Variability of the Analysis of the Tear Meniscus Height by Optical Coherence Tomography

Lower tear meniscus height measured by optical coherence tomography in children

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bony nasolacrimal duct size and outcomes of nasolacrimal silicone intubation for incomplete primary acquired nasolacrimal duct obstruction

Purpose

To investigate the association between the bony nasolacrimal duct (NLD) size and outcomes of nasolacrimal silicone intubation for incomplete primary acquired nasolacrimal duct obstruction (PANDO).

Methods

Patients who underwent silicone intubation for incomplete PANDO and had undergone facial computed tomography (CT) were included. Surgical success was judged by both epiphora improvement and normalized tear meniscus height (TMH; < 300 μm) on anterior segment optical coherence tomography at 3 months after tube removal. The area, major axis diameter, and minor axis diameter of the elliptic bony NLD sections were measured in 1.0 mm-thick axial CT images. These bony NLD sizes were analyzed for associations with surgical success and TMH normalization.

Results

Eighty-one eyes of 48 patients were investigated. The smallest area and the smallest minor axis diameter were significantly larger in the success group (49 eyes), compared with those in the failure group (median smallest minor axis diameter: 4.7 mm vs. 3.8 mm, P = 0.008, Mann–Whitney U test). There was also a tendency for the TMH normalization rate to significantly increase as the smallest area and the smallest minor axis diameter increased (P = 0.028 and 0.037, respectively, Fisher’s 2 × 4 tests). Under multivariable logistic regression analysis using generalized estimating equation, a larger smallest minor axis diameter was associated with success of the nasolacrimal silicone intubation (odds ratio: 2.481, 95% confidence interval: 1.143–5.384).

Conclusion

Surgical success of the nasolacrimal silicone intubation in incomplete PANDO is associated with a larger smallest minor axis diameter of the bony NLD. This finding will help understand the pathophysiology of surgical failure after nasolacrimal silicone intubation.

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.

Evaluation of tear meniscus by optical coherence tomography after different sodium hyaluronate eyedrops instillation

PURPOSE

To evaluate changes in tear meniscus dynamics using optical coherence tomography (OCT) after the instillation of different concentrations of sodium hyaluronate (SH) ophthalmic solutions.

METHODS

An experimental, double-masked, randomized study was performed. Twenty-three healthy subjects (16 women and seven men; mean age 23.57 ± 2.56 years) participated in this study. About 35 μl of 0.1%, 0.2%, 0.3% SH ophthalmic solutions and saline solution was instilled in a randomly assigned eye. Tear meniscus measurements (height, depth and turbidity) were taken with OCT at 30 seconds and 1, 3, 5, 10 and 20 min after instillation. Subsequently, the Schirmer test and tear break-up time (TBUT) were evaluated.

RESULTS

Tear meniscus depth and tear meniscus height showed a significant increase with all solutions compared to basal values: up to 3 min for 0.1% SH, up to 5 min for 0.2% and up to 10 min for 0.3% SH ophthalmic solution. Tear meniscus turbidity was also increased at 30 seconds for 0.1%, 0.2% and 0.3% SH artificial tears (p < 0.05). This increase remained significant for up to 1 min for 0.2% and 0.3% SH solutions (p < 0.05). After 5 min of saline and 0.1% SH instillation, the turbidity was lower than basal values (p < 0.05). There was a significant increase in the TBUT for all solutions after instillation (p < 0.05). No differences between the Schirmer pre- and postinstillation were found (p > 0.05). Finally, the comfort was significantly improved for all ophthalmic solutions (p < 0.05).

CONCLUSION

Sodium hyaluronate (SH) ophthalmic solutions increase residence time in healthy subjects and are positively correlated with its concentration and therefore the viscosity.

