Is There a Role for Inflammation in Contact Lens Discomfort?

Tear levels of Transforming Growth Factor-β1 and Interleukin 1-β, and clinical correlations in new contact lens users

PURPOSE

To assess alterations in the tear Transforming Growth Factor (TGF)-β1 and Interleukin (IL1)-β concentration in new contact lens wearers; and explore correlations with tear film stability, and ocular physiological response.

METHODS

In this clinical setting, 12 neophytes (5 males), with an average age of 24.0 ± 5.0 years were fitted with delefilcon A contact lenses. Physiological responses (bulbar and limbal hyperemia), Pre-corneal (NIBUT), Pre-lens (PL-NIBUT) non-Invasive Break-Up Times, and tear samples were collected in the morning (before lens insertion; 9 - 10 a.m.) and afternoon (before lens removal; 7 - 8p.m.) of the same day. NIBUT and PL-NIBUT were measured using a tearscope. Tear samples were assayed for TGF-β1 and IL1-β concentrations using Enzyme-Linked Immunosorbent Assay kits. An 11-members control group (6 males) aged 25.0 ± 5.0, served to assess biomarker levels in non-contact lens wearers' tears.

RESULTS

Subjects wore lenses for an average of 7 h and 20 min (range: 6 to 9 h). Bulbar and limbal hyperemia increased significantly throughout the day (p < 0.001). PL-NIBUT were lower than NIBUT (4.7 ± 2.0 Vs. 12.2 ± 8.8 s; p < 0.001). The IL1-β levels were higher in neophytes than controls (3.2 ± 4.7 Vs. 0.1 ± 0.1 pg/ml; p = 0.05), correlating significantly with bulbar (r = 0.405, p = 0.008) and limbal hyperemia (r = 0.499, p = 0.027). No substantial changes were reported for TGF-β1.

CONCLUSION

The presence of TGF-β1 in tears does not appear significantly affected by lens wear. The association between physiological parameters and IL1-β levels suggests that lenses may disrupt ocular surface homeostasis by altering cytokine regulatory mechanisms. However, due to its low concentration, IL1-β's role in the subclinical inflammatory response to lens wear is limited.

Conjunctival microbiome changes in soft contact lens users and contact lens discomfort patients

INTRODUCTION

Contact lens discomfort (CLD) acts as a challenging problem, and the associated conjunctival microbiome changes were unclear.

MATERIAL AND METHODS

Conjunctival sac swab samples were collected from 12 eyes of nonwearers (NW), 12 eyes of asymptomatic contact lens (ACL) wearers, and 11 eyes of CLD. The V3-V4 region of the 16S rRNA gene sequencing was used to investigate differences among three groups.

RESULTS

No differences in alpha diversity were observed among the three groups. The beta diversity showed a distinct microbiome composition between ACL and CLD group (P = 0.018) with principal coordinate analysis. The relative abundance of Firmicutes was significantly higher in CLD (48.18%) than in ACL (13.21%) group (P = 0.018). The abundance of Bacillus in patients with ACL (0.05%) or with CLD (0.02%) were significantly lower than that in the NW (1.27%) group (P = 0.024, 0.028, respectively). Moreover, the abundance of Firmicutes was positively correlated with the OSDI scores in CLD patients (r = 0.817, P < 0. 01, Spearman).

DISCUSSIONS

Patients with CLD have various degrees of bacterial microbiota imbalance in the conjunctival sac, compared with NW and ACL groups.

CONCLUSION

Firmicutes may serve as a potential biomarker for the CLD patients.

Silicone hydrogel contact lenses retain and document ocular surface lipid mediator profiles

CLINICAL RELEVANCE

A leading reason for patients to abandon their contact lenses is discomfort. Mechanisms and biomarkers for lens discomfort remain to be elucidated.

BACKGROUND

Physical stress and tear film interaction are likely factors for lens discomfort. Lipid mediators are generated from polyunsaturated fatty acids. They regulate ocular surface physiology and pathophysiology, are constituents of human tears and may interact with contact lenses. This study set out to determine if hydrogel lenses and silicone hydrogel lenses interact with tear film polyunsaturated fatty acids and polyunsaturated fatty acids-derived mediators.

