combination with imaging technologies to create reliable and effective systems to detect and visualize ocular surface pathologies. AS OCT continues to be a key imaging tool and future development of μOCT technology may further enhance its utility.

Automatic screening of tear meniscus from lacrimal duct obstructions using anterior segment optical coherence tomography images by deep learning

PURPOSE

We assessed the ability of deep learning (DL) models to distinguish between tear meniscus of lacrimal duct obstruction (LDO) patients and normal subjects using anterior segment optical coherence tomography (ASOCT) images.

METHODS

The study included 117 ASOCT images (19 men and 98 women; mean age, 66.6 ± 13.6 years) from 101 LDO patients and 113 ASOCT images (29 men and 84 women; mean age, 38.3 ± 19.9 years) from 71 normal subjects. We trained to construct 9 single and 502 ensemble DL models with 9 different network structures, and calculated the area under the curve (AUC), sensitivity, and specificity to compare the distinguishing abilities of these single and ensemble DL models.

RESULTS

For the highest single DL model (DenseNet169), the AUC, sensitivity, and specificity for distinguishing LDO were 0.778, 64.6%, and 72.1%, respectively. For the highest ensemble DL model (VGG16, ResNet50, DenseNet121, DenseNet169, InceptionResNetV2, InceptionV3, and Xception), the AUC, sensitivity, and specificity for distinguishing LDO were 0.824, 84.8%, and 58.8%, respectively. The heat maps indicated that these DL models placed their focus on the tear meniscus region of the ASOCT images.

CONCLUSION

The combination of DL and ASOCT images could distinguish between tear meniscus of LDO patients and normal subjects with a high level of accuracy. These results suggest that DL might be useful for automatic screening of patients for LDO.

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.

Imaging Biomarkers for Dry Eye Disease

The clinical, scientific, economic, and regulatory impact of validated biomarkers and surrogate endpoints has the potential to revolutionize the approach to ocular surface diseases. At present, there is a growing interest in developing biomarkers for dry eye disease, and other ocular surface disorders and imaging are of the most promising approaches to this issue. Among the several and constantly evolving imaging technologies, some tools that are aimed to assess tear film stability and volume, meibomian gland morphology and function, and ocular surface microanatomy are now supported by a good body of evidence. To date, clinical trials on ocular surface diseases have slowly started incorporating imaging biomarkers for disease diagnosis and stratification and as surrogate endpoints. Major efforts are still needed, mainly aimed to improve automatic acquisition and quantitative analysis, standardization (standard operating procedures, normative databases etc.), and validation of imaging biomarkers.

[Precorneal tear film after corneal collagen cross-linking in keratoconus (preliminary report)]

PURPOSE

To study the condition of precorneal tear film in keratoconus patients after corneal collagen cross-linking (CXL).

MATERIAL AND METHODS

The study enrolled 24 patients (30 eyes) with stages I-III progressive keratoconus. All study patients underwent standard (Dresden) protocol CXL. Patients were examined before the surgery and 1 week, 1 month, and 3 months postoperatively. The condition of precorneal tear film was evaluated based on the results of Norn test (the tear film break-up time), Schirmer test, Jones test, optical coherence tomography based lacrimal meniscometry, and improved tearscopy.

RESULTS

One month after CXL, patients with keratoconus experienced transient changes in the precorneal tear film condition - the tear film break-up time was reduced, the tear secretion was elevated, the lacrimal meniscus biometry parameters were increased, and the thickness of the tear film lipid layer was decreased.

CONCLUSION

Corneal changes resulting from CXL lead to transient disorders of the mucin and lipid layers of the precorneal tear film, which requires adequate tear substitute therapy in the postoperative period.

Punctate fluorescein staining scores in dogs with or without aqueous tear deficiency

OBJECTIVE

To compare the superficial punctate fluorescein staining in dogs with and without aqueous tear deficiency.

