Pathophysiology of dry eye disease and novel therapeutic targets.

The pathophysiology of Dry Eye Disease (DED) is complex, and therapy may be a challenge. Tear film instability, tear film hyperosmolarity, ocular surface damage and ocular surface inflammation are accepted key events in the pathogenesis of the disease. New anti-inflammatory targets have been identified and novel anti-inflammatory treatments may enrich our therapeutic armamentarium in the future. Neurosensory changes in DED secondary to neuroinflammation in the corneal nerves, the trigeminal ganglion, and the trigeminal brainstem sensitivity complex have recently been reported and may play an important role in the pathophysiology of DED. Receptor complexes on the axonal membranes of corneal nerves may be promising novel therapeutic targets. Recent studies have shown changes in the both the systemic and local (conjunctival) microbiomes with DED as well as an association of DED with laryngopharyngeal reflux. These new insights into DED suggest new treatment approaches. In hyperevaporative DED typically associated with meibomian gland dysfunction (MGD), hyperkeratinized and obstructed meibomian glands are important treatment targets, and novel techniques may be available soon to better manage patients with MGD. The observation of changes in brain function in patients with DED sheds a completely new light on the pathophysiology of the disease. Increased understanding of the pathogenetic events described above may define novel treatment targets, guide management and may allow customized treatment of DED in the future.

Defining Dry Eye from a Clinical Perspective.

Over the past decades, the number of patients with dry eye disease (DED) has increased dramatically. The incidence of DED is higher in Asia than in Europe and North America, suggesting the involvement of cultural or racial factors in DED etiology. Although many definitions of DED have been used, discrepancies exist between the various definitions of dry eye disease (DED) used across the globe. This article presents a clinical consensus on the definition of DED, as formulated in four meetings with global DED experts. The proposed new definition is as follows: "Dry eye is a multifactorial disease characterized by a persistently unstable and/or deficient tear film (TF) causing discomfort and/or visual impairment, accompanied by variable degrees of ocular surface epitheliopathy, inflammation and neurosensory abnormalities." The key criteria for the diagnosis of DED are unstable TF, inflammation, ocular discomfort and visual impairment. This definition also recommends the assessment of ocular surface epitheliopathy and neurosensory abnormalities in each patient with suspected DED. It is easily applicable in clinical practice and should help practitioners diagnose DED consistently. This consensus definition of DED should also help to guide research and clinical trials that, to date, have been hampered by the lack of an established surrogate endpoint.

[Tear Film Osmolarity in Normal Individuals: Comparison of Two Osmometers]. / Tränenfilmosmolarität gesunder Probanden: Vergleichbarkeit zweier Osmometer.

INTENTION: The hyperosmolarity of the tear film is an important clinical sign of dry eye disease. It is the most important diagnostic parameter. In addition to the TearLab osmometer (TearLab Corp, San Diego, CA), which has been available for several years, the I-Pen osmometer (I-MED Pharma Inc, Dollard-des-Ormeaux, Quebec, Canada) has been recently marketed. The intention of our study was to compare tear film osmolarities in normal individuals as measured by TearLab and I-Pen. METHODS: 51 healthy subjects (mean age 40.6 years, range 17 - 63 years, 66.7% females) without dry eye disease (ocular surface disease index < 13, tear film break-up time > 7 s, normal Schirmer test > 10 mm/5 min) were included in this study. Tear film osmolarity was measured in the tear meniscus (TearLab) and the palpebral conjunctiva (I-Pen) with a 30 min interval. The osmolarity testing techniques were alternated. Statistical analysis was performed using Wilcoxon tests and Spearman correlations. RESULTS: Mean TearLab osmolarities were 295.1 mosmol/l (right eye), 294.0 mosmol/l (left eye), and 294.6 mosmol/l (mean of both eyes) with a range of 268 to 394 mosmol/l. I-Pen measured mean osmolarites of 301.6 mosmol/l (right eye), 302.5 mosmol/l (left eye), and 302.1 mosmol/l (mean of both eyes) with a range of 276 to 394 mosmol/l. There was a significant difference in tear film osmolarities for the two techniques for both single eyes (p < 0.02) and the mean value of both eyes (p < 0.001). TearLab and I-Pen measurements did not correlate significantly in any eye (r = 0.27 and r = 0.08 for right and left eye, respectively). With a cut-off value of 308 mosmol/l (as suggested for TearLab), 98.0% of TearLab values and 68.6% of I-Pen values were in the normal range. CONCLUSIONS: I-Pen measured significantly higher tear film osmolarities than TearLab. The location of the measurement site in the palpebral conjunctiva could be responsible for this difference. Our results indicate that cut-off values should be changed when using I-Pen for evaluation of tear film osmolarity. Further examinations and studies with greater cohorts of healthy subjects and patients suffering from dry eye disease are necessary.

