Use of the Tearscope Plus and attachments in the routine examination of the marginal dry eye contact lens patient

Blink completeness and rate in dry eye disease: An investigator-masked, prospective registry-based, cross-sectional, prognostic study

PURPOSE

To investigate the prognostic ability of blink rate and the proportion of incomplete blinking to predict dry eye disease diagnosis, as defined by the TFOS DEWS II criteria.

METHODS

A total of 453 community residents (282 females, 171 males; mean ± SD age, 37 ± 19 years) were recruited in an investigator-masked, prospective registry-based, cross-sectional, prognostic study. Dry eye symptomology, tear film quality, and ocular surface characteristics were assessed in a single clinical session, and blink parameters evaluated by an independent masked observer.

RESULTS

Overall, 214 (47 %) participants fulfilled the TFOS DEWS II criteria for dry eye disease. Multivariate regression analysis demonstrated that an increased proportion of incomplete blinking was associated with a higher odds of dry eye disease (odds ratio, 1.12 per 10 % increase; 95 % CI, 1.05-1.19; p < 0.001), with the Youden-optimal prognostic threshold proportion being ≥ 40 % incomplete blinking. Higher levels of incomplete blinking were also associated with poorer dry eye symptomology, tear film stability, corneal and lid margin staining, lipid layer thickness, meibography, and meibum quality (all p ≤ 0.03). No significant associations were detected between blink rate and ocular surface parameters (all p > 0.10).

CONCLUSIONS

The degree of incomplete blinking is a significant predictor of dry eye disease, and the utility of incorporating blink assessment into diagnostic workup algorithms warrants further investigation. The association with meibomian gland dropout, expressed meibum quality, and lipid layer thickness would suggest that incomplete blinking may predispose towards the development of meibomian gland dysfunction.

Repeatability of tear film lipid layer interferometry measurements: A randomized, crossover study

PURPOSE

This study aimed to assess intrasession repeatability, diurnal intravisit and day-to-day intervisit reproducibility of qualitative tear film lipid layer interferometry grading obtained from the Keratograph 5M (Oculus Optikgeräte GmbH, Wetzlar, Germany), and automated quantitative layer thickness measurements obtained from the TearScience LipiView II Ocular Surface Interferometer (Johnson & Johnson Vision, Milpitas, CA), in community residents, not stratified by dry eye or blepharitis status.

METHODS

Forty community residents (24 women, 16 men; age mean ± standard deviation, 36 ± 14 years) were recruited in an investigator-masked, randomized, crossover study. Participants attended two sessions 6 hours apart on the same day and a third session on a separate day. During each session, tear film lipid layer grading and thickness measurements were performed in triplicate, in a masked manner, with 10-minute intervals between each measurement.

RESULTS

There were no significant differences in lipid layer grading and thickness measurements in all pairwise intrasession, diurnal intravisit, and day-to-day intervisit comparisons (all p≥0.19), and positive correlations were observed in all cases (all p<0.001). The weighted Cohen κ coefficients for intrasession repeatability and diurnal intravisit and day-to-day intervisit reproducibility of qualitative lipid layer grading ranged from 0.670 to 0.867. The test-retest repeatability of quantitative lipid layer thickness measurements ranged from 4.5 to 11.7 nm, and the Bland-Altman biases were within the order of 3 nm in all pairwise comparisons. The intraclass correlation coefficients for lipid layer thickness measurements exceeded 0.80 for all intrasession comparisons and were between 0.60 and 0.80 for all diurnal intravisit and day-to-day intervisit comparisons.

CONCLUSIONS

Both qualitative grading and automated quantitative thickness measurements of tear film lipid layer interferometry demonstrated relatively favorable levels of intrasession repeatability and diurnal intravisit and day-to-day intervisit reproducibility. The study findings would support the use of either qualitative or quantitative measurement in clinical and research settings, as a reliable tool for assessing lipid layer interferometry.

Diagnostic Cut-Off Values Based on Lipid Layer Pattern for Dry Eye Disease Subtypes Assessment

Background: The aim of the present study was to establish a cut-off value of the Lipid Layer Pattern (LLP) between participants with different subtypes of Dry Eye Disease (DED) including Deficient Dry Eye (ADDE), Evaporative Dry Eye (EDE), and Mixed Dry Eye (MDE). Methods: 240 participants diagnosed with DED according to the Tear Film and Ocular Surface Society in the Dry Eye Workshop II guidelines were included in the study. Tear Meniscus Height (TMH) using the Tearscope illumination and Meibomian Gland Loss Area (MGLA) using the Keratograph 5M were assessed to categorize the participants into an ADDE group, EDE group, or MDE group. Then, the LLP was assessed using the Tearscope following the Guillon (LLP-G) and Colour (LLP-C) schemes. Results: Receiver Operating Characteristics (ROC) showed that both LLP-G and LLP-C have no diagnostic potential in distinguishing between ADDE and EDE participants (both p ≥ 0.724). However, to differentiate the ADDE participants from the MDE, ROC procedures showed a good diagnostic potential with cut-off values of Closed Meshwork-Wave (AUC ± SD = 0.609 ± 0.049, p = 0.038, sensitivity: 23.9%; specificity: 76.1%) and Grey-White (AUC ± SD = 0.611 ± 0.050, p = 0.034, sensitivity: 40.7%; specificity: 73.9%) for LLP-G and LLP-C, respectively. Also, a significant potential to distinguish between the EDE from MDE participants was found, with cut-off values of Closed Meshwork (AUC ± SD = 0.604 ± 0.049, p = 0.043, sensitivity: 40.8%; specificity: 76.1%) and Grey-White (AUC ± SD = 0.604 ± 0.051, p = 0.038, sensitivity: 44.7%; specificity: 73.9%) for LLP-G and LLP-C, respectively. Conclusions: Using the Tearscope, both LLP-G and LLP-C has diagnostic potential to distinguish MDE participants from the other subtypes of DED.

Temporal Progression of Entry Factors into the Vicious Circle of Dry Eye in Untreated Sufferers

BACKGROUND

Dry eye disease (DED) is characterized by the loss of ocular surface homeostasis with specific signs and symptoms. Studying the progression of a multifactorial disease is exceedingly challenging for researchers because several factors can influence it. The present study aims to study changes in tear meniscus height (TMH), lipid layer pattern (LLP), and bulbar hyperemia over time in untreated DED participants.

METHODS

This retrospective longitudinal study included 73 participants (146 eyes) diagnosed with DED since at least 2013. Participants underwent new examinations between 2021 and 2023, grouped by 8-, 6-, or 4-year follow-up periods. TMH, LLP, and bulbar hyperemia were assessed in both examinations. No participant received pharmacological treatment for DED.

