The significance of meibomian gland changes in asymptomatic children

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.

Body mass index, diet, and outdoor activity linked with meibomian gland abnormalities in children

SIGNIFICANCE

Dry eye disease is frequently underdiagnosed in pediatric patients. Meibomian gland morphology abnormalities (atrophy and tortuosity) may be associated with dry eye. This study examined risk factors for gland morphology abnormalities in children.

PURPOSE

This study aimed to characterize meibomian gland morphological abnormalities (atrophy and tortuosity) and identify risk factors for the same in children.

METHODS

A total of 160 children, primarily African American and Hispanic, aged 5 to <18 years underwent a comprehensive eye exam including slit-lamp examination to evaluate the meibomian glands, conjunctival papillae, and tear film. Infrared photography was performed including assessment of noninvasive tear film breakup time and tear meniscus height. Meibomian gland atrophy and tortuosity were assessed. A modified Ocular Surface Disease Index survey was administered along with surveys on screen time, diet, and outdoor activity. Linear multiple regression was performed to determine risk factors for meibomian gland abnormalities.

RESULTS

The average age of participants (76 male, 84 female) was 10.9 ± 3.0 years. Severe meibomian gland atrophy (score ≥2) was found in 31.0% of participants in at least one eyelid. Severe meibomian gland tortuosity (score ≥2) was found in 84.0% of participants in at least one eyelid. The median symptom score was 9.8 (range, 0 to 71), with 16.9, 8.8, and 12.5% of the children having mild, moderate, and severe dry eye symptoms, respectively. Elevated body mass index (p<0.001), reduced outdoor activity (p=0.02), and unhealthy diet (p=0.01) were found to be risk factors for meibomian gland abnormalities. Screen time, symptom score, age, gender, and race/ethnicity were not associated with gland abnormalities (all p values >0.05).

CONCLUSIONS

This study determined that meibomian gland morphological abnormalities were commonly found in children aged 5 to <18 years. Risk factors for these abnormalities include elevated body mass index, an unhealthy diet, and reduced outdoor activity.

Influential Signs of Dry Eye-Related Ocular Symptoms in Participants With Unstable Tear Film

PURPOSE

The aim of this study was to investigate the factors influencing dry eye disease (DED)-related ocular symptoms in participants with short fluorescein tear break-up time (FTBUT).

METHODS

This cross-sectional study included 82 participants with short FTBUT (<10 seconds). Examinations included Ocular Surface Disease Index (OSDI), FTBUT, average noninvasive tear break-up time (NIBUTave), lid wiper epitheliopathy, lipid layer thickness, blink rate, partial blink, tear meniscus height, and meibomian gland (MG) evaluation which included ratio of residual MG area (RMGA) and MG grade in tarsal plates. One-way analysis of variance was used to detect differences between symptomatic tear film instability group (FTBUT <5 s, OSDI ≥13), asymptomatic tear film instability group (FTBUT <5 s, OSDI <13), and control group (FTBUT ≥5 s, OSDI <13). A bivariate correlation, partial correlation, and multiple linear regression analyses were used to identify major factors. Only the right eye was included.

RESULTS

Among the participants with FTBUT <5 seconds, symptomatic group showed less upper RMGA ( P < 0.001) and NIBUTave ( P = 0.010). OSDI was negatively associated with upper RMGA ( r = -0.450, P < 0.001) and NIBUTave ( r = -0.414, P = 0.001), and positively associated with upper MG grade ( r = 0.277, P = 0.027). Linear regression analysis showed that the upper RMGA significantly affected OSDI (B = -41.895, P = 0.001), while not significantly correlated with age, upper MG grade, and NIBUTave.

CONCLUSIONS

The upper RMGA might be the main factor affecting DED-related discomfort in participants with unstable tear film, indicating an early ocular change in DED.

Morphological and functional characteristics of the meibomian gland in pediatric patients with epiblepharon

BACKGROUND

To observe morphologic and functional changes in meibomian glands in pediatric patients with and without lower eyelid epiblepharon.