[Sterile Keratitis]. / Sterile Keratitis.

Sterile keratitis shows multiple manifestations. It may occur as an ophthalmological problem but can also be part of a systemic disease, including potentially lethal systemic vasculitis. Diagnosis as well as management of this disease is a challenging task for the ophthalmologist. There are therapeutic principles which apply to all non-infectious cases of keratitis and corneal ulcerations. Specific treatments, however, are determined by the pathogenesis and may differ. Therefore, an accurate diagnosis must guide therapeutic decision making. The correct diagnosis and management of sterile ulcerative keratitis is able to restore the patient's vision in most cases. In potentially lethal systemic disease it may even be able to save the patient's life.

[Lidline Tattoo Associated with Basal Cell Carcinoma of the Lid Margin - Coincidence or Association?] / Lidstrichtattoo assoziiert mit Lidkantenbasaliom ­ Zufall oder Assoziation?

A cystic lesion of the lid margin was excised suspecting basal cell carcinoma. On histology, black-turquoise pigment was seen in the dermis adjacent to the basal cell carcinoma. It was pronounced perivascular, intracellular in macrophages and fibroblasts, but also extracellular as free pigment in the tissue, compatible with an eyelid line tattoo. Typical tissue reactions to tattoo ink, meibomian gland dysfunction after lid margin tattoo, as well as inflammatory reactions in the retina and choroid associated with tattoos distant from the eye are discussed. The correlation of lid tumors and lid margin tattoos seems coincidental.

Matrix Metalloproteinase 9 Testing in Dry Eye Disease Using a Commercially Available Point-of-Care Immunoassay.

PURPOSE: To measure matrix metalloproteinase 9 (MMP-9) in the tear film of patients with dry eye disease (DED) compared with controls and to correlate clinical findings. DESIGN: In a prospective study, 101 patients and controls underwent MMP-9 testing of the tear film. Thereafter, they were evaluated for symptoms and signs of DED. PARTICIPANTS: Included patients were those who showed 3 of the following 4 dry eye criteria: ocular surface disease index (OSDI) score of more than 12, tear film break-up time (TBUT) of 10 seconds or less, Schirmer test results without anesthesia of less than 10 mm/5 minutes, and corneal staining results of 1 or more. Fifty-four healthy eyes and 47 eyes fulfilling diagnostic criteria for DED of various levels of severity were included in this study. METHODS: The tear film was analyzed for MMP-9 by a commercially available test (InflammaDry; Rapid Pathogen Screening, Inc, Sarasota, FL) detecting MMP-9 levels of more than 40 ng/ml. Symptoms and signs of DED were evaluated using the OSDI questionnaire, TBUT, conjunctival and corneal staining, Schirmer test results without anesthesia, and meibomian gland examination. These findings were correlated to results of the MMP-9 test in tears. MAIN OUTCOME MEASURES: Positive MMP-9 results in tears. RESULTS: In 19 of 47 patients confirmed with dry eye (40.4%) and in 3 of 54 controls (5.6%), the MMP-9 results were positive. This difference was statistically significant (P < 0.001). Thus, the MMP-9 results indicated a clinically significant inflammation in 40% of dry eye patients. Positive results correlated well with subjective symptoms of DED evaluated by OSDI (P = 0.001), TBUT of less than 5 seconds (P < 0.013), Schirmer test results (P < 0.001), conjunctival staining (P < 0.001), and corneal staining (P = 0.007). Moreover, MMP-9 results correlated with the number of obstructed meibomian ducts (P = 0.005) and a pathologic meibomian gland secretion (P = 0.001). The MMP-9 results were increased significantly in women (P < 0.001) and in patients with autoimmune disease (P = 0.005), especially Sjögren's syndrome (P = 0.001) and thyroid disease (P = 0.012). CONCLUSIONS: Matrix metalloproteinase 9 testing in DED is a valuable new diagnostic tool. It correlated well with other dry eye tests and identified the presence of ocular surface inflammation in 40% of confirmed dry eye patients. It may be especially helpful to identify patients with ocular surface inflammation and autoimmune disease and may facilitate the decision to institute anti-inflammatory treatment in these patients.