RESULTS

Differences in TMH, bulbar hyperemia, and LLP between sessions were obtained in the 8-year group (p ≤ 0.027). Differences in bulbar hyperemia and LLP between sessions were obtained in the 6-year group (p ≤ 0.022). The only differences in LLP between sessions were obtained in the 4-year group (p < 0.005).

CONCLUSION

Changes in TMH were obtained after periods of eight years from the first eye examination. Also, changes in bulbar hyperemia were obtained at periods of 8 and 6 years; however, changes in LLP could be found from 4-year follow-ups.

Sutureless Dehydrated Amniotic Membrane (Omnigen) Application Using a Specialised Bandage Contact Lens (OmniLenz) for the Treatment of Dry Eye Disease: A 6-Month Randomised Control Trial

Background and Objectives: Dry Eye Disease (DED) is a chronic condition characterised by tear film instability and ocular surface disruption, significantly impacting patients' quality of life. This study aimed to provide top-level clinical evidence for the long-term efficacy of dehydrated amniotic membrane (dAM, Omnigen®) delivered via a specialised bandage contact lens (sBCL, OmniLenz) for managing moderate-to-severe DED. Materials and Methods: This randomised controlled trial (NCT04553432) involved 93 participants with moderate-to-severe DED, randomised to receive a 1-week bilateral treatment of either dAM (17 mm diameter with 6 mm central 'window') applied under a sBCL or sBCL alone. Participants were assessed at baseline and followed up at 1, 3, and 6 months post-treatment. Outcomes included changes in symptomatology, tear film and ocular surface measurements, and in vivo confocal microscopy imaging of corneal nerve parameters and corneal dendritic cell (CDC) counts. Results: The dAM-sBCL group demonstrated a 65% reduction in OSDI scores at 6 months (p < 0.001), with 88% of participants showing improvement at 1 month. Corneal staining was significantly reduced in both groups. dAM-sBCL provided significant improvements in corneal nerve parameters at 1 month, with sustained positive trends at 3 months. Additionally, dAM-sBCL significantly reduced mature CDC counts, suggesting an anti-inflammatory effect. Conclusions: Treatment with dAM-sBCL for just 1 week significantly and rapidly improved dry eye symptoms as well as ocular surface signs for at least 3 months. It also enhanced corneal nerve health while reducing activated/mature corneal inflammatory cell numbers, presenting a safe and promising new treatment for moderate-to-severe DED.

Bilateral Sutureless Application of Human Dehydrated Amniotic Membrane with a Specialised Bandage Contact Lens for Moderate-to-Severe Dry Eye Disease: A Prospective Study with 1-Month Follow-Up

Purpose

To assess changes in symptoms and ocular surface signs following a bilateral sutureless treatment of dehydrated amniotic membrane (dAM) under a specialised bandage contact lens (sBCL) in patients with moderate-to-severe dry eye disease (DED).

Patients and Methods

In this prospective pre-post interventional study, 35 patients diagnosed with moderate-to-severe DED, with an Ocular Surface Disease Index (OSDI) score >30 on current treatment, were enrolled. Assessments were conducted at baseline (day -30), after 30 days run-in with no additional treatment (day 0 - control), and 30 days post sBCL+dAM treatment (day 30 - treatment). Intervention involved two successive bilateral 4-5 day sutureless applications of dAM (17mm diameter, with a 6 mm central aperture, Omnigen® VIEW) under an 18mm sBCL (OmniLenz®). Symptomatology and ocular signs were measured using OSDI, Dry Eye Questionnaire-5 (DEQ-5), Symptom Assessment iN Dry Eye (SANDE), and other ocular surface health indicators including non-invasive breakup time, corneal and conjunctival staining, and lid wiper epitheliopathy length and width (LWE).

Results

While symptomatology remained stable during the 30-day no-treatment run-in, 1-month post-dAM treatment, there was a significant reduction in OSDI scores (from 55.8 to 32.3, p<0.001), DEQ-5 (from 14.6 to 10.0, p<0.001), SANDE frequency (from 65.2 to 43.6, p<0.001), and SANDE severity (from 59.8 to 41.1, p<0.001). Additionally, there was a notable decrease in the width of LWE staining, from grade 2 (50-75% of the lid wiper) to grade 1 (25-50% of the lid wiper) (p=0.011).

Conclusion

A bilateral 8-10-day treatment duration with dAM applied with sBCL demonstrated a 31 to 42% improvement in symptomatology and a decrease in ocular surface signs of mechanical stress. This innovative bilateral treatment approach offers a promising treatment modality for patients with refractory moderate-to-severe DED.

Diagnostic accuracy of non-invasive tear film break-up time assessed by the simple manual interferometric device

AIM

To determine the diagnostic accuracy of non-invasive tear film break-up time (NIBUT) measured by the handheld lipid layer examination instrument.

METHODS

108 patients were enrolled in this cross-sectional study and divided into two groups: patients with dry eye (n = 57) categorized by the presence of dry eye symptoms obtained by Schein Questionnaire and minimally-one objective dry eye sign (tear film break-up time <10 s or corneal, conjunctival and lid margin fluorescein staining), and healthy subjects (n = 51).

RESULTS

Dry eye subjects had significantly shorter NIBUT than healthy subjects (6 s vs 20 s, p < 0.001). Logistic regression analysis showed that shorter NIBUT values were excellent indicators of dry eye disease (p < 0.001), with consistency and no significant difference between measurements, even after standardizing the results for age and sex. NIBUT cut-off point to distinguish dry eye from healthy subjects was 12 s (sensitivity 90.2 %, specificity 88.5 %, PPV 92.5 %, NPV 85.2 %, LR +7.82, LR- 0.11, DOR 70.92, DE 89.6 %). Good, but lower accuracy was observed at cut-off value of 10 s (sensitivity 87.8 %, specificity 88.5 %, PPV 92.3 %, NPV 82.1 %, LR+ 7.61, LR- 0.14, DOR 55.2, DE 88.1 %). The area under the ROC curve (AUC) of 0.944 classified NIBUT as a diagnostic test with very high accuracy.

CONCLUSION

This study showed a high diagnostic accuracy of NIBUT measured by the handheld lipid layer examination instrument. This simple, reliable, objective and available instrument might regularly take place in routine, standard dry eye diagnostic and can be used by almost every eye specialist.

Effects of cleaning spray use on eyes, airways, and ergonomic load

BACKGROUND

Cleaning workers are exposed to chemicals and high physical workload, commonly resulting in airway problems and pain. In this study the response in the upper airways and the physical workload following airborne and ergonomic exposure of cleaning spray was investigated.