METHODS

In vitro incubations, rat experiments and analysis of worn human lenses assessed polyunsaturated fatty acids and lipid mediator interactions with lenses. Silicone hydrogel and hydrogel lenses were incubated with lipid mediators and polyunsaturated fatty acids up to 24 hours. Rats were fitted with custom silicone hydrogel lenses and basal tears collected. Silicone hydrogel lenses worn for 2 weeks were obtained from 57 human subjects. Tear and lens lipidomes were quantified by mass spectrometry.

RESULTS

Silicone hydrogel lenses retained polyunsaturated fatty acids and lipid mediators within 15 minutes in vitro. Lenses contained 90% of total polyunsaturated fatty acids and 83-89% of total monohydroxy fatty acids by 12 hours. Retention correlated with polarity of lipid mediators and lipophilic properties of silicone hydrogel lenses. Polyunsaturated fatty acids and lipid mediators such as lipoxygenase- and cyclooxygenase-derived eicosanoids were present in tears and worn lenses from rats. Worn silicone hydrogel lenses from human subjects established robust and lens-type specific lipidomes with high levels of polyunsaturated fatty acids, lipoxygenase-pathway markers and subject-specific differences in lipoxin A₄ and leukotriene B₄.

CONCLUSION

Worn silicone hydrogel lenses rapidly retain and accumulate tear polyunsaturated fatty acids and lipid mediators. Marked subject and lens type differences in the lipidome may document changes in ocular surface physiology, cell activation or infection that are associated with lens wear. If contact lens discomfort and adverse events induce specific tear and lens fatty acid and lipid mediator profiles warrants further studies.

Comparison Between Heated Eye Mask and Intense Pulsed Light Treatment for Contact Lens-Related Dry Eye

Background: Contact lens-related dry eye (CLDE) is common in contact lens (CL) wearers and can lead to ocular pain, decreased visual quality, and reduced quality of life. Objective: The purpose of this prospective, randomized, examiner masked study was to compare the effectiveness of intense pulsed light (IPL) and heated eye mask (HEM) for relieving CLDE. Methods: The final analysis included 60 patients (30 in the IPL group and 30 in the HEM group) who were using CL and had been suffering contact lens discomfort for more than a year. The IPL treatment group had two IPL treatments spaced 3 weeks apart, whereas the HEM group received HEM daily for 6 weeks (42 days). Non-invasive tear break-up time (NITBUT), tear-film lipid layer (TFLL), conjunctival fluorescein staining, meibum gland quality and expression, conjunctival redness score, ocular surface disease index (OSDI), best-corrected visual acuity, endothelial cell count, and intraocular pressure were assessed at baseline: first visit (V1), second visit (V2), and third visit (V3). Results: The mean age of the IPL group was 28.6 ± 4.3 years (16 females, 53%) and that of the HEM group was 28.6 ± 4.2 years (16 females, 53%). Mean NITBUT for the IPL group at V2 was 5.53 ± 0.77 sec (p < 0.001) and at V3 was 7.72 ± 0.88 sec (p < 0.001); the IPL group demonstrated a clinically and statistically significant improvement in mean NITBUT. In addition, the HEM group showed a clinically and statistically significant improvement in mean NITBUT at V3 (5.86 ± 0.76 sec, p < 0.001). At V3, the C-OSDI, TFLL score, and meibum gland quality and expressibility all increased considerably (p < 0.05) in both groups. Conclusions: Our results imply that IPL or HEM treatment of CLDE can be safely used to relieve symptoms of CLDE. In addition, IPL treatment is more effective in improving the general stability of the tear-film and decreasing the need for artificial tears in CLDE.

