Effect of airflow exposure on the tear meniscus

Tear meniscus height agreement and reproducibility between two corneal topographers and spectral-domain optical coherence tomography

CLINICAL RELEVANCE

Tear meniscus height (TMH) is an important clinical marker in dry eye diagnosis and management.

PURPOSE

To evaluate the reproducibility and agreement of TMH measurements in non-clinical participants using the Oculus Keratograph 5 M, Medmont Meridia, and Spectral-domain optical coherence tomography (Spectralis SD-OCT).

METHODS

Fifty-six participants (mean 43.8 ± 22.4 years) were recruited for this cross-sectional study. Image acquisitions were performed on the three devices, sequentially and randomized. The repeatability and reproducibility of inter-observer and inter-device analysis were performed. Repeated measures ANOVA and Bland-Altman Plots were used to evaluate the agreement between devices.

RESULTS

The mean TMH with the Oculus Keratograph 5 M, Medmont Meridia and Spectralis SD-OCT were 0.29 ± 0.16 mm, 0.24 ± 0.09 mm and 0.27 ± 0.16 mm, respectively. There were no significant inter-observer differences (paired t-tests, p < 0.001). All the devices exhibited good inter-observer reliability (ICC ≥ 0.877), and good repeatability (CV ≤ 16.53%). Inter-device reliability is moderate (ICC = 0.621, p < 0.001). Repeated measures ANOVA revealed that TMH measurements given by the Spectralis SD-OCT are not significantly different from the Oculus Keratograph 5 M (p = 0.19) and the Medmont Meridia (p = 0.38). TMH measurements from Oculus Keratograph 5 M were significantly higher than those from Medmont Meridia (p = 0.02). Correlations between the mean TMH and the difference in the TMH measurements were positive for Oculus Keratograph 5 M and Medmont Meridia (r2 = 0.62, p < 0.001), negative for Medmont Meridia and Spectralis SD-OCT (r2 = -0.59, p < 0.001), and not significant for Oculus Keratograph 5 M and Spectralis SD-OCT (r2 = 0.05, p = 0.74). A strong correlation was found for TMH measured with all devices (r2 = 0.55 to 0.81, p < 0.001).

CONCLUSIONS

The Oculus Keratograph 5 M, Medmont Meridia, and Spectralis SD-OCT provide reliable and reproducible inter-observer TMH measurements. Inter-device reliability is moderate, with a close correlation between Spectralis SD-OCT and the Oculus Keratograph 5 M. Oculus Keratograph 5 M and Medmont Meridia are repeatable devices appropriate for the measurement of TMH, but they are not interchangeable in clinical practice.

Dry Eye-Related Risk Factors for Digital Eye Strain

OBJECTIVES

To evaluate dry eye-related lifestyle and demographic factors associated with digital eye strain (DES).

METHODS

An anonymous online survey was conducted in 851 university students. Participants were classified into DES (computer vision syndrome questionnaire [CVS-Q]≥6) or non-DES (CVS-Q<6). Respondents completed three dry eye questionnaires (Ocular Surface Disease Index [OSDI]; 5-item Dry Eye Questionnaire [DEQ-5]; 8-item Contact Lens Dry Eye Questionnaire) and were surveyed on dry eye risk factors contemplated by the Tear Film and Ocular Surface Society Dry Eye Workshop II.

RESULTS

Six hundred twenty-eight participants were classified into the group with DES and 222 into the group without DES. Participants with DES slept fewer hours, spent more hours indoors with air conditioning, drank more caffeinated beverages, used the computer for longer periods, reported poorer health quality, and obtained a higher score in all questionnaires (P<0.025). A higher proportion of the participants were female, had several health disorders, and took several medications associated with dry eye (P<0.029). Multivariate logistic regression analysis revealed that stress (P=0.035), contact lens wear (P=0.011), hours of computer use per day (P=0.010), migraine headaches (P=0.013), and a higher OSDI (P<0.001) and DEQ-5 score (P<0.001) were associated with DES.