METHODS

In this prospective observation study, 55 eyes of 55 patients( 24 males, 31 females; mean age ± SD,9.82 ± 2.59 years; range 6-14 years) and 60 eyes of 60 controls ( 32 males, 28 females; mean age ± SD,10.57 ± 2.75 years; range 6-14 years) were included. The following tests were performed: eyelid margin abnormality by slit-lamp examination, measurement of noninvasive keratographic break-up time (NIKBUT), grading of absence of meibomian gland (meibography score) assessed with noncontact meibography, morphologic changes of meibomian glands (thinning, dilatation and distortion), tear production by the Schirmer 1 test, and grading of meibum quality and meibomian gland expressibility.

RESULTS

The morphologic changes in meibomian glands were more common in the epiblepharon group (56.36%) than in the control group (28.33%) (p = 0.002). The meibum quality was worse in the epiblepharon group than in the control group (p = 0.009), and the NIKBUT was significantly shorter in the epiblepharon group than in the control group (p = 0.012). There was no significant difference in the Schirmer 1 test, meibomian gland expressibility, eyelid margin abnormality score or total meibography score between the two groups. Morphologic changes in the meibomian glands in the upper eyelids (38.18%) were more common than those in the lower eyelids (20%) (p = 0.036) in the epiblepharon group, and the meibography score was higher in the upper eyelids than in the lower eyelids (p = 0.001).

CONCLUSION

There are morphological and functional changes in meibomian glands in pediatric patients with lower eyelid epiblepharon. Although the inverted eyelashes were located in the lower eyelid, morphological changes in the meibomian glands were more common in the upper eyelid.

Dry eye disease in the young: A narrative review

Dry eye disease (DED), a multifactorial ocular disease that significantly impacts quality of life, is most commonly reported in adults. This review describes the prevalence, risk factors, diagnosis and management of DED in children. A literature search, conducted from January 2000-December 2022, identified 54 relevant publications. Using similar diagnostic criteria to those reported in adults, namely standardized questionnaires and evaluation of tear film homeostatic signs, the prevalence of DED in children ranged from 5.5% to 23.1 %. There was limited evidence for the influence of ethnicity in children, however some studies reported an effect of sex in older children. Factors independently associated with DED included digital device use, duration of digital device use, outdoor time and urban living, Rates of DED were higher in children with ocular allergy and underlying systemic diseases. Compared with similar studies in adults, the prevalence of a prior DED diagnosis or a diagnosis based on signs and symptoms was lower in children, but symptoms were commonly reported. Treatment options were similar to those in adults, including lifestyle modifications, blinking, management of lid disease and unpreserved lubricants in mild disease with escalating treatment with severity. Management requires careful exploration of symptoms, medical history and the diagnosis and management of ocular comorbidities such as allergy and anterior blepharitis. Appropriately powered population-based studies are required to understand the prevalence of and risk factors for DED in children. Development of age-appropriate thresholds for signs and symptoms of DED would support better diagnosis of disease and understanding of natural history.

Characteristics of the Ocular Surface in Myopic Child Candidates of Orthokeratology Lens Wear

INTRODUCTION

The purpose of this study was to investigate the characteristics of objective ocular surface parameters using non-invasive objective instruments in children with myopia who are candidates for orthokeratology lens wear.

METHODS

Children with myopia who are candidates for orthokeratology lens wear were retrospectively investigated. The subjects were divided into three age groups. The Keratograph 5M and LipiView interferometry were used to assess non-invasive tear meniscus height (TMH), non-invasive tear film break-up time (NIBUT), conjunctival hyperemia redness score (RS), meibomian gland loss (MGL) score, lipid layer thickness (LLT), and blink pattern analysis, including the number of partial blinks (PB) and total blinks (TB), as well as the partial blink rate (PBR).

RESULTS

A total of 1119 children with myopia (2070 eyes) aged 7-18 years were selected. The mean TMH, NIBUT, and LLT of the subjects was 0.21 mm, 12.45 s, and 65.28 nm, respectively. The mean RS and upper and lower MGL scores were 0.64, 1.00, and 1.06, respectively. The mean PB, TB, and PBR was 5.13, 6.46, and 0.81, respectively. Age was significantly correlated to all ocular surface parameters (p = 0.00), except for PB. NIBUT and LLT did not differ between male participants and female participants (all p > 0.05). TMH, RS, and upper and lower MGL were significantly higher in male participants than in female participants (all p < 0.01). In addition, NIBUT was positively associated with TMH (r = 0.13, p = 0.00) and LLT (r = 0.28, p = 0.00). Both upper and lower MGL were positively correlated with TMH, PB, and TB (all p = 0.00), whereas upper MGL was negatively correlated with NIBUT and LLT (all p < 0.05). TB was negatively correlated with NIBUT and LLT (all p = 0.00). PB had no relation with TMH, NIBUT, and LLT (all p > 0.05). In addition, PBR was positively correlated with NIBUT and LLT (all p = 0.00) but not with TMH, RS, or MGL (all p > 0.05). Overall, 57.00% had a TMH ≤ 0.2 mm, 43.20% had a NIBUT ≤ 10 s, 48.10% had an LLT ≤ 60 nm, and 88.10% had a PBR > 0.4.

