Tear meniscus height determination using the OCT2 and the RTVue-100

A major review of punctal stenosis: Updated anatomy, epidemiology, etiology, and clinical presentation

We aim to provide a detailed and updated literature review on the epidemiology, etiology, clinical presentations, histopathology, and ultrastructural features of punctal stenosis. There are inconsistencies in the definition and staging of punctal stenosis. While advanced optical coherence tomography imaging techniques have revolutionized the way the punctum and vertical canaliculi are assessed or monitored following treatment, the planes of measurement to characterize punctum anatomy need to evolve further. The current criteria for diagnosing and grading punctal stenosis are inadequate and based on empirical clinical findings. There is increasing evidence of the role of lymphocytes and myofibroblasts in the pathogenesis of punctal stenosis. There is a need for a uniform assessment of punctal stenosis and a uniform reporting of severity that would help standardize the several management options available in the lacrimal armamentarium.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

Changes in Tear Volume after 3% Diquafosol Treatment in Patients with Dry Eye Syndrome: An Anterior Segment Spectral-domain Optical Coherence Tomography Study

Purpose

To evaluate changes in the tear meniscus area and tear meniscus height over time in patients with dry eye syndrome, using anterior segment spectral-domain optical coherence tomography after the instillation of 3% diquafosol ophthalmic solution.

Methods

Sixty eyes from 30 patients with mild to moderate dry eye syndrome were included. Tear meniscus images acquired by anterior segment spectral-domain optical coherence tomography were analyzed using National Institutes of Health's image-analysis software (ImageJ 1.44p). Tear meniscus area and tear meniscus height were measured at baseline, 5 minutes, 10 minutes, and 30 minutes after instillation of a drop of diquafosol in one eye and normal saline in the other eye. Changes in ocular surface disease index score, tear film break-up time, corneal staining score by Oxford schema, and meibomian expressibility were also evaluated at baseline, and after 1 week and 1 month of a diquafosol daily regimen.

Results

Sixty eyes from 30 subjects (mean age, 29.3 years; 8 men and 22 women) were included. In eyes receiving diquafosol, tear volume was increased at 5 and 10 minutes compared with baseline. It was also higher than saline instilled eyes at 5, 10, and 30 minutes. Changes in tear volume with respect to baseline were not statistically different after the use of diquafosol for 1 month. Ocular surface disease index score, tear film break-up time, and Oxford cornea stain score were significantly improved after 1 week and 1 month of daily diquafosol instillation, but meibomian expressibility did not change.

Conclusions

Topical diquafosol ophthalmic solution effectively increased tear volume for up to 30 minutes, compared to normal saline in patients with dry eye syndrome.

Anterior Segment Optical Coherence Tomography for Tear Meniscus Evaluation and its Correlation with other Tear Variables in Healthy Individuals

INTRODUCTION

Dry eye is one of the most common ocular diseases in this cyber era. Despite availability of multiple tests, no single test is accurate for the diagnosis of dry eye. Anterior segment optical coherence tomography is the recent tool which can be added in the armentarium of dry eye tests.

AIM

To evaluate tear meniscus with anterior segment optical coherence tomography and its correlation with other tear variables in normal healthy individuals.

MATERIALS AND METHODS

In this prospective cross-sectional observational study, right eye of 203 consecutive patients were studied. All the patients were divided into three groups Group 1, 2 and 3 according to their age ≤20 years, 21-40 years and >40 years respectively. All patients underwent routine ophthalmologic examinations along with slit-lamp bio-microscopy for tear meniscus height measurement, tear film break up time, Schirmer's I test (with anaesthesia) and optical coherence tomography imaging of inferior tear meniscus height. After focusing of the instrument with a Cross Line (CL) centered on lower tear meniscus at 6'0 clock of cornea, a 6 mm long scan was obtained. The tear meniscus height (μm) and tear meniscus area (mm(2)) were measured manually with help of callipers by joining upper corneo-meniscus junction to the lower lid-meniscus junction and tear meniscus height and area within the plotted line respectively and calculated by using the integrated analysis available in the custom software.

RESULTS

There was significant decrease in the all tear variables with the increase in the age. According to age groups in group 1, the mean Schirmer's (24.0±4.9)mm, tear film break up time (11.1±1.9) sec, tear meniscus height on slit lamp (600.2±167.3)mm were higher but decreased in group 2 (21.5±5.4,10.8±1.4, 597.5±186.3) and group 3 (19.8 ± 5.1, 10.2 ± 1.6, 485.6 ± 157.7) respectively. Schirmer's test values and tear film break up time were similar in both sexes (p=0.1 and p= 0.9). Tear meniscus height on slit lamp and Optical coherence based tear meniscus area were similar in both sexes (p=0.5 and p=0.1). However, tear meniscus height on optical coherence tomography was significantly higher in females (p=0.04). Value of Schirmer's and tear film break up time (r =0.2; p= 0.001) and Schirmer's and tear meniscus height on slit lamp (r=0.6; p<0.001) had positive correlation. Tear meniscus height and tear meniscus area on optical coherence tomography had positive correlation (r =.9; p<0.001).