CONCLUSIONS

Several dry eye-related risk factors and health conditions are associated with suffering from DES. Clinicians should acknowledge the relevance of triaging questions and dry eye disease risk factors when dealing with patients who view screens for extended periods.

Ocular Surface Changes Associated with Face Masks in Healthcare Personnel during COVID-19 Pandemic

The aim of this study was to investigate ocular surface changes associated with face mask (FMs) use of healthcare personnel during the COVID-19 pandemic. We prospectively evaluated 200 eyes of 100 individuals during working hours and 40 eyes of 20 individuals during their rest days as a control group. Dry eye symptoms were assessed with the Ocular Surface Disease Index (OSDI) and McMonnies questionnaire. The clinical investigation included the best corrected visual acuity (BCVA), corneal fluorescein staining (FS), break-up time (BUT), and Schirmer test I before and after a 7-h work shift with a continuative use of surgical or N95 masks. The control group was evaluated similarly twice a day, at 8:00 a.m. and at 3:00 p.m.. In the study group, BCVA, FS, BUT, and Schirmer test were investigated and there was a significant negative variation at the end of the shift. On the contrary, the control group did not show significant variations of any clinical feature. Furthermore, no significant changes in clinical parameters were observed during the use of surgical or N95 masks. In conclusion, FMs continuative use resulted in daily ocular surface modifications specifically in healthcare personnel.

Ocular surface disturbance in patients after acute COVID-19

Background

We investigated the ocular surface disturbances in COVID‐19 patients discharged from the hospital.

Methods

One hundred and seventy‐nine eyes of 109 healthy participants and 456 eyes of 228 post‐COVID‐19 patients received comprehensive eye examinations; the latter were interviewed with questionnaires on ocular symptoms before and after COVID‐19 diagnosis. Associations of ocular surface manifestations with virological and ophthalmic parameters were evaluated by multivariable mixed linear or logistic regression models.

Results

Mean interval between COVID‐19 diagnosis and ophthalmic evaluation was 52.23 ± 16.12 days. The severity of meibomian gland dysfunction (MGD) based on clinical staging was higher in post‐COVID‐19 than healthy eyes (1.14 ± 0.67 vs. 0.92 ± 0.68, p = 0.002) and so was ocular surface staining score (0.60 ± 0.69 vs. 0.49 ± 0.68, p = 0.044). Patients requiring supplementary oxygen during hospitalisation had shorter tear break‐up time (β −1.63, 95% CI ‐2.61 to −0.65). Cycle threshold (Ct) value from upper respiratory samples (inversely correlated with viral load) at diagnosis had an OR = 0.91 (95% CI 0.84–0.98) with new ocular surface symptoms 4 weeks after diagnosis. The presence of ocular surface symptoms 1 week prior to COVID‐19 diagnosis showed an OR of 20.89 (95% CI 6.35–68.66) of persistent or new ocular symptoms 4 weeks afterward.

Conclusions

MGD and ocular surface staining are more common and severe in post‐COVID‐19 patients. Patients with higher viral loads have greater risks of ocular surface symptoms. Patients requiring supplementary oxygen are more likely to show tear film instability. Ocular surface evaluation should be considered 1–3 months following hospital discharge for any COVID‐19 patient.

Face Mask-Related Ocular Surface Modifications During COVID-19 Pandemic: A Clinical, In Vivo Confocal Microscopy, and Immune-Cytology Study

Purpose

The purpose of this study was to describe the face mask (FM)-related ocular surface changes using clinical tests, in vivo confocal microscopy (IVCM) and impression cytology (IC), and to investigate the Dry Eye-related Quality of life Score (DEQS).