Ocular surface microvascular response and its relation to contact lens fitting and ocular comfort: an update of recent research

This review examines vascular responses in the ocular surface to contact lens wear and its relation to lens fitting characteristics and contact lens-related discomfort. A search of PubMed was performed to find original research in English, within the past 10 years, that studied the ocular surface, including lid-wiper vascular responses to the lens. The interaction between the lens and ocular surface triggers vascular responses, impacting the lens fitting and contact lens-related discomfort. Contact lens-related discomfort is a multifactorial event, which is affected by lens characteristics. Overall, contact lenses with low modulus and a relatively tight fit produce significant ocular comfort. If an appropriate lens fit is achieved, lens fitting characteristics may not play a critical role in contact lens-related discomfort. On the other hand, the pathogenic and vascular changes of lid-wiper vascular responses appear to play an essential role in developing contact lens-related discomfort, in concert with reactions of the cornea (compression and staining) and conjunctiva (indentation and staining). Robust evaluation of lid-wiper changes at the cellular and microvascular level may hold the key to better understanding the mechanism of contact lens-related discomfort and reveal strategies for eliminating lid wiper epitheliopathy and improving ocular comfort in contact lens wearers.

Effect of material and care system combination on subclinical inflammation of the ocular surface in soft contact lens wear

PURPOSE

To investigate the ocular subclinical inflammatory response in two soft contact lens materials when used in combination with two different care systems ('solutions').

METHODS

Fifteen established soft contact lens wearers wore each of two lenses: Acuvue® 2 (CH) and Acuvue® Oasys® (SiH) or no lenses in random sequence for one week. Two care systems were used: a peroxide system: Oxysept 1 Step® (P) for the right lens and Opti-Free® Replenish® (MPS) for the left lens. After one week of lens/no lens wear, in vivo confocal microscopy (IVCM) of corneal and conjunctival regions was carried out. Density of presumed dendritic cells (DC) and 'white spots' (WS) were quantified. Impression cytology of the bulbar and upper eyelid margin conjunctivae was carried out and samples were analysed for CD45+, CD3+ and CD11c+ cells.

RESULTS

The SiH + MPS combination showed a greater inflammatory response compared to SiH + P in seven out of 12 parameters investigated (p < 0.05). The remaining five were not statistically different between the two solutions. The converse was found for the CH lens, with four of the 12 parameters showing a greater response with the P solution compared to the MPS (p < 0.05).

CONCLUSION

This study suggests that the SiH lens investigated demonstrated an upregulated response when used with a MPS compared to a P solution whereas the converse is true for the CH lens which showed a reduced response when used with a MPS compared to a P solution. This finding aids in the understanding of the biological underpinnings of manifest corneal inflammatory events during contact lens wear.

Could contact lens dryness discomfort symptoms sometimes have a neuropathic basis?

Symptoms of dryness discomfort in soft contact lens wearers frequently lead to discontinuation from wear. The negative influence of pre-fitting tear dysfunctions appears likely to be exacerbated by the challenges to tear homeostasis caused by contact lenses. The corneal mechanisms for symptoms in contact lens wearers are different to those for dry eye disease because the cornea is insulated by the lens from ambient conditions as well as from lid wiper friction during blinking. Symptoms of dryness discomfort might be the consequence of increased lid wiper friction during blinking when the lens front surface becomes soiled and dry and exhibits very rapid tear break up. It is possible that some cases of contact lens intolerance and discontinuation could be a function of lid wiper neuropathy. In relation to the possibility of corneal neuropathy, a stagnant post-lens tear pool with the possibility of increased concentrations of metabolic by-products, cellular debris, and bacterial exotoxins, might have the potential to disturb the corneal epithelial and sub-basal nerves. Contributions by contact lens-induced inflammation to any neuropathic changes may partly depend on the degree to which inflammatory mediators are concentrated in a stagnant post-lens tear pool. It does not appear to be known if corneal neuropathic changes could develop under these conditions. The chances of neuropathic involvement may be greater if discomfort develops after a significant period of successful wear and there is a history of comorbid pain conditions. Esthesiometry and in vivo confocal microscopy in discontinued contact lens wearers may support a diagnosis of contact lens-related corneal neuralgia.

Inflammatory proteins associated with contact lens-related dry eye

PURPOSE

To evaluate the levels and regulation of tear film inflammatory proteins in contact lens-related dry eye (CLDE).

