Meibomian Gland Morphology Is a Sensitive Early Indicator of Meibomian Gland Dysfunction

Advances in artificial intelligence for meibomian gland evaluation: A comprehensive review

Meibomian gland dysfunction (MGD) is increasingly recognized as a critical contributor to evaporative dry eye, significantly impacting visual quality. With a global prevalence estimated at 35.8 %, it presents substantial challenges for clinicians. Conventional manual evaluation techniques for MGD face limitations characterized by inefficiencies, high subjectivity, limited big data processing capabilities, and a dearth of quantitative analytical tools. With rapidly advancing artificial intelligence (AI) techniques revolutionizing ophthalmology, studies are now leveraging sophisticated AI methodologies--including computer vision, unsupervised learning, and supervised learning--to facilitate comprehensive analyses of meibomian gland (MG) evaluations. These evaluations employ various techniques, including slit lamp examination, infrared imaging, confocal microscopy, and optical coherence tomography. This paradigm shift promises enhanced accuracy and consistency in disease evaluation and severity classification. While AI has achieved preliminary strides in meibomian gland evaluation, ongoing advancements in system development and clinical validation are imperative. We review the evolution of MG evaluation, juxtapose AI-driven methods with traditional approaches, elucidate the specific roles of diverse AI technologies, and explore their practical applications using various evaluation techniques. Moreover, we delve into critical considerations for the clinical deployment of AI technologies and envisages future prospects, providing novel insights into MG evaluation and fostering technological and clinical progress in this arena.

Expression of ATP-Binding Cassette Transporter A1 (ABCA1) in Eyelid Tissues and Meibomian Gland Epithelial Cells

Purpose

To validate the adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) expression and distribution in human eyelid tissues and meibomian gland epithelial cells.

Methods

Meibomian gland tissues from human eyelids were isolated by collagenase A digestion and cultured in defined keratinocyte serum-free medium (DKSFM). Infrared imaging was used to analyze the general morphology of meibomian glands. Hematoxylin and eosin (H&E) staining and Oil Red O staining were used to observe the morphological structure and lipid secretion in the human meibomian gland tissues. Quantitative real-time polymerase chain reaction, western blotting, and immunostaining were used to detect the mRNA and protein expression and cytolocalization of ABCA1 in the meibomian gland tissues and cultured cells.

Results

The degree of loss of human meibomian gland tissue was related to age. Meibomian gland lipid metabolism was also associated with age. Additionally, human meibomian gland tissues express ABCA1 mRNA and protein; glandular epithelial cells express more ABCA1 mRNA and protein than acinar cells, and their expression in acinar cells decreases with differentiation. Furthermore, the expression of ABCA1 was downregulated in abnormal meibomian gland tissues. ABCA1 was mainly localized on the cell membrane in primary human meibomian gland epithelial cells (pHMGECs), whereas it was localized in the cytoplasm of immortalized human meibomian gland epithelial cells (iHMGECs). The mRNA and protein levels of ABCA1 in pHMGECs were higher than those in iHMGECs.

Conclusions

Meibomian gland tissues of the human eyelid degenerate with age. ABCA1 expression in acinar cells decreases after differentiation and plays an important role in meibomian gland metabolism.

The Use of Infrared Auto Refractometer for Meibomian Gland Imaging

Introduction This study proposes the utility of an infrared auto refractometer for meibography and compares miebographs obtained by an auto refractometer to meibographs obtained by a designated meibography machine. Methods A prospective observational comparative study of meibographs of patients with clinical signs of meibomian gland dysfunction (MGD) using a designated meibography machine and an infrared auto refractometer. Five masked, experienced interpreters graded the images of the two machines. The Kappa test was used to calculate Intra-rater and inter-rater agreements between the meibography machine and automated refractor grading of meibomian gland dysfunction. Results High-quality photos of all 30 eyes delineating the meibomian glands (MG) were successfully obtained with both the meibography machine and the autorefractor. Both methods had a good intra-rater agreement (κ= 0.667 to 0.784, average 0.738). Poor to fair interrater agreement was noticed in the grading of autorefractor images (k= -0.030 to 0.343, average 0.092) and poor to moderate agreements between investigators for meibography machine images (K= -0.016 to 0.420, average 0.173). Conclusion A commercially available auto refractometer could capture high-quality non-contact IR digital meibographs.

Contact lens wear and follow-up and its association with signs and symptoms of meibomian gland dysfunction

INTRODUCTION

This study investigated the equivocal association between contact lens (CL) wear and meibomian gland dysfunction (MGD) by comparing the morphological, functional and subjective outcomes of CL wearers versus control, non-CL wearers. CL wearers were examined as two cohorts based on the annual attendance of follow-up visits (FLU-attended these visits, whereas non-FLU did not).

METHODS

Habitual logMAR visual acuity, invasive and non-invasive tear break-up time, Schirmer test, Efron grading scales, meibum quality score (MQS), meibum expressibility score (MES), meibomian gland (MG) loss, lid margin abnormalities and subjective dry eye (DE) symptoms were assessed.

RESULTS

Of the 128 participants, 31 were in the FLU cohort, 43 were in the non-FLU cohort and 54 were controls (mean ages: 22.2 ± 3.1, 23.0 ± 4.6 and 22.3 ± 3.5, respectively). Non-FLU CL wearers had more symptoms than controls (3.7 ± 2.4 vs. 2.3 ± 2.1, p < 0.01). Morphologically, FLU (16.9 ± 8.8%, p = 0.02) and non-FLU (18.6 ± 11.3%, p = 0.001) had more MG loss than controls (11.2 ± 6.8%). Functionally, FLU (0.6 ± 0.7, p = 0.01) and non-FLU (0.8 ± 0.9, p = 0.001) had worse MES than controls (0.2 ± 0.5). FLU and non-FLU were both associated with corneal staining (odds ratio [OR] = 3.42, 95% CI: 1.16-10.11, p = 0.03 and OR = 5.23, 95% CI: 1.89-14.48, p = 0.001, respectively) and MG loss (OR = 10.47, 95% CI: 1.14-96.29, p = 0.04 and OR = 16.63, 95% CI: 1.96-140.86, p = 0.01, respectively). Non-FLU CL wear was also associated with abnormal MQS (OR = 12.87, 95% CI: 1.12-148.41, p = 0.04), conjunctival staining (OR = 12.18, 95% CI: 3.66-40.51, p < 0.001) and lid margin telangiectasia (OR = 3.78, 95% CI: 1.55-9.21, p = 0.003). MGD was three times more prevalent in CL wearers (12%) than in controls (4%).

CONCLUSIONS

Both CL-wearing cohorts demonstrated significantly more MG abnormalities than controls though the difference was not clinically significant. Non-FLU CL wearers had more DE symptoms. Non-FLU CL wear is an independent predictor for more abnormalities than FLU CL wear, emphasising the importance of follow-ups.

Risk Factors for Meibomian Gland Disease Assessed by Meibography

Purpose

To elucidate risk factors for meibomian gland disease (MGD) and understand associated changes in meibography and in relation to ocular surface disease.

Patients and Methods

As part of the standard workup for ocular surface disease at a tertiary academic center, 203 patients received an ocular history and lifestyle questionnaire. The questionnaire included detailed inquiries about ocular health and lifestyle, including makeup use, cosmetic eyelid procedures, screen time, and contact lens habits. Subjects also took the standardized patient evaluation of eye dryness (SPEED) II questionnaire. Meibomian gland (MG) dropout and structural changes were evaluated on meibography and scored by three independent graders using meiboscores. Statistical analysis was conducted to identify significant risk factors associated with MG loss.

Results

This retrospective, cross-sectional study included 189 patients (378 eyes) with high-quality images for grading, and the average age was 67 years (77% female). Patients older than 45 years had significantly more dropout than younger patients (p < 0.01). Self-reported eye makeup use did not significantly impact MG loss. Patients with a history of blepharoplasty trended toward higher meiboscores, but the difference was not statistically significant. Self-reported screen time did not affect meiboscores. Contact lens use over 20 years was associated with significant MG loss (p < 0.05). SPEED II scores had no relationship to meiboscores (p = 0.75).

Conclusion

Older age is a significant risk factor for MG loss. Any contact lens use over 20 years also impacted MG dropout. Highlighting the incongruence of symptoms to signs, SPEED II scores showed no relationship to the structural integrity of MGs.