Methods

Sixty-six patients with dry eye disease (DED) and 62 healthy subjects (group 2) using FM were enrolled. Groups were divided into: groups 1A and 2A: < 3 hours of FM wear; groups 1B and 2B: 3 to 6 hours; and groups 1C and 2C: > 6 hours. Patients underwent DEQS questionnaire, break-up time (BUT), Schirmer test I (STI), fluorescein and lissamine staining (FS and LS), IVCM to determine corneal dendritic cell density (DCD) and goblet cell density (GCD), and IC to measure HLA-DR, at baseline and after 3 months.

Results

FM use duration before enrollment was 27 ± 2.3 and 30 ± 4.1 (days ± SD) for groups 1 and 2 (P > 0.05). After 3 months, DEQS worsened in groups 1B and 1C, STI in groups 1A to 1C, FS and LS in group 1C (P < 0.05); in controls, BUT and FS worsened only in group 2C (P < 0.05). DCD significantly increased in groups 1A to 1C and HLA-DR in groups 1B and 1C (P < 0.05), whereas GCD did not significantly change. DCD and HLA-DR increased only in group 2C (P < 0.05). DEQS significantly correlated with DCD (P = 0.05, r = 0.698; P < 0.001, r = 0.832) and HLA-DR (P = 0.043, r = -0.687; P < 0.001, r = 0.861) at baseline and 3 months.

Conclusions

Use of FM increases ocular surface inflammation and negatively impacts the quality of life in patients with DED.

Translational Relevance

The study of the prolonged use of FM effects may be relevant to managing DED.

Use of digital displays and ocular surface alterations: A review

Digital display use has been accepted to be implicated as a contributing factor for dry eye disease (DED). Abnormal blinking during computer operation, including a reduced blink rate and an incomplete eyelid closure, increased palpebral fissure as consequence of high visualization angles, and meibomian gland dysfunction associated to long-term display use, are behind the increased prevalence of dry eye signs and symptoms found in digital display users. Previous research reveals significant reductions in tear volume and stability, alterations in tear film composition, including increased osmolarity, inflammatory cytokines, oxidative stress markers and reduced mucin secretion, eyelid abnormalities and ocular surface damage, encompassing corneal and conjunctival staining and bulbar redness, as a direct consequence of digital display use. In this regard, individual differences in the way that the various digital displays are typically set up and used may account for differences in their effects on induced dryness signs and symptoms. Furthermore, factors such as the use of contact lenses or inappropriate working environments, usually accompanying the use of displays, may significantly increase the prevalence and the severity of induced dry eye. Other factors, such as old age and female gender are also relevant in the appearance of associated alterations. Finally, clinicians should adopt a treatment strategy based on a multidirectional approach, with various treatments being applied in conjunction.

The protective efficacy and safety of bandage contact lenses in children aged 5 to 11 after frontalis muscle flap suspension for congenital blepharoptosis: A single-center randomized controlled trial

BACKGROUND

Postoperative complications, lagophthalmos and exposure keratopathy sometimes occur after surgery for congenital blepharoptosis. Bandage contact lenses (BCL) can help prevent some ocular surface disorders. The study aims to evaluate the efficacy and safety of BCL for protection of the ocular surface in children aged 5 to 11 years after frontalis muscle flap suspension for congenital blepharoptosis.

METHODS

We conducted a prospective randomized clinical study of 30 eyes of 30 patients with congenital blepharoptosis consecutively enrolled at the Ophthalmology Ward of the Children's Hospital of Chongqing Medical University, China from September 1, 2016, to February 30, 2017. After frontalis muscle flap suspension surgery, patients were randomly assigned to undergo BCL application (BCL group, 15 eyes) or no BCL application (control group, 15 eyes). All patients were treated with bramycin 0.3% and polyvinyl alcohol drops after surgery. The primary outcomes were dry eye assessed by tear film break time (TFBUT), fluoresce in corneal staining (FCS) on slit-lamp on days 1, 3, and 15 postoperatively, and lower tear meniscus height (LTMH) on optical coherence tomography on days 1 and 15 postoperatively. Secondary outcomes were pairwise correlation of TFBUT, FCS and LTMH.

