Meibomian secretions in chronic blepharitis

Effect of low-level light therapy in individuals with dry eye disease

INTRODUCTION

Low-level light therapy (LLLT) or photobiomodulation, the application of red light to the eye, is used for the treatment of dry eye. Limited studies have investigated the efficacy of LLLT as a stand-alone treatment. The investigation aimed to evaluate the effect of LLLT on signs and symptoms of dry eye.

METHODS

Participants with mild to moderate dry eye were recruited for this three-visit study. Visits were 7 (±3) days apart and all participants received 633 nm LLLT (eye-light®) for 15 min at each visit. Clinical measures including first and average non-invasive keratograph tear break-up time (NIKBUT), tear meniscus height (TMH), meibomian gland (MG) loss for upper and lower eyelids, ocular surface disease index (OSDI) score, tear film lipid layer thickness, meibum quality score, Schirmer's test, corneal fluorescein staining and eyelid temperature for external upper (EUL) and external lower (ELL) eyelids were measured from the right eye of participants before and after treatment.

RESULTS

Thirty participants (mean [SD] age: 31.1 [9.5] years) completed the study. Treatment with LLLT resulted in significant differences in first and average NIKBUT, TMH, tear film lipid layer thickness, OSDI score, Schirmer's test, meibum quality score and eyelid temperature over time (all p < 0.05). Compared to baseline, TMH, tear film lipid layer thickness and eyelid temperature significantly increased by 0.06 mm (95% CI: 0.01-0.11), 12.9 nm (95% CI: 1.18-24.55), and 7.0°C, respectively, for both EUL (95% CI: 6.17-7.84) and ELL (95% CI: 6.17-7.73). The respective decrease in the OSDI score and Schirmer's test was 10.2 (95% CI: -15.15 to -5.26) and 4.4 mm (95% CI: -7.31 to -1.42; all p < 0.05). There was no significant difference in corneal fluorescein staining and MG loss after LLLT.

CONCLUSION

Low-level light therapy treatment significantly improved signs and symptoms of dry eye in the early phases of treatment, suggesting its efficacy for dry eye management.

Understanding Ocular Graft-Versus-Host Disease to Facilitate an Integrated Multidisciplinary Approach

Ocular Graft-versus-Host Disease (oGVHD) remains a challenging and potentially devastating complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). It significantly impacts the quality of life of affected survivors, however, is often underrecognized particularly during the early stages. Targeting all providers in the HSCT community who see patients regularly and frequently for their post-allo-HSCT care, this review and opinion piece introduces the basic concepts of ocular surface pathophysiology, dissects the different stages of clinical presentation of oGVHD, explains why the current diagnostic criteria tend to capture the late disease stages, highlights the warning signs of early disease development, in hope to facilitate prompt referral of oGVHD suspects for ocular specialist care. In addition to introducing a comprehensive list of treatment options, this review emphasizes basic therapeutic strategy and options that are safe and effective to be initiated by any care provider. We believe in empowering the patients as well as the care providers beyond disciplinary boundaries, in order to provide the most cohesive and integrated care to our patients in a multidisciplinary approach.

The Yin and Yang of non-immune and immune responses in meibomian gland dysfunction

Meibomian gland dysfunction (MGD) is a leading cause of dry eye disease and one of the most common ophthalmic conditions encountered in eye clinics worldwide. These holocrine glands are situated in the eyelid, where they produce specialized lipids, or meibum, needed to lubricate the eye surface and slow tear film evaporation - functions which are critical to preserving high-resolution vision. MGD results in tear instability, rapid tear evaporation, changes in local microflora, and dry eye disease, amongst other pathological entities. While studies identifying the mechanisms of MGD have generally focused on gland obstruction, we now know that age is a major risk factor for MGD that is associated with abnormal cell differentiation and renewal. It is also now appreciated that immune-inflammatory disorders, such as certain autoimmune diseases and atopy, may trigger MGD, as demonstrated through a T cell-driven neutrophil response. Here, we independently discuss the underlying roles of gland and immune related factors in MGD, as well as the integration of these two distinct mechanisms into a unified perspective that may aid future studies. From this unique standpoint, we propose a revised model in which glandular dysfunction and immunopathogenic pathways are not primary versus secondary contributors in MGD, but are fluid, interactive, and dynamic, which we likened to the Yin and Yang of MGD.

Thermal effect on eyelid and tear film after low-level light therapy and warm compress

CLINICAL RELEVANCE

The warming effect of low-level light therapy may contribute to its therapeutic mechanism which is beneficial for dry eye management.

BACKGROUND

Low-level light therapy is proposed to work via cellular photobiomodulation and a potential thermal effect in dry eye management. This study examined the change in eyelid temperature and tear film stability after low-level light therapy compared to warm compress.

METHODS

Participants with no to mild dry eye disease were randomised into control, warm compress, and low-level light therapy groups. The low-level light therapy group was treated with Eyelight mask (633 nm) for 15 minutes, the warm compress group with Bruder mask for 10 minutes, and the control group with an Eyelight mask having inactive LEDs for 15 minutes. Eyelid temperature was measured using the FLIR One® Pro thermal camera (Teledyne FLIR, Santa Barbara, CA, USA), and clinical measures of tear film stability were evaluated before and after treatment.

RESULTS

Thirty-five participants (mean age ± SD, 27.3 ± 4.3 years) completed the study. Eyelid temperatures for external upper, external lower, internal upper and internal lower eyelids were significantly greater in the low-level light therapy and warm compress groups immediately after treatment compared to the control group (all p < 0.001). No difference in temperature was observed between the low-level light therapy and warm compress groups at all time points (all p > 0.05). Tear film lipid layer thickness was significantly greater after treatment (mean (95% CI), 13.1 nm (5.3 to 21.0), p < 0.005) but not different between groups (p > 0.05).

CONCLUSION

A single treatment of low-level light therapy increased eyelid temperature immediately after treatment, but the increase was not significantly different from warm compress. This suggests that thermal effects may in part contribute to the therapeutic mechanism of low-level light therapy.

Modeling meibum secretion: Alternatives for obstructive Meibomian Gland Dysfunction (MGD)

PURPOSE

While changes in meibum quality are correlated with severity of meibomian gland dysfunction (MGD) and dry eye disease, little is known regarding the mechanics of meibum secretion. The purpose of this study was to develop a finite element model of meibum secretion and evaluate the effect of various factors that might impact meibum delivery to the ocular surface.

METHODS

A finite element analysis in COMSOL 6.0 was used to simulate the flow of meibum within the gland's terminal excretory duct. Historical normal human meibum rheology data taken over the meibum melting range from fluid (35-40 °C) to solid (25-30 °C) were then used to calculate the minimum yield stress and plastic viscosity of meibum. The effects of meibum melting state, eyelid pressure and terminal duct diameter on meibum flow rates were then systematically investigated.

RESULTS

The melting state of meibum from liquid to solid was associated with an increase in the minimum yield stress and plastic viscosity that caused an exponential decrease in meibum flow. Modeling also established that there was a linear correlation between meibum flow rate and eyelid pressure needed to express meibum and the 4th power of the terminal duct radius.

