Estrogen therapy in keratoconjunctivitis sicca

TFOS DEWS II Sex, Gender, and Hormones Report

One of the most compelling features of dry eye disease (DED) is that it occurs more frequently in women than men. In fact, the female sex is a significant risk factor for the development of DED. This sex-related difference in DED prevalence is attributed in large part to the effects of sex steroids (e.g. androgens, estrogens), hypothalamic-pituitary hormones, glucocorticoids, insulin, insulin-like growth factor 1 and thyroid hormones, as well as to the sex chromosome complement, sex-specific autosomal factors and epigenetics (e.g. microRNAs). In addition to sex, gender also appears to be a risk factor for DED. "Gender" and "sex" are words that are often used interchangeably, but they have distinct meanings. "Gender" refers to a person's self-representation as a man or woman, whereas "sex" distinguishes males and females based on their biological characteristics. Both gender and sex affect DED risk, presentation of the disease, immune responses, pain, care-seeking behaviors, service utilization, and myriad other facets of eye health. Overall, sex, gender and hormones play a major role in the regulation of ocular surface and adnexal tissues, and in the difference in DED prevalence between women and men. The purpose of this Subcommittee report is to review and critique the nature of this role, as well as to recommend areas for future research to advance our understanding of the interrelationships between sex, gender, hormones and DED.

Sex hormones and the dry eye

The greater prevalence of dry eye in women compared to men suggests that sex hormones may have a role in this condition. This review aims to present evidence for how sex hormones may affect the ocular structures involved in the production, regulation and maintenance of the normal tear film. It is hypothesised that hormone changes alter the homeostasis of the ocular surface and contribute to dry eye. Androgens impact on the structure and function of the meibomian and lacrimal glands and therefore androgen deficiency is, at least in part, associated with the aetiology of dry eye. In contrast, reports of the effects of oestrogen and progesterone on these ocular structures and on the conjunctiva are contradictory and the mechanisms of action of these female-specific sex hormones in the eye are not well understood. The uncertainty of the effects of oestrogen and progesterone on dry eye symptoms is reflected in the controversial relationship between hormone replacement therapy and the signs and symptoms of dry eye. Current understanding of sex hormone influences on the immune system suggests that oestrogen may modulate a cascade of inflammatory events, which underlie dry eye.

Tear secretion and tear stability of women on hormonal contraceptives

Purpose

To investigate the effects of injectable hormonal contraceptives on tear secretion and tear stability of females within child bearing age in Nigeria.

Methods

The experimental group consisted of 32 healthy females (mean age was 34.72 ± 5.44) on injectable hormonal contraceptives; and the control group comprised 32 females (mean age was 34.66 ± 5.24) who were not on hormonal contraceptives. The tear stability and tear secretion were measured using the non-invasive tear break up time (NITBUT) technique and Schirmer's strips, respectively. All the females were at follicular phase of menstrual cycle. The plasma levels of progesterone and estradiol of all subjects were determined.

Results

There were no remarkable effects of injectable hormonal contraceptives on tear secretion (P  = 0.929) and tear stability (P  = 0.814). There were weak correlations between the plasma levels of progesterone and tear secretion (r  = −0.232, P  > 0.05), as well as with tear stability (r  = −0.322, P  > 0.05). Also, there were weak positive correlation between plasma levels of estradiol and tear secretion (r  = 0.304, P  > 0.05), as well as with tear stability (r  = 0.262, P  > 0.05). There were no significant differences in tear stability between the experimental and control groups (P  > 0.05).

Conclusions

Injectable hormonal contraceptives had no significant effects on tear secretion and tear stability of healthy women of childbearing age. Further studies may be required to determine the effects of hormonal contraceptives on tear volume and stability of women with dry eyes.

Sex- and gender-based differences in healthy and diseased eyes

PURPOSE

The aim of this study was to identify sex- and gender-based differences in ocular anatomy, physiology, and disease susceptibility or manifestation.

METHODS

Review of current indexed literature was conducted.

RESULTS

Sex and sex hormones influence the lacrimal system, eyelids and blinking, corneal anatomy and disease, aqueous humor dynamics and glaucoma, crystalline lens and cataract, uveitis and retinal disease, ocular circulation, and optic nerve anatomy and disease. Systemic conditions, particularly autoimmune disease, and conditions that are unique to women, such as pregnancy and menopause, further illustrate the effects of sex hormones on the eye. Gender-based differences in ocular conditions and disease should be considered within the context of the underlying physical and social environment.