METHODS

A survey was answered by professional cleaning workers to investigate their use of cleaning sprays and the perceived effects on eyes, airways and musculoskeletal pain. A human chamber exposure study was then conducted with 11 professional cleaning workers and 8 non-professional cleaning workers to investigate the airborne exposure, acute effects on eyes and airways, and physical load during cleaning with sprays, foam application and microfiber cloths premoistened with water. All cleaning products used were bleach, chlorine, and ammonia free. The medical assessment included eye and airway parameters, inflammatory markers in blood and nasal lavage, as well as technical recordings of the physical workload.

RESULTS

A high frequency of spray use (77%) was found among the 225 professional cleaning workers that answered the survey. Based on the survey, there was an eight times higher risk (p < 0.001) of self-experienced symptoms (including symptoms in the nose, eyes and throat, coughing or difficulty breathing) when they used sprays compared to when they cleaned with other methods. During the chamber study, when switching from spray to foam, the airborne particle and volatile organic compound (VOC) concentrations showed a decrease by 7 and 2.5 times, respectively. For the whole group, the peak nasal inspiratory flow decreased (-10.9 L/min, p = 0.01) during spray use compared to using only water-premoistened microfiber cloths. These effects were lower during foam use (-4.7 L/min, p = 0.19). The technical recordings showed a high physical workload regardless of cleaning with spray or with water.

CONCLUSION

Switching from a spraying to a foaming nozzle decreases the exposure of both airborne particles and VOCs, and thereby reduces eye and airway effects, and does not increase the ergonomic load. If the use of cleaning products tested in this study, i.e. bleach, chlorine, and ammonia free, cannot be avoided, foam application is preferable to spray application to improve the occupational environment.

Categorization of the Aqueous Deficient Dry Eye by a Cut-Off Criterion of TMH Measured with Tearscope

A decrease of the Tear Meniscus Height (TMH) has been proposed as a useful indicator for Aqueous Deficient Dry Eye (ADDE) categorization. The present study aimed to calculate a TMH cut-off criterion for the categorization or severity assessment of ADDE with the Tearscope. 200 participants with a previous Dry Eye Disease (DED) diagnosis according to TFOS DEWS-II criteria were recruited. TMH by slit-lamp illumination and Lipid Layer Pattern (LLP) with Tearscope were assessed to categorise the participants into the ADDE or the Evaporative Dry Eye (EDE) group. The ADDE group was also subdivided into Mild-moderate ADDE and Moderate-severe ADDE based on TMH with slit-lamp. Additionally, the TMH was measured by Tearscope (TMH-Tc). Receiver Operating Characteristics showed that the TMH-Tc have a diagnostic capability to differentiate between ADDE and EDE participants, and between Mild-moderate or Moderate-severe ADDE, with a cut-off value of 0.159 mm (AUC = 0.843 ± 0.035, p < 0.001; sensitivity: 86.4%; specificity: 75.4%) and 0.105 mm (AUC = 0.953 ± 0.025, p < 0.001; sensitivity: 98.1%; specificity: 80.0%), respectively. The present study proposed a cut-off criterion to differentiate between ADDE and EDE participants, or between ADDE severities through TMH assessed by Tearscope.

Alterations in the ocular surface and tear film following keratoplasty

The purpose of this study was to evaluate any alterations in the tear film and ocular surface beyond the early postoperative period following penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK). This cross-sectional, contralateral-eye study compared ocular surface and tear film parameters of eyes with a previous PK or DALK in one eye and no prior surgery in the contralateral eye. Overall, 14 (87.5%) participants underwent PK, and 2 (12.5%) underwent DALK using a mechanical dissection. The median time from surgery was 3.4 years (range 1.5 to 38.7 years). The indication for unilateral keratoplasty was keratoconus in 15 (94%) participants, and corneal scarring in 1 (6%) eye, secondary to microbial keratitis. Operated eyes exhibited poorer non-invasive tear film breakup time, lower corneal sensitivity, lower sub-basal nerve density and more severe fluorescein staining scores than unoperated fellow eyes (all Q < 0.05). There were no significant differences in tear film lipid layer quality, tear meniscus height, conjunctival hyperaemia, lissamine green staining score, or meibography grade between operated and fellow eyes (all Q ≥ 0.20). Higher corneal esthesiometry threshold (lower corneal sensitivity) was correlated with shorter non-invasive tear film breakup time (Spearman’s rho =  − 0.361, p = 0.04) and increased fluorescein staining score (Spearman’s rho = 0.417, p = 0.02). Keratoplasty can induce persistent changes in the ocular surface and tear film, including: increased fluorescein staining, decreased tear film breakup time, decreased corneal sub-basal nerve plexus density, and reduced corneal sensitivity.

Analysis of Ocular Surface Characteristics and Incidence of Dry Eye Disease in Systemic Lupus Erythematosus Patients Without Secondary Sjögren's Syndrome

Objective

To investigate the differences in ocular surface characteristics, tear film quality, and the incidence of dry eye disease (DED) between Systemic Lupus Erythematosus (SLE) patients and healthy populations.

Methods

This age and gender-matched cross-sectional study included 96 SLE patients without secondary Sjögren's syndrome (SS) and 72 healthy subjects. The Ocular Surface Disease Index (OSDI), tear meniscus height (TMH), non-invasive tear film breakup time (NIKBUT), meibography, and tear film lipid layer grade were assessed. A receiver operative characteristic (ROC) curve was constructed to evaluate the predictive value of risk factors.

Results

Compared with the control subjects, a significantly greater proportion of SLE patients met the TFOS DEWS II DED diagnostic criteria (34.3 vs. 18.1%, P = 0.019). SLE patients without SS had higher OSDI scores [10.0 (4.5,18.0) vs. 5.0 (2.5,11.9), P < 0.001], and shorter NIKBUT [9.6 (6.6,15.0) vs. 12.3 (8.4, 15.8), P = 0.035]. Furthermore, TMH, Tear film lipid layer grade, and Meibomian gland (MG) dropout in SLE patients were worse than those in control subjects (all P < 0.05). For ROC analysis, the area under curve (AUC), sensitivity and specificity of prediction were 0.915, 75.8 and 92.1% for the combination of SLE disease activity index (SLEDAI), age and NIKBUT.

Conclusions

SLE patients without SS exhibited a higher risk for DED than healthy subjects, and the poorer Meibomian gland function in SLE patients may potentially contribute to the development of DED. The combined parameters of SLEDAI, age and NIKBUT showed a high efficiency for the diagnosis of DED in SLE patients, with practical clinical applications.

Validation of a new objective method to assess lipid layer thickness without the need of an interferometer

PURPOSE

This study aimed to develop and validate new metrics to objectively assess the lipid layer thickness (LLT) through the analysis of grey intensity values obtained from the Placido disk pattern reflected onto the tear film.