Prospective, randomized, double-blind trial to investigate the efficacy and safety of corneal cross-linking to halt the progression of keratoconus.

BACKGROUND: Corneal cross-linking is widely used to treat keratoconus. However, to date, only limited data from randomized trials support its efficacy. METHODS: The efficacy and safety of corneal cross-linking for halting progression of keratoconus were investigated in a prospective, randomized, blinded, placebo controlled, multicentre trial. Twenty-nine keratoconus patients were randomized in three trial centres. The mean age at inclusion was 28 years. Longitudinal changes in corneal refraction were assessed by linear regression. The best corrected visual acuity, surface defects and corneal inflammation were also assessed. These data were analysed with a multifactorial linear regression model. RESULTS: A total of 15 eyes were randomized to the treatment and 14 to the control group. Follow-up averaged 1098 days. Corneal refractive power decreased on average (+/-standard deviation) by 0.35 +/- 0.58 dioptres/year in the treatment group. The controls showed an increase of 0.11 +/- 0.61 dioptres/year. This difference was statistically significant (p = 0.02). CONCLUSIONS: Our data suggest that corneal cross-linking is an effective treatment for some patients to halt the progression of keratoconus. However, some of the treated patients still progressed, whereas some untreated controls improved. Therefore, further investigations are necessary to decide which patients require treatment and which do not. TRIAL REGISTRATION: NCT00626717, Date of registration: February 20, 2008.

[Current aspects of vernal and atopic keratoconjunctivitis]. / Aktuelles zur Keratoconjunctivitis vernalis und atopica.

BACKGROUND: Vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC) are complex and rare diseases. Thus, their diagnosis and treatment are often a challenge. OBJECTIVE: Discussion on the epidemiology, new pathogenetic concepts, interesting clinical findings, diagnostic possibilities and new treatment options and their side effects in severe ocular allergies. Analysis of the presentation of VKC in the internet. MATERIAL AND METHODS: Evaluation of recent review articles, original publications, and case reports on the topics of VKC and AKC over the past 5 years. RESULTS: Ocular allergies have significantly increased over the last decades. Recent concepts discussed in the pathogenesis of VKC and AKC are the role of the local and gut microbiome as well as the influence of neuroinflammation. Keratoconus is significantly more common in patients with VKC and AKC compared to the normal population. It is associated with faster progression and a more severe course of disease. A conjunctival provocation test is only rarely necessary in the diagnosis of allergic conjunctivitis. Treatment of atopic dermatitis with dupilumab, an interleukin 4 receptor alpha (IL-4Ra) antagonist, can cause ocular side effects. Unfortunately, information available on the internet for patients and parents on the topic of VKC is sometimes dangerously incorrect. CONCLUSION: From the abovementioned new pathogenetic concepts, preventive and personalized treatment options could be developed in the future. Keratoconus in AKC/VKC must be recognized and treated early. Official guidelines are now available for a standardized conjunctival provocation test in the diagnosis of allergic conjunctivitis. The unwanted ocular side effects of dupilumab are often difficult to discriminate from the actual underlying AKC and respond well to anti-inflammatory treatment. Patients with VKC must be informed about the incorrect information on the internet regarding their disease.

