Identification of androgen, estrogen and progesterone receptor mRNAs in the eye

Progesterone, Lipoic Acid, and Sulforaphane as Promising Antioxidants for Retinal Diseases: A Review

Oxidative stress has been documented to be a key factor in the cause and progression of different retinal diseases. Oxidative cellular unbalance triggers a sequence of reactions which prompt cell degeneration and retinal dysfunction, both hallmarks of several retinal pathologies. There is no effective treatment, yet, for many retinal diseases. Antioxidant treatment have been pointed out to be an encouraging palliative treatment; the beneficial effects documented involve slowing the progression of the disease, a reduction of cell degeneration, and improvement of retinal functions. There is a vast information corpus on antioxidant candidates. In this review, we expose three of the main antioxidant treatments, selected for their promising results that has been reported to date. Recently, the sulforaphane, an isothiocyanate molecule, has been unveiled as a neuroprotective candidate, by its antioxidant properties. Progesterone, a neurosteroid has been proposed to be a solid and effective neuroprotective agent. Finally, the lipoic acid, an organosulfur compound, is a well-recognized antioxidant. All of them, have been tested and studied on different retinal disease models. In this review, we summarized the published results of these works, to offer a general view of the current antioxidant treatment advances, including the main effects and mechanisms described.

Changes in visual function and ocular morphology in women who have undergone ART treatment and children born as a result of ART treatment: a systematic review

As all the structures of the human eye are characterized by sex hormone receptors, this study tested the hypothesis that assisted reproductive technology (ART) treatment influences visual function and ocular morphology in women who have undergone ART treatment and children born as a result of ART treatment. A systematic literature search of all original articles published up to August 2018 was performed using the PubMed database, including all original studies available in the literature. Review articles, studies in which participants underwent mixed interventions (i.e. other than ART treatment), studies reporting data on ocular malformations in ART offspring, and studies written in languages other than English were excluded. All selected articles were analysed to assess the level of evidence according to the Oxford Centre for Evidence-Based Medicine 2011 guidelines, and the quality of evidence according to the Grading of Recommendations Assessment, Development and Evaluation system. Although sparse data suggest that ART treatment can influence visual function and ocular morphology in women who have undergone ART treatment and children born as a result of ART treatment, the available evidence is inconclusive given its low level and quality. More high-quality research is needed to assess the potential interaction between ART treatment and the eye.

Sex Hormones and Optic Nerve Disorders: A Review

Aim: This review article presents a comprehensive overview of the literature on sex hormones (estrogens, androgens, progesterone) and optic nerve disorders, with a discussion of the implications for therapy and prevention.

Methods: Epidemiological, pre-clinical and clinical studies were reviewed.

Results: Analysis of the biological basis for a relationship between eye diseases and sex hormones showed that some types of hormones can exert a protective effect either directly on the retina and optic nerve or indirectly by modulating ocular blood flow. For example, it seems that estrogen exposure has a protective effect against glaucoma, whereas its deficit may lead to early onset of the disease. If further studies confirm the data in the literature, estrogen therapy, because of its antioxidant action, may be effective in the treatment of Leber's hereditary optic neuropathy, whereas, in the light of current studies, there does not seem to be an influence of estrogen on non-arteritic anterior ischemic optic neuritis (NAION).

Conclusions: Although there is some evidence that in some optic nerve pathologies the sex hormones seem to play an important role there are still too few studies providing evidence for its wider use in clinical practice.

The role of endocrine disruptors in ocular surface diseases

Endocrine disruptors are a group of compounds that occur in increasing amounts in the environment. These compounds change the hormone homeostasis of the target organs regulated by those hormones, mostly by binding to their receptors and affecting their signaling pathways. Among the hormones altered by endocrine disruptors are sex hormones, thyroid hormones, and insulin. Studies have documented abnormalities in the reproductive and metabolic systems of various animal species exposed to endocrine disruptors. Endocrine disruptors can play a significant role in ocular diseases once hormone deficiency or excess are involved in the mechanism of that disease. Cataracts, dry eye disease and retinal diseases, such as macular hole and diabetic retinopathy, are some of the frequent problems where hormones have been implicated. We found that some compounds function as endocrine disruptors in the metabolism of body organs and systems. The increasing frequency of dry eye and other ocular diseases indicates the need to better investigate the potential relationships beyond the isolated associations mentioned by patients and documented as rare case reports. The evidence from case-control studies and experimental assays can provide the information necessary to confirm the endocrine effects of these chemicals in the pathophysiology of dry eye disease. We hypothesize that endocrine disruptors may contribute to the increase of ocular diseases, such as dry eye disease, in recent years.

