Meibomian Gland Dysfunction in a Hospital-Based Population in Central India

Physiological Effects of Soat1 Inactivation on Homeostasis of the Mouse Ocular Surface

Purpose

Soat1/SOAT1 have been previously reported to be critical for the biosynthesis of cholesteryl esters (CEs) in the mouse Meibomian glands (MGs) as the loss of function led to an arrest of CE production and a substantial accumulation of nonesterified cholesterol in the meibum, causing an increase in its melting temperature. The purpose of this study was to further investigate the role of Soat1 in meibogenesis and ocular surface physiology.

Methods

The mouse ocular features of knockout Soat1-/- and wild type (WT) mice were studied using various ophthalmic and histological techniques, mouse lipidomes were monitored using liquid chromatography/mass spectrometry, whereas their transcriptomes were compared to characterize the effects of the mutation on the gene expression profiles in the MG and cornea.

Results

Soat1-/- mice displayed increased tear production and severe corneal abnormalities, such as corneal thinning, (neo)vascularization, ulceration, and opacification that progressed with aging. Transcriptomic analyses led to identification of a range of significantly disrupted pathways, which included general and specific lipid metabolism-related pathways, keratinization, angiogenesis/(neo)vascularization, muscle contraction, and several other pathways. In addition, histological and histochemical experiments revealed morphological changes in the MG, cornea, and conjunctiva in Soat1-/- mice. Notably, the mRNA microarray expression level of Soat1 in WT MGs (log2 17.5) was 1000 × of that in the mouse cornea (log2 7.5).

Conclusions

These findings suggest a direct involvement of Soat1/SOAT1 in MGs in maintaining ocular surface homeostasis, in general, and corneal health, specifically.

Sex Differences in the Prevalence of Meibomian Gland Dysfunction: A Mini Review

PURPOSE

In this review, we aimed to investigate the literature on sex-specific prevalence of meibomian gland dysfunction (MGD) and to determine whether women or men are more at risk for MGD.

METHODS

A search was conducted on PubMed using the terms: (Sex OR Gender OR prevalence) AND (Meibomian gland).

RESULTS

Twenty-four relevant studies on MGD prevalence were identified, including 10 population-based and 14 hospital-based studies. Among the population-based studies, five studies reported higher rates among men, three studies found no differences, and one study observed higher rates among women. In the hospital-based studies, 10 studies reported no difference, two found higher rates among men, and one found higher among women. In the reviewed literature, there was a considerable variation between studies in terms of quality, sample size, age ranges, diagnostic criteria.

CONCLUSIONS

While most of the population-based studies suggest a higher prevalence among men, the majority of clinic-based studies show no significant difference. Further research with larger samples and standardized criteria is needed to determine whether men are indeed more susceptible to MGD.

Prevalence, Severity, and Treatment Outcomes of Meibomian Gland Dysfunction in Patients With Dry Eye Symptoms at a Tertiary Care Center in South India

Background and objective

Dry eye disease (DED) is one of the most common reasons why patients seek eye care. With increasing age, widespread adoption of technology, and environmental changes, its prevalence has been on the rise, and will likely increase further. Meibomian gland dysfunction (MGD) is the most common cause of DED; however, for a variety of reasons, it is currently underrecognized. We aimed to determine the etiology of DED from a sample of patients visiting our center with dry eye symptoms and study the characteristics of those diagnosed with MGD.

Methodology

We conducted this prospective observational study from 2016 to 2018. We included patients with two or more dry eye symptoms and excluded those with systemic conditions or structural issues causing dry eye. Each patient underwent a detailed evaluation of the dry eye, including the Ocular Surface Disease Index (OSDI) questionnaire, Oxford corneal staining, Schirmer test 1, tear film break-up time (TBUT), tear meniscus height, and non-contact meibography. All patients subsequently received appropriate treatment. Patients with MGD were evaluated once again after one month.

Results

We included 250 patients in the study. Their mean (standard deviation) age was 45.3 (16.9) years, and 138 (55%) of them were males. Grittiness and itching were the most common symptoms. MGD was the most common diagnosis, seen in 100 (40%), followed by chronic allergic conjunctivitis. Patients with MGD were more likely to be elderly and had significantly worse DED parameters. Over half of all MGD cases were mild or less severe. With appropriate treatment, all DED metrics improved significantly.

Conclusions

MGD was the most common cause of DED in our sample. Patients with MGD were more likely to be elderly and had more severe DED, consistent with other studies in the literature. With specific treatment of MGD, there was a significant improvement in the patients' condition. DED is a growing ocular health issue that causes great detriment to patients’ quality of life and finances. Our findings support the need for a detailed evaluation and specific treatment of patients presenting with dry eye symptoms.

Orthokeratology Lens Wear for 2 Years in Children Did Not Alter Tear Film Lipid Thickness by Non-Invasive Interferometry

Purpose

Previous studies suggest that overnight orthokeratology (OOK) may be detrimental to tear function. We aimed to investigate the effect of OOK on lipid layer thickness (LLT), blink pattern, and meibomian gland and elucidate the relationship of these variables.