PROCEDURES

An eye from each client-owned dogs presented to Triangle Animal Eye Clinic between January and December 2018 underwent tear and ocular surface tests, which included the Schirmer tear test (STT), phenol red thread test (PRT), and strip meniscometry tube tear test (SMT). Punctate fluorescein staining of the cornea (PFS-C) and the upper palpebral conjunctiva (PFS-UPC) were also performed. Fifty-seven dogs with STT results of <15 mm/min had aqueous tear deficiency (AD); 31 dogs had <10 mm/min and 26 dogs had ≥10 mm/min. The 162 dogs with STT results of ≥15 mm/min did not have AD. The test results of the groups were compared using Kruskal-Wallis and Steel-Dwass multiple comparison tests.

RESULTS

Two hundred and nineteen eyes from 219 dogs were enrolled in this study. The PRT and SMT results, presented as mean ± SD, were significantly lower in the AD group than in the non-AD group (PRT: 29.5 ± 8.1 vs 36.9 ± 5.6 mm/15 s; SMT: 6.2 ± 3.8 vs 10.8 ± 2.8 mm/5 s). The PFS scores were significantly higher in the AD group than in the non-AD group (PFS-C: 4.4 ± 0.7 and 3.7 ± 0.8; PFS-UPC: 2.3 ± 0.5 and 1.7 ± 0.5).

CONCLUSIONS

These results suggest that aqueous tear deficiency is not only reflected by PRT and SMT but also PFS-C and PFS-UPC.

The effect of conjunctivochalasis detected by anterior segment optical coherence tomography on tear function in an elderly population

Introduction:

The aim of this study was to evaluate conjunctivochalasis (CCH) and its relationship with tear meniscus and tear function in an elderly population.

Materials and methods:

This prospective, observational study included 144 eyes of 144 patients aged >65 years who were referred to our clinic for various reasons. The patients were separated into group 1 including 64 eyes of 64 patients with CCH and group 2 including 80 eyes of 80 patients without CCH. All patients in both groups underwent a full ophthalmological examination, and the presence of CCH, fluorescein tear break-up time (FTBUT) test, Schirmer test, ocular surface staining (Oxford grading score) and OSDI (Ocular Surface Disease Index) test results were recorded. Measurements of the conjunctivochalasis area (CCHA), tear meniscus height (TMH) and tear meniscus area (TMA) were taken using anterior segment optic coherence tomography (AS-OCT).

Results:

Group 1 comprised 34 females and 30 males with a mean age of 71.15 ± 12.34 years. Group 2 comprised 43 females and 37 males with a mean age of 68.16 ± 6.05 years (p = 0.122). The CCH rate was 44.4% in all of the examined patients. The OSDI score and the ocular surface staining test were significantly higher (p < 0.05), and the FTBUT, TMH and TMA were significantly lower (p < 0.05) in group 1 than in group 2. The Schirmer I test results were not significantly different between the two groups.

Conclusion:

The prevalence of CCH is quite high in elderly individuals and may disrupt tear function in these patients.

Effect of Ultra-high-definition Television on Ocular Surface and Fatigue

PURPOSE

To investigate the effects of watching ultra-high-definition television (UHD TV) on subjective ocular fatigue and objective ocular surface indices.

METHODS

A total of 76 volunteers were recruited for this study. Subjects watched UHD TV for 10 minutes at a viewing distance of 110 cm. Best-corrected visual acuity, refractive errors, tear break-up time, corneal staining grading, conjunctival redness grading by slit-lamp examination, tear meniscus measurement by anterior segment optical coherence tomography, and ocular symptom scores were obtained before and immediately after watching UHD TV. Subgroup analyses were conducted according to participant age (old age group &gt;50 years vs. young age group ≤50 years) and dry-eye syndrome (presence vs. absence). The relationship between subjective and objective indices was evaluated.

RESULTS

The mean age of subjects was 39.6 ± 12.4 years. Watching UHD TV induced a decrease in tear break-up time in the non-dry-eye group (p &lt; 0.001) but not in the dry-eye group (p = 0.726). Corneal staining grades increased in all subgroups, and the changes were particularly larger in the older group (p = 0.038). The increase in ocular symptom scores was larger in the dry-eye group (p = 0.08) and in the older group (p = 0.016). The decrease in tear break-up time and ocular symptom scores after watching UHD TV was significantly correlated with tear break-up time.

CONCLUSIONS

Tear break-up time significantly decreased in non-dry-eye subjects after watching UHD TV. Subjective ocular discomfort increased significantly in subjects over the age of 50 and in participants with dry-eye syndrome.