CONCLUSIONS

Our results suggest that changes in the melting state of meibum from fluid to solid, as well as changes in the radius of the terminal excretory duct and the force exerted by the eyelid can lead to dramatic decreases in the flow of meibum. Together these findings suggest alternative mechanisms for meibomian gland obstruction.

Meibomian Gland Dysfunction: A Route of Ocular Graft-Versus-Host Disease Progression That Drives a Vicious Cycle of Ocular Surface Inflammatory Damage

PURPOSE

To investigate the role of aggressive meibomian gland dysfunction (MGD) in the immune pathogenesis of ocular graft-vs-host disease (GVHD).

METHODS

In mice, an allogeneic GVHD model was established by transferring bone marrow (BM) and purified splenic T cells from C57BL/6J mice into irradiated C3-SW.H2b mice (BM+T). Control groups received BM only. Mice were scored clinically across the post-transplantation period. MGD severity was categorized using the degree of atrophy on harvested lids. Immune disease was analyzed using flow cytometry of tissues along with fluorescent tracking of BM cells onto the ocular surface. In humans, parameters from 57 patients with ocular GVHD presenting to the Duke Eye Center were retrospectively reviewed. MGD was categorized using the degree of atrophy on meibographs. Immune analysis was done using high-parameter flow cytometry on tear samples.

RESULTS

Compared with BM only, BM+T mice had higher systemic disease scores that correlated with tear fluid loss and eyelid edema. BM+T had higher immune cell infiltration in the ocular tissues and higher CD4+-cell cytokine expression in draining lymph nodes. BM+T mice with worse MGD scores had significantly worse corneal staining. In patients with ocular GVHD, 96% had other organs affected. Patients with ocular GVHD had abnormal parameters on dry eye testing, high matrix metalloproteinase-9 positivity (92%), and abundance of immune cells in tear samples. Ocular surface disease signs were worse in patients with higher MGD severity scores.

CONCLUSIONS

Ocular GVHD is driven by a systemic, T-cell-dependent process that causes meibomian gland damage and induces a robust form of ocular surface disease that correlates with MGD severity. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Immediate and Quantitative Changes in Tear Film Parameters and Meibomian Gland Structures after Warm Compression and Meibomian Gland Squeezing in Meibomian Gland Dysfunction Patients and Normal Subjects

Meibomian gland dysfunction (MGD), a chronic abnormality of meibomian glands, causes various dry eye symptoms. Principal treatments for MGD are warm compression and mechanical squeezing of the eyelids. In this study, the immediate impact of this treatment on tear film lipid layer thickness (TFLLT) and the meibomian gland (MG) structure in MGD and normal groups was investigated to establish its efficacy and potential side effects. Nineteen MGD patients and seven normal subjects were enrolled. TFLLT and blinking parameters were evaluated before and after warm compression. Morphological changes of MG structures after mechanical squeezing were analyzed using Image J and Fiji. Differential analysis of the MGD and the normal groups of TFLLT changes after warm compression showed a significant increase in the normal group. In normal eyes, the average, maximum, and minimum TFLLT were significantly increased, and in the MGD group, only the minimum TFLLT was improved. Blinking parameters showed no significant change in either group. Morphometric analysis showed no damages of the MG after MG squeezing. A significant increase in MG length was observed in normal eyes. Warm compression immediately increased TFLLT more significantly in the normal group than in the MGD patients. Mechanical expression is a safe therapeutic option without remarkable structural MG damages.

Latest developments on meibomian gland dysfunction: Diagnosis, treatment and management

Background: Meibomian gland dysfunction (MGD) is one of the leading causes of evaporative dry eye disease and one of the most common ophthalmic conditions found in clinical practice. Meibomian gland dysfunction tends to be overlooked because its signs and symptoms do not cause blindness. Meibomian gland dysfunction is characterised by the obstruction of the meibomian gland terminal ducts resulting in tear film instability.Aim: The purpose of this article was to provide an update on MGD’s diagnosis and treatment.Method: A literature review was conducted using search engines such as Google Scholar, Medline and ScienceDirect databases. Keywords such as MGD diagnosis and management and treatment of MGD were used to search the databases.Results: A total of 44 relevant papers were reviewed. These papers were then curated to include only those concerning diagnosis of meibomian gland dysfunction, treatment of meibomian gland dysfunction and management options of meibomian gland dysfunction. The references of individual papers from the curated results were checked to yield a further 13 papers.Conclusion: Meibomian gland dysfunction is not a single entity but is multifactorial in origin; however, our understanding of the condition is evolving rapidly because of newer imaging technology. There is no gold standard treatment option for MGD, but many options are available that include medications and other procedures. 

Alteration in meibum lipid composition and subjective symptoms due to aging and meibomian gland dysfunction

PURPOSE

To investigate the alteration in lipid composition of meibum, objective clinical signs, and subjective symptoms associated with aging and meibomian gland (MG) dysfunction (MGD).

METHODS

In 10 MGD patients [4 males/6 females, mean age: 65.6 ± 7.9 years (range: 50-79 years)] and 24 healthy volunteer subjects [young subjects: 6 males/6 females, mean age: 25.7 ± 3.8 years (range: 20-35 years), elderly subjects: 6 males/6 females, mean age: 58.4 ± 7.5 years (range: 50-79 years)], three objective clinical signs were evaluated: MG orifice obstruction, meibum score, and tear film lipid layer interference pattern. Subjective symptoms were analyzed via a 15-item questionnaire. After careful collection of meibum samples, comprehensive lipid analysis was performed via liquid chromatography-mass spectrometry. Data was analyzed via JMP® ver. 13 (SAS Institute, Inc., Cary, NC) statistical analysis software.

RESULTS

In the MGD patients and elderly subjects, there was a significant decrease in non-polar lipids such as cholesterol esters (ChEs), while a significant increase in polar lipids [cholesterol (Ch), (O-acyl)-ω-hydroxy fatty acid (OAHFA), and free fatty acid (FA)] in total lipids (Tukey-Kramer test: p < 0.05). Triglyceride was significantly increased only in MGD patients (p < 0.05). Symptom scores representative of vision quality (i.e., blurred vision/haziness) were significantly negatively-correlated with the ratio of the non-polar lipid ChE, while significantly positively correlated with the polar lipids Ch, OAHFA, and FA (Spearman's rank correlation coefficient: p < 0.05).

CONCLUSIONS

Our findings revealed that both MGD and aging affect the composition ratio of major meibum lipids, resulting in the appearance of subjective symptoms.

Effects of Lipiflow Treatment Prior to Cataract Surgery: A Prospective, Randomized, Controlled Study

To investigate the effects of preoperative Lipiflow (Johnson & Johnson, Jacksonville, FL, USA) treatment before cataract surgery on meibomian gland dysfunction (MGD) and dry eye induced by surgery.

DESIGN

Prospective, randomized controlled study.