Morphologic variants of Meibomian glands: age-wise distribution and differences between upper and lower eyelids

Purpose

To evaluate the distribution of various Meibomian gland morphologies across different age groups in healthy individuals.

Methods

The infrared meibographic morphologies of the Meibomian glands from the upper and lower eyelids of 236 healthy individuals (472 eyes; mean age 38.4 ± 17.5 years; 80 female participants: 156 male participants) were evaluated for their prevalence and differences across six decades of life, from 10 to 80 years. A linear mixed-effects modeling test was performed for statistical analysis.

Results

Of 14,452 glands, 8,830 (61%) glands were located in the upper eyelid. No significant differences in frequency were noted between different age groups for distorted, tortuous, hooked, overlapping, abnormal gap, fluffy areas, dropout (except for 51-60 vs. 10-20 years, P = 0.023), and thick and thin morphologies. Short glands were significantly more common in individuals aged over 30 years (P = 0.015), whereas moderately short and severely short glands were more common in the upper eyelids of individuals older than 50 years compared to those aged 10-20 years (P = 0.035). The frequency of distorted, hooked, tortuous, overlapping, and tadpole-shaped Meibomian glands was significantly higher in the upper eyelids than in the lower eyelids for all age groups. Dropout glands were more common in the lower eyelids of individuals younger than 50 years, but no difference was observed in the upper and lower eyelids of individuals over 50 years. Dropout (P = 0.006) and severely short glands (0.026) of the lower eyelid were associated with low non-invasive tear break-up time (NIBUT) values.

Conclusion

Various morphologic characteristics of the Meibomian glands that are considered abnormal can be present in healthy individuals, and only moderate to severely short glands display an increase in abnormal morphologic characteristics of the Meibomian glands with age.

Impacts of gender and age on meibomian gland in aged people using artificial intelligence

Purpose: To evaluate the effects of age and gender on meibomian gland (MG) parameters and the associations among MG parameters in aged people using a deep-learning based artificial intelligence (AI). Methods: A total of 119 subjects aged ≥60 were enrolled. Subjects completed an ocular surface disease index (OSDI) questionnaire, received ocular surface examinations including Meibography images captured by Keratograph 5M, diagnosis of meibomian gland dysfunction (MGD) and assessment of lid margin and meibum. Images were analyzed using an AI system to evaluate the MG area, density, number, height, width and tortuosity. Results: The mean age of the subjects was 71.61 ± 7.36 years. The prevalence of severe MGD and meibomian gland loss (MGL) increased with age, as well as the lid margin abnormities. Gender differences of MG morphological parameters were most significant in subjects less than 70 years old. The MG morphological parameters detected by AI system had strong relationship with the traditional manual evaluation of MGL and lid margin parameters. Lid margin abnormities were significantly correlated with MG height and MGL. OSDI was related to MGL, MG area, MG height, plugging and lipid extrusion test (LET). Male subjects, especially the ones who smoke or drink, had severe lid margin abnormities, and significantly decreased MG number, height, and area than the females. Conclusion: The AI system is a reliable and high-efficient method for evaluating MG morphology and function. MG morphological abnormities developed with age and were worse in the aging males, and smoking and drinking were risk factors.

Meibomian Gland Dysfunction in Primary Acquired Nasolacrimal Duct Obstruction

This study was designed to investigate the influence of primary nasolacrimal duct obstruction (PANDO) on the structure and function of the Meibomian gland and to examine whether it is related to functional failure after dacryocystorhinostomy surgery. Medical records of patients diagnosed as PANDO from August 2021 to February 2022 were retrospectively studied. Results of slit lamp examination, lacrimal drainage test, tear break-up time, anterior segment optical coherence tomography, and meibography were collected. Tear meniscus height, tear break-up time, meiboscore, and lipid layer thickness of tear membrane were parameters compared between the eyes with complete PANDO and the control group. Medical records of 44 patients, therefore 88 eyes were collected, and there were 28 eyes with complete PANDO (total obstruction group), while normal eyes (control group) were 30. Mean tear meniscus height was significantly higher than that of the control group ( P value<0.001), but tear break-up time ( P value=0.322), lipid layer thickness ( P value=0.755), and meiboscore ( P value=0.268) were not significantly different. However, in the cases with moderate and severe meibomian gland destruction, the lipid layer thickness of the total obstruction group was significantly thinner than the control group. Lipid secretion of meibomian glands was less in eyes with PANDO than in eyes without PANDO, under moderate to severe meibomian gland destruction. It can lead to persistent epiphora after dacryocystorhinostomy due to a compensatory response against evaporative dry eye disease. Patients should be educated before the decision to undergo surgeries about the possibilities of persistent epiphora. Further studies are needed to prove the mechanism of meibomian gland function disturbance in PANDO.

Association of meibomian gland morphology with orifice plugging and lid margin thickening in meibomian gland dysfunction patients

PURPOSE

We sought to investigate the association of meibomian gland morphology with lid margin abnormalities in patients with meibomian gland dysfunction.

METHODS

This retrospective study included 368 eyes of 184 patients. Meibography was used to evaluate meibomian gland (MG) morphological features, such as dropout, distortion, thickened ratio and thinned ratio. Lid margin photography was used to evaluate lid margin abnormalities including orifice plugging, vascularity, irregularity and thickening. The association between MG morphological features and lid margin abnormalities was analyzed using a mixed linear model.

RESULTS

The study found a positive correlation between plugging of gland orifices grade and MG dropout grade in both the upper lids (B = 0.40, p = 0.007) and the lower lids (B = 0.55, p = 0.001). Plugging of gland orifices grade was also positively correlated to MG distortion grade in the upper lids (B = 0.75, p = 0.006). In the upper lids, MG thickened ratio increased first (B = 0.21, p = 0.003) and then decreased (B = - 0.14, p = 0.010) with a higher lid margin thickening grade. MG thinned ratio was negatively correlated with lid margin thickening (B = - 0.14, p = 0.002, B = - 0.13, p = 0.007). MG distortion grade decreased with lid margin thickening (B = - 0.61, p = 0.012).

CONCLUSION

Orifice plugging was correlated to meibomian gland distortion and dropout. Lid margin thickening was associated with meibomian gland thickened ratio, thinned ratio, and distortion. The study also suggested that distorted and thinned glands may be transitional phases between thickened glands and glands dropout.

The influence of overnight orthokeratology and soft contact lens on the meibomian gland evaluated using an artificial intelligence analytic system

PURPOSE

To test the changes of meibomian gland (MG) morphology using an artificial intelligence (AI) analytic system in asymptomatic children wearing overnight orthokeratology (OOK) and soft contact lens (SCL).

METHODS

A retrospective study was conducted including 89 participants treated with OOK and 70 participants with SCL. Tear meniscus height (TMH), noninvasive tear breakup time (NIBUT), and meibography were obtained using Keratograph 5 M. MG tortuosity, height, width, density, and vagueness value were measured using an artificial intelligence (AI) analytic system.

RESULTS

In an average of 20.80 ± 10.83 months follow-up, MG width of the upper eyelid significantly increased and MG vagueness value significantly decreased after OOK and SCL treatment (all P < 0.05). MG tortuosity of the upper eyelid significantly increased after OOK treatment (P < 0.05). TMH and NIBUT did not differ significantly pre- and post- OOK and SCL treatment (all P > 0.05). The results from the GEE model demonstrated that OOK treatment positively affected MG tortuosity of both upper and lower eyelids (P < 0.001; P = 0.041, respectively) and MG width of the upper eyelid (P = 0.038), while it negatively affected MG density of the upper eyelid (P = 0.036) and MG vagueness value of both upper and lower eyelids (P < 0.001; P < 0.001, respectively). SCL treatment positively affected MG width of both upper and lower eyelids (P < 0.001; P = 0.049, respectively) as well as MG height of the lower eyelid (P = 0.009) and tortuosity of the upper eyelid, (P = 0.034) while it negatively affected MG vagueness value of both upper and lower eyelids (P < 0.001; P < 0.001, respectively). However, no significant relationship was found between the treatment duration and TMH, NIBUT, MG morphological parameters in OOK group. SCL treatment duration negatively affected MG height of the lower eyelid (P = 0.002).

CONCLUSIONS

OOK and SCL treatment in asymptomatic children can influence MG morphology. The AI analytic system may be an effective method to facilitate the quantitative detection of MG morphological changes.