Tear Meniscus Imaging by Anterior Segment-Optical Coherence Tomography in Medically Controlled Glaucoma

PURPOSE

The purpose of this study was to investigate the tear meniscus in medically controlled glaucoma patients (MCGP) using anterior segment-optical coherence tomography (AS-OCT).

MATERIALS AND METHODS

Fifty-six MCGP, 24 patients with evaporative dry eye (EDE), and 30 healthy subjects (controls), were enrolled. MCGP were divided into group 1 (14 eyes): β-blockers; group 2 (14 eyes): prostaglandin analogs; group 3 (28 eyes) ≥2 drugs. Ocular Surface Disease Index (OSDI) questionnaire, tear film break-up time, corneal fluorescein staining, Schirmer Test I, and tear meniscus height (lower and upper: L-TMH, U-TMH) and area (L-TMA, U-TMA) using AS-OCT, were performed.

RESULTS

OSDI score was higher (P<0.05) in patients with EDE and in group 3 compared with groups 1, 2, and controls. No significant differences were found between group 3 and patients with EDE for all clinical parameters. L-TMA was significantly lower in groups 1 to 3 (P<0.05) and in EDE patients (P<0.001) compared with controls, and it was lower in group 3 and in EDE patients compared with groups 1 and 2 (P<0.05). L-TMH was lower in groups 1 to 3 and in EDE patients compared with controls (P<0.001), and in EDE patients and in group 3 compared with groups 1 and 2 (P<0.05). U-TMA was lower in EDE and MCGP groups compared with controls (P<0.05). L-TMA and L-TMH negatively correlated with OSDI score (P<0.01, r=-0.379 and P<0.01, r=-0.352, respectively).

CONCLUSIONS

AS-OCT permits a noninvasive and reliable tear meniscus imaging in medically controlled glaucoma, depicting the glaucoma-related ocular surface disease as a dry eye disease-like condition. Thus, reduced values of TMH and TMA can be proposed as structural indicators of glaucoma therapy-related ocular surface disease.

Objective Imaging Diagnostics for Dry Eye Disease

Traditional diagnostic tests for dry eye disease (DED), such as fluorescein tear film break-up time and the Schirmer test, are often associated with poor reproducibility and reliability, which make the diagnosis, follow-up, and management of the disease challenging. Advances in ocular imaging technology enables objective and reproducible measurement of changes in the ocular surface, tear film, and optical quality associated with DED. In this review, the authors will discuss the application of various imaging techniques, such as, noninvasive tear break-up time, anterior segment optical coherence tomography, in vivo confocal microscopy, meibography, interferometry, aberrometry, thermometry, and tear film imager in DED. Many studies have shown these devices to correlate with clinical symptoms and signs of DED, suggesting the potential of these imaging modalities as alternative tests for diagnosis and monitoring of the condition.

Normalized ocular surface temperature models for tear film characteristics and dry eye disease evaluation

PURPOSE

To construct normalized ocular surface temperature (NOST) models for different tear film characteristics and evaluate its potential in dry-eyes screening.

METHODS

We included 227 right eyes of 227 patients. Tear film characteristics were categorized into 4 types according to fluorescein tear film breakup time (FTBUT) and Schirmer test results, namely type 1: FTBUT >5 s and Schirmer >5 mm; type 2: FTBUT ≤5 s and Schirmer >5 mm; type 3: FTBUT ≤5 s and Schirmer ≤5 mm; and type4: FTBUT >5 s and Schirmer ≤5 mm. Ocular surface temperature was measured by a video-thermographer. Mean temperatures of the central cornea were calculated from the videos of each frame during the 4-s blink interval. We first constructed individual NOST model for every tear characteristic. Participants were included for further analysis when their OSDI was ≥23, FTBUT ≤5 s, and Schirmer >5 mm. They were subdivided into short-BUT and short BUT with SPK subgroups according to the absence or presence of corneal fluorescein-stain. The NOST models of the normal, short-BUT and short BUT with SPK groups were separately constructed and the potential of screening analyzed via ROC curves.