METHODS

One hundred healthy, daily wear (non-overnight), experienced soft contact lens wearers were classified into normal (n = 50) and CLDE (n = 50) groups based on Contact Lens and Dry Eye Questionnaire scores, tear break-up times, and comfort (a two-hour difference between total and comfortable daily lens wear hours). Tear samples (up to 5 μL) were collected by capillary extraction from the inferior meniscus of each eye, and pooled tear samples (10 per group) were tested using a customized Quantibody array. Mann Whitney tests with the Benjamini-Hochberg procedure with a 5% false discovery rate were used to compare the normal and CLDE groups.

RESULTS

Relative to the normal group, the CLDE group showed a significantly increased tear concentration of several inflammatory mediators, including interleukin (IL)-7 (p = 0.001), IL-8 (p = 0.001), IL-13 (p = 0.001), IL-15 (p = 0.001), IL-12 p70 (p = 0.002), growth-related oncogene-alpha/ chemokine (CXC motif) ligand 1 (p = 0.003), granulocyte-colony stimulating factor (p = 0.005), IL-11 (p = 0.008), epidermal growth factor receptor (p = 0.01), IL-1 receptor antagonist (RA) (p = 0.013), macrophage colony-stimulating factor (p = 0.013), Eotaxin/CC motif chemokine ligand 11 (CCL11) (p = 0.016), and IL-2 (p = 0.016). The following cytokines were increased three-fold or more in the CLDE group: IL-13 (p = 0.001), Eotaxin/CCL11 (p = 0.016), and IL-1RA (p = 0.013).

CONCLUSIONS

Several inflammatory markers, including interleukins, were increased in tears of subjects with CLDE. These results support a growing body of evidence that suggests a potential role of inflammation in CLDE.

Anatomical and physiological considerations in scleral lens wear: Eyelids and tear film

Scleral lenses can affect a range of anterior segment structures including the eyelids and the tears. The eyelids, consisting of the outer skin layer, the middle tarsal plate, and the posterior palpebral conjunctiva, provide physical protection and house the meibomian glands and cilia which have important and unique functions. Tears consist of a mix of aqueous, mucus, and lipidomic components that serve vital functions of lubricity, protection, and nourishment to the ocular surface. Both the eyelids and the tear film interact directly with scleral lenses on the eye and can affect but also be impacted by scleral lens wear. The purpose of this paper is to review the anatomy and physiology of the eyelids and tear film, discuss the effects and impacts of the scleral lenses on these structures, and identify areas that require further research.

The potential of lipid mediator networks as ocular surface therapeutics and biomarkers

In the last twenty years an impressive body of evidence in diverse inflammatory animal disease models and human tissues, has established polyunsaturated fatty acids (PUFA) derived specialized-pro-resolving mediators (SPM), as essential mediators for controlling acute inflammation, immune responses, wound healing and for resolving acute inflammation in many non-ocular tissues. SPM pathways and receptors are highly expressed in the ocular surface where they regulate wound healing, nerve regeneration, innate immunity and sex-specific regulation of auto-immune responses. Recent evidence indicates that in the eye these resident SPM networks are important for maintaining ocular surface health and immune homeostasis. Here, we will review and discuss evidence for SPMs and other PUFA-derived mediators as important endogenous regulators, biomarkers for ocular surface health and disease and their therapeutic potential.

Inflammatory status predicts contact lens discomfort under adverse environmental conditions

PURPOSE

To characterize and predict the clinical and tear molecular response of contact lens (CL) wearers exposed to a controlled adverse desiccating environment (CADE).

METHODS

Objective and subjective variables and tear cytokine levels were evaluated of monthly silicone hydrogel CL wearers pre- and post-90 min of CADE exposure. Unsupervised hierarchical agglomerative clustering based on relative change from baseline values was used to identify response profiles (clusters). A multiple logistic regression model was used to identify cluster membership predictors.