A Review of Applications and Intracellular Mechanisms of Intense Pulsed Light in Eyelid Inflammatory Diseases

Objective: To evaluate relevant clinical outcomes and conclude possible mechanisms of intense pulsed light (IPL) in eyelid inflammation. Background: IPL devices were primarily applied in cutaneous vascular malformations and have been used in ocular diseases for about 20 years, mostly including meibomian gland dysfunction (MGD), blepharitis, and ocular rosacea. Recent findings: Seventy-two original clinical researches were included, 57 for MGD, 4 for blepharitis or blepharitis-related keratoconjunctivitis, and 11 for rosacea. Dry eye symptoms, (tear) break-up time (BUT), and meibomian structure and/or functions were improved in most patients, but production of reactive oxygen species is an important link in the photobiomodulation mediated by IPL, which can influence numerous signal pathways to achieve anti-inflammatory, anti-infective, and prodifferentiation effects. Conclusions: The evidence suggests that IPL is an effective therapeutic tool for most patients with MGD, but more clinical evidence is needed for other indications.

Repeatability and reproducibility of Cobra HD fundus camera meibography in young adults with and without symptoms of dry eye

PURPOSE

The inter-session repeatability (ISR), inter-examiner reproducibility (IER) and within-subject variability (WSV) of the Cobra HD fundus camera meibographer were examined in participants with and without dry eye symptoms.

METHODS

Symptoms were determined based on Ocular Surface Disease Index scores (≥13 being considered symptomatic), and subgroups were compared using the Mann-Whitney U-test. Images of meibomian glands (MGs) from the upper and lower right eyelids were captured by two examiners on the same day (S1) to determine IER. One examiner repeated the measurements on a second day (S2) to obtain the ISR. ISR, IER and WSV were calculated using Friedman, correlation tests and Bland and Altman analyses with mean differences (md) and 95% confidence intervals (CIs), within-subject standard deviations (Sw) and intra-class correlation coefficients (ICC).

RESULTS

The ISR experiment included 72 participants (mean age: 23 ± 5 years, range: 19-43, 36 symptomatic). Mean MG loss of the upper (S1: 13.5 ± 9.5%, S2: 12.8 ± 8.5%) and lower eyelids (S1: 7.5 ± 6.9%, S2: 7.3 ± 6.3%) was not significantly different between sessions for all participants, symptomatic and asymptomatic subgroups for both eyelids. The ISR Sw for the upper and lower eyelids was 1.3% and 1.0%; md was 0.7 ± 3.5% (CI:-6.25% to 7.62%) and 0.1 ± 2.1% (CI: -3.94% to 4.17%), respectively. The IER experiment included 74 participants (mean age: 23 ± 5 years, range: 19-43, 37 symptomatic). Mean MG loss of the upper (Examiner 1: 12.7 ± 8.2%, Examiner 2: 13.1 ± 8.0%) and lower eyelids (Examiner 1: 7.0 ± 6.2%, Examiner 2: 7.4 ± 6.2%) was not significantly different between examiners for all participants, symptomatic and asymptomatic subgroups for both eyelids. The IER ICC values were >0.86 for all conditions, Sw was 1.3% and 1.2%, with a md of -0.4 ± 3.2% (CI: -6.65% to 5.90%) and -0.4 ± 2.9% (CI: -6.15% to 5.31%), respectively. The WSV Sw values were <1.4%, and ICC values were >0.89 for both eyelids, examiners and experimental sessions.

CONCLUSIONS

The Cobra HD fundus camera demonstrates good repeatability, reproducibility and low WSV, and is a reliable clinical instrument for meibography.

Predicting an unstable tear film through artificial intelligence

Dry eye disease is one of the most common ophthalmological complaints and is defined by a loss of tear film homeostasis. Establishing a diagnosis can be time-consuming, resource demanding and unpleasant for the patient. In this pilot study, we retrospectively included clinical data from 431 patients with dry eye disease examined in the Norwegian Dry Eye Clinic to evaluate how artificial intelligence algorithms perform on clinical data related to dry eye disease. The data was processed and subjected to numerous machine learning classification algorithms with the aim to predict decreased tear film break-up time. Moreover, feature selection techniques (information gain and information gain ratio) were applied to determine which clinical factors contribute most to an unstable tear film. The applied machine learning algorithms outperformed baseline classifications performed with ZeroR according to included evaluation metrics. Clinical features such as ocular surface staining, meibomian gland expressibility and dropout, blink frequency, osmolarity, meibum quality and symptom score were recognized as important predictors for tear film instability. We identify and discuss potential limitations and pitfalls.

Meibomian gland morphological changes in ocular herpes zoster patients based on AI analysis

Varicella-zoster virus (VZV) infections result in a series of ophthalmic complications. Clinically, we also discover that the proportion of dry eye symptoms was significantly higher in patients with herpes zoster ophthalmicus (HZO) than in healthy individuals. Meibomian gland dysfunction (MGD) is one of the main reasons for dry eye. Therefore, we hypothesize that HZO may associate with MGD, affecting the morphology of meibomian gland (MG) because of immune response and inflammation. The purpose of this study is to retrospectively analyze the effect of HZO with craniofacial herpes zoster on dry eye and MG morphology based on an Artificial intelligence (AI) MG morphology analytic system. In this study, 26 patients were diagnosed as HZO based on a history of craniofacial herpes zoster accompanied by abnormal ocular signs. We found that the average height of all MGs of the upper eyelid and both eyelids were significantly lower in the research group than in the normal control group (p &lt; 0.05 for all). The average width and tortuosity of all MGs for both upper and lower eyelids were not significantly different between the two groups. The MG density of the upper eyelid and both eyelids were significantly lower in the HZO group than in the normal control group (p = 0.020 and p = 0.022). Therefore, HZO may lead to dry eye, coupled with the morphological changes of MGs, mainly including a reduction in MG density and height. Moreover, it is important to control HZO early and timely, which could prevent potential long-term severe ocular surface injury.

Another Etiological Factor of Meibomian Gland Loss in Patients with Polycystic Ovary Syndrome: Inflammation

Purpose: The purpose of this prospective study was to compare the tear film pattern, meibomian gland (MG) losses in patients with polycystic ovary syndrome (PCOS) and healthy individuals in the control group, and to examine the correlation between peripheral blood values and findings in patients with PCOS. Methods: Eighty-one eyes of 81 patients with PCOS and 78 eyes of 78 healthy individuals were included in this study. Mean noninvasive first tear film break-up time (NIF-BUT) values and the mean noninvasive average tear film break-up time (NIAvg-BUT) values of all breaking-up occurring in the test were compared. MG losses were compared between the groups. In the second step of this study, we examined the correlation between NIF-BUT and NIAvg-BUT values and MG losses with inflammatory parameters. Results: NIF-BUT values were 7.21 ± 5.75 and 10.18 ± 5.90 s, respectively, in PCOS and control groups (P = 0.001). Loss of MG in the upper eyelids (SM-SCL) of PCOS and control group was 39.81 ± 16.34 and 17.84 ± 9.48, respectively (P = 0.000). Positive correlation was detected between SM-SCL value and neutrophil/lymphocyte ratio; platelet/lymphocyte ratio (P/L); and systemic immune-inflammation index, the value obtained from platelet count × (neutrophil/lymphocyte). Conclusion: Increased tear film instability and increased MG loss rates were detected in PCOS patients. In addition, we found a positive correlation between MG losses and inflammatory indices of patients with PCOS. We think that inflammatory processes also provide an additive effect, in addition to hormonal changes on the physiopathological process on the ocular surface in patients with PCOS.

Predicting demographics from meibography using deep learning

This study introduces a deep learning approach to predicting demographic features from meibography images. A total of 689 meibography images with corresponding subject demographic data were used to develop a deep learning model for predicting gland morphology and demographics from images. The model achieved on average 77%, 76%, and 86% accuracies for predicting Meibomian gland morphological features, subject age, and ethnicity, respectively. The model was further analyzed to identify the most highly weighted gland morphological features used by the algorithm to predict demographic characteristics. The two most important gland morphological features for predicting age were the percent area of gland atrophy and the percentage of ghost glands. The two most important morphological features for predicting ethnicity were gland density and the percentage of ghost glands. The approach offers an alternative to traditional associative modeling to identify relationships between Meibomian gland morphological features and subject demographic characteristics. This deep learning methodology can currently predict demographic features from de-identified meibography images with better than 75% accuracy, a number which is highly likely to improve in future models using larger training datasets, which has significant implications for patient privacy in biomedical imaging.