Changes in Tear Meniscus Height Following Lower Blepharoplasty as Measured by Optical Coherence Tomography

Purpose

The lower eyelid serves important roles in tear distribution and drainage. The purpose of this study was to measure the tear meniscus height (TMH) with anterior segment optical coherence tomography after lower blepharoplasty.

Methods

A total of 52 eyes from 26 patients treated between July 2012 and June 2015 were included in the study. A transcutaneous or transconjunctival approach was performed, depending on whether (1) the supportive lower lid orbicularis oculi muscle was tightened, (2) the middle lamella was elongated, (3) minimal fat was removed or transpositioned, and (4) lateral canthal support was established. Marginal reflex distance 2 and marginal nose distance were analyzed with Image J software. TMH was measured with anterior segment optical coherence tomography. A paired t-test and Wilcoxon signed-rank test were used for statistical comparisons.

Results

Marginal reflex distance 2 decreased and marginal nose distance increased with both surgical techniques. TMH decreased from 337.3 ± 117.9 to 289.3 ± 69.1 µm (p = 0.024) in patients who had transcutaneous lower blepharoplasty, but increased from 186.5 ± 35.5 to 274.8 ± 58.3 µm (p = 0.000) in patients who had transconjunctival lower blepharoplasty. Medial and lateral TMHs decreased significantly from 228.8 ± 80.7 to 152.7 ± 42.1 µm (p = 0.008) in patients with transcutaneous lower blepharoplasty. TMH was significantly restored after lower blepharoplasty with either approach.

Conclusions

Enhancing the lower eyelid position combined with orbicularis muscle tightening and lateral canthal support can normalize the TMH following lower eyelid blepharoplasty.

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

PURPOSE:

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

METHODS:

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

RESULTS:

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

CONCLUSION:

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

Measurement of lacrimal punctum using spectralis domain anterior optical coherence tomography

PURPOSE

Anterior segment optical coherence tomography (AS-OCT) was used to image the lacrimal punctum and establish normal punctal parameters including the tear volume inside the punctum.

METHODS

This study included totally 67 eyes from 38 normal subjects. Punctal parameters and tear meniscus height (TMH) were measured using spectralis OCT anterior-segment scans. Outer punctal diameter (OPD), punctal depth, tear well diameter (TWD), tear well depth, punctal reserve (PR) and lower eyelid TMH were assessed. Authors defined a 'tear well' as a pool of standing tears in the punctum. Punctal reserve was defined as the difference between punctal depth and tear well depth.

RESULTS

Outer punctal diameter was 614.6 ± 195.6 μm, the punctal depth was 545.8 ± 270.1 μm, TWD was 229.9 ± 133.8 μm, the tear well depth was 434.9 ± 247.8 μm, the PR was 110.9 ± 72.9 μm, the PR ratio was 0.20 ± 0.17, and the TMH was 222.9 ± 88.8 μm. The punctal depth decreased significantly according to the patient's age (correlation coefficient = -0.352, respectively).

CONCLUSION

AS-OCT is useful for improving anatomical understanding of the lacrimal punctal structure. Quantitative punctum and tear well measurements were correlated with TMH.

Ocular Surface Disease in Patients under Topical Treatment for Glaucoma

Purpose

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

Methods

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

Results

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

Conclusions

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

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Assessment of the Tear Meniscus Using Optical Coherence Tomography in Patients With Type 2 Diabetes Mellitus

PURPOSE

To analyze tear meniscus dimensions with Fourier domain-optical coherence tomography (FD-OCT) in patients with type 2 diabetes mellitus.

METHODS

Patients with type 2 diabetes without diabetic retinopathy (DR) (n = 54), with nonproliferative DR (n = 45), with proliferative DR (PDR) (n = 25), and controls (n = 45) were enrolled. Hemoglobin A1c and Early Treatment Diabetic Retinopathy Study (ETDRS) stages of DR were evaluated. Schirmer test (ST), tear breakup time test, and fluorescein corneal staining were carried out. Tear meniscus height (TMH), tear meniscus depth (TMD), and tear meniscus area (TMA) were obtained by FD-OCT.