RESULTS

Forty-seven CL wearers were divided into 3 clusters having similar age (mean: 27.7 ± 7.7 years) and sex distribution. All of them showed a significant (p ≤ 0.05) increase in limbal hyperemia and staining after CADE exposure. Additionally, Cluster-1 (n = 22, 46.8%) membership was characterized by a significant (p ≤ 0.05) higher worsening of corneal and limbal staining, increased CL wear symptoms, and reduced epidermal-growth-factor and increased interleukin (IL)-4 and IL-6 tear levels. Cluster-2 (n = 22, 46.8%) showed no changes (p > 0.05) in symptoms after CADE; however, their IL-12p70, monocyte-chemoattractant-protein-1 and regulated-on-activation, normal-T-cell-expressed-and-secreted (RANTES) post-exposure tear levels significantly (p ≤ 0.05) increased. Finally, Cluster-3 (n = 3, 6.4%) mainly showed significant higher blink rate (78.1 ± 21.7) during CADE. Corneal staining and tear IL-12p70 levels were identified as Cluster-1 membership predictors.

CONCLUSIONS

Most of silicone hydrogel CL wearers exposed to CADE showed a worsening of the ocular surface integrity and an upregulated tear inflammatory status. However, only half of them reported worsening of CL wear symptoms. These CL wearers were detected based on corneal integrity and tear inflammatory status. These findings can help reduce CL wear discontinuation and drop out.

Questionnaire survey on complications during 24-h measurement of intraocular pressure-related patterns with a contact lens sensor

PURPOSE

We investigated glaucoma patients' complications, subjective symptoms, and side effects of continuous 24-h measurement of intraocular pressure (IOP)-related patterns with a contact lens sensor (CLS). We asked the patients to complete a questionnaire about their subjective symptoms after wearing the CLS.

MATERIALS AND METHODS

This was an observational single-facility study. We analyzed 56 patients (35 men, 21 women) who underwent 24-h continuous measurement of their IOP-related patterns with a Triggerfish^® CLS. The four questionnaire items asked whether blurred vision, ocular pain, conjunctival hyperemia, and sleep disorder were present/absent. All questionnaire items were answered subjectively. We examined the relationship between the patients' questionnaire results and their visual acuity and visual field.

RESULTS

The rate of blurred vision was 55%; ocular pain, 30%; conjunctival hyperemia, 14%; sleeping disorder, 29%. Patients with good visual acuity tended to report experiencing blurred vision.

CONCLUSIONS

When 24-h continuous measurement of IOP-related patterns with a CLS is considered, clinicians should tell the patient about the possibility of blurred vision, ocular pain, conjunctival hyperemia, and/or sleeping disorder.

Conjunctival Neuropathic and Inflammatory Pain-Related Gene Expression with Contact Lens Wear and Discomfort

Purpose: To identify alterations in neuropathic and inflammatory pain gene expression associated with contact lens (CL) wear and CL discomfort (CLD).Methods: Eight non-wearers, eight asymptomatic CL wearers (CLWs) and eight symptomatic CLWs were included. Conjunctival cells were collected by impression cytology and the mRNA expression levels of 85 genes were analyzed. Differentially expressed genes between non-wearers and CLWs and between asymptomatic and symptomatic CLWs were analyzed. An enrichment analysis was also performed.Results: Twelve genes were upregulated (including IL10, PDYN and PENK) and 28 downregulated (CCL2, IL1A, IL1B, IL2 and NGF) in CLWs (p ≤ 0.050). Eleven genes were upregulated (CCL2, IL1A, IL1B, IL2 and NGF) and nine downregulated (PDYN and PENK) in symptomatic CLWs (p ≤ 0.035). Enriched overrepresented terms were related to pain, neuronal transmission and inflammation.Conclusion: Contact lens wear might produce a desensitization-like mechanism responsible for comfortable CL wear. A malfunction of this mechanism might contribute to CLD.

Tear film, contact lenses and tear biomarkers

This article summarises research undertaken since 1993 in the Willcox laboratory at the University of New South Wales, Sydney on the tear film, its interactions with contact lenses, and the use of tears as a source of biomarkers for ocular and non-ocular diseases. The proteome, lipidome and glycome of tears all contribute to important aspects of the tear film, including its structure, its ability to defend the ocular surface against microbes and to help heal ocular surface injuries. The tear film interacts with contact lenses in vivo and interactions between tears and lenses can affect the biocompatibility of lenses, and may be important in mediating discomfort responses during lens wear. Suggestions are made for follow-up research.