Uneven Meibomian Gland Dropout in Patients with Meibomian Gland Dysfunction and Demodex Infestation

The purpose of this study was to compare the differences between uneven meibomian gland (MG) atrophy with and without Demodex infestation based on the index of uneven atrophy score (UAS). In this retrospective cohort study, 158 subjects were recruited, including 66 subjects in the Demodex-positive MGD group, 49 subjects in the Demodex-negative MGD group, and 43 subjects as normal control. No significant difference was verified in OSDI, TMH, TBUT, CFS, lid margin score, and meibograde (all p > 0.05) between the Demodex-positive MGD group and the Demodex-negative MGD group. The UAS index of the upper eyelid or both eyelids was significantly higher in the Demodex-positive group in comparison with the normal control group and Demodex-negative group and the difference was statistically significant between the three groups. The UAS was significantly positive correlation with OSDI (r = 0.209, p < 0.05), lid margin score (r = 0.287, p < 0.001), and meibograde (r = 0.356, p < 0.001), which has a significant negative correlation with TBUT (r = −0.248, p < 0.05). Thus, Demodex infestation can cause uneven MG atrophy and we propose a novel index of UAS, which is used to evaluate uneven atrophy of MGs and as a morphological index of Demodex infestation.

Changes in the tear film and meibomian gland morphology between preclinical dry eye and normal subjects represented by ocular surface disease index scores

Tear film and MG morphology play an essential role in detecting dry eyes and Meibomian Gland Dysfunction (MGD). Previous studies have reported these changes in cases diagnosed with dry eyes. However, it is important to study these changes among subjects with symptoms of dry eyes without signs. Hence, this study evaluated the changes in the tear film and meibomian gland (MG) morphology among subjects with pre-clinical dry eye and compared it with the normals defined by the Ocular Surface Disease Index score. One hundred and fifty subjects were enrolled in this prospective cross-sectional study. All the subjects completed the Ocular Surface Disease Index (OSDI) questionnaire and the Computer Vision Syndrome Questionnaire (CVS-Q). Tear film tests such as non-invasive break-up time (NIBUT), tear meniscus height (TMH), lipid layer pattern, Schirmer's test, and corneal staining were performed. Images were captured from both the upper and the lower eyelids to study the MG morphology. TMH, MG length, thickness, loss, and tortuosity were measured using ImageJ software. Subjects were differentiated into two groups based on an OSDI threshold score of ≥13 as preclinical dry eye and normals. Among all the subjects, 43.6% of them were categorized as pre-clinical dry eye, and 56.4% as normals. In the pre-clinical dry eye group, a significant reduction in NIBUT (Z = -2.13, p = 0.03) and MG length of the lower lid (Z = -2.58, p = 0.01) was found when compared to normals. TMH, Schirmer's test, and MG width did not vary among both groups (p > 0.05). Similarly, MG loss and tortuosity score was higher in the pre-clinical dry eye group, but did not show any statistical significance (p > 0.05). The majority of the young individuals presenting for the regular eye examination may have pre-clinical dry eye based on their OSDI scores. Hence, it is important to administer the OSDI questionnaire and perform non-invasive tests such as NIBUT and IR imaging of MG as a part of the routine eye examination.

2D Short-Time Fourier Transform for local morphological analysis of meibomian gland images

Meibography is becoming an integral part of dry eye diagnosis. Being objective and repeatable this imaging technique is used to guide treatment decisions and determine the disease status. Especially desirable is the possibility of automatic (or semi-automatic) analysis of a meibomian image for quantification of a particular gland’s feature. Recent reports suggest that in addition to the measure of gland atrophy (quantified by the well-established “drop-out area” parameter), the gland’s morphological changes may carry equally clinically useful information. Here we demonstrate the novel image analysis method providing detailed information on local deformation of meibomian gland pattern. The developed approach extracts from every Meibomian image a set of six morphometric color-coded maps, each visualizing spatial behavior of different morphometric parameter. A more detailed analysis of those maps was used to perform automatic classification of Meibomian glands images. The method for isolating individual morphometric components from the original meibomian image can be helpful in the diagnostic process. It may help clinicians to see in which part of the eyelid the disturbance is taking place and also to quantify it with a numerical value providing essential insight into Meibomian gland dysfunction pathophysiology.

Improvement of Ocular Surface Disease by Lateral Tarsoconjunctival Flap in Thyroid-Associated Orbitopathy Patients with Lid Retraction

There is a high incidence of ocular surface disease (OSD) in thyroid-associated orbitopathy (TAO) patients as a result of incomplete eyelid closure and chronic inflammatory eyelid status. This study was performed to evaluate the efficacy of a lateral tarsoconjunctival flap (LTF) in improving OSD in TAO patients from the perspective of correcting eyelid closures. As a study design, TAO patients were enrolled in this study to evaluate OSD perioperatively before they were scheduled for LTF surgery. Additional lid surgery was also recorded. The outcome was evaluated with perioperative OSD measurements and tear inflammatory mediators at baseline and one month and three months postoperatively. As a result, 42 patients (5 male, 37 female) underwent LTF surgery, and 13 patients received medial pretarsal support with collagen grafts. Eleven patients underwent blepharotomy, and 6 patients received Botox injections for upper lid retraction. The mean age of the participants was 46.4 years old, and the mean follow-up period was 10.6 months. Their clinical activity score (CAS) at the time of the operation was 2.1. Dry eye parameters, such as ocular surface disease index, tear breakup time, Schirmer’s I test score, and meibomian gland dropout were all significantly improved 3 months postoperatively. Tear osmolarity and inflammatory mediators in tear fluid, such as IL-6, IL-8, IL-18 and MCP-1, were also significantly improved after the procedures. After the surgery, all complications were mild and temporary. As a conclusion, LTF could provide TAO patients with both lid retraction correction and improvement of ocular surface disorders. Dry eye parameters significantly improved 3 months postoperatively. This method can serve as an alternative treatment option for lid correction in TAO patients.

The influence of congenital and developmental cataract surgery on the ocular surface in a six-month follow-up prospective clinical study

BACKGROUND

The purpose of this study was to identify changes in tear film function and meibomian gland function in children after congenital/developmental cataract surgery.

METHODS

This study enrolled 16 eyes of 16 congenital/developmental cataract patients (mean age: 8.05 ± 1.43 years) who underwent cataract surgery and 16 eyes of 16 normal volunteers (mean age: 8.31 ± 2.18 years). Clinical assessments were conducted preoperatively and at 1 week, 1, 3 and 6 months postoperatively. Symptom questionnaires, non-invasive tear film break-up time, tear meniscus height, corneal fluorescein staining, lid margin abnormality, meibomian gland expressibility, and meibography were assessed.

RESULTS

The ocular symptom score was significantly higher in congenital/developmental cataract patients compared to normal controls during the 5 visits (P = 0.009). And the average non-invasive tear film break-up time was significantly lower in congenital/developmental cataract patients compared to normal controls (P = 0.017). The first non-invasive tear film break-up time and average non-invasive tear film break-up time were lowest at 1 month postoperatively compared to baseline levels (P = 0.008 and P = 0.012, respectively). The lid margin score of the upper eyelid was significantly higher in congenital/developmental cataract patients compared to normal controls at 1 week postoperatively (P = 0.027). The meibum expressibility score decreased significantly during the 5 visits (P = 0.024). No significant difference was observed in meibomian gland tortuosity, meibomian gland width, meibomian gland area and meibomian gland length between the congenital/developmental group and normal controls preoperatively and at 6 months postoperatively (P > 0.05).

CONCLUSION

Tear film stability and meibomian gland function are worsened transiently after congenital/developmental cataract surgery without accompanying meibomian gland morphological changes.

Dermatochalasis Aggravates Meibomian Gland Dysfunction Related Dry Eyes

This study aimed to investigate the relationships between subjective symptoms, objective signs, and dermatochalasis severity in dry-eye patients and the effects of lid hygiene on dry-eye parameters. We retrospectively enrolled 2328 patients who underwent dry-eye examinations and classified them into four groups by dermatochalasis severity. The SPEED and OSDI questionnaires were used to evaluate subjective symptoms. LipiView® II interferometry was used to measure lipid-layer thickness (LLT) and blink/incomplete blink rates and perform meibography. A slit-lamp–aided standardized evaluator measured meibomian gland expressibility (MGE). A meiboscale was used to grade meibomian gland dropout. Fluorescein tear-film break-up time (FTBUT) and superficial punctate keratitis (SPK) were recorded. The Schirmer test II with anesthetics was used to evaluate aqueous tear secretion. The effects of lid hygiene were evaluated in 644 patients who underwent second comprehensive examinations. The median age of patients was 55.3 [46.0–66.0] years (76.0% female). Patients with more severe dermatochalasis were less symptomatic and had less MGE, higher meiboscale grades and average LLT. Dermatochalasis severity was significantly associated with MGE and meiboscale grade in the upper lid. There were no significant differences in the Schirmer test, FTBUT, and SPK among the severity groups. Females were older and had higher LLT and less severe dermatochalasis. Lid hygiene significantly decreased subjective symptoms, LLT, and Schirmer results, increased FTBUT, but did not change MGE or meiboscale grades. Dermatochalasis severity participated in the pathophysiology of dry eyes. Lid hygiene significantly improved subjective symptoms and reduced LLT, more significantly in patients with less severe dermatochalasis.