RESULTS

TMH, TMD, and TMA in the diabetes and control groups were 233 ± 79 μm, 148 ± 53 μm, and 0.026 ± 0.015 mm, and 261 ± 67 μm, 167 ± 49 μm, and 0.032 ± 0.017 mm, respectively. All parameters were lower in diabetes (all P < 0.01). And the values in PDR were 185 ± 90 μm, 117 ± 50 μm, and 0.017 ± 0.010 mm which were lower than those in control and nonproliferative DR (227 ± 71 μm, 144 ± 50 μm, and 0.023 ± 0.010 mm) (all P < 0.01). TMH, TMD, and TMA correlated with ST (P < 0.01, P = 0.02, and P < 0.01, respectively) and the corneal staining score (all P < 0.01). Patients with longer diabetes duration and a history of panretinal photocoagulation showed significantly decreased TMH, TMD, and TMA (P < 0.01).

CONCLUSIONS

OCT, along with tear breakup time and ST, is an effective way to assess tear function in type 2 diabetes. Patients with PDR and a history of panretinal photocoagulation showed lower tear meniscus parameters. The decrease in tear meniscus parameters was correlated with diabetes duration.

An investigation of non-invasive tear break up time and tear meniscus height of keratoconic versus non-keratoconic individuals

Keratoconus is a debilitating condition where the cornea develops a conical shape rather than the characteristic round shape due to various physiological and structural changes taking place within the layers of the cornea. As a result of the pathogenesis of keratoconus, there are numerous changes that may occur within the tears of these patients. Research has shown changes in the tear metabolome, the presence of degradation products as well as loss of goblet cells into the tears. Could the changes occurring within the tear structure of these patients affect the results of various tear quantity and quality tests? Non-invasive tear break up time (NTBUT) is a diagnostic test used to determine the quality of the tear film and has been used extensively when diagnosing dry eye disease. This test is utilised in order to determine the time taken for the tear film to begin breaking apart, signalling thinning of the tears. Shorter break up times are therefore indicative of instability or changes occurring within the tear film which could be diagnostic of dry eye disease. Tear meniscus height (TMH) measurements have also been utilised in clinical practice, where these measurements provide an indication of the volume of tears contained within the upper and lower menisci. Lower tear volumes have been shown to be present in cases of dry eye disease where either tear production or tear drainage may be affected. Changes in the quality and quantity of the tear film in subjects with dry eye disease have been thoroughly investigated; however, the same cannot be said for subjects with keratoconus. Could the same findings be possible in subjects with keratoconus? Is it possible that the changes occurring within the tears of keratoconic subjects could lead to abnormal NTBUT and TMH measurements when compared to those of control subjects? Could the results of the NTBUT and TMH tests be related to one another? This study compares the NTBUT and TMH measurements of both keratoconic and control subjects by making use of a single type of instrumentation, namely the Oculus Keratograph 4 (OK4). The results of this study reveal that the values obtained for each of the two subject groups are not shown to be statistically significantly different and that there is no significant correlation between the NTBUT and TMH measurements when comparing keratoconic and control subjects.

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.

Neurostimulation of the lacrimal nerve for enhanced tear production

PURPOSE

To design a proof-of-concept study to assess the effect of lacrimal nerve stimulation (LNS) with an implantable pulse generator (IPG) to increase aqueous tear production.

METHODS

Experimental animal study design of 6 Dutch Belted rabbits. Ultra high-resolution optical coherence tomography (UHR-OCT) quantified tear production by measuring the baseline tear volume of each rabbit's OD and OS. A neurostimulator was implanted adjacent to the right lacrimal nerve. After 2 minutes of LNS (100 μs, 1.6 mA, 20 Hz, 5-8 V), the tear volumes were measured with UHR-OCT. The change in tear volume was quantified and compared with the nonstimulated OS. Three rabbits underwent chronic LNS (100 μs, 1.6 mA, 10 Hz, 2 V) and their lacrimal glands were harvested for histopathologic analysis.