METHODS

Ocular surface parameters were measured using Oculus Keratograph 5 M in 94 healthy volunteers (43.8 ± 26.8 years). Subjects' LLT was subjectively classified into 4 groups using an interferometry-based grading scale. New metrics based on the intensity of the Placido disk images were calculated and compared between groups. The repeatability of the new metrics and their diagnostic ability was analysed through receiver operating characteristics (ROC) curves. The level of agreement between the new objective tool and the existing subjective classification scale was analysed by means accuracy, weighted Kappa index and F-measure.

RESULTS

Mean pixel intensity, median pixel intensity and relative energy at 5.33 s after blinking achieved the highest performance, with a correlation with LLT between r = 0.655 and 0.674 (p < 0.001), sensitivity between 0.92 and 0.94, specificity between 0.79 and 0.81, area under the ROC curve between 0.89 and 0.91, accuracy between 0.76 and 0.77, weighted Kappa index of 0.77 and F-measure between 0.86 and 0.87.

CONCLUSION

The analysis of grey intensity values in videokeratography can be used as an objective tool to assess LLT. These new metrics could be included in a battery of clinical tests as an easy, repeatable, objective and accessible method to improve the detection and monitoring of dry eye disease and meibomian gland dysfunction.

Efficacy of Intense Pulsed Light Treatment in Patients with Sjögren’s Syndrome Associated with Meibomian Gland Dysfunction

Purpose: To investigate the efficacy of intense pulsed light (IPL) treatment in patients with meibomian gland dysfunction (MGD) associated with Sjögren’s syndrome.Methods: This study included 43 patients with MGD and Sjögren’s syndrome. Patients received either IPL with meibomian gland expression (IPL/MGX) (n = 22) or MGX only (n = 21). Treatments were administered three times at a 3-week interval. Patients were followed up 6 weeks after the end of the treatment. Ocular Surface Disease Index (OSDI), tear film breakup time with fluorescein dye (FBUT), non-invasive tear breakup time, tear meniscus height (TMH), Schirmer test, SICCA ocular surface staining score, meibum quality score (MQS), and meibum expression score (MES) were evaluated at each visit. Meibomian gland dropouts (meiboscore) and tear film lipid layer grade were measured using keratography.Results: OSDI, FBUT, corneal surface staining score, MQS, meiboscore, and tear film lipid layer grade improved after IPL/MGX treatment (p < 0.05). In both treatment groups, MES significantly improved (p < 0.01 and p < 0.05 for IPL/MGX and MGX groups, respectively). The Schirmer test score, conjunctival surface staining score, and TMH after treatment were not significantly different between the groups. After treatment, the IPL/MGX group had significantly lower OSDI, FBUT, corneal staining score, MQS, and MES, but higher FBUT, compared with the MGX group (p < 0.05).Conclusions: IPL treatment effectively improved tear film, ocular surface parameters, meibomian gland function, and lipid layer grade in patients with Sjögren’s syndrome and MGD.

Evaluation of the MGDRx eyebag treatment in young and older subjects with dry eye symptoms

OBJECTIVES

This study aims to evaluate the relationship between application of the MGDRx thermal eyebag and dry eye signs and symptoms in young and older subjects and to compare the results between the two groups.

METHODS

Thirty young, healthily volunteers between 18 and 31 years of age (23.95±3.94 years) and thirty older subjects between 61 and 90 years of age (77.97±8.11 years) participated in this study. Ocular surface parameters were assessed using the Oculus Keratograph 5M, following the guidelines of the Tear Film and Ocular Surface Dry Eye Workshop II Diagnostic Methodology report. Only subjects with a positive score on at least one questionnaire and an initial Non-Invasive Keratograph Break-Up Time (NIKBUT) under 10seconds were included in the study. After thermal bag self-application in both eyes every day for 2 weeks, the protocol was carried out again. Lid massage was performed after lid warming. Compliance and degree of improvement were also assessed.

MAIN RESULTS

The young volunteer group showed an improvement in NIKBUT, lipid layer score, upper eyelid gland drop-out percentage and dry eye symptoms over the two week treatment period. Improvements in meibum quality, gland obstruction, telangiectasia scores, and dry eye symptoms were found in the older subjects. Mixed ANOVA revealed better NIKBUT and lipid layer values in the young subjects. Despite the treatment compliance being statistically higher in the older group than in the younger subjects (P=0.002), there were no significant differences in subjective improvement between groups (P=0.097).

CONCLUSION

Dry eye-related symptoms were improved after thermal bag application, while NIKBUT and lipid layer thickness were improved only in the younger subjects.

Effect of Eye Spray Phospholipid Concentration on the Tear Film and Ocular Comfort

OBJECTIVES

To evaluate the effect of eye spray phospholipid concentration on symptoms and tear film stability.

METHODS

High-concentration (Tears Again, Optima Pharma GmbH, Hallbergmoos, Germany) and low-concentration (Ocuvers, Innomedis AG, Germany) phospholipid eye sprays were sprayed onto the closed eyelids of 30 subjects (33.2±1.8 years; 20 women) in a multicentered, prospective, crossover study. Ocular comfort (visual analog scale) and noninvasive tear film stability (NIBUT) of each eye were evaluated before application (along with the Ocular Surface Disease Index), 10 min after application, and 30 min after application.

RESULTS

Comfort (high concentration: 68.5±16.4 vs. low concentration: 70.7±14.5 phospholipid) and NIBUT (high concentration: 11.5±4.6 sec vs. low concentration: 11.2±6.0 sec phospholipid) were not different (P>0.3) between sprays before application, but comfort (by 12 points, P=0.001) and NIBUT (by 5 sec, P=0.016) were significantly better with a high-concentration phospholipid spray at both 10 min and 30 min time points than those with the low-concentration phospholipid spray.

CONCLUSIONS

The liposomal eye spray with higher concentration of phospholipids significantly improved ocular comfort and tear film stability in contrast to the eye spray with lower concentration of phospholipids, hence practitioners need to choose an appropriate eye spray to maximize the patient benefit.

Demographic and lifestyle risk factors of dry eye disease subtypes: A cross-sectional study

PURPOSE

To evaluate demographic and lifestyle factors associated with aqueous deficient and evaporative dry eye disease.

METHODS

A total of 1125 general public visitors (707 females, mean ± SD age, 33 ± 21, range 5-90 years) at the Royal Society Summer Science Exhibition were recruited in a cross-sectional study. A demographic and lifestyle factor questionnaire was administered, and dry eye symptomology (DEQ-5 score), ocular surface characteristics (conjunctival hyperaemia, and infrared meibography), and tear film parameters (tear meniscus height, non-invasive breakup time, and lipid layer grade) were evaluated for the left eye of each participant within a single session. The diagnostic criteria for dry eye disease subtypes were adapted from the rapid non-invasive dry eye assessment algorithm.