Comparable meibomian gland changes in patients with and without ocular graft-versus-host disease after hematopoietic stem cell transplantation

PURPOSE

To compare the presentation and severity of meibomian gland dysfunction (MGD) in patients with and without chronic ocular graft-versus-host disease (coGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS

This prospective cross-sectional study included 79 patients (47 with coGVHD and 32 without) after allo-HSCT. All participants completed ocular surface disease index questionnaire, and received slit lamp, ocular surface interferometer, meibography and confocal microscopy examination. The prevalence and severity of MGD were compared between two groups and related factors were analyzed. Main outcome measures were lipid layer thickness (LLT) and meiboscore.

RESULTS

Similarly high prevalence of MGD was detected in coGVHD and non-coGVHD groups (87.2% vs 84.4%, P = 0.977). Among those with MGD, although patients without coGVHD had longer noninvasive break-up time [5.54 (2.87, 9.37) vs 2.29 (0.00, 3.82) s, P < 0.001], patients in two groups presented similarly decreased LLT (53.5 ± 22.3 vs 47.1 ± 25.2 nm, P = 0.286), increased meiboscore (2.7 ± 1.5 vs 3.5 ± 1.8, P = 0.060) and enlarged acinar unit area (1647.7 ± 942.9 vs 1808.8 ± 1211.5 μm², P = 0.592). Meibomian gland inflammation and fibrosis were observed in both groups, but more predominant in coGVHD group. Results were consistent when patients within a comparable post-HSCT time interval were compared. Regression analysis revealed neither LLT nor meiboscore was associated with coGVHD severity. LLT was positively correlated with systemic immunosuppressant use (β = 12.0, P = 0.044), while meiboscore was positively correlated with lymphoma (β = 1.78, P = 0.040) and matched unrelated donor (β = 1.59,P = 0.008).

CONCLUSIONS

MGD was common and evident in patients after allo-HSCT. MGD is not different between coGVHD and non-coGVHD patients except more inflammation and fibrosis in the former.

Prevalence of symptomatic dry eye disease with associated risk factors among medical students at Chiang Mai University due to increased screen time and stress during COVID-19 pandemic

Dry eye disease (DED) is one of the most common ophthalmological disorders, resulting from several systemic and ocular etiologies including meibomian gland dysfunction (MGD). During the COVID-19 pandemic, medical students are among the high-risk group for DED, mainly due to the increasing use of a visual display terminal (VDT) for online lectures and psychological stress from encountering several changes. Our study aimed to explore the prevalence of DED using the symptom-based definition and potential risk factors in medical students. This is a prospective cross-sectional study that included medical students at Chiang Mai University between November 2020 and January 2021. All participants were assessed using the Ocular Surface Disease Index (OSDI) questionnaire, the Thai version of the 10-Item Perceived Stress Scale-10 (T-PSS-10), the LipiView® II interferometer, and an interview for other possible risk factors. Overall, 528 participants were included in the study; half of the participants were female. The prevalence of DED was 70.8%. In the univariate analysis, female sex, contact lens wear, and T-PSS-10 stress scores were significantly higher in the DED group (P = 0.002, 0.002, and <0.001, respectively). Moreover, participants with severe DED were likely to have higher meibomian gland tortuosity but not statistically significant. In the multivariate analysis, contact lens use and T-PSS-10 score were significant risk factors associated with the severity of DED. In conclusions, the prevalence of DED in medical students was as high as 70.8%. Contact lens use and psychological stress evaluated using the T-PSS-10 questionnaire had a significant correlation with a risk of DED. Female gender and duration of VDT use were also associated. Most of the risk factors were modifiable and may be used as initial management in patients with DED.

Questionnaire Analysis on Incidence and Risk Factors of Dry Eye in Children From a Myopia Outpatient Clinic

Objective

To analyze the incidence and risk factors of dry eye in children from a myopia outpatient clinic via a questionnaire and Keratograph 5M.

Methods

A cross–sectional study was performed. sThere were 214 children (428 eyes) selected from the myopia outpatient clinic of the affiliated Eye Hospital of Shandong First Medical University from July 2021 to September 2021, including 105 boys (210 eyes) and 109 girls (218 eyes), with an average age of 10.1 ± 2.5 years. The incidence rate and influence factors for dry eye were calculated.

Results

Thirty–four of 214 children were diagnosed with dry eye, accounting for 15.9% of the patients. The correlation between fussy eating and the tear meniscus height was statistically significant (Z = −2.158, p = 0.039), along with the correlation between short–distance use of eyes and the tear meniscus height (Z = −2.135, p = 0.033). The degree of meibomian gland deficiency was graded. The meibomian gland was graded as grade 1 in 242 eyes (68.9%), grade 2 in 104 eyes (29.6%), and grade 3 in 5 eyes (1.4%). There was a significant difference in the correlation between eye rubbing and the incidence of dry eye in children (Z = −2.747, p = 0.008). There was also a significant difference in the correlation between picky eating and the incidence of dry eye in children (Z = −2.347; p = 0.024). There was a statistically significant correlation between the time of looking at electronic products and the morphology of the meibomian gland (Z = −2.201, p = 0.028). The results showed that the effect of mild and moderate ametropia on the non–invasive tear breakup time in children was statistically significant (Z = −2.027; p = 0.043).

Conclusion

There is a high incidence of dry eye in children in the myopia outpatient clinic. There is a significant correlation between picky eating, eye rubbing, and the incidence of dry eye. Looking at electronic products for a long time will also affect the morphology of the meibomian gland in children.

Meibum sphingolipid composition is altered in individuals with meibomian gland dysfunction-a side by side comparison of Meibum and Tear Sphingolipids

PURPOSE

Sphingolipids (SPL) play a role in cell signaling, inflammation, and apoptosis. The purpose of this study was to examine meibum and tear SPL composition in individuals with poor versus good meibum quality.

METHODS

Individuals were grouped by meibum quality (n = 25 with poor quality, case group and n = 25 with good quality, control group). Meibum and tears were analyzed with liquid chromatography-mass spectrometry (LC-MS) to quantify SPL classes. Semiquantitative and relative composition (mole percent) of SPL and major classes, Ceramide (Cer), Hexosyl-Ceramide (Hex-Cer), Sphingomyelin (SM), Sphingosine (Sph), and sphingosine 1-phosphate (S1P) were compared between groups.

RESULTS

Demographic characteristics were similar between the two groups. Overall, individuals with poor meibum quality had more SPL pmole in meibum and tears than controls. Relative composition analysis revealed that individuals with poor meibum quality had SPL composed of less Cer, Hex-Cer, and Sph and more SM compared to individuals with good quality meibum. This pattern was not reproduced in tears as individuals with poor meibum quality had SPL composed of a similar amount of Cer, but more Hex-Cer, Sph and SM compared to controls. In meibum, SPL pmole and relative composition most strongly correlated with MG metrics while in tears, SPL pmole and relative composition most strongly correlated with tear production. SPL in both compartments, specifically Cer pmole in meibum and S1P% in tears, correlated with DE symptoms.

CONCLUSION

SPL composition differs in meibum and tears in patients with poor vs good meibum quality. These findings may be translated into therapeutic targets for disease.