RESULTS

The UHR-OCT imaging of the OD tear volume showed a 441% average increase in tear production after LNS as a percent of baseline. After stimulation, OD had statistically significant greater increase in tear volumes than OS (p = 0.028, Wilcoxon test). Poststimulation OD tear volumes were significantly greater compared with baseline (p = 0.028, Wilcoxon test). Histopathologic examination of the lacrimal glands showed no discernible tissue damage from chronic neurostimulation. In addition, there were no gross adverse effects on the general well-being of the animals due to chronic stimulation.

CONCLUSIONS

LNS with an IPG appears to increase aqueous tear production. Chronic LNS showed no histopathologic lacrimal gland damage. This study suggests that LNS is a promising new treatment strategy to increase aqueous tear production.

Automatic dynamic tear meniscus measurement in optical coherence tomography

An image processing algorithm is developed for quantitative assessment of tear meniscus dynamics from continuous optical coherence tomography (OCT) measurements. Clinical utility of dynamic OCT tear meniscus measurement is assessed in studies of tear meniscus parameters. The results indicate that any apparent changes in the early post-blink phase meniscus parameters are essentially related to the longitudinal movements of the eye and not to the formation of tear meniscus corresponding to tear film build-up. Dynamic acquisition of tear film meniscus is essential for providing reliable estimates of its parameters such as height, depth, and area.

Dynamic changes of tear fluid after cosmetic transcutaneous lower blepharoplasty measured by optical coherence tomography

PURPOSE

To investigate the dynamic changes of tear fluid after cosmetic transcutaneous lower blepharoplasty.

DESIGN

Prospective, observational case series study.

METHODS

A total of 60 eyes of 30 patients with transcutaneous lower blepharoplasty were involved in the study. All subjects completed the Ocular Surface Disease Index questionnaire and underwent tear film break-up time measurements and the Schirmer test before surgery and 1 week, 1 month, and 3 months after surgery. Tear meniscus parameters measured by optical coherence tomography were recorded. Lower lid margin reflex distance was also measured. At each time point after surgery, these parameters were compared with the baseline parameters. The incidence of dry eye and chemosis after surgery was assessed.

RESULTS

The Ocular Surface Disease Index score increased significantly 1 week after surgery (P < .01). The Schirmer test values were significantly decreased 1 week postoperatively (P < .01), and they returned to baseline by 3 months. There was no significant change in tear film break-up time before and after surgery. The tear meniscus height, depth, and cross section area values were significantly increased at 1 week postoperatively, decreased at 1 month (P < .01), and returned to baseline at 3 months (P > .05). The cornea-lower eyelid angle significantly decreased at 1 week postoperatively (P < .01), increased at 1 month (P < .01), and returned to baseline by 3 months (P > .05). The lower lid margin reflex distance was increased 1 week after surgery (P < .01), and gradually recovered but had not returned to the baseline 3 months after surgery (P < .01). The increased tear meniscus height had a positive correlation with lower lid margin reflex distance. The incidence of dry eye and chemosis at 1 week postoperatively was 16.7% and 15%, respectively.

CONCLUSIONS

Cosmetic transcutaneous lower blepharoplasty affects ocular surface and tear fluid, which leads to dryness, tearful eyes, and chemosis. However, this influence is temporary after surgery, and the symptoms resolve within 3 months. A positive correlation between tear meniscus height and lower lid margin reflex distance was observed. Assessment of the tear meniscus with optical coherence tomography provided a quick, noninvasive, and quantitative method to investigate the dynamic changes of the tear fluid after blepharoplasty.