RESULTS

Overall, 428 (38%) participants fulfilled the diagnostic criteria for dry eye disease, 161 (14%) with aqueous deficient dry eye disease, and 339 (30%) with evaporative dry eye disease. Multivariate logistic regression demonstrated that advancing age, female sex, reduced sleep duration, higher psychological stress, and poorer self-perceived health status were independently associated with aqueous deficient dry eye disease (all p < 0.05). Significant risk factors for evaporative dry eye disease included advancing age, East and South Asian ethnicity, contact lens wear, increased digital device screen exposure, higher psychological stress, and poorer self-perceived health status (all p < 0.05).

CONCLUSIONS

Both subtypes of dry eye disease were associated with several unique and shared demographic and lifestyle factors. The findings of this study could inform future research design investigating the utility of targeted screening and risk factor modification for the prevention and management of dry eye disease.

Association between dry eye disease, self-perceived health status, and self-reported psychological stress burden

Clinical relevance: Dry eye disease is a common chronic ocular condition, which is acknowledged to have adverse impacts on quality of life and work productivity.Background: The wide-reaching impacts of dry eye disease on mental health and quality of life have received growing attention in recent years. The purpose of this study was therefore to investigate the relationship between dry eye disease, self-perceived health status, and self-reported psychological stress burden.Methods: Three hundred and twelve community residents (178 females, 134 males; mean ± SD age, 38 ± 21 years) with no major systemic, ophthalmic, or psychiatric conditions (other than dry eye disease), were recruited in a cross-sectional study. Self-perceived health status and self-reported psychological stress burden were assessed, and dry eye symptomology, ocular surface characteristics, and tear film quality were evaluated for each participant within a single clinical session, in accordance with the global consensus recommendations of the Tear Film and Ocular Surface Society Dry Eye Workshop II reports.Results: Multivariate regression analysis, adjusted for age, sex, ethnicity, and contact lens wear, demonstrated that improved self-perceived health status was associated with decreased odds of dry eye disease, aqueous tear deficiency and meibomian gland dysfunction (all p < 0.05). Increased self-reported psychological stress burden was positively associated with dry eye disease, aqueous tear deficiency and meibomian gland dysfunction (all p ≤ 0.01).Conclusion: Dry eye disease is associated with poorer self-perceived health status and greater self-reported psychological stress burden. The findings of this study highlight the wide-reaching impacts of dry eye disease, and the importance of minimising the impacts of the condition with optimised management and actioning inter-disciplinary referral for affected patients where necessary.

Manual interferometric device for routine non-invasive tear film break-up time assessment

Purpose: To determine the feasibility of non-invasive tear break-up time (NIBUT) assessment using the Handheld tear lipid layer thickness assessment instrument and compare it with the standard tear break-up time (TBUT) test and other dry eye tests.Subjects and methods: 108 subjects were enrolled, 56 with and 52 without dry eye symptoms. Schein questionnaire was used to determine the severity of dry eye symptoms. Ocular signs were assessed by NIBUT, TBUT, lipid layer thickness (LLT), lid-parallel conjunctival folds (LIPCOF), conjunctival hyperemia, and corneal staining.Results: Median NIBUT and TBUT, and other clinical test values significantly differed among the dry eye symptoms group and control group. NIBUT yielded the most significant difference between the groups (NIBUT: 7 sec vs. 17.5 sec, p < .001, Z = 5.94; TBUT: 5 sec vs. 10 sec, p < .001, Z = 4.38; LLT: p = .007; LIPCOF: p < .001, conjunctival hyperemia: p < .047, corneal staining: p < .010). Spearman's test showed a significant correlation between NIBUT and TBUT (p < .001), NIBUT and LLT (p = .001), NIBUT and LIPCOF (p = .019), NIBUT and conjunctival hyperemia (p = .002), and NIBUT and corneal staining (p = .012) in the dry eye symptoms group. NIBUT did not significantly differ among the three measurements in both groups of patients (p = .061, p = .096), while TBUT values did in the control group (p < .001). Short NIBUT values were the main predictors and indicators of dry eye complaints (AOR = 0.87, p < .001), superior to TBUT (AOR = 0.88, p = .008) and other tests even after adjustment for age and gender.Conclusion: NIBUT measured by Handheld instrument is a simple, accessible, practical, and, most of all, reproducible and objective method that might allow NIBUT assessment on a regular basis.

An Emerging Method to Assess Tear Film Spread and Dynamics as Possible Tear Film Homeostasis Markers

Purpose: This study aims to assess the performance of an analysis method to measure in vivo the movement speed of tear film particles post-blink as a measure of tear film spreading.Materials and methods: Ocular surface parameters and the recording of tear film particles' spreading post-blink were assessed in eighty-one healthy volunteers (43.7 ± 27.0 years) using Keratograph 5 M. The developed software automatically decomposed the video into frames to manually track particles' position for 1.75 seconds after a blink. The following tear film-dynamic metrics were automatically calculated: mean, median, maximum, and minimum particles' speed at different times after blinking and time for particle speed to decrease to <1.20 mm/second. Repeatability of each tear film-dynamic metric and its correlations with ocular surface signs and symptoms were analyzed. Binomial logistic regression was performed to assess the predictability of new metrics to ocular parameters.Results: Repeatability tended to be lower just after blinking (variability of 12.24%), whereas the metrics from 0.5 s onwards had acceptable repeatability (variability below 10%). Tear film-dynamic metrics correlated positively with Non-Invasive Break-Up Time (NIKBUT) while negatively with meibomian gland drop-out. Binomial logistic regression analysis revealed that tear film-dynamic metrics were able to predict NIKBUT. Nevertheless, no statistically significant association was found with gland drop-out. This means that higher particle speed is related to larger NIKBUT. The metric "time for particle speed to decrease to <1.20 mm/second" can be considered the best metric to assess the quality of the tear film, since it was more strongly correlated with NIKBUT (r = 0.42, p = .004), it was more strongly associated in the binomial logistic regression analysis with NIKBUT and showed good repeatability (variability = 5.49%).Conclusions: Tear film-dynamic metrics are emerging homeostasis parameters for assessing indirectly the tear film quality in natural conditions with acceptable repeatability.

Modifiable lifestyle risk factors for dry eye disease

PURPOSE

To examine the association between modifiable lifestyle factors and dry eye disease.

METHODS

Three hundred and twenty-two community residents (186 females, 136 males; mean ± SD age, 41 ± 22 years) with no major systemic or ophthalmic conditions (other than dry eye disease) were recruited in a cross-sectional study. A lifestyle factor questionnaire was administered, and dry eye symptomology, ocular surface characteristics, and tear film quality were evaluated for each participant within a single clinical session, in accordance with the global consensus recommendations of the TFOS DEWS II reports.