RESULTS

In the BCL group, abnormal TFBUT and FCS were only found in 2 patients (13.33%) on postoperative day 15. In the control group, the incidence of dry eye assessed by TFBUT was 67.00% (10/15 eyes) on day 1, 73.33% (11/15 eyes) on day 3, and 53.33% (8/15 eyes) on day 15 (P < .001). LTMH were significantly higher in the BCL group than the control group postoperatively (P < .001). Significant positive correlations were found between LTMH and TFBUT pre-operation and on days 1 and 15 post-operation. For LTMH and FCSS (R = -0.815, P < .001), and TFBUT and FCS (R = -0.837, P < .001), the Pearson coefficient was negative on postoperative day 1, but not correlated on day 15.

CONCLUSIONS

Silicone hydrogel BCL were safe and efficacious for protective use in children after frontalis muscle flap suspension for congenital blepharoptosis.

External eye symptoms in indoor environments

Eye irritation, for example dry or irritated eyes, is generally among top three reported symptoms in office-like environments, in particular among workplaces with cognitive demanding visual display unit (VDU) work. The symptoms are especially among middle and advanced ages and particularly among women more than men. The symptoms are also among the most commonly reported complaints in the eye clinic. To be in a position to interpret the high prevalence of eye symptoms, a multidisciplinary and integrated approach is necessary that involves the external eye physiology (separate from internal eye effects), eye diseases (evaporative dry eye (DE), aqueous-deficient DE, and gland dysfunctions), and risk factors that aggravate the stability of precorneal tear film (PTF) resulting in hyperosmolarity and initiation of inflammatory reactions. Indoor environmental, occupational and personal risk factors may aggravate the PTF stability; factors such as age, contact lenses, cosmetics, diet, draft, gender, low humidity and high temperature, medication, outdoor and combustion pollutants, and VDU work. Psychological stressors may further influence the reporting behavior of eye symptoms. The impact of the risk factors may occur in a combined and exacerbating manner.

The Effects of Increasing Ocular Surface Stimulation on Blinking and Tear Secretion

PURPOSE

To investigate the effect of varying levels of ocular surface stimulation on the timing and amplitude of the blink and tear secretion.

METHODS

Following instillation of fluorescein dye, increasing levels of air flow were directed toward the central corneas of 10 healthy subjects. Interblink interval (IBI), tear meniscus height (TMH), and fluorescence intensity were measured simultaneously. Because blinking can obscure changes in TMH, we developed novel measures of tear secretion by calculating tear meniscus fluorescein concentration (TMFC) from intensity using a mathematical model. The change of TMH and TMFC over trials and the slope of the TMFC within each IBI (IBI-TTR) were further calculated.

RESULTS

The mean IBI was decreased by 8.08 ± 8.54 seconds from baseline to maximum air stimulation. The TMH increase was highly variable (0.41 ± 0.39 mm) among subjects, compared to the fluorescence tear turnover metrics: decrease in TMFC of 2.84 ± 0.98 natural logarithm or ln(%) and IBI-TTR of 0.065 ± 0.032 ln(%)/sec. Ocular surface stimulation was highly correlated with the TMFC and IBI-TTR, but less so with TMH (Pearson's r = 0.71, 0.69, and 0.40, P < 0.01, respectively). Blinking and tearing were significantly correlated with each other (Pearson's r = 0.56, P < 0.01), but tearing lagged behind by an average of 6.54 ± 4.07 seconds.

CONCLUSIONS

Blinking and tearing share a common origin with sensory stimulation at the ocular surface. Both showed a dose-response increase with surface stimulation and were correlated with each other. These methods can potentially be used to understand alterations in ocular surface sensory function and associated protective responses in dry eye and other disorders of the ocular surface.

