Tear film and ocular surface neuropeptides: Characteristics, synthesis, signaling and implications for ocular surface and systemic diseases.

Ocular surface neuropeptides are vital molecules primarily involved in maintaining ocular surface integrity and homeostasis. They also serve as communication channels between the nervous system and the immune system, maintaining the homeostasis of the ocular surface. Tear film and ocular surface neuropeptides have a role in disease often due to abnormalities in their synthesis (either high or low production), signaling through defective receptors, or both.

Tear Osmolarity in the Diagnosis of Systemic Dehydration and Dry Eye Disease.

Systemic dehydration due to inadequate water intake or excessive water loss, is common in the elderly and results in a high morbidity and significant mortality. Diagnosis is often overlooked and there is a need for a simple, bedside diagnostic test in at-risk populations. Body hydration is highly regulated with plasma osmolality (pOsm) being tightly controlled over a wide range of physiological conditions.

Estimating basal tear osmolarity in normal and dry eye subjects.

Purpose: Tear osmolarity (tOsm) is used as a measure of severity in dry eye disease (DED) and has been proposed as an index of body hydration. In DED the level of tear hyperosmolarity is compared with that of a control population. It is proposed here that a better index of body hydration and a more valid reference point in DED can be acquired by measuring the tOsm after a period of evaporative suppression.

TFOS DEWS II Report Executive Summary.

This article presents an Executive Summary of the conclusions and recommendations of the 10-chapter TFOS DEWS II report. The entire TFOS DEWS II report was published in the July 2017 issue of The Ocular Surface. A downloadable version of the document and additional material, including videos of diagnostic and management techniques, are available on the TFOS website: www.

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.

Central Connections of the Lacrimal Functional Unit.

Purpose: To study the contribution of each eye to the reflex tear response, after unilateral and bilateral topical anesthesia.

Method: A closed-eye, modified Schirmer test was performed bilaterally in 8 normal subjects, in a controlled environment chamber set to 23°C, 45% relative humidity, and 0.08 m/s airflow.

Rasch analysis of three dry eye questionnaires and correlates with objective clinical tests.

Purpose: To assess the psychometric properties of Chinese versions of the Ocular Comfort Index (OCI), Ocular Surface Disease Index (OSDI) and McMonnies questionnaires. Further, to assess the correlation between questionnaire scores and objective dry eye disease (DED) clinical tests.

Methods: Translated versions of the OCI, OSDI and McMonnies questionnaires were completed in a random order by 238 participants with DED.

Defining Ocular Surface Disease Activity and Damage Indices by an International Delphi Consultation.

Purpose: Unifying terminology for the description of ocular surface disease (OSD) is vital for determining treatment responses and ensuring robust clinical trial outcomes. To date, there are no agreed parameters describing 'activity' and 'damage' phases of disease.

Methods: A working group of international experts in OSD, oculoplastics, and uveitis from a range of backgrounds (university, teaching, district general and private hospitals) participated in a modified Delphi consensus-building exercise (October 31, 2011 to March 20, 2015).

Report of the Inaugural Meeting of the TFOS i(2) = initiating innovation Series: Targeting the Unmet Need for Dry Eye Treatment.

On March 21, 2015, a meeting was held in London, United Kingdom, to address the progress in targeting the unmet need for dry eye disease (DED) treatment. The meeting, which launched the i(2) = initiating innovation series, was sponsored by the Tear Film & Ocular Surface Society (TFOS; www.TearFilm.

The precorneal tear film as a fluid shell: the effect of blinking and saccades on tear film distribution and dynamics.

We conducted a series of experiments to elucidate the behavior of the human precorneal tear film (PCTF) during blinking and horizontal and vertical saccades. Methodology included video-interferometry with subsequent image cross-correlation (tear film lipid layer [TFLL]) and video-microscopy (mucoaqueous subphase [MAS]). We observed that the TFLL interference pattern deteriorates rapidly with successive blinks and degrades slowly with repeated horizontal saccades during blink suppression when dark arcs of thinning appear in the fluorescein-stained PCTF.

Rethinking dry eye disease: a perspective on clinical implications.

Publication of the DEWS report in 2007 established the state of the science of dry eye disease (DED). Since that time, new evidence suggests that a rethinking of traditional concepts of dry eye disease is in order. Specifically, new evidence on the epidemiology of the disease, as well as strategies for diagnosis, have changed the understanding of DED, which is a heterogeneous disease associated with considerable variability in presentation.

A new portable digital meniscometer.

Purpose: The aims of this study were (i) to develop a new portable slit-lamp mounted digital meniscometer (PDM) and (ii) to test its accuracy and repeatability compared to the existing Yokoi et al. videomeniscometer (VM).

Methods: We developed a novel application for an iPod or iPhone, which created an illuminated target of parallel black and white bands.

Marginal corneal vascular arcades.

Purpose: To determine the metrics of the marginal corneal vascular arcades (MCA).

Methods: The MCA and filling pattern was investigated using indocyanine green dye angiography (ICGA) in the fellow eye of patients with treated unilateral keratitis. Images were acquired using a scanning laser ophthalmoscope.

Improving awareness, identification, and management of meibomian gland dysfunction.

Ocular surface disorder--and dry eye, in particular--is a leading reason for visits to eye care professionals. It has been generally accepted that meibomian gland dysfunction (MGD) is a leading cause of evaporative dry eye, as well as being associated with aqueous-deficient dry eye. Yet, researchers and clinicians have lacked a global consensus on the definition of MGD, its epidemiology, pathophysiology, and management.

Franceschetti hereditary recurrent corneal erosion.

Purpose: To describe new affected individuals of Franceschetti's original pedigree of hereditary recurrent erosion and to classify a unique entity called Franceschetti corneal dystrophy.

Design: Observational case series.

Methods: Slit-lamp examination of 10 affected individuals was conducted.

Distribution of aqueous-deficient and evaporative dry eye in a clinic-based patient cohort: a retrospective study.

Purpose: To evaluate in a general clinic-based cohort of patients with dry eye disease (DED) the distribution of patients with aqueous-deficient or evaporative subtype of DED.

Methods: Schirmer tests and meibomian gland dysfunction (MGD) (Foulks-Bron scoring) were evaluated in both eyes of 299 normal subjects and DED patients (218 women and 81 men) across 10 sites in the European Union and the United States. Using the more severe measurement of the 2 eyes, subjects were considered to have pure aqueous-deficient dry eye (ADDE) with Schirmer values of <7 mm and MGD grades of ≤5.

An explanation for the central to peripheral thickness variation in the mouse cornea.

Background: The mouse corneal stroma varies in thickness across its diameter. The purpose of the present study was to explain this variation and to advance our understanding of stromal lamellar architecture in the mammalian cornea.

Methods: Eight C57BL/6 mice were killed, eyes enucleated, immersed in 2% glutaraldehyde fixative, processed and sectioned transversely for light and transmission electron microscopy.

A solute gradient in the tear meniscus. II. Implications for lid margin disease, including meibomian gland dysfunction.

We have hypothesized previously that evaporation from the tears generates a solute gradient across the tear meniscus, which delivers hyperosmolar stress to the mucocutaneous junction (MCJ) of the lid margin. This is proposed as the basis for Marx's line, a line of staining with topically applied dyes that lies directly behind the MCJ. In this article, we consider the implications of this hypothesis for progressive damage to the lid margin as an age-related phenomenon, its amplification in dry eye states, and its possible role in the etiology of meibomian gland dysfunction (MGD).