RESULTS

A total of 111 (34 %) participants fulfilled the TFOS DEWS II diagnostic criteria for dry eye disease. Multivariate regression analysis demonstrated that advancing age, female sex, East Asian ethnicity, and increased digital screen exposure time were positive risk factors for dry eye disease (all p < 0.05), while increased caffeine consumption was a protective factor (p = 0.04).

CONCLUSIONS

Increased digital screen exposure time and reduced caffeine consumption were modifiable lifestyle factors associated with higher odds of dry eye disease. These findings might contribute to informing the design of future prospective research investigating the efficacy of preventative intervention and risk factor modification strategies.

Prophylactic action of lipid and non-lipid tear supplements in adverse environmental conditions: A randomised crossover trial

PURPOSE

To evaluate the prophylactic benefits of lipid-based and non-lipid-based artificial tear lubricants, in dry eye disease, after adverse environmental exposure.

METHODS

Twenty-eight participants with dry eye disease were recruited in a prospective, double-masked, randomised crossover trial. On separate days, participants were randomised to receive a single application of a lipid-containing tear supplement (Systane Complete) to one eye, and a non-lipid containing eye drop (Systane Ultra) to the contralateral eye. Participants were then exposed to a previously validated simulated adverse environment. Symptoms, non-invasive tear film breakup time, lipid layer grade, and tear meniscus height were assessed at three time points; baseline, following eye drop instillation, and after exposure to the adverse environment.

RESULTS

Both treatments effected improvements in symptoms and non-invasive tear film stability following instillation (all p < 0.05), although an improvement in lipid layer quality was limited to the lipid-containing nano-emulsion tear supplement (p = 0.003). Although protective effects were conferred by both treatments following exposure to the simulated adverse environment, more favourable symptomology scores, non-invasive tear film stability, and lipid layer quality were observed in the lipid-containing tear supplement group (all p < 0.05). No significant changes were observed in tear meniscus height in both treatment groups (all p > 0.05).

CONCLUSIONS

Both the lipid and non-lipid-based artificial tear supplement demonstrated prophylactic benefits in a simulated adverse environment. However, the ability to preserve tear film quality and reduce dry eye symptomology was greater with the lipid-containing eye drop.

TRIAL REGISTRATION NUMBER

ACTRN12619000361101.

Ageing and the natural history of dry eye disease: A prospective registry-based cross-sectional study

PURPOSE

To investigate the impact of ageing on ocular surface parameters, and empirically determine optimal prognostic cut-off ages for clinical markers of dry eye disease, aqueous tear deficiency, and meibomian gland dysfunction.

METHODS

A total of 1331 community residents (785 females, 546 males; mean ± SD age, 38 ± 19 years) were recruited in a prospective registry-based cross-sectional study. Dry eye symptomology, ocular surface characteristics, and tear film quality were evaluated for each participant within a single clinical session, in accordance with the global consensus recommendations of the TFOS DEWS II reports.

RESULTS

Multivariate regression analysis demonstrated positive associations between ageing and clinical markers of dry eye disease (all p ≤ 0.001). The Youden-optimal prognostic cut-off ages for signs of meibomian gland dysfunction occurred during the third decade of life (24-29 years); the optimal predictive ages for lid wiper epitheliopathy, tear film instability, hyperosmolarity, and dry eye symptoms occurred during the fourth decade of life (31-38 years); while the optimal prognostic thresholds for signs of aqueous tear deficiency and ocular surface staining occurred in the fifth and sixth decades of life (46-52 years).

CONCLUSIONS

Advancing age is a significant risk factor for dry eye disease, which represents a growing public health concern with the ageing population worldwide. Signs of meibomian gland dysfunction appeared earlier in the natural history of disease progression, and the brief delay prior to the development of other clinical dry eye signs might represent a window of opportunity for preventative interventions in the young adult age group.

Improved Demodex diagnosis in the clinical setting using a novel in situ technique

PURPOSE

To compare existing and novel diagnostic techniques for confirming ocular Demodex infestation and to recommend the most reliable method for routine use by eye care practitioners, based on yield and clinical applicability.

METHODS

Fifteen participants with a prior Demodex blepharitis diagnosis or featuring typical cylindrical dandruff (CD) collarettes, and seven healthy controls were enrolled. Demodex presence was assessed using five techniques, applied consecutively, on a minimum of two different eyelashes on each eyelid of every participant, for each test, in situ: 1. using fine-point forceps and 25-40x biomicroscopy magnification, by eyelash rotation as proposed by Mastrota (ROT); 2. by removing cylindrical dandruff and exposing the eyelash insertion point at the lid margin (CDR); and 3. by laterally tensioning the eyelash (LET) following CDR. The typical appearance of cigar-shaped mite tails protruding from each assessed eyelash follicle was observed, and mite tails counted and averaged per participant for each assessment technique. 4. Lash epilation, and mite presence evaluated using bright-field microscopy at 10-40x magnification (EPI). 5. Finally, eyelash follicles were imaged using in vivo confocal microscopy (IVCM) and the images visually inspected for mite presence.

RESULTS

In the Demodex group, the highest numbers of mites/eyelash were identified by LET (3.8 ± 1.4), versus CDR (2.4 ± 1.6) and ROT (1.1 ± 1.2), alone (all p < 0.002). An average of 1.0 ± 0.8 mites/lash was identified by EPI. IVCM failed to offer unequivocal evidence of Demodex presence even in confimed cases.

CONCLUSIONS

A novel technique for the clinical diagnosis and grading of Demodex in situ is described. By removing cylindrical dandruff and applying static, lateral tension to the eyelash without epilation, large numbers of mites are visible at the exposed eyelash follicle. The proposed method is convenient and clinically applicable, requiring only forceps and 25-40x biomicroscope magnification, and allowing rapid, efficient evaluation of large numbers of eyelashes.

Therapeutic profile of a latent heat eyelid warming device with temperature setting variation

PURPOSE

To compare the effects on ocular temperature and tear film parameters following a single application of a latent heat eyelid warming device at a range of temperature settings.

METHODS

Fifteen subjects were enrolled in a prospective, investigator-masked, randomised, cross-over trial. On separate days, participants were randomised to 10-minute application of a research latent heat device (Laboratoires Théa) at device temperature settings of 45 °C, 50 °C and 55 °C. Outer eyelid and corneal temperatures, tear film lipid layer grade, and non-invasive tear film breakup time (NIBUT) were measured at baseline and immediately after 10 min of device application.

RESULTS

Baseline measurements did not differ between treatment groups (all p > 0.05). Ocular temperatures, lipid layer grade and non-invasive tear film stability rose significantly following device application in all treatment groups (all p < 0.05). The 55 °C setting effected a mean ocular surface temperature rise in the order of +4 °C from baseline, which was 1.46 and 1.26 times greater than at the 45 °C and 50 °C temperature settings, respectively (all p < 0.05). Similarly, improvements in mean non-invasive tear film stability from baseline in the order of +7 s were observed, which were 2.43 and 1.66 times greater than those at the lower temperature settings of 45 °C and 50 °C, respectively (all p < 0.05).