New method for evaluation of early phase tear clearance by anterior segment optical coherence tomography

PURPOSE

To describe a new method of measuring early phase tear clearance by anterior segment optical coherence tomography (AS-OCT).

METHODS

Sixty normal subjects were divided into a young group (30 subjects; 29.6 ± 7.2 years) and an elder group (30 subjects; 71.4 ± 10.8 years). AS-OCT (CASIA SS-1000, Tomey, Japan) with customized software was used to record the tear meniscus at the centre of the lower eyelid. Five microlitres of lukewarm saline solution was dropped into the lower conjunctival sac, and an image of the tear meniscus was obtained immediately and again 30 seconds after natural blinking. The tear meniscus height (TMH) and tear meniscus area (TMA) were measured in the AS-OCT images, and the percentage decrease in the TMH and TMA was used as a measure of the tear clearance. Correlations between tear clearance and clinical features including degree of conjunctivochalasis, degree of protrusion of inferior lacrimal punctum, distance of lacrimal punctum from the Marx line and fluorescein clearance rates were also determined in another healthy population consisting of 30 subjects.

RESULTS

The OCT tear clearance rate was 35.2 ± 11% for TMH and 28.1 ± 12.4% for TMA in the young group, and 12.4 ± 7.3% and 6.2 ± 9.1%, respectively in the elder group. The differences were significant for both the TMH (p = 0.017) and the TMA (p = 0.024). The OCT-determined tear clearance was positively correlated with the fluorescein clearance rate, and negatively correlated with the distance between the lacrimal punctum and Marx line, degree of conjunctivochalasis and degree of lacrimal punctum protrusion.

CONCLUSION

AS-OCT can be used as a rapid, non-invasive and quantitative method of determining the early phase tear clearance rate in a normal healthy population.

TearLab® Osmolarity System for diagnosing dry eye

Dry eye (DE) disease is an impairment of the lachrymal unit function and one the most frequent eye problems. A major challenge is to find accurate diagnostic criteria to be able to define DE severity, as symptoms poorly correlate with clinical signs. Tear osmolarity is considered a key factor in DE onset and perpetuation; its measurement is now possible in clinical setting by an innovative electrical impedance-based lab-on-a-chip technology. This article outlines the features of DE disease and the limitations of current clinical tests. The role of tear osmolarity in DE etiopathogenesis is surveyed, and the pitfalls in measurement are discussed. Diagnostic performance, accuracy and clinical applications of the technology in focus are critically reviewed. The instrument offers the possibility to measure tear osmolarity in a rapid and reliable way in daily practice. As scientific evidence grows, it is expected in the future that it will represent an objective indicator of ocular surface health in the management of DE disease and in clinical trials.

Long-term results of treatment with diquafosol ophthalmic solution for aqueous-deficient dry eye

PURPOSE

To evaluate the preliminary long-term efficacy of diquafosol ophthalmic solution for aqueous-deficient dry eye.

METHODS

Fifteen patients with mild-to-moderate aqueous-deficient dry eye were enrolled. After a washout period, the patients were treated with 3 % diquafosol ophthalmic solution for 6 months. We assessed 12 subjective dry eye symptoms, corneal and conjunctival staining with fluorescein, tear film break-up time (BUT), lower tear meniscus height measured with anterior-segment optical coherence tomography, Schirmer's testing, and adverse reactions at baseline and 1, 3, and 6 months after the start of treatment.

RESULTS

Treatment with diquafosol ophthalmic solution significantly improved dry eye symptoms, corneal staining, BUT, and tear meniscus height at 1 month and maintained the effectiveness for 6 months. Conjunctival staining significantly improved 3 and 6 months after treatment. No significant adverse reactions developed.

CONCLUSIONS

Prolonged use of diquafosol ophthalmic solution for 6 months produced significant improvement both subjectively (dry eye symptom score) and objectively (ocular staining score and tear function tests) for aqueous-deficient dry eye.