Meibomian Gland Morphology Changes After Cataract Surgery: A Contra-Lateral Eye Study

Purpose: To evaluate the morphology changes of meibomian glands (MGs) after cataract surgery. Setting: Hangzhou Branch of the Eye Hospital of Wenzhou Medical University, Zhejiang, China. Methods: In this contra-lateral eye study, 40 patients received unilateral cataract surgery for age-related cataract. All the patients underwent the evaluation of non-invasive break-up time (NIBUT) and lower tear meniscus height (TMH) before the surgery and 6 months post-operatively. The MGs were evaluated via ImageJ and Meibomian Gland Bio-image Analyzer. MG dropout, length, width, area, gland diameter deformation index (DI), and gland signal index (SI) were recorded. Results: MG length, width, area, DI, and SI were significantly decreased after cataract surgery in the study group (operated eyes, P < 0.001, P = 0.003, P < 0.001, P = 0.001, and P < 0.001, respectively) and showed no significant changes in the control group (non-operated eyes) (all P > 0.05). MG loss increased more in the study group (P = 0.030), and the changes in TMH and NIBUT were not significantly different between the two eyes (both P > 0.05). Conclusion: Cataract surgery aggravated meibomian gland morphology, such as MG loss, MG length, width, area, and SI, and produced no change in NIBUT and TMH at 6 months post-operatively.

Artificial Intelligence to Detect Meibomian Gland Dysfunction From in-vivo Laser Confocal Microscopy

Background: In recent years, deep learning has been widely used in a variety of ophthalmic diseases. As a common ophthalmic disease, meibomian gland dysfunction (MGD) has a unique phenotype in in-vivo laser confocal microscope imaging (VLCMI). The purpose of our study was to investigate a deep learning algorithm to differentiate and classify obstructive MGD (OMGD), atrophic MGD (AMGD) and normal groups. Methods: In this study, a multi-layer deep convolution neural network (CNN) was trained using VLCMI from OMGD, AMGD and healthy subjects as verified by medical experts. The automatic differential diagnosis of OMGD, AMGD and healthy people was tested by comparing its image-based identification of each group with the medical expert diagnosis. The CNN was trained and validated with 4,985 and 1,663 VLCMI images, respectively. By using established enhancement techniques, 1,663 untrained VLCMI images were tested. Results: In this study, we included 2,766 healthy control VLCMIs, 2,744 from OMGD and 2,801 from AMGD. Of the three models, differential diagnostic accuracy of the DenseNet169 CNN was highest at over 97%. The sensitivity and specificity of the DenseNet169 model for OMGD were 88.8 and 95.4%, respectively; and for AMGD 89.4 and 98.4%, respectively. Conclusion: This study described a deep learning algorithm to automatically check and classify VLCMI images of MGD. By optimizing the algorithm, the classifier model displayed excellent accuracy. With further development, this model may become an effective tool for the differential diagnosis of MGD.

Comparative of meibomian gland morphology in patients with evaporative dry eye disease versus non-dry eye disease

Many recent studies have showed that morphological changes are one of the key signs of meibomian gland disease (MGD). These changes can be seen even before symptom onset, potentially underestimating the prevalence of MGD; however, until now, there is no conclusive information about the impact of meibomian gland (MG) morphology in tear film physiology and disease. This study aimed to investigate the prevalence of anatomical and morphological MG alterations between patients with evaporative dry eye disease (DED) and healthy controls. Retrospective chart review of seventy-five patients with evaporative DED and healthy individuals who had dry eye assessments included Ocular Surface Disease Index questionnaire, meibum quality, meibum expressibility, lid margin abnormality, ocular staining, non-invasive tear film break-up time, and meibography. We did not find significant differences in MG alterations in the upper lid between healthy and DED subjects. Patients with evaporative DED presented MG alterations in the lower lid more frequently than healthy subjects (54.8 vs. 30.3%; p = 0.03). The presence of shortened glands was the only MG alteration that was more prevalent in the lower lid in dry-eye patients than in healthy subjects (p < 0.05). Subjects with evaporative DED presented more alterations in the lower lid than healthy subjects.

New Indicator of Children's Excessive Electronic Screen Use and Factors in Meibomian Gland Atrophy

PURPOSE

To evaluate the association of children's daily electronic screen use with severe meibomian gland atrophy (MGA).

DESIGN

Retrospective cross-sectional study.

METHODS

Children (aged 6-17years) presenting at clinical practice December 2016 - October 2017 were evaluated for ≥grade 2 MGA vs age-matched controls with insignificant atrophy (<grade 1 atrophy). Questionnaires assessed dry eye symptoms, daily electronic screen use hours, diet, and outdoor time. Meibography imaging assessed for severe meibomian gland atrophy (≥grade 2 atrophy; ≥1 eyelid on validated, 4-point, ImageJ scale: 0 [normal] - 3 [severe]). Autoimmune disease biomarker positivity was assessed in 16 severe meibomian gland atrophy cases after being found relevant in firstcase.

RESULTS

A total of 172 children were evaluated. Patients with known meibomian gland atrophy causes or poor-quality meibographies were excluded. Forty-one met inclusion criteria (mean age, 11 years; 49% female): 17 cases had severe meibomian gland atrophy; 24 controls had insignificant gland atrophy. All severe meibomian gland atrophy cases had ocular symptoms/signs of dry eye disease including corneal neovascularization (29%), best-corrected visual acuity loss (41%), and central corneal neovascularization (14%). No controls had significant dry eye symptoms/signs. Controls had lower/"better" meibogrades vs cases (P < .01). In severe meibomian gland atrophy cases, 86% reported ≥4 hours of daily electronic screen use; 50% reported ≥8 hours. No controls exceeded 2 hours. Increased electronic screen use was positively associated with increased/"worse" meibogrades (odds ratio: 2.74; 95% confidence interval, 1.39-5.41). In 16 severe meibomian gland atrophy cases, 62.5% tested positive for autoimmune biomarker(s), though none had systemic symptoms: 18.8% rheumatoid factor; 6.25% SS-A/SS-B; 31.3% early Sjögren syndrome biomarkers; 6.25% ANA-positive/RF-negative. Autoimmune disease biomarker positivity was not significantly associated with severe meibomian gland atrophy vs controls (P = .34, right-eye; P = .71, left-eye).

CONCLUSIONS

Children's excessive electronic screen use is associated with severe meibomian gland atrophy. Further research is needed to establish formal electronic screen use limits based on meibography grade and evaluate correlation of autoimmune disease biomarker positivity in children with severe meibomian gland-atrophy.

Diagnostic Capability of a New Objective Method to Assess Meibomian Gland Visibility

SIGNIFICANCE

The diagnosis of dry eye disease and meibomian gland dysfunction (MGD) is challenging. Measuring meibomian gland visibility may provide an additional objective method to diagnose MGD.

PURPOSE

This study aimed to evaluate the ability of new metrics to better diagnose MGD, based on measuring meibomian gland visibility.

METHODS

One hundred twelve healthy volunteers (age, 48.3 ± 27.5 years) were enrolled in this study. Ocular surface parameters were measured using the Oculus Keratograph 5M (Oculus GmbH, Wetzlar). Subjects were classified according to the presence or absence of MGD. New metrics based on the visibility of the meibomian glands were calculated and later compared between groups. The diagnostic ability of ocular surface parameters and gland visibility metrics was studied through receiver operating characteristic curves. Logistic regression was used to obtain the combined receiver operating characteristic curve of the metrics with the best diagnostic ability.

RESULTS

Statistically significant differences were found between groups for all ocular surface parameters and new gland visibility metrics, except for the first noninvasive keratograph breakup time and gland expressibility. New gland visibility metrics showed higher sensitivity and specificity than did current single metrics when their diagnostic ability was assessed without any combination. The diagnostic capability increased when gland visibility metrics were incorporated into the logistic regression analysis together with gland dropout percentage, tear meniscus height, dry eye symptoms, and lid margin abnormality score (P < .001). The combination of median pixel intensity of meibography gray values and the aforementioned ocular surface metrics achieved the highest area under the curve (0.99), along with excellent sensitivity (1.00) and specificity (0.93).

CONCLUSIONS

New meibomian gland visibility metrics are more powerful to diagnose MGD than current single metrics and can serve as a complementary tool for supporting the diagnosis of MGD.

Middle East Preferred Practice Patterns for Dry Eye Disease: A Modified Delphi Consensus

Background:

Dry Eye Disease (DED) is a common ophthalmic condition resulting from dysfunction in the ocular surface, main lacrimal gland, meibomian glands, or connecting nerves.

Objective:

A group of local experts met to discuss local challenges and establish consensus in DED management across the Middle East.

Methods:

A modified Delphi method was used to reach consensus, comprising two rounds of the survey and a face-to-face meeting. An expert panel of 8 ophthalmologists voted on 23 statements, with consensus reached if ≥75% responded “strongly agree” or “agree” to a statement.