CONCLUSIONS

At all temperature settings, the latent heat device resulted in clinically and statistically significant increases in ocular temperature, lipid layer grade, and non-invasive tear film stability. However, the 55 °C setting proved to be most effective at raising ocular temperature (in the order of +4 °C from baseline) and improving tear film stability.

Randomised trial of the clinical utility of an eyelid massage device for the management of meibomian gland dysfunction

PURPOSE

To compare the single application and two week treatment effects of device-applied (Eyepeace) and manually-applied eyelid massage techniques, as an adjunct to warm compress therapy, on ocular surface and tear film parameters.

METHODS

Twenty participants (11 females, 9 males; mean age, 27 ± 11 years) with dry eye symptoms were recruited in a two week, investigator-masked, randomised, contralateral-eye trial. Following 10 min of warm compress therapy application (MGDRx EyeBag^®) on both eyes, eyelid massage therapy was applied to one eye (randomised) by device, and to the fellow eye by manual eyelid massage, once daily for 14 days. Ocular surface and tear film measurements were conducted at baseline, and 15 min post-application by a clinician, then again after 14 days of self-administered daily treatment at home.

RESULTS

Baseline clinical measurements did not differ between the treatment groups (all p > 0.05). Following two weeks of treatment, tear film lipid layer grade improved significantly with device massage (p = 0.008), and was marginally greater than manual massage by less than 1 grade (p = 0.03). Although immediate post-treatment improvements in tear film stability were observed in both groups (both p < 0.05), no significant long-term cumulative effects or inter-treatment differences in stability measures were detected (all p > 0.05). Visual acuity, tear meniscus height, conjunctival hyperaemia, ocular surface staining, and meibomian gland dropout did not change during the treatment period (all p > 0.05).

CONCLUSIONS

Two weeks of treatment with the eyelid massage device, as an adjunct to warm compress therapy, effected marginally greater improvements in tear film lipid layer thickness than the conventional manual technique, which were statistically but not clinically significant. Future parallel group trials with longer treatment periods and a greater range of disease severity are required.

Relationships Between Meibomian Gland Loss and Age, Sex, and Dry Eye

PURPOSE

This study evaluated relationships between meibomian gland loss (MGL) and age, sex, and dry eye.

METHODS

Dry eye and MGL of the lower eyelid was evaluated from 112 randomly selected subjects (66 women; mean age 62.8; SD ±15.7; and age range: 19-89 years) from Horst Riede GmbH, Weinheim, Germany. In addition, subjects were grouped into dry eye and non-dry eye by the Ocular Surface Disease Index (OSDI) score, lid-parallel conjunctival folds and non-invasive break-up time. Symptoms were evaluated by the OSDI. Meibography of the lower eyelid was performed using a Cobra camera (bon Optic, Lübeck, Germany), and images were analyzed by its digital grading tool. Data were analyzed by backward, multiple regression analyses and Pearson correlation.

RESULTS

Analyzing all subjects, multiple regression analyses detected that age and dry eye status (dry eye diagnosis or OSDI) but not sex were significantly related to MGL. In both, non-dry eye (n=66) and dry eye subjects (n=46), dry eye status (OSDI) but not age or sex was significantly related to MGL. Ocular Surface Disease Index scores were significantly correlated with MGL, but this correlation was stronger among all subjects (Pearson correlation; r=0.536, P<0.001) and dry eye group subjects (r=0.520, P<0.001) than in non-dry eye group subjects (r=0.275, P=0.014).

CONCLUSIONS

Dry eye group subjects showed significantly increased MGL of the lower eyelid. Age and dry eye status were related to MGL of the lower eyelid, but sex was not; dry eye status was the dominant factor.

Ethnic differences between the Asian and Caucasian ocular surface: A co-located adult migrant population cohort study

PURPOSE

To investigate the ethnic differences in tear film quality, ocular surface parameters, and dry eye symptomology between co-located Asian and Caucasian populations.

METHODS

Two hundred and six participants (103 East Asian and 103 Caucasian) were recruited in an age and gender-matched cross-sectional study. Dry eye symptomology, ocular surface parameters, and tear film quality were evaluated for each participant within a single clinical session.

RESULTS

The mean ± SD age of the 206 participants (82 male, 124 female) was 45 ± 16 years. Overall, a greater proportion of Asian participants were symptomatic of dry eye and fulfilled the TFOS DEWS II dry eye diagnostic criteria than Caucasian participants (74% versus 51%, p = 0.002), with an odds ratio (95% CI) of 2.7 (1.5-4.8) times. Poorer OSDI scores, tear film stability, lipid layer quality, tear osmolarity, lid wiper epitheliopathy, meibomian gland dropout, and expressed meibum quality were observed in the Asian group (all p < 0.05). A significantly higher proportion of participants exhibited incomplete blinking in the Asian group than the Caucasian group (81% versus 45%, p < 0.001).

CONCLUSIONS

Asian participants exhibited more severe dry eye signs and symptoms than Caucasian participants. The poorer meibomian gland function and higher degree of incomplete blinking observed among Asian participants may potentially contribute towards the ethnic predisposition towards dry eye development.

Exploring the Asian ethnic predisposition to dry eye disease in a pediatric population

PURPOSE

To investigate the differences in ocular surface characteristics, tear film parameters, and dry eye symptomology between co-located pediatric populations of Asian and Caucasian ethnicity.

METHODS

Seventy New Zealand-born pediatric participants, aged between 5 and 18 years, were recruited in an age and environmentally controlled cross-sectional study. Participants were classified into three groups according to ethnicity and eyelid morphology: Asian single lid (ASL), Asian double lid (ADL), and Caucasian double lid (CDL). Ocular biometry, tear film parameters, ocular surface characteristics, and dry eye symptomology were evaluated in a single clinical session.

RESULTS

Overall, no significant intergroup differences were observed in tear film quality, dry eye symptomology, and meibomian gland dropout. A higher proportion of ASL and ADL participants exhibited incomplete blinking than the Caucasian group (both p < 0.001). Meibomian gland shortening was more frequently observed among the two Asian groups (both p < 0.05), while gland tortuosity was more common in the Caucasian group (both p < 0.001). ASL participants exhibited greater inferior lid wiper epitheliopathy grades than ADL participants (p = 0.01), and corneal astigmatism was more pronounced in the ASL than CDL group (p = 0.02).