METHODS

This study comprised 124 eyes of 124 patients with planned surgery for senile cataract. Participants were randomly allocated into control and Lipiflow groups based on administration of Lipiflow treatment 3 weeks before cataract surgery. For meibomian gland (MG) evaluation, MG atrophy, degree of gland expressibility, and quality of gland secretions were examined at the baseline visit and 1 and 3 months postoperatively. Ocular surface parameters of tear film break-up time, Oxford corneal staining score, and tear film lipid layer thickness were measured at each visit. Ocular Surface Disease Index and Dry Eye Questionnaire were also assessed.

RESULTS

The control group exhibited a significant decrease in MG expressibility, worsened meibum quality, decreased lipid layer thickness, and worsened corneal staining after cataract surgery. Also, dry eye symptom showed significant worsening. Conversely, the Lipiflow group showed significantly improved MG patency and meibum quality, increased tear film break-up time, and reduced corneal staining, and presented improved subjective outcomes reported on both Ocular Surface Disease Index and Dry Eye Questionnaire. The improvement of each parameter in the Lipiflow group showed a linear correlation with baseline MGD grade. In addition, patients without baseline MGD showed less worsening or improvement of MGD and dry eye induced by surgery, with preoperative Lipiflow treatment.

CONCLUSIONS

Preoperative Lipiflow treatment conducted before cataract surgery may be a safe and effective intervention for relieving MGD and dry eye induced by surgery. It might be recommended not only for the patients with preoperative MGD but also for those without baseline MGD, to prevent the development of MGD and dry eye induced by ocular surgeries.

Obese Mice with Dyslipidemia Exhibit Meibomian Gland Hypertrophy and Alterations in Meibum Composition and Aqueous Tear Production

BACKGROUND

Dyslipidemia may be linked to meibomian gland dysfunction (MGD) and altered meibum lipid composition. The purpose was to determine if plasma and meibum cholesteryl esters (CE), triglycerides (TG), ceramides (Cer) and sphingomyelins (SM) change in a mouse model of diet-induced obesity where mice develop dyslipidemia.

METHODS

Male C57/BL6 mice (8/group, age = 6 wks) were fed a normal (ND; 15% kcal fat) or an obesogenic high-fat diet (HFD; 42% kcal fat) for 10 wks. Tear production was measured and meibography was performed. Body and epididymal adipose tissue (eAT) weights were determined. Nano-ESI-MS/MS and LC-ESI-MS/MS were used to detect CE, TG, Cer and SM species. Data were analyzed by principal component analysis, Pearson's correlation and unpaired t-tests adjusted for multiple comparisons; significance set at p ≤ 0.05.

RESULTS

Compared to ND mice, HFD mice gained more weight and showed heavier eAT and dyslipidemia with higher levels of plasma CE, TG, Cer and SM. HFD mice had hypertrophic meibomian glands, increased levels of lipid species acylated by saturated fatty acids in plasma and meibum and excessive tear production.

CONCLUSIONS

The majority of meibum lipid species with saturated fatty acids increased with HFD feeding with evidence of meibomian gland hypertrophy and excessive tearing. The dyslipidemia is associated with altered meibum composition, a key feature of MGD.

Non-pharmaceutical treatment options for meibomian gland dysfunction

This review examines currently available non‐pharmaceutical treatment modalities for meibomian gland dysfunction. A detailed search of the PubMed and MEDLINE databases was performed to identify original articles in English that have evaluated such nonpharmaceutical therapies in patients with this condition. Conventional therapies such as application of a warming compress, the practice of lid hygiene, and manual expression of meibomian glands as well as more technologically advanced approaches such as intraductal probing, thermal pulsation, and intense pulsed light therapy are included in the review. These non‐pharmaceutical treatment options may each have a role to play in the management of meibomian gland dysfunction, but more studies are necessary to compare treatments directly under identical experimental conditions in order to determine their relative efficacy. Additional large‐scale, randomised, controlled trials are also required to provide more information such as the specific indications best suited to each treatment modality, the efficacy of such approaches in combination with pharmaceutical‐based therapy, and the mechanisms of action of some of the more technologically advanced systems.

The Efficacy of Warm Compresses in the Treatment of Meibomian Gland Dysfunction and Demodex Folliculorum Blepharitis

Purpose: To investigate and compare the effect of warm compresses on meibomian gland dysfunction and Demodex folliculorum blepharitis.Methods: Forty-two subjects (13 males, 29 females; mean age of 56.45 years) enrolled and completed the two-month warm compress treatment study. Three warm compress therapies were compared: Warm face cloth, MGDRx EyeBag® and OPTASE^TM Moist Heat Mask. Subjects attended for four visits: baseline, two weeks, four weeks, and eight weeks. Subjective symptoms, osmolarity, non-invasive tear break-up time, ocular surface staining, Schirmer I test, meibum expressibility and clarity, and eyelash manipulation and epilation to assess for the presence of Demodex folliculorum, were measured at each visit.Results: Meibomian gland dysfunction, based on a composite score of meibum quality and expressibility, reduced significantly with the MGDRx EyeBag® and the OPTASE^TM Moist Heat Mask (p < .05). There was no significant difference in efficacy for treating meibomian gland dysfunction between the two devices (p = .29). No improvement in meibomian gland dysfunction was detected with the warm face cloth. Only the OPTASE^TM Moist Heat Mask significantly reduced the quantity of Demodex folliculorum over eight-weeks of treatment (p = .036, only baseline to week eight significant p = .008). Symptoms and ocular surface staining improved significantly in all three groups (p < .05). There was no significant change observed in osmolarity, non-invasive tear break-up time or Schirmer I test within each group (p > .05, respectively).Conclusion: The MGDRx EyeBag® and the OPTASE^TM Moist Heat Mask exhibited superior efficacy in treating signs and symptoms of meibomian gland dysfunction, compared to the use of a warm face cloth, over the eight-week period. The OPTASE^TM Moist Heat Mask demonstrated dual therapeutic abilities, treating both meibomian gland dysfunction and Demodex folliculorum blepharitis. Repeated application of heat for the treatment of meibomian gland dysfunction may continue to present a good home-remedy option for patients.

Neutrophils cause obstruction of eyelid sebaceous glands in inflammatory eye disease in mice

Meibomian glands (MGs) are sebaceous glands of the eyelid margin that secrete lipids needed to avert tear evaporation and to help maintain ocular surface homeostasis. Obstruction of MGs or other forms of MG dysfunction can promote chronic diseases of the ocular surface. Although chronic eyelid inflammation, such as allergic eye disease, is an associated risk factor for obstructive MG dysfunction, it is not clear whether inflammatory processes contribute to the pathophysiology of MG obstruction. We show that polymorphonuclear neutrophils (PMNs) promoted MG obstruction in a chronic inflammatory model of allergic eye disease in mice. Analysis of leukocytes in tears of patients with MG dysfunction showed an increase in PMN numbers compared to healthy subjects. Moreover, PMN numbers in tears positively correlated with clinical severity of MG dysfunction. Our findings point to a role for PMNs in the pathogenesis and progression of MG dysfunction.

Assessment of meibomian gland morphology by noncontact infrared meibography in Shih Tzu dogs with or without keratoconjunctivitis sicca

Objective

To investigate meibomian gland (MG) morphology by noncontact infrared meibography in Shih Tzu dogs with or without keratoconjunctivitis sicca (KCS).