Comparison of a new portable digital meniscometer and optical coherence tomography in tear meniscus radius measurement

PURPOSE

Non-invasive measurement of tear meniscus radius (TMR) is useful in the assessment of tear volume for dry eye diagnosis. This study investigates the agreement between a new, portable, slit-lamp mounted, digital meniscometer (PDM) and optical coherence tomography (OCT) in the measurement of human TMR.

METHODS

Images of the tear meniscus at the centre of the lower lid of 30 normal subjects (8M, 22F; mean age 27.5 SD ± 9.6 years) were taken using the PDM and the OCT. On the PDM and OCT images, TMR was measured using imagej 1.46b software. The meniscus on the OCT images was subdivided vertically into three equal sections and the radius calculated for each: bottom (BTMR), centre (CTMR) and top (TTMR). The relationship between PDM and OCT measurements was analysed using Spearman's rank coefficient, and differences between PDM and OCT subsection measurements were evaluated using Bland-Altman plots.

RESULTS

Tear meniscus radius measured with the PDM (0.25 ± 0.06 mm) and OCT (0.29 ± 0.09 mm) was significantly correlated (r = 0.675; p < 0.001). The mean differences between TMR using the PDM and the subsections from OCT showed that TMR measured with PDM was greater for BTMR (0.07 mm; CI 0.05-0.10; p < 0.001), similar for CTMR (-0.01 mm; CI -0.04 to 0.02; p = 0.636) and steeper for TTMR (-0.07 mm; CI -0.10 to -0.04; p < 0.001).

CONCLUSIONS

Portable digital meniscometer and OCT measurements of the TMR are significantly correlated, suggesting that the new PDM is a useful surrogate for OCT in this respect. The PDM appears to measure the radius of the central section of the tear meniscus.

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.

Ultra high-resolution anterior segment optical coherence tomography in the diagnosis and management of ocular surface squamous neoplasia

The development of optical coherence tomography (OCT) technology has helped to usher in a new era of in vivo diagnostic imaging of the eye. The utilization of OCT for imaging of the anterior segment and ocular surface has evolved from time-domain devices to spectral-domain devices with greater penetrance and resolution, providing novel images of anterior segment pathology to assist in diagnosis and management of disease. Ocular surface squamous neoplasia (OSSN) is one such pathology that has proven demonstrable by certain anterior segment OCT machines, specifically the newer devices capable of performing ultra high-resolution OCT (UHR-OCT). Distinctive features of OSSN on high resolution OCT allow for diagnosis and differentiation from other ocular surface pathologies. Subtle findings on these images help to characterize the OSSN lesions beyond what is apparent with the clinical examination, providing guidance for clinical management. The purpose of this review is to examine the published literature on the utilization of UHR-OCT for the diagnosis and management of OSSN, as well as to report novel uses of this technology and potential directions for its future development.

Evaluation of dry eye

Dry eye is a common yet complex condition. Intrinsic and extrinsic factors can cause dysfunction of the lids, lacrimal glands, meibomian glands, ocular surface cells, or neural network. These problems would ultimately be expressed at the tear film-ocular surface interface. The manifestations of these problems are experienced as symptoms such as grittiness, discomfort, burning sensation, hyperemia, and secondary epiphora in some cases. Accurate investigation of dry eye is crucial to correct management of the condition. Techniques can be classed according to their investigation of tear production, tear stability, and surface damage (including histological tests). The application, validity, reliability, compatibility, protocols, and indications for these are important. The use of a diagnostic algorithm may lead to more accurate diagnosis and management. The lack of correlation between signs and symptoms seems to favor tear film osmolarity, an objective biomarker, as the best current clue to correct diagnosis.

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.

Correlation between optical coherence tomography-derived assessments of lower tear meniscus parameters and clinical features of dry eye disease

PURPOSE

To measure the correlation between subjective symptom score, conventional clinical tests, and Fourier-domain optical coherence tomography (FD-OCT) of lower tear meniscus parameters in patients with dry eye disease.