CONCLUSIONS

Child orthokeratology candidates have enhanced tear secretion and increased meibomian gland deficiency with aging. In addition, the adult dry eye diagnostic criteria may apply to orthokeratology candidates aged 12-18 years but should be lower for younger candidates. Given the proportion of abnormal risk, it is necessary to assess tear film status and blink pattern by reliable and feasible objective examination before fitting orthokeratology.

Blinking and normal ocular surface in school-aged children and the effects of age and screen time

PURPOSE

Baseline ocular surface characteristics in children require investigation. This study characterised blinking and relationships with ocular symptoms, tear film and digital device use.

METHODS

45 children aged 6-15 years (56% female) participated in a cross-sectional study. Ocular surface symptoms (Instant Ocular Symptoms Survey, Dry Eye Questionnaire 5, Symptoms Assessment in Dry Eye, Ocular Surface Disease Index, Ocular Comfort Index and Numerical Rating Scale) and clinical indices (lipid layer thickness, tear secretion and stability, meibomian gland) were assessed. Blink rate and interblink interval were measured in situ using a wearable eye-tracking headset (Pupil Labs GmbH, Germany). Associations between blinking, ocular surface, age, and digital device use (bivariate and partial correlations) and between automated and manually counted blink rate (Bland & Altman) were examined.

RESULTS

Mean blink rate and interblink interval were 20.5±10.5 blinks/min and 2.9±1.9 s during conversation. There was no difference between automated and manual blink rate (p=0.78) and no relationship between blinking and digital device use, age or sex. Mean group symptoms were within normal range and not associated with clinical measurements including blinking. Greater tear volume was associated with a faster blink rate (r=0.46, p=0.001) and shorter interblink interval (r=-0.36, p=0.02). Older age was associated with improved tear volume (r=0.37, p=0.01) and stability (r=0.38, p=0.01).

CONCLUSIONS

Blinking characterised in situ was not impacted by age or habitual digital device use. A faster blink rate was associated with greater tear volume but not symptoms. Improved tear function was found with age suggesting that the ocular surface continues to develop through childhood.

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.

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.

Differential characteristics among asymptomatic and symptomatic meibomian gland dysfunction and those with dry eye

PURPOSE

To identify the characteristics of asymptomatic meibomian gland dysfunction (MGD), symptomatic MGD, and MGD coexisting with dry eye disease (DED).

METHODS

This cross sectional study enrolled a total of 153 eyes of 87 MGD patients. Participants filled in ocular surface disease index (OSDI) questionnaires. Age, gender, Schirmer's test, meibomian gland (MG) related parameters, lipid layer thickness (LLT) and blinking were compared among patients with asymptomatic MGD, symptomatic MGD, and MGD with DED. Multivariate regression was used to analyze the significant factor of DED in MGD. Spearman's rank correlation analysis was used to evaluate the association between the significant factors and MG function.

RESULTS

There was no difference in age, Schirmer's test, lid changes, MG secretion, and MG morphology among three groups. The OSDI of asymptomatic MGD, symptomatic MGD and MGD coexisting with DED were 8.5 ± 2.9, 28.5 ± 12.8 and 27.9 ± 10.5, respectively. Patients with MGD coexisting with DED exhibited more frequent eye blinking than that of patients with asymptomatic MGD (8.1 ± 4.1 vs. 6.1 ± 3.5 blinks/20 sec, P = 0.022), and reduced LLT than that of patients with asymptomatic MGD (68.6 ± 17.2 vs. 77.6 ± 14.5 nm, P = 0.010) and symptomatic MGD (78.0 ± 17.1 nm, P = 0.015). Multivariate analysis identified LLT (per nm, OR = 0.96, 95% CI = 0.93-0.99, P = 0.002) as a significant factor associated with DED development in MGD. The number of expressible MG was positively correlated with LLT (Spearman's correlation coefficient = 0.299, P = 0.016) but negatively correlated with the number of blinking (Spearman's correlation coefficient = -0.298, P = 0.016) in MGD patients with DED, and these findings were not identified in those without DED.