Procedures

Fourteen eyes of 12 Shih Tzu dogs (mean age of 10.7 years, range of 7‐13 years) presented to Yakumo Animal Hospital or Triangle Animal Eye Clinic from 2011 to 2017 with clinical signs and a Schirmer tear test (STT) result consistent with KCS (<10 mm/min) were examined. Twenty‐eight eyes of 16 Shih Tzu dogs (mean age of 12.4 years, range of 8 to 15 years) with a STT > 15 mm/min served as healthy controls. Both groups of dogs underwent routine slitlamp biomicroscopy followed by noncontact infrared meibography of the upper eyelid with both desktop‐type and mobile‐type systems.

TFOS DEWS II pathophysiology report

The TFOS DEWS II Pathophysiology Subcommittee reviewed the mechanisms involved in the initiation and perpetuation of dry eye disease. Its central mechanism is evaporative water loss leading to hyperosmolar tissue damage. Research in human disease and in animal models has shown that this, either directly or by inducing inflammation, causes a loss of both epithelial and goblet cells. The consequent decrease in surface wettability leads to early tear film breakup and amplifies hyperosmolarity via a Vicious Circle. Pain in dry eye is caused by tear hyperosmolarity, loss of lubrication, inflammatory mediators and neurosensory factors, while visual symptoms arise from tear and ocular surface irregularity. Increased friction targets damage to the lids and ocular surface, resulting in characteristic punctate epithelial keratitis, superior limbic keratoconjunctivitis, filamentary keratitis, lid parallel conjunctival folds, and lid wiper epitheliopathy. Hybrid dry eye disease, with features of both aqueous deficiency and increased evaporation, is common and efforts should be made to determine the relative contribution of each form to the total picture. To this end, practical methods are needed to measure tear evaporation in the clinic, and similarly, methods are needed to measure osmolarity at the tissue level across the ocular surface, to better determine the severity of dry eye. Areas for future research include the role of genetic mechanisms in non-Sjögren syndrome dry eye, the targeting of the terminal duct in meibomian gland disease and the influence of gaze dynamics and the closed eye state on tear stability and ocular surface inflammation.

Dysfunctional tear syndrome: dry eye disease and associated tear film disorders - new strategies for diagnosis and treatment

Dysfunctional tear syndrome (DTS) is a common and complex condition affecting the ocular surface. The health and normal functioning of the ocular surface is dependent on a stable and sufficient tear film. Clinician awareness of conditions affecting the ocular surface has increased in recent years because of expanded research and the publication of diagnosis and treatment guidelines pertaining to disorders resulting in DTS, including the Delphi panel treatment recommendations for DTS (2006), the International Dry Eye Workshop (DEWS) (2007), the Meibomian Gland Dysfunction (MGD) Workshop (2011), and the updated Preferred Practice Pattern guidelines from the American Academy of Ophthalmology pertaining to dry eye and blepharitis (2013). Since the publication of the existing guidelines, new diagnostic techniques and treatment options that provide an opportunity for better management of patients have become available. Clinicians are now able to access a wealth of information that can help them obtain a differential diagnosis and treatment approach for patients presenting with DTS. This review provides a practical and directed approach to the diagnosis and treatment of patients with DTS, emphasizing treatment that is tailored to the specific disease subtype as well as the severity of the condition.

The pathophysiology, diagnosis, and treatment of dry eye disease

BACKGROUND

Dry eye disease (DED) is common; its prevalence around the world varies from 5% to 34%. Its putative pathogenetic mechanisms include hyperosmolarity of the tear film and inflammation of the ocular surface and lacrimal gland. Dry eye is clinically subdivided into two subtypes: one with decreased tear secretion (aqueous-deficient DED), and one with increased tear evaporation (hyperevaporative DED).

METHODS

This review is based on pertinent publications retrieved by a selective PubMed search and on the authors' own clinical and scientific experience.

RESULTS

The diagnostic evaluation of dry eye disease should include a detailed patient history, thorough split-lamp examination, and additional tests as indicated. Few randomized controlled therapeutic trials for dry eye have been published to date. Artificial tears of various kinds are recommended if the symptoms are mild. Lid hygiene is helpful in the treatment of hyperevaporative dry eye, while collagen or silicon plugs can be used for partial occlusion of the efferent lacrimal ducts to treat severe hyposecretory dry eye. The benefit of long-term topical anti-inflammatory treatment of moderate or severe dry eye disease with corticosteroids or cyclosporine A eye drops has been documented in clinical trials on a high evidence level. Orally administered tetraycycline derivatives and omega-3 or omega-6 fatty acids are also used.

CONCLUSION

The treatment of dry eye has evolved from tear substitution alone to a rationally based therapeutic algorithm. Current research focuses on pathophysiology, new diagnostic techniques, and novel therapies including secretagogues, topical androgens, and new anti- inflammatory drugs.

Effects of Eyelid Warming Devices on Tear Film Parameters in Normal Subjects and Patients with Meibomian Gland Dysfunction

PURPOSE

To evaluate the effects of commercially available eyelid warming devices on ocular temperatures, tear film function, and meibomian glands in normal subjects and patients with meibomian gland dysfunction (MGD).

METHODS

Ten healthy volunteers were enrolled to evaluate the effects of a single warming and of repeated warming for 2 weeks. Ten MGD patients were enrolled for evaluation of repeated warming over 1 month. Two non-wet (Azuki no Chikara, Eye Hot R) and three wet (hot towel, Hot Eye Mask, Memoto Este) devices were compared in a masked manner. Visual analog scale (VAS) score for ocular symptoms, tear film breakup time (TFBUT), meibum grade, temperatures (eyelid skin, tarsal conjunctiva, central cornea), Schirmer test value, and meibomian gland area were measured before and after warming application.

RESULTS

The single application of the five warming devices improved the VAS score, TFBUT, and ocular temperatures. In the repeated warming application, Azuki no Chikara as a representative non-wet warming device induced a stable and significant improvement in TFBUT and increased the tarsal conjunctival temperature and meibomian gland area in both normal subjects and MGD patients. It also improved meibum grade in MGD patients.

CONCLUSION

Our results suggest that repeated eyelid warming with a non-wet device improves tear film function in normal individuals and may have beneficial effects on both tear film and meibomian gland function in MGD patients.

Six-month effects of a thermodynamic treatment for MGD and implications of meibomian gland atrophy

PURPOSE

The aim of this study was to evaluate the 6-month effect of a single automated thermodynamic treatment (LipiFlow) and implications of meibomian gland atrophy on treatment efficacy 6 months after application.

METHODS

We analyzed the data of 26 subjects with meibomian gland dysfunction before and 6 months after treatment. Investigated parameters included subjective symptoms, lipid layer thickness, meibomian gland assessment, tear osmolarity, corneal and conjunctival staining, lid margin parallel conjunctival folds, Schirmer test values, bulbar redness, tear meniscus height, meibomian gland atrophy, and noninvasive tear break-up time.