[New and future treatment approaches for allergic conjunctivitis]. / Neue und zukünftige Therapieansätze in der Behandlung der allergischen Konjunktivitis.

BACKGROUND: In severe and recurrent ocular allergies conventional ophthalmic drugs can reach their limits, especially in chronic forms. The first novel immunomodulators and biologicals are already in clinical use and could provide relief. OBJECTIVE: Based on the immunopathophysiological mechanisms of ocular allergies, possible targets for innovative treatment approaches are presented. An overview of promising new and future immunomodulators and biologicals and their modes of action is also given. MATERIAL AND METHODS: Current reviews on ocular allergies and the treatment of systemic allergic diseases were screened. Case reports on the treatment of ocular allergy using immunomodulators and biologicals were analyzed. The clinical relevance and possible applications are presented. RESULTS: In chronic forms of ocular allergies, complex ocular surface inflammatory responses mediated via immunoglobulin E (IgE), mast cells, CD4-positive type 2 T­helper cells and eosinophilic granulocytes are predominant. Cyclosporine A 0.1% eyedrops have been approved in Europe since 2018 for children aged 4 years and older with severe vernal keratoconjunctivitis (VKC). In addition, case reports present promising data on the systemic off-label use of biologicals, such as dupilumab or omalizumab, in refractory VKC or atopic keratoconjunctivitis (AKC). CONCLUSION: A profound understanding of the immunopathophysiology of ocular allergies is necessary to detect further targets for future immunomodulators and biologicals. Currently, immunomodulatory therapy remains limited to cyclosporine A eyedrops. Other immunomodulatory agents, such as tacrolimus and biologicals can only be used off-label. Further studies on the controlled clinical use of these substances in the treatment of VKC or AKC are underway.

How gut microbiota may impact ocular surface homeostasis and related disorders.

Changes in the bacterial flora in the gut, also described as gut microbiota, are readily acknowledged to be associated with several systemic diseases, especially those with an inflammatory, neuronal, psychological or hormonal factor involved in the pathogenesis and/or the perception of the disease. Maintaining ocular surface homeostasis is also based on all these four factors, and there is accumulating evidence in the literature on the relationship between gut microbiota and ocular surface diseases. The mechanisms involved are mostly interconnected due to the interaction of central and peripheral neuronal networks, inflammatory effectors and the hormonal system. A better understanding of the influence of the gut microbiota on the maintenance of ocular surface homeostasis, and on the onset or persistence of ocular surface disorders could bring new insights and help elucidate the epidemiology and pathology of ocular surface dynamics in health and disease. Revealing the exact nature of these associations could be of paramount importance for developing a holistic approach using highly promising new therapeutic strategies targeting ocular surface diseases.

Expert Consensus Recommendations for the Management of Ocular Surface Inflammation in Patients with Glaucoma.

PRECIS: We have developed via a consensus process 24 clinical recommendations for the comprehensive management of ocular surface inflammation in glaucoma patients, including diagnostic criteria, prevention measures, and treatment strategies according to ocular surface disease severity. PURPOSE: To obtain expert consensus on the diagnosis, prevention and management of ocular surface inflammation (OSI) in patients with glaucoma. METHODS: An international steering committee of glaucoma and/or ocular surface disease (OSD) experts and a wider faculty of members from the Educational Club of Ocular Surface and Glaucoma (ECOS-G) collaborated to develop clinical recommendations on best practice in the management of OSI in glaucoma patients using a non-anonymous interactive quasi-Delphi process. Clinical recommendations were formulated by the steering committee based on an analysis of the recent literature to determine unmet needs, together with a web-based interactive survey of faculty members' opinion in seven identified areas of OSI management in glaucoma. Topics included 1) diagnosis of OSD, 2) diagnosis of OSI, 3) causes of OSI, 4) impact of OSD/OSI, 5) prevention of OSI, 6) treatment of OSI, and 7) inflammation and the deep structures of the eye. Faculty members were invited to vote on the clinical recommendations, and the steering committee then determined whether consensus had been achieved. RESULTS: Consensus was obtained on 24 clinical recommendations by 80-100% of faculty members. There was consensus that OSI should be investigated in all glaucoma patients. The main prevention measure in glaucoma patients with pre-existing OSD was the elimination/minimisation of preserved medications, especially BAK-preserved eye drops. A subtractive treatment strategy rather than an additive strategy is recommended according to OSI/OSD severity to improve the ocular health and/or before glaucoma surgery. CONCLUSION: These recommendations for the management of OSI in glaucoma should be useful to guide decision-making in clinical practice.