CONCLUSIONS

Asymptomatic MGD, symptomatic MGD, and MGD coexisting with DED share similar characteristics, including meibum secretion and morphology, but MGD patients coexisting with DED exhibited significantly reduced LLT.

Morphological variants of meibomian glands: correlation of meibography features with histopathology findings

PURPOSE

This study describes the histopathological features of different morphological variants of human meibomian glands (MGs) seen on infrared imaging.

METHODS

Tarsal plates dissected from seven cadaveric upper eyelids were imaged using infrared meibography, and then studied histopathologically using H&E, peroxisome proliferator-activated receptor gamma (PPARγ, meibocyte differentiation marker) and Ki-67 (cellular proliferation marker) antibody staining. The different morphological characteristics (varying size and shape) of MGs on meibography were correlated with histopathology findings using image analysis software.

RESULTS

Of the total 127 glands, the morphological variants observed on meibography based on size were: normal (n=62), short (n=18), severely short (n=6) and dropout (n=12) glands, and on shape were: hooked (n=2), tortuous (n=5), overlapping (n=1), thick (n=15) and fluffy (n=6) glands. Short, hooked, tortuous and overlapping glands had similar acinar and ductal histology as seen in normal glands whereas thick, and fluffy glands had increased acinar diameter. All glands except the severely short type demonstrated normal signs of holocrine secretory activity and normal nuclear and cytoplasmic PPARγ expression. Severely short glands had nil while short glands had reduced Ki-67 proliferation index (3%±1%) as compared with normal and other variants (8%±5.2%). Gland dropout areas showed no evidence of any glandular tissue on histology.

CONCLUSION

Hooked, tortuous and overlapping glands had completely normal glandular histology, whereas severely short glands showed atrophic changes with loss of meibocyte differentiation and cellular proliferation. Dropout areas showed total loss of glandular elements. Further studies are needed to validate and to explore the clinical implications of these findings.

Evaluation of Dry Eye After Refractive Surgery According to Preoperative Meibomian Gland Status

Purpose

To investigate the effect of the preoperative meibomian gland (MG) status on dry eye symptoms after corneal refractive surgery.

Methods

This is a prospective, observational study. Subjects were enrolled and classified into 3 groups according to their MG loss grades. Ocular surface parameters were measured preoperatively and at 1, 3, and 6 months, postoperatively, including the ocular surface disease index questionnaire (OSDI), non-invasive tear film break up time (NIBUT), tear meniscus height and Schirmer I test. All the parameters were analyzed among the three groups, and different time points.

Results

Seventy-eight patients were included in this study. The grade of MG loss varied from 0 to 2, thus the subjects were divided into group 1–3 corresponding to the MG loss. There were no significant differences in all parameters at baseline. The OSDI score increased in all groups at 1 month postoperatively and then decreased after other follow-ups. The OSDI was higher in group 3 than group 1 at all time points postoperatively (P = 0.005, 0.002, 0.034). Besides, it was higher in group 2 at 3 months and 6 months, compared with group 1 (P = 0.006, 0.029). The average NIBUT was shorter in group 3, compared with group 1 and group 2 since 1 month after surgery. At 1 and 3 month postoperatively, the grade of MG loss was positively correlated with the total OSDI and the vision-related scores. And it showed a positive correlation only with the environmental score at 6 months postoperatively.

Conclusions

The dry eye discomfortable symptoms significantly differed post operatively according to their preoperative MG loss grade, though no difference was found at baseline. Dry eye was associated more with vision-related discomfort at first and environmental factors later.

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.

Clinical, Meibographic, and Interferometric Evaluation in Children With Ocular Rosacea

PURPOSE

To describe clinical, meibographic, and interferometric signs in children with ocular rosacea.

DESIGN

Prospective case-control study.

METHODS

This single-center study at the Fondation Ophtalmologique Rothschild (Paris, France) included 42 children with ocular rosacea and 44 healthy volunteers (median ages of 10 and 11 years old, respectively) who had infrared meibography images of their lower lids and tear lipid layer thickness measurements taken with the LipiView II device (Tearscience). Clinical severity was graded on a 0 to 4 scale and compared with meiboscores (range 0-4) and tear film lipid layer thickness (range 0-100 nm).