RESULTS

Subjective symptoms (mean Ocular Surface Disease Index, 42 ± 19 to 33 ± 21; P = 0.004, mean Standard Patient Evaluation of Eye Dryness 16 ± 7 to 12 ± 7; P = 0.0001), lipid layer thickness (44.0 ± 15.6 to 51.3 ± 20.4; P = 0.014), number of expressible glands (2.9 ± 1.6 to 6.4 ± 4.6; P < 0.0001), lid margin parallel conjunctival folds (2.3 ± 1.0 to 2.0 ± 0.9; P = 0.04), and bulbar redness (1.4 ± 0.5 to 1.2 ± 0.5; P = 0.0001) were all improved 6 months after treatment. Symptomatic improvement was higher in patients with less severe meibomian gland atrophy compared with patients with more dropout at treatment. There was no change of meibomian gland atrophy 6 months after treatment.

CONCLUSIONS

In summary, the results showed that a single thermodynamic treatment is effective in the treatment of meibomian gland dysfunction and that the effects last for at least 6 months. We suggest performing meibography in every patient before treatment for better prediction of therapeutic effects.

Evaluation of Meibomian Gland Dysfunction and Local Distribution of Meibomian Gland Atrophy by Non-contact Infrared Meibography

AIMS

The main purpose of this study was to investigate the relationship between Meibomian gland atrophy (meiboscore) and Meibomian gland expressibility. In addition, the local distribution of Meibomian gland loss was analyzed.

METHODS

A retrospective analysis of 128 patients (92 women and 36 men, 57 ± 17 years) from our dry eye clinic was performed. Infrared meibography was performed using the Keratograph 5 M (Oculus, Wetzlar, Germany) and evaluated with a scoring system introduced by Arita et al.

RESULTS

A significant inverse correlation between Meibomian gland atrophy measured by meibography and expressible Meibomian glands (r = -0.197, p = 0.003) as well as between meiboscore and TBUT (r = -0.1615, p = 0.012) was found. There also was a significant correlation between the total meiboscore and the age (r = 0.33, p < 0.0001). We could find a strong and highly significant correlation between the total meiboscore and the individual meiboscore of the upper eyelid (r = 0.905, p < 0.0001) and the lower eyelid (r = 0.892, p < 0.0001). There was no significant difference of Meibomian gland atrophy between the individual thirds of the upper eyelid, but for the lower eyelid, we could find a higher degree of Meibomian gland atrophy in the nasal third compared with the middle and the temporal third (Dunn's post hoc test, p < 0.0001).

CONCLUSIONS

Meibomian gland atrophy seems to be not constant over the tarsal plate but the examination of the lower tarsus might be sufficient in most of the cases. The correlation of the meiboscore with functional dry eye parameters suggest that in patients with detectable Meibomian gland atrophy there is also an impaired Meibomian gland function. However, meibography seems not to be sufficient as a single test for the diagnosis of MGD. For the future larger, prospective studies are needed to confirm these results and further evaluate the potential of meibography in the diagnosis of MGD.

Short-term effects of topical cyclosporine A 0.05% (Restasis) in long-standing prosthetic eye wearers: a pilot study

PURPOSE

Long-standing prosthetic eye wearing induces ocular surface inflammation. We investigated the short-term effects of topical cyclosporine A 0.05% (Restasis) in patients with ocular discomfort resulting from long-standing prosthetic eye wearing.

METHODS

This was a prospective, interventional case series. Patients who were unilateral prosthetic eye wearers over a period of 5 years were enrolled at a single institution from March to July 2013. The subjects were instructed to instill topical cyclosporine A 0.05% twice per day. Measurements were made pre-treatment and after 1 and 3 months of treatment. Outcome measures were the ocular symptom score, the lid margin abnormality score, the Schirmer test, and the tear meniscus amount, using Fourier-domain optical coherence tomography.

RESULTS

In total, 20 consecutive patients (mean age: 60.1 years, 8 males, 12 females) were included. Ocular symptoms were improved after treatment for 1 month in all patients (ocular symptom score pre-treatment 76.83 vs 46.75 after treatment; P<0.001). There was no statistically significant difference in lid margin abnormality score or tear meniscus amount. The Schirmer test results were improved after treatment for 3 months (pre- and after treatment, 6.70 vs 11.40; P<0.001).

CONCLUSIONS

Topical cyclosporine A 0.05% showed a satisfactory effect in long-standing prosthetic eye wearers. Ocular symptoms were markedly relieved in all subjects after treatment for 1 month.

Biophysical investigations of the structure and function of the tear fluid lipid layer and the effect of ectoine. Part A: natural meibomian lipid films

The tear fluid lipid layer is the outermost part of the tear film on the ocular surface which protects the eye from inflammations and injuries. We investigated the influence of ectoine on the structural organization of natural meibomian lipid films using surface activity analysis and topographical studies. These films exhibit a continuous pressure-area isotherm without any phase transition. With the addition of ectoine, the isotherm is expanded towards higher area per molecule values suggesting an increased area occupied by the interfacial lipid molecules. The AFM topology scans of natural meibomian lipid films reveal a presence of fiber-like structures. The addition of ectoine causes an appearance of droplet-like structures which are hypothesized to be tri-acyl-glycerols and other hydrophobic components excluded from the lipid film. Further the material properties of the droplet-like structure with respect to the surrounding were determined by using the quantitative imaging mode of the AFM technique. The droplet-like structures were found to be comparatively softer than the surrounding. Based on the observations a preliminary hypothesis is proposed explaining the mechanism of action of ectoine leading to the fluidization of meibomian lipid films. This suggests the possibility of ectoine as a treatment for the dry eye syndrome.

Evaluation of lipid layer thickness measurement of the tear film as a diagnostic tool for Meibomian gland dysfunction

PURPOSE

The LipiView interferometer (TearScience Inc, Morrisville, NC) is capable of delivering quantitative values of the tear-film lipid layer thickness (LLT). The purpose of this study was to investigate whether there is a correlation between the LLT and other diagnostic criteria for Meibomian gland dysfunction (MGD).

METHODS

We performed a retrospective analysis of 110 patients (199 eyes) from our dry eye clinic. Subjective symptoms, break-up time (BUT), expressible Meibomian glands, and LLT were measured.

RESULTS

There was a significant correlation between expressible Meibomian glands and LLT (r = 0.36, P < 0.0001). Also, a possible trend of inverse correlation between subjective symptoms (standard patient evaluation of eye dryness) and the LLT was observed; however, this was not significant (r = -0.13, P < 0.08). Analysis of the whole study collective revealed no correlation between the BUT and the LLT (r = 0.003, P = 0.97). A subgroup analysis of the patients with an LLT ≤ 60 showed a better correlation between the LLT and the BUT, which was marginally not significant (r = 0.21; P = 0.059). For a cut-off value of ≤ 75-nm LLT, we found a sensitivity of 65.8% and a specificity of 63.4% for the detection of an MGD. For a cut-off value of ≤ 60, the sensitivity was 47.9%, and the specificity was 90.2%.

CONCLUSIONS

The positive correlation between the LLT and expressible meibomian glands found in this study suggests a higher probability of MGD in patients with a low LLT. This automated assessment of the LLT might be a suitable screening test for detecting MGD. However, further prospective studies are needed to confirm these results and to identify potential confounders.