RESULTS

Each tear film type had a different NOST model. At 3 s after blinking, the order of NOST was type 4 >type 1 >type 3 >type 2. In dry-eye screening, the NOST was normal > short-BUT > short BUT with SPK. The NOST displayed a sensitivity 0.87, specificity 0.80, and AUC 0.88 for diagnosing short BUT with SPK.

CONCLUSION

NOST models are useful in differentiating tear film characteristics and screening dry-eyes. It alleviates the discomfort and inconvenience encountered during conventional dry-eye diagnosis.

Comprehensive Clinical, Diagnostic, and Advanced Imaging Characterization of the Ocular Surface in Spontaneous Aqueous Deficient Dry Eye Disease in Dogs

PURPOSE

To perform a comprehensive clinical, diagnostic, and imaging characterization of the ocular surface in West Highland White Terriers (WHWTs) diagnosed with aqueous deficient dry eye (ADDE) disease.

METHODS

Six ADDE-affected and 13 ADDE-unaffected WHWT dogs were enrolled and underwent clinical assessment and disease scoring, tear osmolarity, phenol red thread test, Schirmer tear test, tear film breakup time, fluorescein staining, Rose bengal and lissamine green vital dye staining, meibometry, corneal esthesiometry, ultrasound pachymetry, optical coherence tomography, in vivo confocal microscopy, and conjunctival biopsy. Subjective assessment of their condition was provided by owner-reported surveys.

RESULTS

ADDE-affected WHWT dogs had higher median clinical disease (conjunctiva: 5.75 vs. 0.00; cornea: 14.00 vs. 5.00; total: 17.50 vs. 5.00), vital staining (Rose bengal: 2.25 vs. 1.50; lissamine green: 2.00 vs. 1.00), and histologic disease (conjunctiva: 2 vs. 0) scores when compared with the controls. In addition, ADDE-affected WHWTs had significantly lower phenol red thread test (5.0 vs. 17.5, mm/15 s), Schirmer tear test (3 vs. 20, mm/min), tear film breakup time (3.6 vs. 13.9, s) values and higher area under the curve values for meibometry (394 vs. 245, meibometry units [MU]). There were no significant differences in other tear film tests performed. Advanced imaging revealed decreased tear meniscus height (optical coherence tomography) and variable pigment deposition within corneal epithelial cells (in vivo confocal microscopy).

CONCLUSIONS

This comprehensive assessment of ADDE-affected WHWTs depicts the ocular surface changes associated with quantitative lacrimal gland dysfunction. Importantly, ADDE-affected WHWTs may prove a valuable naturally occurring ADDE model for investigating underlying pathophysiological mechanisms and the development of novel therapeutics.

Feasibility of Strip Meniscometry for Tear Volume Evaluation in Lacrimal Passage Obstruction

Strip meniscometry tube (SMTube) is useful for assessing tear volume in dry eye disease. We performed an in vitro and a clinical study to examine whether the SMTube can also be used to evaluate tear quantity in lacrimal passage obstruction (LPO). In vitro experiments showed that the SMTube value and the amount of water absorption were significantly correlated (R² = 0.816, p = 0.0008), but the measured value peaked when 4 μL was absorbed. In the clinical study, 12 eyes of 9 LPO patients and 17 eyes of 17 healthy control subjects were included. The patients’ SMTube values were significantly higher than those of the control subjects (p < 0.05). The SMTube value significantly decreased after silicon tube intubation (p < 0.05). Tear meniscus height (TMH) and area (TMA), measured by anterior segment optical coherence tomography, exhibited a significant positive correlation with the SMTube value (TMH, p < 0.001, R² = 0.396; TMA, p < 0.001, R² = 0.366). Moreover, the SMTube value significantly correlated positively with the subjective symptom of epiphora (p = 0.012, R² = 0.255). Thus, SMTube was useful for evaluating the tear volume and therapeutic effects in patients with LPO.