RESULTS

Seven patients presented with unilateral disease and 29 had an asymmetrical form. Twenty-four patients had associated cutaneous rosacea. Ten of 84 eyes presented with a loss of vision <20/25. The mean clinical severity grade was 2.5 ± 1.4. Meibographic abnormalities were significantly more important in children with ocular rosacea (mean meiboscore 2.1 ± 1.36) than in healthy volunteers (0.61 ± 0.78, P < .001). Clinical severity (r = 0.44, P < .001), duration of disease (r = 0.28, P = .011), and a history of chalazia (r = 0.30, P = .006) were correlated to meibographic severity. Mean lipid layer thickness was not significantly different between cases and controls (74.4 ± 18.7 nm and 76.6 ± 18 nm, respectively, P = .47).

CONCLUSION

Meibomian structural alterations in children can be severe and are correlated to ocular rosacea severity. Meibography is an essential tool for diagnosis and follow-up, whereas the contribution of tear film interferometry is uncertain.

Evaluation of the meibomian glands using the tear interferometer wearing orthokeratology lenses

Background

To investigate the impact of orthokeratology wear on meibomian glands in Korean pediatric population using the tear interferometer.

Methods

Fifty-three orthokeratology wearers and 79 non-lens wearers were evaluated using the LipiView® II ocular surface interferometer which shows incomplete blink rate, average lipid layer thickness, and meiboscores.

Results

No significant differences in the incomplete blink rate and meiboscores for upper eyelids, but the lipid layer thickness and meiboscores for lower eyelids were significantly higher in the Ortho-K group than in the control group (p = 0.024 and 0.007, respectively). Correlation analysis showed no significant correlation between the duration of orthokeratology wear and the parameters measured by LipiView® (p > 0.05 for all). Among subgroups based on average duration of lens wear, the longer duration (≥ 24 months) subgroup showed higher meiboscores of lower eyelids (p = 0.011), but no other significant differences.

Conclusions

Ortho-K wearers showed no significant differences in the incomplete blink rate and meiboscores of upper eyelids, but they were associated with increased LLT and higher meiboscores of lower eyelids. Thorough examination and close monitoring of orthokeratology wearers is necessary. Prospective and observational studies are needed to further elucidate the relationship between Orthokeratology and meibomian glands.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02365-3.

Morphological and Functional Changes of Meibomian Glands in Pediatric and Adult Patients with Allergic Conjunctivitis

Allergic conjunctivitis (AC) is one of the most common ocular disorders in clinical practice and is associated with meibomian gland dysfunction. This study aimed to explore the morphological and functional changes of meibomian glands (MGs) in pediatric and adult patients with AC and to analyze their potential predictors. In our prospective, observational cohort study, a total of 59 patients with AC were enrolled, with 30 patients aged ≤16 years in the pediatric group and 29 patients in the adult group. All patients underwent examinations at baseline and last visit when the complete resolution of conjunctival papillae was identified. An automatic MG analyzer was used to measure the morphological and functional parameters of MGs, including their area ratio (GA), tortuosity index (TI), and signal index (SI). Two groups were comparable at baseline in terms of characteristics and MG parameters (p > 0.05). The morphological (length, square, and GA) and functional MG parameters (SI) of AC patients significantly improved in the pediatric group after treatment (all p < 0.05), but not in the adult group. The change in the GA correlated with age, sex, GA, TI, and SI at baseline (all p < 0.05). Age (p = 0.001) and GA (p < 0.001) at baseline were predictors of an improvement in the GA of MGs. The findings showed that the structure and function of MGs in pediatric patients with AC seem to improve after the conjunctival papillae disappear, but not in adult patients.

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.

Quantitative analysis of morphological and functional features in Meibography for Meibomian Gland Dysfunction: Diagnosis and Grading

BACKGROUND

To explore the performance of quantitative morphological and functional analysis in meibography images by an automatic meibomian glands (MGs) analyser in diagnosis and grading Meibomian Gland Dysfunction (MGD).