Effect of a commercially available warm compress on eyelid temperature and tear film in healthy eyes

PURPOSE

To evaluate eyelid temperature change and short-term effects on tear film stability and lipid layer thickness in healthy patients using a commercially available warm compress (MGDRx EyeBag) for ophthalmic use.

METHODS

Eyelid temperature, noninvasive tear film breakup time (NITBUT), and tear film lipid layer thickness (TFLLT) of 22 healthy subjects were measured at baseline, immediately after, and 10 minutes after application of a heated eyebag for 5 minutes to one eye selected at random. A nonheated eyebag was applied to the contralateral eye as a control.

RESULTS

Eyelid temperatures, NITBUT, and TFLLT increased significantly from baseline in test eyes immediately after removal of the heated eyebag compared with those in control eyes (maximum temperature change, 2.3 ± 1.2 °C vs. 0.3 ± 0.5 °C, F = 20.533, p < 0.001; NITBUT change, 4.0 ± 2.3 seconds vs. 0.4 ± 1.7 seconds, p < 0.001; TFLLT change, 2.0 ± 0.9 grades vs. 0.1 ± 0.4 grades, Z = -4.035, p < 0.001). After 10 minutes, measurements remained significantly higher than those in controls (maximum temperature change, 1.0 ± 0.7 °C vs. 0.1 ± 0.3 °C, F = 14.247, p < 0.001; NITBUT change, 3.6 ± 2.1 seconds vs. 0.1 ± 1.9 seconds, p < 0.001; TFLLT change, 1.5 ± 0.9 vs. 0.2 ± 0.5 grades, Z = -3.835, p < 0.001). No adverse events occurred during the study.

CONCLUSIONS

The MGDRx EyeBag is a simple device for heating the eyelids, resulting in increased NITBUT and TFLLT in subjects without meibomian gland dysfunction that seem to be clinically significant. Future studies are required to determine clinical efficacy and evaluate safety after long-term therapy in meibomian gland dysfunction patients.

Dry eye symptoms are increased in mice deficient in phospholipid transfer protein (PLTP)

In the tear fluid the outermost part facing the tear-air interface is composed of lipids preventing evaporation of the tears. Phospholipid transfer protein (PLTP) mediates phospholipid transfer processes between serum lipoproteins and is also a normal component of human tears. To study whether PLTP plays any functional role in tear fluid we investigated PLTP-deficient mice, applying functional and morphologic analyses under normal housing and experimentally induced dry eye conditions. Aqueous tear fluid production, corneal epithelial morphology, barrier function, and occludin expression were assessed. In mice with a full deficiency of functional PLTP enhanced corneal epithelial damage, increased corneal permeability to carboxyfluorescein, and decreased corneal epithelial occludin expression were shown. These pathologic signs were worsened by experimentally induced dry eye both in wild-type and PLTP knock-out mice. Deficiency in the production of tear PLTP in mice is accompanied by corneal epithelial damage, a feature that is typical in human dry eye syndrome (DES). To complement animal experiments we collected tear fluid from human dry eye patients as well as healthy control subjects. Increased tear fluid PLTP activity was observed among DES patients. In conclusion, the presence of PLTP in tear fluid appears to be essential for maintaining a healthy and functional ocular surface. Increased PLTP activity in human tear fluid in DES patients suggests an ocular surface protective role for this lipid transfer protein.

Effects of free fatty acids on meibomian lipid films

The purpose of this study was to evaluate the impact of free fatty acids (FFA), namely oleic (OA) and linoleic (LA) ones, on meibomian lipid films (MLF) using a Langmuir trough (LT) and a Brewster angle microscope (BAM). Human meibum was collected from healthy volunteers. A Tris-buffered saline (TBS, pH 7.4) was used as the control aqueous subphase for LT experiments. Then, varying amounts of OA and LA were dissolved in TBS to make FFA-containing subphases. Predetermined amounts of meibum were loaded onto the surface of the (TBS/±FFA) subphases to form MLF. Then, surface pressure-area (π/A) isotherms of MLF were recorded. Standard rheological parameters such as rigidity, elasticity, and hysteresis, were computed. In a separate experiment, OA and LA were pre-mixed with meibum at different weight ratios prior their spreading onto the control TBS subphase, and the (π/A) isotherms of the resulting mixed films of meibum and FFA were studied and analyzed in the same fashion as described above. When studied at the normal corneal temperature of 34 °C with the (TBS/-FFA) subphase, meibum formed stable films. When (TBS/+FFA) subphase was used, both FFA quickly disrupted the MLF, acting in a similar fashion. BAM revealed that the most dramatic changes in the structure of MLF occurred in the range of OA concentrations between 5 and 15 μM. However, this effect was apparent even with 2.5 μM OA. When OA was pre-mixed with meibum, but was absent from the subphase, it caused gradual concentration-dependent changes in the (π/A) isotherms, but the MLF did not disappear from the surface. Thus, tested FFA showed a remarkable ability to disrupt, and/or prevent the formation of, human MLF, which could contribute to the onset of those forms of dry eye disease that are associated with enhanced activity of lipolytic enzymes, such as chronic blepharitis.

Lipidomics of human Meibomian gland secretions: Chemistry, biophysics, and physiological role of Meibomian lipids

Human Meibomian gland secretions (MGS) are a complex mixture of diverse lipids that are produced by Meibomian glands that are located in the upper and the lower eyelids. During blinking, MGS are excreted onto the ocular surface, spread and mix with aqueous tears that are produced by lachrymal glands, and form an outermost part of an ocular structure called "the tear film" (TF). The main physiological role of TF is to protect delicate ocular structures (such as cornea and conjunctiva) from desiccating. Lipids that are produced by Meibomian glands are believed to "seal" the aqueous portion of TF by creating a hydrophobic barrier and, thus, retard evaporation of water from the ocular surface, which enhances the protective properties of TF. As lipids of MGS are interacting with underlying aqueous sublayer of TF, the chemical composition of MGS is critical for maintaining the overall stability of TF. There is a consensus that a small, but important part of Meibomian lipids, namely polar, or amphiphilic lipids, is of especial importance as it forms an intermediate layer between the aqueous layer of TF and its upper (and much thicker) lipid layer formed mostly of very nonpolar lipids, such as wax esters and cholesteryl esters. The purpose of this review is to summarize the current knowledge on the lipidomics of human MGS, including the discussions of the most effective modern analytical techniques, chemical composition of MGS, biophysical properties of Meibomian lipid films, and their relevance for the physiology of TF. Previously published results obtained in numerous laboratories, as well as novel data generated in the author's laboratory, are discussed. It is concluded that despite a substantial progress in the area of Meibomian glands lipidomics, there are large areas of uncertainty that need to be addressed in future experiments.