CONCLUSIONS

Many sex- and gender-based differences exist in healthy and diseased eyes.

Pharmacological management of dry eye in the elderly patient

Dry eye disease is a common and increasingly prevalent condition particularly associated with advancing age and postmenopausal women. Epidemiological studies identify prevalence rates ranging from 7% in the US to 33% in the Asian population. Research increasingly identifies risk factors of increasing age, female sex, smoking, use of video display terminals and use of certain medications as well as environmental stresses as aggravating factors for the disease. Basic and clinical investigations provide cumulative evidence of hyperosmolarity of the tear film and ocular surface/lacrimal gland inflammation as pathogenic features of dry eye disease. A decline in systemic and local levels of sex hormones is associated with advancing age and advancing disease. Pharmacological therapeutic interventions include enhanced lubricants and anti-inflammatory drugs such as topical corticosteroids and ciclosporin (cyclosporine A). Secretagogues and hormonal supplementation are potential future therapies. The increased understanding of the contributing and pathogenetic factors responsible for dry eye provides a rationale for multiple therapeutic options for this multi-factorial disease. In the elderly patient it is important to recognize the physical and cognitive limitations that will influence the selection of appropriate topical medication.

Tearful relationships? Sex, hormones, the lacrimal gland, and aqueous-deficient dry eye

Sex and the endocrine system exert a significant influence on the physiology and pathophysiology of the lacrimal gland. The purpose of this article is to briefly review the nature and magnitude of these interactions between sex, hormones and lacrimal tissue, and to address how they may relate to the pathogenesis of aqueous-deficient dry eye. Towards this end, this article has a 3-fold approach: first, to summarize the influence of androgens, estrogens, glucocorticoids, mineralocorticoids, retinoic acid, prolactin, alpha-melanocyte stimulating hormone, adrenocorticotropic hormone, luteinizing hormone, follicle-stimulating hormone, growth hormone, thyroid-stimulating hormone, arginine vasopressin, oxytocin, thyroxine, parathyroid hormone, insulin, glucagon, melatonin, human chorionic gonadotropin and cholecystokinin on the structure and function of the lacrimal gland; second, to discuss the mechanism of action of each hormone on lacrimal tissue; and third, to discuss the clinical relevance of the endocrine-lacrimal gland interrelationship, with a particular focus on each hormone's role (i.e. if relevant) in the development of aqueous-tear deficiency.

Dry eye in post-menopausal women using hormone replacement therapy

PURPOSE

To evaluate the effect of hormone replacement therapy (HRT) on dry eye in post-menopausal women.

METHODS

Forty post-menopausal women with dry eye (20 patients, group 1) and without dry eye (20 patients, group 2), and planning to receive HRT (estrogen plus progesterone), were recruited as the study groups. Forty age-matched untreated women were enrolled as controls (group 3 with dry eye, 5 patients; group 4 without dry eye, 35 patients). Patients having at least one of the symptoms (dryness, itching, photophobia, foreign body sensation, and tearing) together with two of the tests with positive results for dry eye (tear film break-up time (BUT), fluorescein staining of the cornea, analysis of the meibomian gland, and Schirmer I test) in both eyes were considered dry eye positive. Hormonal assay for follicle stimulating hormone, luteinizing hormone, estradiol, and free testosterone was performed. Dry eye statuses in the groups were evaluated statistically.

RESULTS

Four patients with incomplete follow-up data were excluded. HRT use increased estradiol levels in the groups. Mean ages of patients (50.2+/-4.8 and 50.7+/-3.9 years, and 50.0+/-4.6 and 53.0+/-3.9 years) were similar (p=0.67). Duration of menopause in groups 1 and 2 (3.2+/-2.2 and 1.4+/-1.2 years; p=0.01), and in groups 3 and 4 (3.0+/-1.6 and 1.7+/-1.3 years; p=0.014) were different. At the third month examinations, all of the patients in group 1, and 11 patients (61.1%) in group 2 had dry eye (p=0.003).

CONCLUSION

Duration of menopause and use of HRT may increase the incidence of dry eye in post-menopausal woman.

Effects of hormone replacement therapy on ocular function in postmenopause

OBJECTIVE

To evaluate the effect of hormone replacement therapy on climacteric ocular complaints, lacrimal secretion, intraocular pressure (IOP), and corneal thickness.