Methods

Thirty-seven participants who wore OOK lenses every night for at least 2 years and twenty-four healthy non-contact lens wearers (controls) were enrolled in this retrospective study. LipiView interferometry, blink pattern analysis, the ocular surface status, and morphology and function of the meibomian gland were determined.

Results

The OOK group and healthy controls had similar LLT, blink patterns, ocular surface status, and the function of the meibomian gland. OOK participants demonstrated higher meiboscore in the lower eyelids (p < 0.05) but not in the upper eyelids. Within the OOK group, LLT was significantly impacted by the partial blink rate (p < 0.05) and the total score of the upper meibomian gland (p = 0.10).

Conclusions

Wearing OOK for 2 or more years increased lower eyelid meibomian gland dropout but did not have a reduction of LLT.

Factors influencing the clinical outcomes of intense pulsed light for meibomian gland dysfunction

To observe the clinical outcomes of intense pulsed light (IPL) for meibomian gland dysfunction (MGD) and identify its influencing factors.Forty-eight eyes of 48 patients with MGD were included. Subjects were followed up 5 times on day 1, day 15, day 30, day 45, and day 120, and underwent 3 sessions of the IPL treatment on day 1, day 15 and day 30. Gender, age, duration of MGD, time of video display terminal usage, and severity of MGD were recorded at baseline. At every visit, Ocular Surface Disease Index (OSDI), eyelid margin abnormality score, tear film breakup time, Schirmer I test (S ɪ t) and corneal fluorescein staining were recorded. The clinical parameters before and after 3 IPL treatments were compared. Univariate and multivariable logistic regression analyses were performed to explore influencing factors.Compared with baseline, the tear film breakup time was increased and the corneal fluorescein staining score and OSDI were significantly decreased on day 45 and day 120 (all P < .001). In univariate analysis, among the patients with a younger age (18-39 years), moderate MGD, higher baseline S ɪ t and higher baseline OSDI, the IPL treatment had a higher effective rate (P = .032, .004, .024, and .014 respectively). The MGD severity was strongly associated with effective IPL, and patients with moderate MGD had an OR of 22.454 compared with the severe MGD patients (OR = 22.454, 95% CI: 2.890-174.436, P = .003).IPL effectively improves clinical symptoms and some signs in MGD patients. Age, MGD severity, baseline S ɪ t and baseline OSDI are potential factors that may influence the clinical outcomes of IPL. MGD severity is an independent influencing factor.

Short tear film breakup time-type of dry eye in India

Purpose

The aim of this study was to describe the clinical characteristics and risk factors of short tear film break-up time (TBUT) type of dry eye disease and compare it with other types of dry eye diseases.

Methods

This cross-sectional study included 570 patients (≥ 20 years) from the outpatient department using systematic random sampling.

Results

The age-adjusted prevalence of short TBUT type of dry eye disease was 5.4% (95% confidence interval: 3.2-6.8%). There was no difference (P > 0.05) between the total and subscale scores of the Ocular Surface Disease Index^® questionnaire between patients with short TBUT and those with aqueous tear deficiency. Both these groups differed significantly (P < 0.05) in the findings of TBUT, Schirmer I test, and Lissamine green staining score. The common symptoms in patients with short TBUT type of dry eye disease were eye fatigue (25.4%), heaviness in the eye (19.7%), and an uncomfortable sensation (14.1%). The symptoms in the aqueous tear deficiency group were light sensitivity (28.2%), dryness (19.2%), burning (13.0%), foreign body sensation (12.8%), and blurring of vision (14.1%). The risk factors associated with short TBUT type of dry eye disease were the presence of meibomian gland dysfunction (odds ratio: 3.759 [95% confidence interval: 2.135-6.618], P < 0.0001) and female sex [odds ratio: 1.954 (95% confidence interval: 1.042-3.667), P = 0.037].

Conclusion

Patients with short TBUT type of dry eye disease have symptom severity similar to aqueous tear-deficient dry eyes, but the pattern is different. The finding of this type of dry eye disease in India indicates its global presence, and ophthalmologists should consider it in their differential diagnoses.

Ocular Surface Disease Index© and the five-item dry eye questionnaire: A comparison in Indian patients with dry eye disease

Purpose:

To compare the suitability of the Ocular Surface Disease Index (OSDI) and the 5-item Dry Eye Questionnaire (DEQ-5) in Indian patients with dry eyes.

Methods:

This cross-sectional study evaluated the OSDI and DEQ-5 in patients with tear film abnormalities. Tear film breakup time, tear film height, Schirmer’s I, lissamine green staining, and meibomian gland expressibility were performed on each patient.