Fourier-Domain OCT Imaging of the Ocular Surface and Tear Film Dynamics: A Review of the State of the Art and an Integrative Model of the Tear Behavior During the Inter-Blink Period and Visual Fixation

In the last few decades, the ocular surface and the tear film have been noninvasively investigated in vivo, in a three-dimensional, high resolution, and real-time mode, by optical coherence tomography (OCT). Recently, OCT technology has made great strides in improving the acquisition speed and image resolution, thus increasing its impact in daily clinical practice and in the research setting. All these results have been achieved because of a transition from traditional time-domain (TD) to Fourier-domain (FD) technology. FD-OCT devices include a spectrometer in the receiver that analyzes the spectrum of reflected light on the retina or ocular surface and transforms it into information about the depth of the structures according to the Fourier principle. In this review, we summarize and provide the state-of-the-art in FD-OCT imaging of the ocular surface system, addressing specific aspects such as tear film dynamics and epithelial changes under physiologic and pathologic conditions. A theory on the dynamic nature of the tear film has been developed to explain the variations within the individual compartments. Moreover, an integrative model of tear film behavior during the inter-blink period and visual fixation is proposed.

Advances in the diagnosis and treatment of dry eye

The core mechanism of dry eye is the tear film instability. Tear film-oriented diagnosis (TFOD) is a concept to clarify the cause of tear film instability by tear film, and tear film-oriented treatment (TFOT) is a concept to treat dry eye disease by replacing the lacking components of the tear film layer based on the TFOD. In TFOD, the fluorescein breakup pattern of the tear film is important, and the subtype of dry eye can be judged to some extent from the breakup patterns. Current noninvasive devices related to the dynamic analysis of the tear film and visual acuity enabled the diagnosis of dry eye, subtype analysis, and the extent of severity. In Asian countries, secretagogues represent the main treatment in TFOT. Since meibomian gland dysfunction is a factor that greatly affects the tear breakup time, its treatment is also essential in the dry eye treatment strategy. A newly discovered dry eye subtype is the short breakup time-type (BUT) of dry eye. The only abnormal finding in this disease is the short BUT, suggesting a relationship with ocular neuropathic pain and eye strain. Recently, data from many studies have accumulated which show that dry eye is a life-style disease. In addition to the treatment of dry eyes, it is becoming possible to prevent the onset by intervening with the daily habits, diet, exercise and sleep, etc. It has been pointed out that oxidative stress is also involved in the pathology of dry eye, and intervention is being carried out by improving diet and taking supplements. Future research will be needed to link clinical findings to the molecular biological findings in the tear film.

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.

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

PURPOSE

The aim of the study was to assess the tear film in subjects with a high body mass index (BMI).

METHODS

Twenty male subjects aged 23-42 years (mean ± standard deviation =31.3±5.7 years) with a high BMI [median (interquartile range) =31.8 (5.2) kg/m2] were recruited. An age-matched control group of twenty male subjects aged 22-38 years with a normal BMI [20.5 (2.8) kg/m2] also participated in the study.

RESULTS

There were significant (Kolmogorov-Smirnov test; P<0.05) differences in the BMI, non-invasive tear break-up time (NITBUT), and tear ferning (TF) scores between the study and control groups. There were some differences in the ocular surface disease index (OSDI), tear meniscus height (TMH), and phenol red thread (PRT) scores between the study and control groups, but these differences were not significant (Kolmogorov-Smirnov test; P>0.05). For the study group, the NITBUT and TF tests mean scores showed a dry eye condition (8.5±2.8 s and 2.0±1.1, respectively). However, these two tests showed a normal eye condition within the control group (14.7±2.8 s and 0.7±0.6, respectively). The TMH score had strong correlations with the NITBUT (r=0.711; P=0.001) and PRT scores (r=0.566; P=0.009) and strong negative correlations with age (r=-0.503; P=0.024) and the OSDI scores (r=-0.520; P=0.018). The TF score had a strong correlation with age (r=0.579; P=0.007) and strong negtive correlations with the scores from the NITBUT (r=-0.525; P=0.018), TMH (r=-0.575; P=0.008), and PRT (r=-0.773; P=0.001) tests.

CONCLUSION

The acquired data suggest a high BMI has an effect on the quality of tears. The quality of tears seems to be lower in subjects with a high BMI compared with normal subjects. On the other hand, the tear volume in subjects with a high BMI was just as high and adequate as for normal eye subjects.

Assessment of tear meniscus by optical coherence tomography in patients with canalicular laceration repair

PURPOSE

To analyze tear meniscus measurements with optical coherence tomography (OCT) in patients with canalicular laceration repair.