METHODS

A cross-sectional study collected 256 subjects with symptoms related to dry eye and 56 healthy volunteers who underwent complete ocular surface examination was conducted between January 1, 2019, and December 31, 2020. The 256 symptomatic subjects were classified into MGD group (n = 195) and symptomatic non-MGD group (n = 61). An automatic MGs analyser was used to obtained multi-parametric measurements in meibography images including the MGs area ratio (GA), MGs diameter deformation index (DI), MGs tortuosity index (TI), and MGs signal index (SI). Adjusted odds ratios (ORs) of the multi-parametric measurements of MGs for MGD, and the area under the receiver operating characteristic (AUC-ROC) curves of multi-parametric measurements for MGD diagnosing and grading were conducted.

FINDINGS

When consider age, sex, ocular surface condition together, the estimated ORs for DI was 1.62 (95% CI, 1.29-2.56), low-level SI was 24.34 (95% CI, 2.73-217.3), TI was 0.76(95% CI, 0.54-0.90), and GA was 0.86 (95% CI, 0.74-0.92) for MGD. The combination of DI-TI-GA-SI showed an AUC = 0.82 (P < 0.001) for discriminating MGD from symptomatic subjects. The DI had a higher AUC in identifying early-stage MGD (grade 1-2), while TI and GA had higher AUCs in moderate and advanced stages (grade 3-5). Merging DI-TI-GA showed the highest AUCs in distinguish MGD severities.

INTERPRETATION

The MGs area ratio, diameter deformation, tortuosity and signal intensity could be considered promising biomarkers for MGD diagnosis and objective grading.

FUNDING

This work was supported by the Key-Area Research and Development Program of Guangdong Province (No. 2019B010152001), the National Natural Science Foundation of China under Grant (81901788) and Guangzhou Science and Technology Program (202002030412).

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.

Quantitative evaluation of lipid layer thickness and blinking in children with allergic conjunctivitis

Purpose

To quantitatively evaluate the lipid layer thickness (LLT) and blinking in children with or without allergic conjunctivitis (AC), and to compare those between the different types of AC.

Methods

For this case–control study, 81 children with symptomatic AC with an average age of 9.62 ± 2.67 years were enrolled and subdivided according to the subtypes of AC, including seasonal/perennial allergic conjunctivitis group and vernal keratoconjunctivitis (VKC)/atopic keratoconjunctivitis (AKC) group. Another 82 age-matched healthy children were enrolled as control group. All subjects underwent routine eye examination and measurements of LLT, the number of incomplete or total blinking, partial blinking rate by the LipiView interferometer over a 10-s period. Other ocular surface assessment included fluorescein tear breakup time (TBUT), lower tear meniscus height, meibomian gland loss (MGL), meibum expressibility and quality.

Results

Pediatric patients with AC had significant thinner LLT, shorter TBUT, decreased total blinking but increased partial blinking rate, especially in those with VKC/AKC (all P < 0.05). A significant deterioration of meibomian gland parameters was observed in AC group when compared with control subjects, demonstrated by severe upper and lower MGL, lid margin abnormalities, decreased meibum expressibility, and abnormal meibum quality, all of which were worse in the severe type of AC (all P < 0.05). Thinner LLT was significantly correlated with decreased TBUT (β = 3.666, P < 0.001) and severity of upper MGL (β =  − 7.701, P = 0.002).

Conclusion

Decreased LLT and blinking disorders in pediatric patients with AC may contribute to lipid layer deficiency in the long run, which should be considered and appropriately diagnosed for a more precise treatment.

Topographic and specular microscopic evaluation of cornea and meibomian gland morphology in children with isolated growth hormone deficiency

PURPOSE

To evaluate whether the anterior segment topographic measurements, meibomian gland (MG), and non-invasive tear film break-up time (NITFBUT) differ between healthy children and children with isolated growth hormone deficiency (GHD).

METHODS

A total of 74 eyes of 37 children with GHD and 84 eyes of 42 age- and sex-matched healthy children were included in the study. The spherical equivalence (SE), mean keratometry (Km), corneal thickness, corneal volume (CV), anterior chamber depth (ACD), topographic NITFBUT, qualitative and quantitative MG measurements, corneal endothelial cell density (CD), and proportion of hexagonal cells (HG) were analysed.

RESULTS

The mean SE level of GHD group was similar between groups (p = 0.017). Back Km values were insignificantly steep in children with GHD (p = 0.004, with Bonferroni correction). Specular microscopy analysis was not different between groups. MG loss of GHD group were higher than control group (p < 0.001). The MG morphology analysis and distortion grade were not different between groups (p > 0.05).