CONCLUSION

On optical coherence tomography tear meniscus height and area significantly correlated. Despite higher values of Schirmer's, tear film break up time, Slit lamp based tear meniscus height in younger age group the tear meniscus height and tear meniscus area with optical coherence tomography were lower.

Is optical coherence tomography an effective device for evaluation of tear film meniscus in patients with acne rosacea?

PURPOSE

To investigate the tear meniscus using Fourier-domain optical coherence tomography (FD-OCT) in patients with acne rosacea and to determine the relationship between tear film break-up tests (TBUT), Schirmer test and FD-OCT values and to compare them with that of healthy controls.

METHODS

One hundred and four patients with acne rosacea and 104 body mass index age-sex-matched healthy subjects were enrolled in this prospective case-control study. Tear meniscus height (TMH), tear meniscus depth (TMD), and tear meniscus cross-sectional area (TMA) were measured using FD-OCT (RTVue-100); TBUT, Schirmer test and dry eye questionnaire (OSDI) were evaluated. Correlation was assessed using Spearman's correlation coefficient.

RESULTS

Mean TMH, TMD, TMA, TBUT, and Schirmer test values of acne rosacea patients were significantly lower than and OSDI score significantly higher than those of controls. Tear mensicus values were significantly correlated with OSDI scores, TBUT, and Schirmer test results. The intraobserver intraclass correlation coefficient (ICC) for tear parameters ranged from 0.90 to 0.96 and interobserver ICC ranged from 0.92 to 0.94, which revealed high reproducibility for all measurements parameters both acne rosacea and control subjects. Accuracy of dry eye diagnosis by FD-OCT was 60.4% for TMH, 58.7% for TMD, and 64.8% for TMA.

CONCLUSION

Tear meniscus measurement with FD-OCT could provide acceptable specificity and sensitivity in diagnosis of dry eye in acne rosacea patients.

Assessment of tear meniscus with optical coherence tomography in thyroid-associated ophtalmopathy

PURPOSE

To evaluate the tear-film meniscus with optical coherence tomography (OCT) in patients with Graves' disease (GD).

MATERIALS AND METHODS

Patients with GD without clinical features of thyroid-associated ophthalmopathy (TAO) (Group 1, n=35), patients with signs of TAO (Group 2, n=31) and healthy participants (Group 3, n=31) were enrolled. Palpebral fissure width, Schirmer test, tear break-up time (TBUT) test and tear-film meniscus height and area obtained with Fourier-domain-OCT were analyzed.

RESULTS

TBUT test scores were 8 s (2-25) in Group 1, 8 s (2-15) in Group 2 (p=0.380); and 10 s (5-17) in Group 3 (p=0.000 Group 1 versus 3, and 0.000 for Group 2 versus 3). Tear-film meniscus height did not significantly differ between Groups 1 and 2 (257.5 µm (86-962) and 258 µm (99-1340), respectively, p=0.980). In Group 3, tear-film meniscus height was 316 µm (122-720) (p=0.005 Group 1 versus 3 and 0.004 for Group 2 versus 3). Tear-film meniscus area did not significantly differ between Groups 1 and 2 (0.025 mm(2) (0.004-0.250) and 0.024 mm(2) (0.003-0.316), respectively, p=0.850). In Group 3, tear-film meniscus area was 0.048 mm(2) (0.006-0.75) (p=0.000 Group 1 versus 3 and 0.000 for Group 2 versus 3).

CONCLUSION

Tear function is significantly disturbed in GD. OCT is an effective way to assess the tearing function also in patients with GD.

The diagnostic significance of Fourier-domain optical coherence tomography in Sjögren syndrome, aqueous tear deficiency and lipid tear deficiency patients

PURPOSE

To determine the role of Fourier-domain optical coherence tomography (FD-OCT) in tear meniscus imaging and evaluate its diagnostic significance in Sjögren syndrome (SS), non-Sjögren's aqueous tear deficiency (ATD) and lipid tear deficiency (LTD) patients.

METHODS

Two hundred and thirty-six dry eye patients and 174 healthy controls were enrolled in this study. All subjects were grouped as follows: group A (ATD), group B (LTD), group C (SS) and group D (normal controls). All subjects underwent dry eye questionnaire, FD-OCT scanning, tear film break-up time (BUT), corneal fluorescence staining and Schirmer I test (SIT). Tear meniscus height (TMH), tear meniscus depth (TMD) and tear meniscus cross-sectional area (TMA) were measured using FD-OCT (RTVue-100). The area under the receiver operating characteristic curve and the cut-off point were determined using a logistic regression model.

RESULTS

Mean TMH, TMD, TMA, BUT and SIT of dry eye patients were significantly lower than those of the controls (p < 0.05). Tear meniscus values were significantly decreased in patients with SS compared with ATD and LTD patients. Tear meniscus values were significantly correlated with clinical examination results in all groups. Accuracy of dry eye diagnosis by FD-OCT is highest in patients with SS and lowest in LTD patients. The clinical diagnostic critical points were quite different between groups.

CONCLUSIONS

Fourier-domain optical coherence tomography could provide precise measurement of the tear meniscus with favourable repeatability. Diagnostic significance is more conspicuous in patients with SS. Tear meniscus measurement by FD-OCT is expected to become a valuable technique in ATD dry eye screening and diagnosis.