METHODS

Eighteen patients with dry eye disease requiring medical therapy and/or punctal occlusion were recruited for this prospective, nonrandomized, observational case series. Severity of symptoms of dry eye disease was assessed using the Indiana University Dry Eye Questionnaire 2002. Clinical assessments were completed using slit-lamp biomicroscopy, rose bengal dye staining, fluorescein tear breakup time (TBUT), and a 5-minute Schirmer test with topical anesthesia. The lower tear meniscus was imaged using an FD-OCT system with 5-μm axial resolution and measured manually by a masked grader using computer calipers. Correlation was assessed using Spearman correlation coefficient (ρ).

RESULTS

The mean (±SD) scaled symptom score was 58 ± 21, with a range of 0 to 100. Vital staining test averaged 1.7 ± 3.4, TBUT averaged 4.4 ± 1.8 seconds, and Schirmer tests averaged 10.2 ± 8.1 mm. As determined by optical coherence tomography, the meniscus height was 228 ± 153 μm, depth was 127 ± 79 μm, and cross-sectional area was 0.018 ± 0.021 mm. Optical coherence tomography meniscus area was negatively correlated with the symptom questionnaire score (P < 0.01) and positively correlated with Schirmer test results (P < 0.01). There was no significant correlation between symptom score and rose bengal staining, TBUT, or Schirmer test results (P > 0.01).

CONCLUSIONS

Lower tear meniscus measurement with FD-OCT is an objective noninvasive test that correlates well with symptoms of dry eye disease and the Schirmer test.

Age-related variations of human tear meniscus and diagnosis of dry eye with Fourier-domain anterior segment optical coherence tomography

PURPOSE

To determine the age-related variations in the human tear meniscus using Fourier-domain anterior segment optical coherence tomography (FD-ASOCT) and evaluate its application in dry eye screening and diagnosis.

METHODS

One hundred forty-six patients with dry eye and 160 healthy controls were enrolled in this prospective, randomized, case-control study and grouped according to age: group A (0-19 years), group B (20-39 years), group C (40-59 years), and group D (>60 years). Tear meniscus height, tear meniscus depth, and tear meniscus cross-sectional area (TMA) were measured using FD-ASOCT (RTVue-100); corneal fluorescein staining, tear film breakup time, Schirmer I test, and a dry eye questionnaire were also estimated.

RESULTS

Tear meniscus values were significantly correlated with clinical examination results and dry eye syndrome. Mean tear meniscus height, tear meniscus depth, and TMA values of patients with dry eye were significantly lower than those of the controls (P < 0.05). Tear meniscus values were negatively correlated with age in healthy Chinese subjects. Intraindividual variations in optical coherence tomography results were small in each group. Accuracy of dry eye diagnosis by FD-ASOCT was approximately 70%, and the clinical diagnostic critical point became lower with increasing age. Significant differences were observed in the tear meniscus borderline, TMA, and tear transparency between the 2 groups.

CONCLUSIONS

FD-ASOCT provides blur-free imaging and precise measurement of the tear meniscus, which is consistent with clinical examinations. Therefore, FD-ASOCT is expected to become a valuable technique in dry eye screening and diagnosis.

An investigation of the efficacy of a novel ocular lubricant

OBJECTIVE

To investigate the efficacy of a novel ocular lubricant compared with a commercially marketed ocular lubricant in a group of noncontact lens wearers currently using over-the-counter products for the management of symptoms of moderate to severe dry eye.

METHODS

This was a prospective, double-masked study that randomized 110 subjects in a ratio of 1:1 to receive a novel ocular lubricant (test group) or a marketed ocular lubricant (control group). Subjects were instructed to instill the lubricant eye drops at least three times daily. After enrollment, subjects were evaluated at baseline and at 7 and 30 days. They were also required to complete a series of home-based subjective questionnaires after 15 days. Main outcomes were subjective symptoms and objective clinical assessment at 7 and 30 days.