Results:

There were 101 patients with symptoms and/or signs of tear film abnormality. Both OSDI and DEQ-5 questionnaires significantly correlated (ρ = 0.566, P < 0.0001) with each other. The OSDI questionnaire showed a good correlation with all dry eye tests, whereas the DEQ-5 correlated significantly only with the tear film breakup time and the lissamine green score. None of the questionnaires correlated with meibomian gland expressibility. The Bland–Altman analysis revealed a marginal bias (−0.01 unit) for DEQ-5. The DEQ-5 scored higher in patients with mild symptoms. While 101 (100%) patients answered all the questions in the DEQ-5, only 19 (18.8%) patients answered all the questions in the OSDI questionnaire. The least responses were recorded in the vision-function-related and environmental trigger subscales of the OSDI.

Conclusion:

The OSDI and DEQ-5 scores showed a moderate correlation. The OSDI questionnaire correlated with a higher number of dry eye tests than the DEQ-5. The large number of skipped questions in the vision-function-related and environmental trigger subscales of the OSDI suggests that the questionnaire is not adequately adapted to the Indian population. Patients with a negative OSDI score should be reassessed with the DEQ-5 to exclude symptom positivity.

Prevalence of symptoms of dry eye disease in an urban Indian population

Purpose:

The aim of this study was to estimate the prevalence of symptoms of dry eye disease (DED) in an urban population in India.

Methods:

In this cross-sectional study, a two-stage cluster sampling procedure was conducted across 50 municipal wards in the city of Raipur, India, between December 2019 and February 2020, to include 2500 households. Interviewers collected demographic and lifestyle data from participants aged ≥20 years. DED symptoms were assessed using a standard six-item validated questionnaire. The presence of one or more of the six dry eye symptoms often or all the time was considered positive for DED symptoms.

Results:

In this study, 2378 people completed the survey of whom 1397 (58.7%) were males and 981 (41.3%) were females. The crude and overall age-adjusted prevalence for any positive symptom was 6.5% and 6.8% (95% CI: 5.8–7.8%), respectively. The commonest symptom was red eyes (2.8%) followed by burning sensation (1.8%), foreign body sensation (1.7%), dry eyes (1.2%), gummy eyes (1.2%), and crusts on eyelashes (0.8%). The associated risk factors were female sex, use of digital display, smoking and stay in an air-conditioned environment.

Conclusion:

The prevalence of DED symptoms in this urban Indian population was less than the prevalence reported in most other population-based studies from outside India, and lower than other hospital-based studies from India. Hence, DED prevalence in India is either lower than current estimates or is non-uniform in distribution.

Evaluation of Meibomian Gland Dysfunction Among Ophthalmic Healthcare Workers

Purpose

To evaluate the prevalence of meibomian gland dysfunction (MGD) among ophthalmic healthcare workers.

Setting

A tertiary ophthalmic center.

Design

Prospective, observational study.

Methods

Forty-four volunteer ophthalmologists and ophthalmic nurses were recruited. Information including demographics, contact lens wear, history of refractive surgery and symptom score based on Standardized Patient Evaluation of Eye Dryness (SPEED) II Questionnaire for Dry Eye Disease/Ocular Surface Disease were recorded. Lipid layer thickness (LLT), meibomian glands dropout and dilation grades, and proportion of partial blinking were evaluated using an ocular surface interferometer with dynamic meibomian imaging (LipiView, Johnson & Johnson). Based on the chance of MGD, meibomian gland dropout and dilation, selected subjects also underwent treatment with a thermal pulsation system (LipiFlow, Johnson & Johnson) in one or both eyes.

Results

Eighty-eight eyes of 44 volunteers were evaluated during the study period. The mean LLT was 60.0nm. Twenty-seven (61.4%) subjects had a 90% or high chance of MGD and their mean lower lid meibomian gland dropout and dilation grades were 1.2 and 1.7, respectively. Twenty-eight eyes of 16 volunteers received treatment with the thermal pulsation system. Following treatment, the mean LLT improved from 50.3nm to 61.0nm (Wilcoxon's signed rank test, p=0.001).

Conclusion

Despite being more knowledgeable to MGD and more accessible to treatment, MGD is a highly prevalent condition among ophthalmic healthcare workers, with a 61.4% prevalence among the recruited subjects. This is similar to reported prevalence in Asian populations of up to 74.5%. Targeted therapy based on dynamic meibomian imaging is effective in improving both objective and subjective measures of MGD.

A review of meibography for a refractive surgeon

Refractive surgery has evolved from being a therapeutic correction of high refractive errors to a cosmetic correction. The expectations associated with such a surgery are enormous and one has to anticipate all possible complications and side-effects that come with the procedure and prepare accordingly. The most common amongst these is post-refractive surgery dry eye of which Meibomian gland dysfunction is a commonly associated cause. We present an understanding of various diagnostic imaging modalities that can be used for evaluating meibomian glands which can also serve as a visual aid for patient understanding. We also describe various common conditions which can silently cause changes in the gland architecture and function which are to be considered and evaluated for.