Search results for "tear secretion"

Does endogenous serum oestrogen play a role in meibomian gland dysfunction in postmenopausal women with dry eye?

2016

Aim To explore the relationship between serum concentration of sex hormones and dry eye symptoms and signs in postmenopausal women. Methods A cross-sectional analysis was undertaken. Subjects were 46 postmenopausal women with dry eye (mean age 64.4±5.2 years, 13.7±6.4 years since menopause; not undergoing hormone replacement therapy). Ocular symptoms (Ocular Surface Disease Index (OSDI) and Ocular Comfort Index (OCI)), tear function (tear osmolarity, non-invasive tear break-up time, tear secretion), corneal and conjunctival staining, and meibomian gland (MG) appearance, were recorded. Venous blood was collected and serum concentrations of 17β-oestradiol (E2), 3-α-androstanediol-glucuronide …

Analysis of the Corneal Anterior and Posterior Surface in Patients With Peripheral Hypertrophic Subepithelial Corneal Opacification

2019

PURPOSE To characterize the corneal changes in peripheral hypertrophic subepithelial corneal opacification (PHSCO) considering elevation of the anterior and posterior corneal surface, corneal astigmatism, tear secretion, and endothelial cell density. METHODS Thirty-eight eyes of 22 patients with PHSCO on at least 1 eye and 38 eyes of 22 age- and sex-matched healthy subjects were included in this retrospective cross-sectional study. Using the Pentacam system (Oculus, Wetzlar, Germany), measurement of the anterior and posterior corneal surface was performed. In addition, the Schirmer test was conducted, and endothelial cells were counted in the central cornea with a specular microscope (SP-30…

2021

Muscarinic acetylcholine receptors (mAChRs) belong to the superfamily of G-protein-coupled receptors (GPCRs). The family of mAChRs is composed of five subtypes, M1, M2, M3, M4 and M5, which have distinct expression patterns and functions. In the eye and its adnexa, mAChRs are widely expressed and exert multiple functions, such as modulation of tear secretion, regulation of pupil size, modulation of intraocular pressure, participation in cell-to-cell signaling and modula-tion of vascular diameter in the retina. Due to this variety of functions, it is reasonable to assume that abnormalities in mAChR signaling may contribute to the development of various ocular diseases. On the other hand, mAC…

Aged Mice Devoid of the M3 Muscarinic Acetylcholine Receptor Develop Mild Dry Eye Disease

2021

The parasympathetic nervous system is critically involved in the regulation of tear secretion by activating muscarinic acetylcholine receptors. Hence, various animal models targeting parasympathetic signaling have been developed to induce dry eye disease (DED). However, the muscarinic receptor subtype (M1–M5) mediating tear secretion remains to be determined. This study was conducted to test the hypothesis that the M3 receptor subtype regulates tear secretion and to evaluate the ocular surface phenotype of mice with targeted disruption of the M3 receptor (M3R−/−). The experimental techniques included quantification of tear production, fluorescein staining of the ocular surface, environmenta…

The effects of transdermal testosterone and oestrogen therapy on dry eye in postmenopausal women: a randomised, placebo-controlled, pilot study

2016

Aims Sex hormones could provide a future treatment avenue for dry eye post menopause. However, there are few well-controlled studies. This study investigates the impact of testosterone and oestrogen on dry eye symptoms and signs in postmenopausal women. Methods A randomised double-blind placebo-controlled pilot study was conducted involving 40 women with dry eye (age 63.9±5.1 years, 13.2±6.3 years post menopause). Ten women were assigned to each of four treatment groups: transdermal testosterone, oestradiol, testosterone/oestradiol combination and placebo. Assessment at baseline and after 8 weeks: ocular symptoms, tear osmolarity, tear stability, tear secretion, meibomian gland assessment, …