To See or Not to See: A Systematic Review of the Importance of Human Ocular Surface Cytokine Biosignatures in Ocular Allergy

Cytokines are key cell signalling proteins in a number of immune and homeostatic pathways of the human body. In particular, they mediate intracellular mechanisms of allergy on the ocular surface by triggering cellular responses that result in typical physiological ocular allergy symptoms, such as itchiness, watery eyes, irritation, and swelling. Given the recent research focus in optometry on the aetiology of corneal ectasia subtypes like keratoconus, there is an increasing need for the development of new clinical diagnostic methods. An increasing trend is evident among recent publications in cytokine studies, whereby the concentrations of cytokines in healthy and disease states are compared to derive a specific cytokine profile for that disease referred to as ‘biosignatures’. Biosignatures have diagnostic applications in ocular allergy as a cheap, non-invasive alternative to current techniques like IgE antibody testing and skin prick tests. Cytokine detection from tear samples collected via microcapillary flow can be analysed either by enzyme-linked immunosorbent assays (ELISA), multiplex magnetic bead assays, or immunoblot assays. Characterising patient hypersensitivities through diagnostic tests is the first step to managing exposure to triggers. Investigating cytokine biosignatures in ocular allergy and their links to physiology are imperative and will be the focus of this systematic review article.

Lotrafilcon B with HydraGlyde moisture matrix or Samfilcon A: Contralateral comparison study for comfort

PURPOSE:

The purpose of this study was to compare two new silicone hydrogel contact lens (CL) models of lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde^®) and samfilcon A (Bausch and Lomb Ultra^®) using the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) test.

METHODS:

This prospective study included 30 patients between the ages of 19 and 35 years. Lotrafilcon B with HydraGlyde moisture matrix (Air Optix plus HydraGlyde^®) and samfilcon A (Bausch and Lomb Ultra^®) CLs were fitted on the right and the left eye of the patients, respectively. All of the patients have not used any CLs before. After 4 weeks, the CLs were compared by asking the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8) test.

RESULTS:

The mean scores of CLDEQ-8, frequency and intense of discomfort, dryness, blurry vision, frequency of needing to blink eye, and removal of the CL were assessed. There was no statistically significant difference between two groups (P > 0.05).

CONCLUSION:

The main reasons for CL discontinuation are dryness and discomfort. These two new CLs used new advanced technology have a good compliance among the first-time CL users.

Tear Biomarkers in Dry Eye Disease

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Tear film inflammatory cytokine upregulation in contact lens discomfort

PURPOSE

To investigate the ocular inflammatory response, using clinical and immunological techniques, in people experiencing contact lens (CL) discomfort.

METHODS

This study involved 38 adults who were full-time, silicone-hydrogel CL wearers. Participants were categorized into groups based upon a validated CL dry-eye questionnaire (CLDEQ-8) (n = 17 'asymptomatic', CLDEQ-8 score <9; n = 21 'symptomatic', CLDEQ-8 score ≥13). Examinations were performed at two visits (one with, and one without, CL wear), separated by one-week. Testing included: tear osmolarity, ocular redness, tear stability, ocular surface staining, meibography, tear production and tear collection. Tear osmolarity was taken from the inferior-lateral and superior-lateral menisci. The 'Inferior-Superior Osmotic Difference', I-SOD, was the absolute osmolarity difference between these menisci. Concentrations of seven cytokines (IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-gamma, TNF-alpha) were assayed from basal tears using multiplex cytometric bead array.

RESULTS

At baseline, there was no significant difference in key clinical signs between asymptomatic and symptomatic CL wearers (p > 0.05). The I-SOD was greater in symptomatic than asymptomatic CL wearers (23.1 ± 2.6 versus 11.3 ± 1.4 mOsmol/L, p = 0.001). People experiencing CL discomfort had higher tear IL-17A (122.6 ± 23.7 versus 44.0 ± 10.0 pg/mL, p = 0.02) and reduced tear stability (6.3 ± 1.1 versus 10.4 ± 1.6 s, p = 0.03) after several hours of CL wear. Tear IL-17A levels correlated with both the I-SOD (r = 0.43, p = 0.01) and CLDEQ-8 score (r = 0.40, p = 0.01).