Results:

The expert panel reached consensus on 23 statements relating to the pathophysiology, diagnosis, treatment, and management of DED. Diagnosis begins with recording a detailed patient history and assessing subjective symptoms such as redness, burning, stinging, foreign body sensation, and/or photophobia. Tear Break-up Time (TBUT; <10 s), corneal spots (>5), and fluorescein staining are essential for diagnosing DED, assessing disease severity and ocular surface condition, and differentiating between types of DED. Ocular surface lubricants are the mainstay of treatment for DED. Treatment approaches should be categorized by etiology (if known). An improvement in symptoms can be observed objectively via an increase in TBUT, reduction in corneal and conjunctival spots, and restoration of normal tear production, or subjectively via less dependence on ocular surface lubricants, improved vision quality, and symptom amelioration.

Conclusion:

This consensus will serve to provide a framework for clinical decisions relating to the management of DED across the region.

Characteristics of dry eye patients with thick tear film lipid layers evaluated by a LipiView II interferometer

PURPOSE

To investigate the characteristics of eyes with dry eye disease (DED) whose lipid layer thickness (LLT) measured 100 nm on a LipiView II interferometer and compare the DED parameters of them to those with LLT below 100 nm.

METHODS

A total of 201 eyes of 102 enrolled DED patients (mean age 56.4 ± 11.8 years) were classified into 3 groups according to their average LLT; < 60 nm as thin-LLT (n = 49), 60-99 nm as normal-LLT (n = 77), and 100 nm as thick-LLT (n = 75). LLT, meiboscore, Schirmer I test, tear film break-up time (TBUT), ocular surface staining (OSS), and ocular surface disease index (OSDI) were assessed.

RESULTS

The OSS and TBUT were significantly worse in the thick-LLT group than in the normal-LLT group (p = 0.020, and p = 0.028, respectively). The OSDI was significantly higher in the thick-LLT group than in the thin-LLT group (p = 0.006). However, the meiboscore was not different among the three groups (p = 0.33). Age, OSS, and OSDI showed a positive correlation with LLT (r = 0.16, p = 0.023; r = 0.213, p = 0.003; and r = 0.338, p = 0.001, respectively). In sensitivity analyses, eyes with corneal erosions had a significantly higher average LLT (p = 0.015), higher OSDI (p = 0.009), shorter TBUT (p < 0.001), and shorter Schirmer I value (p = 0.024) than those with clear corneas.

CONCLUSION

The average LLT of eyes with corneal erosions was thicker than those without erosions, suggesting that the LLT of 100 nm in the eyes with corneal erosions should not be regarded as a stable physiologic condition. Cautious interpretation of LLT along with other dry eye parameters is required.

Effect of meibomian gland morphology on functionality with applied treatment

PURPOSE

To determine how Meibomian gland (MG) morphology affects MG function by means of gland expression with the effect of treatment.

METHODS

Fifteen patients (aged 31.6 ± 13.1 years) from a dry eye clinic diagnosed with MG dysfunction had their 365 lower lid MGs visualised with a slit-lamp biomicroscopy. Using infrared meibography (Oculus K5m), MG length, width and tortuosity were objectively measured. Each MG was expressed and the meibum graded (0=clear fluid, 1=cloudy fluid, 2= particulate fluid, 3=inspissated, or 4 = no expression) to determine its functionality. Participants had functionality repeated each time following a sequence of a warm compress, debridement, and forcible expression after 5 min.

RESULTS

Just over 10 % of complete length MGs gave clear expression, while about 5% did not express at all, with most expressed meibum being particulate in nature. In contrast, the majority of partial length glands gave inspissated expression (38 %), with 32 % not expressing at all. No MG of <10 % length expressed. MG gland length was correlated with gland expression (r=-0.507, p < 0.001) and MG tortuosity (r=-0.129, p < 0.001), but not MG width (r=-0.090, p = 0.167). Regardless of MG length, warm compress increased the quality of expression (p < 0.002). Debridement further improved expression in partial MGs (p = 0.003), but not forcible expression (p = 0.529).

CONCLUSIONS

Length is the key functional morphology metric of lower lid MGs. Warm compress and massage increase the quality of expression in all, but the shortest glands and patients with partial length glands also benefit from debridement.

Proposed Algorithm for Management of Meibomian Gland Dysfunction Based on Noninvasive Meibography

Although the pathophysiology of meibomian gland dysfunction (MGD) remains incompletely understood, many treatment options have recently become available. According to an international workshop report, treatment selection for MGD should be based on a comprehensive stage classification dependent on ocular symptoms, lid margin abnormalities, meibum grade, and ocular surface staining. However, it is often difficult to evaluate all parameters required for such classification in routine clinical practice. We have now retrospectively evaluated therapeutic efficacy in MGD patients who received five types of treatment in the clinic setting: (1) meibocare (application of a warm compress and practice of lid hygiene), (2) meibum expression plus meibocare, (3) azithromycin eyedrops plus meibocare, (4) thermal pulsation therapy plus meibocare, or (5) intense pulsed light (IPL) therapy plus meibocare. Patients in each treatment group were classified into three subsets according to the meiboscore determined by noncontact meibography at baseline. Eyes in the IPL group showed improvement even if the meiboscore was high (5 or 6), whereas meibocare tended to be effective only if the meiboscore was low (1 or 2). The meiboscore may thus serve to guide selection of the most appropriate treatment in MGD patients. Prospective studies are warranted to confirm these outcomes.

2D fourier transform for global analysis and classification of meibomian gland images

In recent years, significant progress has been made in the Meibography technique resulting from the use of advanced image analysis methods allowing a quantitative description of the Meibomian gland structures. Many objective measures of gland distortion were previously proposed allowing for user-independent classification of acquired gland images. However, due to the complicated nature of gland deformation, none of the single-valued parameters can fully describe the analyzed gland images. There is a need to increase the number of descriptive factors, selectively sensitive to different gland features. Here we show that global 2D Fourier transform analysis of infra-red gland images provides values of two new such parameters: mean gland frequency and anisotropy in gland periodicity. We show that their values correlate with gland dysfunction and can be used to automatically categorize the images into the three subjective classes (healthy, intermediate and unhealthy). We also demonstrated that classification performance can be improved by dimensionality reduction approach using principal component analysis.

Latest evidences on meibomian gland dysfunction diagnosis and management

Meibomian gland dysfunction (MGD) can be considered the leading cause of dry eye disease (DED) and one of the most common ophthalmic disorders found in clinical practice. The growing body of literature provides a substantial amount of information on this condition, but more efforts are needed to better interpret research data and to properly apply them to daily clinical practice., In this article, we reviewed the most recent publications on MGD diagnosis and management, focusing on the highest available level of evidence, provided by well-designed and well-reported studies on humans., Latest evidences on MGD diagnosis are mainly focused on imaging techniques, including meibography, optical coherence tomography (OCT), and in vivo confocal microscopy. Meibographic parameters, such as drop-out and glands' distortion, show great diagnostic accuracy, which accounts for their widespread use in clinical practice and research., Recent randomized controlled clinical trials on MGD treatment provided data on the role of antibiotics, steroids, essential fatty acids, intraductal meibomian gland probing, electronic heating devices and intense pulsed light therapy.

Association of meibomian gland morphology with symptoms and signs of dry eye disease in the Dry Eye Assessment and Management (DREAM) study

PURPOSE

To describe associations between symptoms and signs of dry eye disease (DED) and meibomian gland (MG) morphology.

METHODS

Cross-sectional study utilizing data from the Dry Eye Assessment and Management (DREAM) Study. Readers graded MG features in the middle third of upper and lower lids on infrared meibography images. Associations with signs and symptoms of DED were evaluated with adjustment for age and sex.

RESULTS

Among 268 patients, no MG features were associated with symptom scores (p > 0.08). Among 394 upper eyelids, better tear break-up times (<2, >2- <3.2and ≥ 3.2 s) were associated with more tortuous glands (mean (SD) 0.58(0.95), 0.83(1.2) and 1.14 (1.4), p = 0.01) and with higher scores on a composite score of MG features (21.90 (9.76), 23.29 (9.50), 26.26 (10.27); p = 0.02). Longer Schirmer test wetting lengths (0-5, >5-10, and >10 mm) were associated with increasing composite scores (22.02 (9.29), 23.80 (10.34), 24.96 (9.96), p = 0.03). Patients with Sjogren syndrome compared to other patients had fewer distorted MGs (mean 3.4 (2.3) vs 4.3 (2.3), p = 0.03) and fewer ghost glands (mean 0.33 (0.88) vs 0.89 (1.8), p = 0.006) in the upper lid.