Molecular organization of the tear fluid lipid layer

The tear fluid protects the corneal epithelium from drying out as well as from invasion by pathogens. It also provides cell nutrients. Similarly to lung surfactant, it is composed of an aqueous phase covered by a lipid layer. Here we describe the molecular organization of the anterior lipid layer of the tear film. Artificial tear fluid lipid layers (ATFLLs) composed of egg yolk phosphatidylcholine (60 mol %), free fatty acids (20 mol %), cholesteryl oleate (10 mol %), and triglycerides (10 mol %) were deposited on the air-water interface and their physico-chemical behavior was compared to egg-yolk phosphatidylcholine monolayers by using Langmuir-film balance techniques, x-ray diffraction, and imaging techniques as well as in silico molecular level simulations. At low surface pressures, ATFLLs were organized at the air-water interface as heterogeneous monomolecular films. Upon compression the ATFLLs collapsed toward the air phase and formed hemispherelike lipid aggregates. This transition was reversible upon relaxation. These results were confirmed by molecular-level simulations of ATFLL, which further provided molecular-scale insight into the molecular distributions inside and dynamics of the tear film. Similar type of behavior is observed in lung surfactant but the folding takes place toward the aqueous phase. The results provide novel information of the function of lipids in the tear fluid.

Efficacy of topical N-acetylcysteine in the treatment of meibomian gland dysfunction

PURPOSE

To evaluate the efficacy of topical N-acetyl-cysteine (NAC) therapy in patients with meibomian gland dysfunction (MGD).

METHODS

Twenty patients with MGD were prospectively randomized and assigned into 2 groups. The patients were instructed to use either NAC 5% or preservative-free artificial tear topically 4 times a day for a month. All patients were instructed to apply lid hygiene once daily. Preservative-free artificial tears treated group served as control. Paired sample Student's t-tests were used to detect differences between the baseline and 1 month after treatment initiation in mean ocular symptoms, fluorescein break-up time (FBUT) values, and Schirmer scores in each group. Difference in mean ocular symptoms, Schirmer's test scores, and FBUT values between the baseline and 1 month after treatment initiation were compared between the groups using Mann-Whitney U test.

RESULTS

One month of topical NAC therapy provided statistically significant improvements in FBUT and Schirmer scores as compared with the initial study visit. The average Schirmer increase rate was significantly better in the NAC group than in the control group. Significant improvements for the symptoms of ocular burning, foreign body sensation, and intermittent filmy or blurred vision were noted in both groups; and only NAC-treated group showed improvement for the symptom of itching, at 1 month as compared with 1 day. NAC provided significantly better improvement in itching symptom when compared with controls.

CONCLUSIONS

Topical administration of NAC is thought to be effective and well tolerated in patients with MGD.

Interaction of phospholipid transfer protein with human tear fluid mucins

In addition to circulation, where it transfers phospholipids between lipoprotein particles, phospholipid transfer protein (PLTP) was also identified as a component of normal tear fluid. The purpose of this study was to clarify the secretion route of tear fluid PLTP and elucidate possible interactions between PLTP and other tear fluid proteins. Human lacrimal gland samples were stained with monoclonal antibodies against PLTP. Heparin-Sepharose (H-S) affinity chromatography was used for specific PLTP binding, and coeluted proteins were identified with MALDI-TOF mass spectrometry or Western blot analysis. Immunoprecipitation assay and blotting with specific antibodies helped to identify and characterize PLTP-mucin interaction in tear fluid. Human tear fluid PLTP is secreted from the lacrimal gland. MALDI-TOF analysis of H-S fractions identified several candidate proteins, but protein-protein interaction assays revealed only ocular mucins as PLTP interaction partners. We suggest a dual role for PLTP in human tear fluid: (1) to scavenge lipophilic substances from ocular mucins and (2) to maintain the stability of the anterior tear lipid film. PLTP may also play a role in the development of ocular surface disease.

Lipidomic analysis of human meibum using HPLC-MSn

High-pressure liquid chromatography-mass spectrometry (HPLC-MS) has become a de facto standard analytical tool in lipidomic analyses of complex biological samples. This technique offers the best combination of selectivity and sensitivity among the currently available analytical methods, and provides not only the retention times of analytes, but also their m/z values, from which molecular masses of the compounds can be deduced. Further enhancement of the technique comes from the fact that some of the MS instruments (also known as ion traps, or MSn instruments) are capable of multistage fragmenting of the analytes, thus enabling the researcher to perform their structural elucidation. These capabilities make HPLC-MSn an ideal tool for analyzing small, complex lipid samples such as human meibum. Meibum is a very complex lipid mixture which is secreted onto the ocular surface by Meibomian glands. Meibum plays a critical role in the biochemistry and physiology of the human ocular surface. However, despite all efforts, its (bio)chemical composition remains elusive. In this chapter, several HPLC-MSn methods developed for lipidomic analysis of human meibum will be discussed. Considering the nature of analytes (all of which are hydrophobic compounds poorly soluble in water, and most of which are electroneutral), the only MS technique used in the study will be atmospheric pressure chemical ionization (APCI) MSn in both the positive and the negative ion modes. Electrospray ionization technique, though useful in phospholipid analyses, was found to be inadequate for analyzing less polar compounds, such as wax esters. As the data provided in this chapter will show that meibum is composed predominantly of nonpolar lipids of wax ester, cholesteryl ester, and triacylglycerol families with no appreciable amounts of more polar lipids present, APCI MSn seems to be a method of choice for lipidomic analysis of meibum and similar lipid mixtures.

On the lipid composition of human meibum and tears: comparative analysis of nonpolar lipids

PURPOSE

To qualitatively compare the nonpolar lipids present in meibomian gland (MG) secretions (samples T1) with aqueous tears (AT) collected from the lower tear menisci of healthy, non-dry eye volunteers using either glass microcapillaries (samples T2) or Schirmer test strips (samples T3).

METHODS

Samples T1 to T3 were analyzed with the use of high-pressure liquid chromatography/positive ion mode atmospheric pressure chemical ionization mass spectrometry. Where possible, the unknown lipids were compared with known standards.

RESULTS

Samples T1 had the simplest lipid composition among all the tested specimens. Samples T2 and T3 were similar to each other but were noticeably different from samples T1. In addition to all the compounds detected in samples T1, lower molecular weight wax esters and other compounds were found in samples T2 and T3. No appreciable amounts of fatty acid amides (e.g., oleamide), ceramides, or monoacyl glycerols were routinely detected. The occasionally observed minor signals of oleamide (m/z 282) in samples T3 were attributed to the contamination of the samples with common plasticizers routinely found in plastic ware extractives and organic solvents.

CONCLUSIONS

The MG is a prominent source of lipids for the tear film. However, it would have been a mistake to exclude from consideration other likely sources of lipids such as conjunctiva, cornea, and tears produced by the lacrimal glands. These data showed that lipids in AT are more complex than MG secretions, which necessitates more cautious interpretation of the functions of the latter in the tear film.