CONCLUSIONS

CL discomfort occurs in individuals having no clinical dry eye signs, and is associated with higher tear levels of the pro-inflammatory cytokine IL-17A. These findings support an association between the discomfort response and low-grade, ocular surface inflammation.

Evaluation of Long-Term Silicone Hydrogel Use on Ocular Surface Inflammation and Tear Function in Patients With and Without Meibomian Gland Dysfunction

OBJECTIVES

To determine whether silicone hydrogel (SH) contact lens (CL) use, with or without meibomian gland dysfunction (MGD), promotes ocular surface inflammation.

METHODS

Subjects wearing SH-CL for at least 6 months who also had coexisting MGD (group 1, n=20), SH-CL users who did not have MGD (group 2, n=20), patients who had MGD but did not use CL (group 3, n=20), and healthy CL-naive individuals with no known systemic or ocular diseases (group 4, n=20) were included in this cross-sectional, single-center study. All subjects underwent tear function tests consisting of tear break-up time (tBUT), ocular surface staining, Schirmer test, and the Ocular Surface Disease Index (OSDI) questionnaire, as well as determination of tear IL-1RA, IL-1β, IL-2, IL-2R, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, IFN-α, IFN-γ, TNF-α, granulocyte-macrophage colony-stimulating factor, IP-10, monokine induced by gamma interferon, RANTES, eotaxin, MIP-1α, MIP-1β, and MCP-1 levels using Luminex multicytokine immunobead assay. Intergroup comparisons were made using one-way analysis of variance or Kruskal-Wallis test.

RESULTS

The tBUT was lower (P=0.048) and ocular surface staining (P=0.032) as well as OSDI scores (P=0.001) were higher in group 1 but not in groups 2 or 3 when compared with those in the control group. Tear cytokine levels were similar across all groups. None of the tear cytokine levels were elevated in CL wearers (groups 1 and 2) or those with MGD (groups 1 and 3) as compared to those in control subjects.

CONCLUSION

Silicone hydrogel contact lens use with concomitant MGD is not associated with cytokine-driven ocular surface inflammation but may impact tear function leading to dry eye symptoms.

An Amplifying Cascade of Contact Lens-Related End-of-Day Hyperaemia and Dryness Symptoms

End-of-day (EOD) symptoms of dryness are too often the cause of poor soft contact lens (SCL) tolerance and abandonment of wear. This review examines an amplifying cascade model for these symptoms, which involve thin tear layers on contact lens (CL) front surfaces being susceptible to evaporation-related short tear breakup (TBU) times. Susceptibility to faster tear loss by evaporation may be exacerbated by other forms of tear instability, such as lipid and mucin deficiencies as well as lens surface soiling. Bulbar and palpebral conjunctival hyperaemia and associated faster evaporation of warmer pre-conjunctival tears could also contribute to evaporative dry eye EOD symptoms. In CL wearers, a cascade of increasing hyperaemia toward the end of day, associated increasing tear temperature and evaporative loss, shortened TBU times (TBUTs) and increased osmolarity, all elevate the risk of higher symptom levels according to progressive amplification of this cascade. Chronic wound healing responses to SCL wear, perhaps related to limbal conjunctival trauma, stem cell deficiency and persistent epitheliopathy, as well as one or more immune responses, may contribute directly or indirectly to inflammation and the amplifying evaporative dryness cascade. A diurnal cycle that culminates in EOD symptoms appears to involve a process of recovery from causal mechanisms after lens removal, which allows lenses to be worn comfortably, at least initially the next day. Possible recovery processes are discussed in this review as are procedures that may help de-amplify an inflammatory, evaporative dryness cascade and alleviate EOD symptoms. Evidence of an accrual of adverse responses over long periods of more or less successful lens wear indicate an incremental failure to recover from EOD hyperaemia. Such incremental failure could help explain how SCL wear too often needs to be abandoned after many years of comfortable wear.