[Corneal disease in childhood-Hereditary, degenerative or infectious?] / Hornhauterkrankungen im Kindesalter ­ Hereditär, degenerativ oder infektiös?

BACKGROUND: Adequate visual acuity significantly contributes to the age-appropriate development of children's neurobehavior. Infantile corneal opacities are rare but implicate a high potential for amblyopia. OBJECTIVE: This review aims to provide an overview of the most common causes of infantile corneal opacities and highlights ophthalmopathological correlations. METHODS: The following review is based on an extensive literature search. RESULTS: If metabolic diseases, traumatic or infectious events can be excluded as a cause for an infantile corneal opacity, it is important to focus on the 3Ds, corneal dysgenesis, corneal dystrophy or corneal degeneration. DISCUSSION: If corneal opacities occur in childhood, early recognition, diagnosis, and initiation of treatment, including prophylaxis of amblyopia, are of utmost importance. In unexplained corneal opacities the histopathological work-up of the explanted cornea can contribute to the final diagnosis.

Management of inflammation in dry eye disease: Recommendations from a European panel of experts.

INTRODUCTION: Early initiation of anti-inflammatory therapies is recommended for dry eye disease (DED) to break the vicious cycle of pathophysiology. However, there is limited guidance on how to implement topical ciclosporin (CsA) and corticosteroid treatment into clinical practice. This expert-led consensus provides practical guidance on the management of DED, including when and how to use topical CsA. METHODS: A steering committee (SC) of seven European DED experts developed a questionnaire to gain information on the unmet needs and management of DED in clinical practice. Consensus statements on four key areas (disease severity and progression; patient management; efficacy, safety and tolerability of CsA; and patient education) were generated based on the responses. The SC and an expanded expert panel of 22 members used a nine-point scale (1 = strongly disagree; 9 = strongly agree) to rate statements; a consensus was reached if ≥75% of experts scored a statement ≥7. RESULTS: A stepwise approach to DED management is required in patients presenting with moderate corneal staining. Early topical CsA initiation, alone or with corticosteroids, should be considered in patients with clinical risk factors for severe DED. Patient education is required before and during treatment to manage expectations regarding efficacy and tolerability in order to optimise adherence. Follow-up visits are required, ideally at Month 1 and every 3 months thereafter. Topical CsA may be continued indefinitely, especially when surgery is required. CONCLUSION: This consensus fills some of the knowledge gaps in previous recommendations regarding the use of topical corticosteroids and CsA in patients with DED.

Patient-reported burden and overall impact of dry eye disease across eight European countries: a cross-sectional web-based survey.