Adsorption of lysozyme to phospholipid and meibomian lipid monolayer films

It is believed that a lipid layer forms the outer layer of the pre-ocular tear film and this layer helps maintain tear film stability by lowering its surface tension. Proteins of the aqueous layer of the tear film (beneath the lipid layer) may also contribute to reducing surface tension by adsorbing to, or penetrating the lipid layer. The purpose of this study was to compare the penetration of lysozyme, a tear protein, into films of meibomian lipids and phospholipids held at different surface pressures to determine if lysozyme were part of the surface layer of the tear film. Films of meibomian lipids or phospholipids were spread onto the surface of a buffered aqueous subphase. Films were compressed to particular pressures and lysozyme was injected into the subphase. Changes in surface pressure were monitored to determine adsorption or penetration of lysozyme into the surface film. Lysozyme penetrated a meibomian lipid film at all pressures tested (max=20 mN/m). It also penetrated phosphatidylglycerol, phosphatidylserine or phosphatidylethanolamine lipid films up to a pressure of 20 mN/m. It was not able to penetrate a phosphatidylcholine film at pressures >or=10 mN/m irrespective of the temperature being at 20 or 37 degrees C. However, it was able to penetrate it at very low pressures (<10 mN/m). Epifluorescence microscopy showed that the protein either adsorbs to or penetrates the lipid layer and the pattern of mixing depended upon the lipid at the surface. These results indicate that lysozyme is present at the surface of the tear film where it contributes to decreasing the surface tension by adsorbing and penetrating the meibomian lipids. Thus it helps to stabilize the tear film.

Efficacy of Commercially Available Topical Cyclosporine A 0.05% in the Treatment of Meibomian Gland Dysfunction

OBJECTIVE

To investigate the efficacy of topical cyclosporine A 0.05% (tCsA) (Restasis, Allergan Pharmaceuticals) in the treatment of meibomian gland dysfunction (posterior blepharitis).

METHODS

Thirty-three patients with symptomatic meibomian gland dysfunction were randomized in a prospective study to either tCsA or placebo (Refresh Plus preservative-free artificial tears), 2 times daily for 3 months. They were evaluated at baseline and at 1, 2, and 3 months for subjective symptoms and objective signs including meibomian gland inclusions, lid margin vascular injection, tarsal telangiectasis, fluorescein staining, tear breakup time, and Schirmer scores.

RESULTS

Twenty-six patients completed the study. All patients were tested for ocular symptoms, lid margin vascularity, tarsal telangiectasis, meibomian gland inclusions, tear breakup time, and fluorescein staining. At the 3-month visit, the tCsA group showed a greater improvement in ocular symptoms than the placebo group, but this difference was not statistically significant. At the 3-month visit, several objective examination findings were statistically significantly (P < 0.05) improved in the tCsA group compared with the placebo group. These differences included lid margin vascular injection, tarsal telangiectasis, and fluorescein staining. The most significant finding (P = 0.001) was the greater decrease in the number of meibomian gland inclusions in the tCsA group compared with the placebo group.

CONCLUSIONS

Topical CsA may be helpful in the treatment of meibomian gland dysfunction (posterior blepharitis). Topical CsA did not induce an improvement in the symptoms, but it did decrease the number of meibomian gland inclusions in patients with meibomian gland dysfunction.

An assessment of grading scales for meibography images

PURPOSE

To evaluate the within- and between-reader reliability and the interrelation between 2 methods of grading meibography images.

METHODS

A video meibography sequence (1200 frames) was captured from 290 patients using near-infrared light (650-700 nm) and a near-infrared CCD camera. One frame was selected for grading by 2 masked readers using 2 scales, where the first reader graded the image on 2 occasions and the second reader graded the image on 1 occasion. The first grading scale was a gestalt assessment (categorically graded), which is an assessment of partial meibomian glands within the image. The second was a count of individual whole glands. Within- and between-reader reliability and concurrent validity between the scales were examined.

RESULTS

Within-reader reliability of the gestalt scale was moderate to high (simple kappa = 0.78, 95% confidence interval [CI] = 0.71-0.85 and weighted kappa = 0.91, 95% CI = 0.88-0.95). Within-reader reliability of individual gland counting was moderate via a 95% limits of agreement analysis (-2.84-2.76 glands). Between-reader reliability of the gestalt scale was fair (simple kappa = 0.38, 95% CI = 0.30-0.46 and weighted kappa = 0.57, 95% CI = 0.47-0.68). Between-reader reliability of gland counting was fair via a 95% limits of agreement analysis (-4.46-5.08 glands). There was a strong relation between the gestalt scale and gland counting indicating good concurrent validity (Z = -15.15, P < 0.0001).

CONCLUSIONS

These methods of grading meibography images demonstrate good within-reader reliability and fair between-reader reliability. Responsiveness to change will need to be addressed in future studies.

Conservative treatment of meibomian gland dysfunction

PURPOSE

To evaluate the effectiveness of lid hygiene and preservative-free artificial tears for the treatment of meibomian gland dysfunction (MGD) during a 6-week period.

METHODS

Suitable patients with MGD were educated about their disease and instructed to begin a regimen of lid hygiene, which included the application of a heated saline solution and the use of nonpreserved artificial tears. Baseline measurements obtained at the time of enrollment included basic tear secretion test, tear breakup time, a questionnaire grading MGD symptoms (i.e., burning, irritation, itching, sharp pains, foreign body sensation, and hazy vision), and lid margin slitlamp photographs. All measurements except for basic tear secretion were repeated at the 6-week follow-up visit. Photographs were unlabeled, and two cornea specialists graded them in a masked fashion for the presence of lid erythema, irregularity, thickness, meibomian gland capping, and telangiectasis.

RESULTS

Thirty-seven patients with a clinical diagnosis of MGD were enrolled, and 26 patients (70%) completed the study. Initial measurement of basic tear secretion averaged 17 mm and was more than 10 mm in 81% of eyes. The tear breakup time was prolonged by an average of 3.4 seconds; in 30% of cases, it was normalized to 10 seconds or more. Symptoms improved in 88% of cases; among those, symptoms were graded mild or less in 83%, and none in 39%. Photographs before and after treatment were not significantly different.

CONCLUSIONS

In this noncontrolled case-cohort study of selected patients with MGD, lid hygiene and preservative-free artificial tears significantly improved tear breakup time and relieved symptoms of the condition.

The diagnosis and management of dry eye: a twenty-five-year review

PURPOSE

To review the advances in the diagnosis, pathogenesis, and management of dry eye disease in the past 25 years.

METHODS

Literature review.

RESULTS

The preocular tear film is a hydrated mucus gel that contains soluble antimicrobial proteins and growth factors that protect and support the ocular surface. The final common pathway in dry eye is a perturbation of the integrated ocular surface/lacrimal gland reflex unit. Diagnostic tests evaluating tear composition and clearance appear to show stronger correlation with the severity of ocular irritation symptoms and keratoconjunctivitis sicca (KCS) than the conventional Schirmer tests. KCS is a condition of abnormal differentiation and mucus production by the ocular surface epithelium that results in a poorly lubricated, abnormally permeable ocular surface that has increased susceptibility to environmental insults. Chronic subclinical ocular surface inflammation appears to play a key role in the pathogenesis of KCS. New therapeutic strategies are aimed at reducing the ocular surface inflammation of dry eye disease.

CONCLUSIONS

There has been a tremendous increase in knowledge regarding dry eye disease in the past 25 years that has resulted in improved diagnostic classification and new targeted therapies.