METHODS

Thirty-four consecutive patients who underwent unilateral canalicular repair due to canalicular laceration between January 2014 and December 2018 were included. All patients had canalicular repair followed by monocanalicular or annular silicone tube intubation. Anatomic patency of canalicular system was tested with probing and irrigation, while functional patency was evaluated with Munk score. Tear meniscus measurements of all patients were obtained following tube removal by spectral OCT. Tear meniscus height (TMH), tear meniscus depth (TMD) and tear meniscus area (TMA) of eyes with canalicular laceration repair and contralateral uninvolved eyes were compared.

RESULTS

Average age of 34 patients was 32.8 ± 21.3 years (range 4-68 years). Lower canaliculus was involved in 27 (79.4%), upper canaliculus in five (14.7%), and both canaliculi in two (5.9%) patients. Mean follow-up period was 6.5 ± 5.7 months. Anatomic patency rate was 100%, and functional patency (patients free of epiphora) was 91.2%. Average TMH (317.9 ± 133.1 µm), TMD (198.1 ± 82.5 µm) and TMA (29,792.1 ± 21,285.3 μm²) values of eyes with canalicular repair were not significantly different from TMH (308.9 ± 111.9 µm), TMD (184.5 ± 61.4 µm) and TMA (26,682.5 ± 16,178.1 μm²) values of contralateral control eyes (p values: 0.758, 0.225 and 0.778, respectively). There was a strong positive correlation between TMA and Munk score (r = 0.637, p < 0.001) and moderate positive correlation between TMH (r = 521, p = 0.002), TMD (r = 0.481, p = 0.004) and Munk score.

CONCLUSION

Tear meniscus measurement with OCT is a rapid, quantitative and objective tool for evaluation of canalicular patency in patients with canalicular laceration repair.

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

PURPOSE

To evaluate and compare the tear ferning patterns of non-stimulated and stimulated tears in normal eye male subjects using the tear ferning test.

METHODS

Thirty-five male subjects aged 20-38 years with normal eyes were enrolled in the study. Subjects with dry eye or with a risk factor for eye dryness (eg, recent ocular surgery, contact-lens wearers, smokers, anemic, diabetes, and thyroid gland problems) were excluded from the study. Dry eye subjects were excluded based on the ocular surface diseases index scores, non-invasive tear break-up time, and tear meniscus height measurements from the right and left eyes. A tear sample was collected from both eyes in each subject to perform the tear ferning test for non-stimulated tears. After 10 mins, the tears were stimulated using a Schirmer strip, a tear sample was collected from both eyes in each participant, the tear ferning test was performed, and the ferns were graded based on the five-point tear ferning grading scale.

RESULTS

The average tear ferning grade [median (interquartile range)] for non-stimulated tears from the right and left eyes was 0.60 (1.25) and 0.50 (1.31), respectively. For stimulated tears, the average tear ferning grade from the right and left eyes was 0.50 (1.05) and 0.75 (1.25), respectively. There was no significant difference in the tear ferning grades obtained from non-stimulated and stimulated tears (Wilcoxon test, P>0.05).

CONCLUSION

This study found no significant difference in the tear ferning patterns obtained from non-stimulated and stimulated tears, or between the tear ferning patterns in the tears collected from the right and left eyes before and after stimulating tears. It seems that there were no changes in the chemical composition of tears before and after stimulation, possibly due to the steady concentration of electrolytes and lipids within the tear film for both non-stimulated and stimulated tears.

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

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

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

Purpose

To evaluate the tear ferning patterns in dry eye and normal eye subjects in the 3 hours following application of Refresh Plus^® preservative-free lubricant eyedrops.

Methods

Thirty men with dry eye (mean age 22.14±2.34 years) and 30 age-matched men with normal eyes (mean age 23.91±3.24 years) were enrolled. Eyes were classified as normal or dry based on their Ocular Surface Disease Index score, tear meniscus height, and noninvasive tear breakup time. The tear ferning test was performed before and 30, 60, 120, and 180 minutes after application of a Refresh Plus eyedrop into the right eye in each subject.