CONCLUSION

In the DREAM study, most MG morphologic features were not associated with the severity of DED symptoms or signs. Tortuous glands and a higher composite score for MG features were associated with longer tear break-up times and longer Schirmer test length in the upper eyelid only. Patients with Sjogren syndrome had fewer distorted and ghost glands.

Clinical efficacy of eyelid hygiene in blepharitis and meibomian gland dysfunction after cataract surgery: a randomized controlled pilot trial

The purpose of this randomized clinical trial is to evaluate the effect of eyelid hygiene on subjective symptoms, anterior blepharitis, and meibomian gland dysfunction (MGD) after cataract surgery. Subjects with obstructive MGD who underwent cataract surgery were randomly divided into two groups. In the eyelid hygiene group, eyelid hygiene was performed twice a day for 10 days from 3 days before to 1 week after cataract surgery. The control group did not perform eyelid hygiene. A subjective symptom questionnaire of SPEED, anterior blepharitis grade, and meibum quality and quantity was evaluated at baseline and at postoperative 1 and 4 weeks. The eyelid hygiene group (n = 36) showed decreased SPEED score after cataract surgery and the control group (n = 33) did not. Anterior blepharitis grade was worse 1 week after surgery in the control group but not in the eyelid hygiene group. The control group had significantly decreased meibum quality and quantity in both the upper and lower eyelids after cataract surgery, but the eyelid hygiene group did not. Eyelid hygiene before/after cataract surgery improved postoperative subjective symptoms and prevented postoperative exacerbation of anterior blepharitis and MGD. Thus, perioperative eyelid hygiene is recommended for patients with obstructive MGD who undergo cataract surgery.

The role of meibography in ocular surface diagnostics: A review

The meibomian glands are lipid-secreting glands located in the tarsal plates, whose secretory products cover the tear film, thereby reducing evaporation as well as ensuring lubrication of the ocular surface. The meibomian glands can be visualized at different levels of magnification by infrared meibography, laser confocal microscopy, and optical coherence tomography. These imaging modalities have been subject to much research and progress in clinical practice and have shaped our current understanding of meibomian glands in health and disease. In this review, we explore the evolution of meibography over the past decades, the major contributions of various meibographic modalities, and discuss their clinical significance.

Enhanced orbital adipogenesis in a mouse model of T-cell-mediated autoimmunity, zymosan A-treated SKG mice: Implications for Graves' ophthalmopathy

Inflammation and remodelling of orbital tissue associated with enhanced adipogenesis commonly occur in Graves' ophthalmopathy (GO), however, the underlying mechanisms that link immune cells and adipocytes in orbital inflammation are not well-known. The primary aim of this study was to elucidate how a genetically determined shift in the T-cell repertoire toward self-reactive T-cells could drive orbital adipogenesis. To induce the T-cell-mediated autoimmune response, SKG mice were intraperitoneally injected with zymosan A once at 8 weeks of age. After three months, orbital magnetic resonance imaging (MRI), histopathologic studies, and in vitro analyses were performed to evaluate inflammation and adipogenesis. The eyes of the zymosan A-treated SKG mice displayed proptosis and blepharitis. A detailed analysis of orbital adipose tissue showed enhanced orbital adipogenesis and cellular infiltration compared to controls. In addition, increased secretion of adipokines and other cytokines in the periorbital tissue was observed, together with elevated serum concentration of inflammatory cytokines. Orbital adipogenesis was enhanced in zymosan A-treated SKG mice, a novel mouse model for GO-like inflammatory adipose phenotypes most likely induced by T-cell mediated autoimmune responses. This mouse model gives us the opportunity to examine the underlying molecular mechanisms of enhanced adipogenesis in GO, ultimately providing a potential therapeutic target alternative to conventional GO treatment.

Functional and Morphological Evaluation of Meibomian Glands in the Assessment of Meibomian Gland Dysfunction Subtype and Severity

PURPOSE

To classify subtypes of meibomian gland dysfunction (MGD) and evaluate the dependency of dry eye signs, symptoms, and parameters on MGD subtype.

DESIGN

Cross-sectional study.

STUDY POPULATION

the right eyes of 447 patients with MGD of various subtypes and 20 healthy volunteers.

METHODS

Patients were divided into 4 subtypes of MGD based on meibum expression, meibum quality, and MG loss on meibography images (meibograde of 0-6). Subtypes were patients with high meibum delivery (hypersecretory and nonobvious MGD) and those with low meibum delivery (hyposecretory and obstructive MGD). Additional clinical tests included tear film break-up time (TFBUT), ocular staining, osmolarity, Schirmer I, blink interval timing and the Ocular Surface Disease Index (OSDI) questionnaire.

RESULTS

A total of 78 eyes had hypersecretory MGD; 49 eyes had nonobvious MGD; 66 eyes had hyposecretory MGD; and 254 eyes had obstructive MGD. Increased tear film osmolarity and lower TFBUT were found in the low-delivery groups; hyposecretory (P = 0.006, P = 0.016) and obstructive MGD (P = 0.008, P = 0.006) relative to high-delivery MGD (hypersecretory and nonobvious groups, respectively). Worse ocular symptoms and ocular staining were also found in low-delivery MGD groups than the high delivery MGD groups (P < 0.01 and P < 0.006, respectively).

CONCLUSIONS

Patients with low-delivery MGD had worse dry eye parameters and ocular symptoms than those with high meibum delivery, indicating the pivotal role of meibum secretion in ocular surface health that should be targeted in MGD therapy. Furthermore, nonobvious MGD cannot be diagnosed using conventional dry eye tests and requires morphologic assessment of meibography images to confirm MG loss.

Diagnostic Test Efficacy of Meibomian Gland Morphology and Function

Meibomian gland dysfunction (MGD) is the leading cause of dry eye and proposed treatments are based on disease severity. Our purpose was to establish reliable morphologic measurements of meibomian glands for evaluating MGD severity. This retrospective, cross-sectional study included 100 MGD patients and 20 controls. The patients were classified into dry eye severity level (DESL) 1–4 based on symptoms and clinical parameters including tear-film breakup time, ocular staining and Schirmer I. The gland loss, length, thickness, density and distortion were analyzed. We compared the morphology between patients and controls; examined their correlations to meibum expressibility, quality, and DESL. Relative to controls, the gland thickness, density and distortion were elevated in patients (p < 0.001 for all tests). The area under the receiver operating characteristic curve was 0.98 (95% confidence interval [CI], 0.96–1.0) for gland loss, and 0.96 (CI 0.91–1.0) for gland distortion, with a cutoff value of six distorted glands yielding a sensitivity of 93% and specificity of 97% for MGD diagnosis. The gland distortion was negatively correlated to the meibum expressibility (r = −0.53; p < 0.001) and DESL (r = −0.22, p = 0.018). In conclusion, evaluation of meibomian gland loss and distortion are valuable complementary clinical parameters to assess MGD status.

Regulatory and Developmental Aspects of Biomarkers in the Treatment of Ocular Surface Disease

The ideal biomarker would be a simple laboratory or clinical evaluation before treatment, which would predict subsequent therapeutic response. This might include selection of which patients might respond to that treatment. While other disciplines such as neurology and oncology have biomarkers, ophthalmology is limited to one-elevated intraocular pressure as a surrogate for progressive glaucomatous field loss. US law in 2016 required the Food and Drug Administration (FDA) to set up a system to qualify biomarkers. The system now exists-with most validated or pending biomarkers limited to safety and infection. The American Academy of Ophthalmology selected dry eye disease as one of three diseases in which to standardize outcomes in ophthalmology research. There have been a number of biomarkers proposed for evaluating ocular surface disease and its treatment. None currently meets the scientific or regulatory basis for being a valid biomarker-however, additional research may result in validity. Given the FDA's scientific basis, it is unlikely that an unproven biomarker could be used for regulatory approval, even for a "SubPart H" conditional new drug application. Elsewhere in ophthalmology, we know that even patients who share the same disease gene or mutation may differ substantially in penetrance and clinical expression. Thus, it is not unexpected that ocular surface disease, a heterogeneous disease with a variable presentation of signs and symptoms, has yet to have validated biomarkers that reach the level of evidence that allows their use for diagnosis, prognosis, therapy, and for making decisions in drug development.