RESULTS

The test group had higher overall comfort ratings than the control group (P = 0.012). Seventy-one percent of the test group and 57% of the control group said the drops used "somewhat" or "definitely" improved ocular comfort; 62% of the test group had greater end-of-day comfort compared with 45% of the control group (P = 0.015). There were no between-group differences in visual acuity, tear quality or quantity, corneal staining, conjunctival staining, or bulbar and limbal conjunctival hyperemia.

CONCLUSIONS

The novel ocular lubricant offers equivalent or superior comfort compared with a marketed lubricant eye drop. Objective clinical outcomes were not statistically significantly different between the two groups.

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

PURPOSE

To compare anterior segment spectral-domain optical coherence tomography (SOCT) tear meniscus height (TMH) measures with those from the more commonly used time-domain OCT (TOCT).

METHODS

The right eye of 50 healthy subjects had images of their TMH captured with TOCT (OCT2) and SOCT (RTVue-100). Data were acquired using two different anterior segment lenses, the cornea/anterior module-short (CAM-S) and long (CAM-L), on the SOCT. Images were then analyzed for differences in their derived TMH.

RESULTS

The average TMH for TOCT was 0.280 ± 0.139 mm, whereas the mean TMH measured using the SOCT was 0.354 ± 0.163 mm and 0.345 ± 0.167 mm for the CAM-S and CAM-L, respectively. There was a significant difference (p < 0.001) when comparing TOCT with either of the SOCT lenses. There was no statistically significant difference between the CAM-L and CAM-S (p = 1.0). Bland-Altman analysis showed poor agreement between TOCT and SOCT (95% limits of agreement -0.138 to + 0.285 mm for the CAM-S and -0.185 to +0.315 mm for the CAM-L).

CONCLUSIONS

The RTVue-100 produces TMH measurements that are significantly higher than OCT2 in a normal patient population. However, the RTVue-100 showed a number of other advantages over the OCT2 in the measurement and analysis of images. Future work needs to determine the causative factors behind the observed differences.

Influence of the blink interval on tear meniscus height in soft contact lens and nonlens wearers

PURPOSE

Tear meniscus height (TMH) is an indirect measurement of tear film volume. This study investigated the temporal changes in the TMH during the blink interval in the morning (8-9 am) and at the end of the day (5-6 pm) in both soft contact lens (CL) and nonlens wearers (NLW).

METHODS

Fifty participants (25 CL; 25 NLW) were evaluated for their subjective symptoms, TMH, noninvasive break up time, and bulbar hyperemia at the am and pm visits on the same day. The TMH was measured at set intervals between 2 and 15 sec during the blink interval, using an optical coherence tomographer.

RESULTS

The NLW group revealed no changes in a variety of symptoms during the day, whereas the CL group reported an increase in dryness (P=0.03) and grittiness (P=0.02) over the day. For both groups, the TMH and calculated tear meniscus volume revealed lower values immediately after the blink and increased progressively afterwards, mainly due to reflex tearing. The am tear meniscus volume values tended to be higher than the pm values for both groups, but this was not significant (NLW P=0.13; CL P=0.82). Noninvasive break up time deteriorated during the day for both groups but was only significant for the CL group (P=0.002), whereas bulbar hyperemia revealed no statistically significant change for either group.

CONCLUSIONS

Reflex tearing may play a substantial role in the TMH differences observed over the blink interval. Standardization of the time when a TMH measurement is performed will be valuable in comparing tear film clinical studies.

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

PURPOSE

To investigate the applicability of tear meniscus height (TMH) measurement using Visante optical coherence tomography (OCT) in the diagnosis of dry eye disease.

DESIGN

Prospective, controlled, single-center study.