Results

There was a significant change in tear ferning grade after application of Refresh Plus eyedrops (P=0.02, Wilcoxon test) in the group with dry eye, but not in the normal eye group (P=0.19, Wilcoxon test). The correlation of tear ferning grade was moderate (r=0.484, P=0.049) at 60 minutes after application of the eyedrops and strong at 120 minutes (r=0.560, P=0.019) and 180 minutes (r=0.726, P=0.001). There was also a strong correlation (r=0.865, P=0.001) between tear ferning grades obtained 120 and 180 minutes after application. In the normal eye group, there was a moderate (r=0.407, P=0.029) correlation between tear ferning grades obtained before and 60 minutes after application of the eyedrops. There was also a strong correlation (r=0.532, P=0.003) between tear ferning grades obtained 120 and 180 minutes after application.

Conclusion

Tear ferning patterns improved significantly after application of Refresh Plus preservative-free lubricant eyedrops in subjects with dry eye. Artificial tears containing sodium carboxymethylcellulose, such as Refresh Plus, can be used to improve tear ferning patterns in dry eye for at least 3 hours.

Degeneration of Corneal Sensation and Innervation in Patients with Facial Paralysis: A Cross-Sectional Study Using in Vivo Confocal Microscopy

Purpose: Facial paralysis (FP) leads to diverse periocular complications which threats visual acuity and affects corneal nerve functionally and morphologically. This study aims to summarize the clinical ophthalmic outcomes, corneal sensation, and morphological alterations of subbasal nerve and dendritic cells (DCs) in patients with facial paralysis.Methods: We performed a cross-sectional study of 48 consecutive patients with facial paralysis at one tertiary hospital. Forty-eight healthy participants were enrolled as controls. The images of corneal nerves and epithelial DCs were detected by in vivo confocal microscopy (IVCM). Each patient received thorough ophthalmic examination, tear film function tests, corneal fluorescence staining and Cochet-Bonnet esthesiometry test. Clinical and morphologic data were compared with controls.Results: Forty patients (83.3%) showed corneal injuries from punctate epithelial defects to corneal ulcers and scars. Visual impairment and eyelid malposition were observed. Corneal sensitivity remarkably decreased (25.1 ± 23.8 mm) in the affected eyes and was correlated to diminished subbasal nerve density (P = .019, r = 0.387). Numbers of corneal main nerve trunks and branches were significantly reduced (P < .0001) while DCs were increased (P < .0001) in patients with FP when compared with controls. Nerve fiber density showed inverse association with DC density (P = .019, r = -0.389).Conclusions: Ocular complications including corneal erosions, loss of corneal sensation, visual impairment and eyelid malposition have largely affected patients with facial paralysis. Morphological changes of diminished corneal subbasal nerve and increased DCs were detected by IVCM. Corneal epithelial defect, corneal opacity, corneal sensation, dendritic cell density are factors associated with corneal subbasal nerve density. Patients with FP are suggested to have complete ophthalmic evaluation and early instruction on ocular prevention.

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

Objective

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

Methods

Forty normal eye subjects (22 men and 18 women) aged 19–39 years were enrolled in the study. Also, an age matching control group (20 males and 20 females) was enrolled for comparison. McMonnies dry eye symptoms questionnaire and slit lamp were used for the exclusion criteria determination. Phenol red thread (PRT) test was performed on both eyes of each subject. A tear sample was collected from the lower tear meniscus of the right eye of each subject for the tear ferning (TF) test, which was performed before (30 minutes) and after (60 minutes) drinking green tea.

Results

The median PRT measurement after green tea consumption was lower (median [IQR]=23.50 [8.00] mm) compared to that before consumption (median [IQR]=27.00 [8.75] mm). In contrast, the median TF grade was significantly higher following green tea consumption than that before consumption (median [IQR]=2.65 [1.23] vs 1.50 [0.88] mm, respectively). The results show that TF grades increased in 97.5%, and the red phenol thread scores decreased in 80% of the subjects after green tea consumption compared to those before consumption. The PRT readings and TF grades were significantly different (P<0.05) before and after green tea consumption.

Conclusion

Drinking green tea could have a significant effect on the eye tear film quality. Tear quality appeared to decrease after green tea consumption.