CONCLUSIONS

Our results showed that the growth hormone (GH) may have an important role on the anterior segment parameters; however, it is not clear that this misregulation leads to a clinical scenario in childhood. Future studies investigating GHD and/or GH therapy on the ocular surface system are required to clearly demonstrate basic mechanism of GH action.

Tear Lipid Layer Thickness in Children after Short-Term Overnight Orthokeratology Contact Lens Wear

Meibomian gland lipid secretion is important to the stability of the tear film and ocular surface comfort. Changes in the tear film’s lipid layer thickness (LLT) after orthokeratology treatment may reflect underlying changes to the meibomian gland function. The purpose of this study was to investigate the features of the tear lipid layer in normal children and the effects of short-term orthokeratology treatment. Altogether, 163 myopic children (age: 10.7 ± 1.9 years, 8–15 years; 71 males) with no contact lens use history were enrolled in this study, of whom 56 were successfully fitted with orthokeratology lenses and completed the 1-month study. The tear film’s LLT (average, maximum, and minimum) and blinking pattern were measured by a LipiView® interferometer in 163 participants at baseline and in 56 orthokeratology participants at 1 week and 1 month after overnight lens wear. Results show that LLT (average) was 58.09 ± 21.66 nm in Chinese normal children. LLT was significantly correlated with rate of partial blinks at every follow-up (all $p<0.05$ ). Compared to baseline, the LLT (average and minimum) and partial blinks (number and rate) at 1 week and 1 month after orthokeratology treatment both significantly increased, and the increase of LLT was correlated with elevation of rate of partial blinks. In conclusion, LLT was shown to be elevated after short-term overnight orthokeratology treatment and was related to change in rate of partial blinks. Further studies are needed to clarify the long-term effect and the underlying mechanism.

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.

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.

A Novel Quantitative Index of Meibomian Gland Dysfunction, the Meibomian Gland Tortuosity

Purpose

To quantitatively measure meibomian gland (MG) tortuosity in meibomian gland dysfunction (MGD) patients and normal controls and to observe the efficacy of evaluating MG tortuosity for the diagnosis of MGD.

Methods

This cross-sectional study enrolled 32 obstructive MGD patients and 28 normal volunteers. Clinical assessments were performed, including symptom questionnaires, tear meniscus height, tear break-up time (TBUT), corneal fluorescein staining, lid margin abnormality, MG expressibility, and meibography. The meibomian gland tortuosity and meibomian gland density were measured by VIA software.

Results

The mean age of the patients in the MGD group was 33.28 ± 9.28 years, and that of the normal controls was 25.25 ± 11.19 years. The average tortuosity of all MGs in the MGD patients was significantly larger than in the normal controls (P< 0.05). We further stratified the MGD patients into symptomatic MGD and asymptomatic groups. The average tortuosity of all MGs and of the central eight MGs was significantly higher in the symptomatic MGD patients than in the asymptomatic MGD patients (P< 0.05). Significant linear correlations were found between MG tortuosity and the lid margin score, meiboscore, meibum expressibility score, and TBUT (P< 0.05). When the diagnosis of obstructive MGD was based on the tortuosity of the central eight MGs of both eyelids, the sensitivity and specificity were 100% and 100%, respectively.

Conclusions

MG tortuosity is an effective index to delineate MG morphology and to diagnose MGD, especially for the diagnosis of early-stage MGD.

Translation Relevance

Calculating tortuosity quantitatively may play an important role in the diagnosis of MGD.

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.

Meibography and corneal volume optical coherence tomography to quantify damage to ocular structures in children with blepharokeratoconjunctivitis

PURPOSE

To evaluate non-contact infrared meibography and anterior segment optical coherence tomography (AS-OCT) to detect meibomian gland (MG) and corneal changes in children with blepharokeratoconjunctivitis (BKC).

METHODS

We acquired infrared meibography images of upper and lower lids and AS-OCT corneal scans. One masked observer graded meiboscore, full/partial MG dropout, and measured total corneal volume and differential corneal volume per quadrant and central corneal thickness (CCT).