CONCLUSIONS

Ethnic differences in meibomian gland morphological patterns were observed in the current pediatric cohort, although overall meibomian gland dropout did not differ between groups. Asian participants exhibited a higher degree of incomplete blinking, and more marked inferior lid wiper epitheliopathy and corneal astigmatism were observed in the ASL group. These findings would suggest that eyelid anatomy and tension may potentially be implicated in the development of ethnic differences in dry eye disease later in life.

Impact of blinking on ocular surface and tear film parameters

PURPOSE

To investigate the influence of blinking on tear film parameters, ocular surface characteristics, and dry eye symptomology.

METHODS

A total of 154 participants were recruited in an age, gender and ethnicity-matched cross-sectional study, of which 77 exhibited clinically detectable incomplete blinking, and 77 did not. Blink rate, dry eye symptomology, tear film parameters, and ocular surface characteristics were assessed in a single clinical session.

RESULTS

Overall, a higher proportion of participants exhibiting incomplete blinking fulfilled the TFOS DEWS II dry eye diagnostic criteria (64% versus 44%, p = 0.02), with an odds ratio (95% CI) of 2.2 (1.2-4.2) times. Participants exhibiting incomplete blinking had higher Ocular Surface Disease Index scores (18 ± 13 versus 12 ± 9, p = 0.01), and greater levels of meibomian gland dropout (41.3 ± 15.7% versus 27.5 ± 14.1%, p < 0.001). Furthermore, poorer tear film lipid layer thickness, non-invasive tear film stability, expressed meibum quality, eyelid notching, and anterior blepharitis grades were also observed in those exhibiting incomplete blinking (all p < 0.05). Blink frequency did not correlate significantly with any ocular surface parameters (all p > 0.05).

CONCLUSIONS

Incomplete blinking was associated with a two-fold increased risk of dry eye disease. The greater levels of meibomian gland dropout, as well as poorer expressed meibum quality and tear film lipid layer thickness, observed would suggest that incomplete blinking may predispose towards the development of evaporative dry eye.

Tear lipid supplement prophylaxis against dry eye in adverse environments

PURPOSE

To compare the prophylactic efficacy of single application of lipid and non-lipid containing tear supplements, prior to exposure of symptomatic dry eye subjects to a simulated adverse environment.

METHODS

Thirty subjects with mild-to-moderate dry eye symptoms participated in the prospective, randomised, double-masked, paired-eye trial. A lipomimetic drop (Systane^® Balance) was applied to one eye (randomised), and a non-lipid containing drop (Systane^® Ultra) applied simultaneously to the contralateral eye. Subjects were subsequently exposed to a validated simulated adverse environment model created by a standing fan directed towards the eye, at a distance of 1m, for 2.5min. Low contrast glare acuity, lipid layer grade (LLG), non-invasive tear break-up time (NIBUT), temperature variation factor (TVF), and tear meniscus height (TMH) were evaluated at baseline, following eye drop instillation and following simulated adverse environment exposure.

RESULTS

Both therapies resulted in increased NIBUT (both p<0.001), and prevented its decline below baseline with simulated adverse environment exposure (both p>0.05). However, only the lipomimetic drop increased LLG (p<0.001) and precluded its fall below baseline post-adverse environment exposure (p=0.15). Furthermore, post-instillation and post-exposure LLGs and NIBUT were significantly higher in the lipomimetic group (all p<0.05). No significant changes were observed in glare acuity, TVF and TMH (all p>0.05). More subjects (67%) reported greater ocular comfort in the eye receiving the lipomimetic.

CONCLUSIONS

Single application of both lipid and non-lipid containing eye drops conferred protective effects against exposure to adverse environmental conditions in subjects with mild-to-moderate dry eye, although the lipomimetic demonstrated superior prophylactic efficacy.

Preclinical development of MGO Manuka Honey microemulsion for blepharitis management

Objective

To evaluate the in vitro antimicrobial effects of cyclodextrin-complexed and uncomplexed Manuka honey on bacteria commonly associated with blepharitis, and in vivo rabbit eye tolerability of a cyclodextrin-complexed methylglyoxal (MGO) Manuka Honey microemulsion (MHME).

Methods and analysis

In vitro phase: Bacterial growth inhibition was assessed by area under the growth curve (AUC) for Staphylococcus aureus, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for S. aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa with cyclodextrin-complexed and uncomplexed Manuka honey were determined.

In vivo phase: Six rabbits were administered 20 µL of MHME (at 1:10 dilution) to the right eye (treated) and 20 µL of saline to the left eye (control) daily, for 5 days. Tear evaporation, production, osmolarity, lipid layer, conjunctival hyperaemia and fluorescein staining were assessed daily, before and 15 min after instillation.

Results

In vitro phase: The relative AUC for cyclodextrin-complexed Manuka honey was lower than that of uncomplexed honey at both 250 and 550 mg/kg of MGO (both p <0.05). Cyclodextrin-complexed honey had lower MIC and MBC than uncomplexed honey for both S. aureus and S. epidermidis, but not P. aeruginosa.

In vivo phase: No significant changes were observed in the parameters assessed in either treated or control eyes (all p >0.05).

Conclusion

Overall, antimicrobial potency of cyclodextrin-complexed Manuka honey was greater than uncomplexed honey. No significant immediate or cumulative adverse effects were observed with MHME application on rabbit eyes, supporting future conduct of clinical safety and tolerability trials in human subjects.

Randomised masked trial of the clinical safety and tolerability of MGO Manuka Honey eye cream for the management of blepharitis

Objective

To assess the clinical safety and tolerability of a novel MGO Manuka Honey microemulsion (MHME) eye cream for the management of blepharitis in human subjects.

Methods and analysis

Twenty-five healthy subjects were enrolled in a prospective, randomised, paired-eye, investigator-masked trial. The MHME eye cream (Manuka Health New Zealand) was applied to the closed eyelids of one eye (randomised) overnight for 2 weeks. LogMAR visual acuity, eyelid irritation symptoms, ocular surface characteristics and tear film parameters were assessed at baseline, day 7 and day 14. Expression of markers of ocular surface inflammation (matrix metalloproteinase-9 and interleukin-6) and goblet cell function (MUC5AC) were quantified using impression cytology at baseline and day 14.

Results

There were no significant changes in visual acuity, eyelid irritation symptoms, ocular surface characteristics, tear film parameters and inflammatory marker expression during the 2-week treatment period in treated and control eyes (all p>0.05), and measurements did not differ significantly between eyes (all p>0.05). No major adverse events were reported. Two subjects experienced transient ocular stinging, presumably due to migration of the product into the eye, which resolved following aqueous irrigation.

Conclusion

The MHME eye cream application was found to be well tolerated in healthy human subjects and was not associated with changes in visual acuity, ocular surface characteristics, tear film parameters, expression of markers of inflammation or goblet cell function. The findings support future clinical efficacy trials in patients with blepharitis.

Trial registration number

ACTRN12616000540415.