Tear film evaluation and management in soft contact lens wear: a systematic approach

The human tear film is a highly ordered structure consisting of a thin layer of lipid on the surface and a thicker aqueous-mucin phase, which increases in mucin concentration toward the corneal epithelial cell layer. The health of the tear film and ocular surface influences the likelihood of being able to achieve successful contact lens wear. Contact lens discomfort and dryness are the most frequent reasons why contact lens wearers experience reduced wearing times, which can eventually lead to contact lens discontinuation. Comprehensive clinical assessment of tear film integrity and ocular surface health is therefore essential prior to commencing contact lens wear, to enable the ocular surface environment to be optimised to support lens wear. These parameters should also be evaluated over the course of contact lens wear, in order to identify any aspects requiring clinical management and ensure maintenance of optimal lens-wearing conditions. This review summarises current knowledge relating to the effects of soft contact lens wear on the tear film and ocular surface. It also provides a systematic approach to evaluating tear film and ocular surface integrity, in order to guide the clinical management of tear film anomalies with respect to contact lens wear.

Sjogren's syndrome from the perspective of ophthalmology

Sjogren's syndrome (SS) is an autoimmune disease affecting the lacrimal glands resulting in dry eye disease (DED). Ophthalmologists may be the first line of detection of Sjogren's syndrome given the frequency of DED in SS and that dry eye is often the presenting symptom. Numerous symptom questionnaires and tests have been developed to help diagnose DED, but as of yet, there is no "gold standard." Minimally invasive objective metrics are needed for a reliable diagnosis of DED. Currently there is no single test to diagnose SS-associated DED. Although there are several approaches to treatment, none are specific for DED in SS, and, generally, several methods need to be tried to find what works best for a specific patient. Treatment for DED continues to be an unmet medical need, especially given that DED in SS is typically on the severe end of the spectrum.

The Growing Need for Validated Biomarkers and Endpoints for Dry Eye Clinical Research

Purpose

Biomarkers with minimally invasive and reproducible objective metrics provide the key to future paradigm shifts in understanding of the underlying causes of dry eye disease (DED) and approaches to treatment of DED. We review biomarkers and their validity in providing objective metrics for DED clinical research and patient care.

Methods

The English-language literature in PubMed primarily over the last decade was surveyed for studies related to identification of biomarkers of DED: (1) inflammation, (2) point-of-care, (3) ocular imaging, and (4) genetics. Relevant studies in each group were individually evaluated for (1) methodological and analytical details, (2) data and concordance with other similar studies, and (3) potential to serve as validated biomarkers with objective metrics.

Results

Significant work has been done to identify biomarkers for DED clinical trials and for patient care. Interstudy variation among studies dealing with the same biomarker type was high. This could be attributed to biologic variations and/or differences in processing, and data analysis. Correlation with other signs and symptoms of DED was not always clear or present.

Conclusions

Many of the biomarkers reviewed show the potential to serve as validated and objective metrics for clinical research and patient care in DED. Interstudy variation for a given biomarker emphasizes the need for detailed reporting of study methodology, including information on subject characteristics, quality control, processing, and analysis methods to optimize development of nonsubjective metrics. Biomarker development offers a rich opportunity to significantly move forward clinical research and patient care in DED.

Overview

DED is an unmet medical need - a chronic pain syndrome associated with variable vision that affects quality of life, is common with advancing age, interferes with the comfortable use of contact lenses, and can diminish results of eye surgeries, such as cataract extraction, LASIK, and glaucoma procedures. It is a worldwide medical challenge with a prevalence rate ranging from 8% to 50%. Many clinicians and researchers across the globe are searching for better answers to understand the mechanisms related to the development and chronicity of DED. Though there have been many clinical trials for DED, few new treatments have emerged over the last decade. Biomarkers may provide the needed breakthrough to propel our understanding of DED to the next level and the potential to realize our goal of truly personalized medicine based on scientific evidence. Clinical trials and research on DED have suffered from the lack of validated biomarkers and less than objective and reproducible endpoints. Current work on biomarkers has provided the groundwork to move forward. This review highlights primarily ocular biomarkers that have been investigated for use in DED, discusses the methodologic outcomes in providing objective metrics for clinical research, and suggests recommendations for further work.