RESULTS

We enrolled 63 children, 31 with BKC and 32 without ocular surface inflammation; median (interquartile range) age BKC 10.6 (7.2-13.9) years, healthy volunteers (HV) 11.4 (9.5-13.8) years. Likert scale scores for meibography and OCT indicate no to low discomfort. Meiboscores for upper and lower lids as well as the total meiboscore were significantly higher in children with BKC than in HV. Subscores for full and partial MG dropout were also significantly higher in children with BKC than in healthy volunteers. There was no statistically significant difference between upper and lower lid for meiboscore nor full/partial MG dropout scores. The corneal volume in the superior quadrant was significantly higher in children with BKC than in HV, whereas the corneal volume in the nasal and inferior quadrants was significantly lower.

CONCLUSIONS

Non-contact imaging technologies objectively demonstrate damage to meibomian glands and changes in corneal volume secondary to BKC. The tests are well tolerated by children with mild/moderate ocular surface inflammation and can detect changes without the requirement for routine eversion of the upper lid. These parameters may be useful both for clinical follow-up and clinical trials.

Noninvasive evaluation of anterior segment and tear film parameters and morphology of meibomian glands in a pediatric population with hypogonadism

PURPOSE

To compare the meibomian gland (MG), non-invasive tear film break-up time (NITFBUT), anterior segment measurements between healthy children and children with hypogonadism.

METHODS

A total of 80 eyes of 40 children with hypogonadism and 86 eyes of 43 age- and sex-matched healthy subjects were included in the study. The mean keratometry (Km), maximum keratometry (Kmax), central (CCT), thinnest (TCT) and apical (ACT) corneal thicknesses, corneal volume (CV), anterior chamber depth (ACD), irido-corneal angle (ICA), first and average non-invasive NITFBUT, MG loss, morphology of MGs, and MG distortion grade, specular endothelial cell density (CD), coefficient of variation (CoV), and percentage of hexagonal cells (HG) were analysed.

RESULTS

The mean CCT and TCT values were approximately 20 μm lower on average in patients with hypogonadism (p < 0.05). MG loss was present 56.1% of the healthy children, the ratio increased to 81.3% in children with hypogonadism (p < 0.001). The morphology and distortion grade did not show any significant differences between groups (p > 0.05). The mean NITFBUT value were similar between groups (p > 0.05). The mean CD value did not show any significant difference between groups, however it decreased in the hormone replacement therapy (HRT) group (p = 0.005).

CONCLUSIONS

MG loss is a physiological process that is prominent in the condition of sex steroid deficiency, but does not cause tear film alterations in children. Future studies investigating sex and gender effect on the ocular surface system in an age-based fashion are required to clearly communicate influences in the arenas of ocular surface research.

Grading and baseline characteristics of meibomian glands in meibography images and their clinical associations in the Dry Eye Assessment and Management (DREAM) study

PURPOSE

To describe and evaluate a comprehensive grading system for meibomian gland (MG) digital infrared images developed for the Dry Eye Assessment and Management (DREAM) Study.

METHODS

Cross-sectional study. Reading Center (RC) certified readers independently evaluated MG features of both lids from meibography images of dry eye disease subjects. Dropout areas were measured using planimetry software. Inter-reader and grade-regrade agreement and comparison of meiboscale scores (Meiboscale^©; Pult) from clinical centers to RC percent dropout and of MG features with clinical parameters were evaluated.

RESULTS

Among 551 eyes of 277 patients at baseline, 62 (11%) upper lid and 5 (1%) lower lid images were missing. Lid eversion was poor in 63 (13%) of upper lids compared to 15 (3%) of lower lids. Intraclass correlation for inter-reader and grade-regrade agreement was moderate to substantial for most MG features. MG features were more frequent in the upper lid (p < 0.001), except for dropout glands, gaps, fluffy gland areas and dropout areas. Clinic meiboscale score was associated with RC percent dropout (p < 0.001), a clinic score of 0% having a mean RC score of 19%, and a clinic score of >75% having a mean RC score of 66%. MG plugging was associated with ghost glands (p = 0.009), dropout glands (p < 0.001) and a composite severity score (p = 0.02); turbid and absent secretions were associated with ghost glands (p = 0.046).

CONCLUSION

RC readers identified MG features with good reproducibility. Upper lids had more MG features. RC dropout areas correlated well with clinic meiboscale scores. Ghost glands were associated with paste like and absent meibomian secretions.