OBJECTIVE: Dry eye disease (DED) is a multifactorial disease involving the tears and ocular surface. It impacts a patient's quality of life (QoL) and ability to perform daily activities. This study assessed the burden of self-reported DED among adults in eight European countries. DESIGN: Online cross-sectional survey. SETTING: General population in France, Italy, Germany, Greece, the Netherlands, Portugal, Spain and Sweden. PARTICIPANTS: Adults aged ≥18 years with (n=6084) and without (n=6161) self-reported DED were recruited via emails and screened. MAIN OUTCOME MEASURES: All participants completed National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25) and EuroQol-5 Dimension-5 Level Questionnaire (EQ-5D-5L). All DED participants completed the Eye Dryness Score (EDS) Visual Analogue Scale, and Ocular Comfort Index and Work Productivity and Activity Impairment Questionnaire: Specific Health Problem questionnaires. In addition, half of the respondents with DED completed Survey A (Impact of Dry Eye on Everyday Life) and the other half completed Survey B (Standard Patient Evaluation of Eye Dryness Questionnaire) and Dry Eye Questionnaire-5. RESULTS: Participants with self-reported DED had lower functional vision and lower overall health status than participants without self-reported DED as measured by the NEI-VFQ and EQ-5D-5L, respectively.Increasing self-reported DED severity as measured by the EDS was shown to correspond with worse symptom severity/frequency, lower functional vision, higher impact on work productivity, daily activities and QoL. CONCLUSION: This study showed that patients' reported burden of self-reported DED was similar across the eight European countries. Those with self-reported DED reported lower health status and functional vision compared to those without self-reported DED and these parameters worsen with increasing disease severity.

Refractive surgery and dry eye.

Refractive surgery is one of the most common elective surgeries performed worldwide. The incidence of dry eye disease (DED) after corneal refractive surgery varies among different studies. Pre-existing untreated DED has been identified as a risk factor for postsurgical dry eye symptoms. On the basis of both evidence and clinical experience, some recommendations for ocular surface and DED management pre- and post-refractive surgery are described. In aqueous deficiency Dry Eye Disease, preservative-free lubricating drops should be preferred, in addition to ointment and gel forms. Topical anti-inflammatory agents (Cyclosporine 0.1%, hydrocortisone phosphate, fluorometholone) should be used for 3-6 months in cases of ocular surface damage. The therapy of evaporative DED includes lifestyle modifications, lid hygiene (either performed by the patient or offered as professional lid hygiene by the physician), use of lubricating eye drops with lipid components, topical and/or systemic antibiotic treatment with anti-inflammatory properties and Intense Pulsed Light (IPL-) Treatment for meibomian gland dysfunction.

TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface.

The word "elective" refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.

Expression of matrix metalloproteinase-1, -9, -13, and tissue inhibitor of metalloproteinases-1 in basal cell carcinomas of the eyelid.

BACKGROUND: Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) function in the remodelling of the extracellular matrix in morphogenesis, angiogenesis, tissue repair, and tumor invasion. Elevated levels of distinct MMPs in tumor tissue are related to worse prognosis. However, no overall consistent pattern of expression in human cancer has been identified. The aim of the present study was to evaluate the expression of MMP-1, -9, -13 and TIMP-1 in tumor epithelial cells and surrounding connective tissue in primary basal cell carcinomas (BCC) of the eyelid, and to assess their role as prognostic markers for tumor recurrence. METHODS: Surgical specimens of 49 histologically proven primary BBCs of the eyelid of different histological subtypes were included. Immunohistological studies were performed using antibodies against MMP-1, MMP-9, MMP-13 and TIMP-1, and staining intensity was analyzed semi-quantitatively. RESULTS: MMP-1, -9, -13, and TIMP-1 were expressed at various intensities in epithelial tumor cells and surrounding stromal cells including fibroblasts, inflammatory cells, and vascular endothelial cells in all tumor subtypes. Staining was especially prominent at the invading edge of the BCC. A statistically significant correlation was seen between increased TIMP-1 expression in tumor and/or stromal cells with the presence of MMP-13 (p = 0.007 and p < 0.0001 respectively). Moreover, TIMP-1 expression in tumor and/or stroma was significantly associated with relapse (p = 0.012 and p = 0.042 respectively). CONCLUSION: MMP-9, MMP-13 and TIMP-1 expression may serve as a prognostic marker for early tumor invasiveness. Moreover, up-regulation of TIMP-1 in tumor and/or surrounding stromal cells may indicate an increased risk for BCC recurrence.