DESIGN

A prospective, controlled, randomized study on 50 healthy women (mean age 53.4 +/- 3.8 years) at least 1 year after spontaneous menopause. Twenty-five women (group A) were treated with transdermal 17beta-estradiol (50 microg/day) and medroxyprogesterone acetate (10 mg/day) for 12 days per cycle. Twenty-five untreated women (group B) were used as a control group. All participants underwent eye examination at the beginning of the study and after 3 and 6 months of therapy to detect ocular diseases and to measure lachrymal secretion, IOP, and corneal thickness.

RESULTS

No significant differences were observed between the two groups at the beginning of the study. After 3 and 6 months of treatment, we observed a significant reduction in the percentage of women in group A affected by ocular symptoms and in the severity of symptomatology in comparison with baseline and with group B (P < 0.01). A significant increase of both basal and stimulated lachrymal secretion was observed after 3 months of therapy in group A in comparison with baseline (P < 0.01). There was a significant decrease of IOP (P < 0.01) after 3 months of therapy in group A (P < 0.01), and a slight, nonsignificant increase of corneal thickness was observed in group A at 3 and 6 months in comparison with basal values.

CONCLUSION

Our data suggest that hormone replacement therapy may exert a beneficial effect on ocular symptomatology, increase lachrymal secretion, reduce IOP, and increase corneal thickness.

Effect of hormone replacement therapy on lacrimal fluid peroxidase activity in woman

OBJECTIVE

Lacrimal fluid peroxidase (POD) is an antioxidant and antimicrobial enzyme involved in the protection of the ocular surface. Our recent findings showed the existence of significant cyclic variations in POD activity that were positively correlated with those of 17beta-estradiol plasma levels throughout the menstrual cycle of fertile women. During the menopause, women lacrimal fluid POD activity significantly (P<0.05) decreased according to the natural oestrogen reduction. Since a possible influence of oestrogen on human POD activity was suggested, aim of the present investigation is to evaluate whether hormone replacement therapy (HRT) might influence this enzyme activity.

METHODS

Lacrimal fluid POD activities of 10 healthy postmenopausal women (mean age: 52.0) and eight healthy postmenopausal women (mean age: 53.0) treated by oral or transdermal routes containing oestrogen or oestrogen plus progestin were determined. Enzyme activity of each tear sample (5 microl) was spectrophotometrically determined by the 5,5'-dithiobis, 2-nitrobenzoic acid thiocyanate (NBS-SCN) assay; total protein content of tears was determined too. 17beta-Estradiol plasma levels were assayed by ELISA test.

RESULTS

HRT significantly (P<0.05) increased tear POD low postmenopausal levels. The significant (P<0.05) rise of 17beta-estradiol plasma levels of treated women was not strictly correlated to the enzyme activity increase in tears.

CONCLUSIONS

The suggested estrogen regulation of lacrimal fluid POD activity could be one possible cause for the female gender predilection in some ocular diseases. HRT is able to increase tear POD activity levels of postmenopausal women, probably contributing to the effective relieve of ocular surface complications occurring during menopause.

The treatment of dry eye

The most widely used therapy for dry eye disease is tear replacement by topical artificial tears. Punctal occlusion to prevent the drainage of natural or artificial tears is the most common non-pharmacological treatment. These and other traditional therapies for dry eye disease are only palliative, however, as they replace or conserve the tears without necessarily correcting the underlying disease process. As our understanding of the pathology of dry eye disease improves, new treatment strategies are being developed. Topical anti-inflammatory and immunomodulatory agents, such as cyclosporin A, are under investigation in the treatment of dry eye, as it is anticipated that they will correct the vicious cycle of inflammation and cell damage on the ocular surface and lacrimal glands.

Expression of sex steroid hormone receptors in human cornea

PURPOSE

Previously we reported the occurrence of estrogen receptor alpha (ER beta), estrogen receptor beta (ER beta) and androgen receptor (AR) in mouse corneas. The present study was designed to investigate the occurrence of various sex steroid hormone receptors, including ER alpha, progesterone receptor (PR) and AR, in human corneas.

METHODS

We used reverse transcription-polymerase chain reaction (RT-PCR) to look for sex hormone receptor mRNAs (ER alpha, PR and AR) in human corneal epithelial cells obtained at autopsy. Next, using an immunocytochemical technique, we localized these receptors in donor human corneas.

RESULTS

mRNAs encoding all receptors tested for were found in corneal epithelial cells obtained from male and female donor eyes. Immunocytochemical examination revealed that the receptors were located in the nuclei of corneal epithelial, stromal, and endothelial cells.

CONCLUSIONS

Since receptors for both male and female sex hormones are present in human corneas of both genders, we postulate that the receptors may influence the biological functions of corneal cells through direct interaction with specific hormones.