PARTICIPANTS

Twenty-four right eyes of 24 patients (6 males, 18 females; mean age, 63.14±13.4 years) with definite dry eye according to the Japanese dry eye diagnostic criteria and 27 right eyes of 27 control subjects (12 males, 15 females; mean age, 56.04±14.22 years) were recruited.

METHODS

All subjects underwent slit-lamp TMH measurement, OCT upper and lower TMH measurements, tear film breakup time (BUT) measurements, vital stainings, and Schirmer test. The results were compared between the 2 groups by Mann-Whitney test.

MAIN OUTCOME MEASURES

The correlation between the clinical findings of slit-lamp TMH, strip meniscometry examination, tear functions, vital staining scores, and the OCT upper and lower TMH parameters were tested by Spearman's correlation test. Receiver operating characteristic (ROC) curve technique was used to evaluate the sensitivity, specificity and cutoff values of OCT TMH examination in the diagnosis of dry eye.

RESULTS

The OCT upper and lower TMH values, slit-lamp TMH, strip meniscometry, tear film BUT, and vital staining scores were significantly lower in the dry eye patients compared with controls (P<0.001). A significant correlation between the OCT upper and lower TMH measurements as well as slit-lamp TMH, strip meniscometry, tear functions, vital staining scores, and the Schirmer test was found. The ROC curve technique analysis of the OCT lower TMH showed that, when the cutoff value was set at <0.30 mm, the sensitivity and specificity of the testing were 67% and 81%, respectively.

CONCLUSIONS

The Visante OCT is a quick, noninvasive method for assessing the TMH, with acceptable sensitivity, specificity, and repeatability, and may have potential applications for the diagnosis and evaluation of dry eye disease.

Tear measurement in prosthetic eye users with fourier-domain optical coherence tomography

PURPOSE

To investigate whether Fourier-domain (FD) optical coherence tomography (OCT) can measure the tear meniscus of anophthalmic patients using prosthetic eyes and to compare the characteristics of normal and artificial eyes.

DESIGN

Prospective, nonrandomized, observational case series.

METHODS

Thirty-one patients who had undergone anophthalmic surgery in 1 eye and had been wearing artificial eyes for more than 6 months were included. Subjects with socket inflammation, contracted sockets, or other known lid disorders were excluded. Patients were asked to complete a questionnaire regarding their demographic status and dry eye symptoms before treatment, and FD OCT scanning and the Schirmer test were performed. Three images were obtained by FD OCT on each normal and anophthalmic eye, and the tear meniscus height, tear meniscus depth, and tear meniscus angle were measured with computer calipers.

RESULTS

FD OCT was able to visualize the tear meniscus of both normal and artificial eyes. The mean tear meniscus height of artificial eyes was significantly lower than that of normal eyes (200.59 +/- 79.68 mum vs 261.24 +/- 86.17 mum; P < .001). Mean tear meniscus depth, tear meniscus area, and tear meniscus volume also were significantly lower in artificial eyes than in normal eyes. The dry eye symptom score showed significantly negative correlation with tear meniscus height. The Schirmer test results correlated with tear meniscus parameters in normal eyes, but not in artificial eyes.

CONCLUSIONS

FD OCT is a valuable clinical tool in the evaluation of tear meniscus height in normal and artificial eyes. In addition, tear meniscus height can be a useful clinical parameter that estimates symptoms of ocular dryness and discomfort in both normal and artificial eyes.

Optical coherence tomography of the anterior segment

Perhaps no diagnostic technology has emerged as rapidly in ophthalmology as optical coherence tomography (OCT). A single clinical device for this noninvasive imaging technique was first released in 1996, and now at least ten clinical devices are available. Although the first clinical anterior segment OCT was marketed only 2 years ago, a substantial amount of work has been done using modified retinal imagers or prototype laboratory-based imagers. In this review, we discuss OCT imaging primarily of the cornea. We also highlight previous and current publications on nonclinical and clinical uses of the device to illustrate how anterior segment OCT can be used to understand corneal structure and function in health and disease.