Effects of glucocorticoid on the eye development in guinea pigs

Glucocorticoid (GC) has been widely used in clinic. However, the effect of GC on normal and myopic development of eyes is still unknown. In this study, 3-week-old guinea pigs were randomly divided into four groups: No-Lens (control), GC+No-Lens, negative lens-induced myopia (LIM), and GC+LIM. To induce myopia, right eyes were covered with a -10 D lens in GC+LIM and LIM groups. GC+No-Lens and GC+LIM groups received intraperitoneal injections of hydrocortisone (10 mg/kg) once daily for 2 weeks, and then received intragastric hydrocortisone (32.5 mg/kg) every other day for the next 4 weeks, while No-Lens (control) and LIM groups were injected intraperitoneally with saline for 2 weeks, and then given saline by intragastric administertion for the next 4 weeks. Several parameters were assessed: ocular axial length and refractive error, sclera thickness, matrix metalloprotein-2 (MMP-2) and tissue inhibitor metalloprotease-2 (TIMP-2) expressions and localization of the posterior sclera, plasma concentrations of free triiodothyronine (FT3), free thyroxine (FT4), testosterone (T), and oestradiol (E2). Results indicated that: (1) in normal eye development, hydrocortisone could inhibit both the axial elongation and the myopic shift; whereas (2) in LIM eye development, hydrocortisone (a) enhanced the axial elongation, myopic shift and sclera thinning; (b) enhanced the MMP-2 expression and decreased TIMP-2 expression, and (c) elevated the plasma concentration of E2 but decreased the levels of FT3, FT4, and T. In conclusion, glucocorticoid may influence both normal and LIM eye development. The balance of the hormones is fundamental for the eye development.

Sex hormone therapy's effect on dry eye syndrome in postmenopausal women: A meta-analysis of randomized controlled trials

THE PURPOSE OF THE STUDY T: o assess the efficacy of sex hormone therapy in the treatment of dry eye syndrome in postmenopausal women.The following electronic databases were searched without language restrictions: PubMed, Embase, Cochrane, and the Chinese Biomedical Database. Two reviewers collected all the literature, which was searched for relevance in English and Chinese from January 1990 to July 2017. Both of the reviewers screened documents independently, identifying the studies that met the inclusion criteria. Then, the included studies were evaluated, and the data were extracted and conversed dependently. Finally, Review Manager 5.3 (offered by the Cochrane collaboration) was used to complete the meta-analysis. An integrated mean difference (MD) with its corresponding 95% confidence interval (CI) was calculated.A total of 358 patients with dry eye were enrolled in 7 randomized controlled trials (RCTs). We observed statistically significant improvements in the Schirmer's test scores (MD, 2.06; 95% CI, 0.74-4.46; I = 97%; P = .006) after sex hormone treatment. However, the scores for tear breakup time (TBUT) (MD, 1.28; 95% CI, -1.03 to 4.68; I = 99%; P = .21) and the ocular comfort index (OCI) (MD, -1.12; 95% CI, -4.42 to 1.98; I = 95%; P = .48) were not improved.This meta-analysis of 7 RCTs suggests that sex hormone therapy may be associated with better Schirmer's test scores. However, no significant differences were detected in the TBUT and OCI test scores. Consequently, sex hormone therapy has a potentially useful role in the effective management of postmenopausal women with dry eye syndrome.

The neuroendocrinology of sexual attraction

Sexual attraction has two components: Emission of sexually attractive stimuli and responsiveness to these stimuli. In rodents, olfactory stimuli are necessary but not sufficient for attraction. We argue that body odors are far superior to odors from excreta (urine, feces) as sexual attractants. Body odors are produced by sebaceous glands all over the body surface and in specialized glands. In primates, visual stimuli, for example the sexual skin, are more important than olfactory. The role of gonadal hormones for the production of and responsiveness to odorants is well established. Both the androgen and the estrogen receptor α are important in male as well as in female rodents. Also in primates, gonadal hormones are necessary for the responsiveness to sexual attractants. In males, the androgen receptor is sufficient for sustaining responsiveness. In female non-human primates, estrogens are needed, whereas androgens seem to contribute to responsiveness in women.

Acute bilateral serous central chorioretinopathy after emergency contraceptive therapy with ulipristal acetate

CASE REPORT

The case concerns a 31 year-old woman with no previous history who consulted due to decreased vision in both eyes. She mentioned taking 1 pill of ulipristal acetate (30mg) as an emergency contraceptive four days before the visual symptoms appeared. In the examination, a better corrected visual acuity of 0.6 was found in the right eye and 0.8 in left eye (by Snellen chart), and bilateral macular serous detachment. It was decided to observe, and 15 days later she showed a functional and anatomical improvement.

DISCUSSION

Ulipristal acetate could lead to serous central chorioretinopathy due to its activity on the progesterone receptors present in choroidal and retinal pigment epithelium.

Neuroprotective strategies for retinal disease

Diseases that affect the eye, including photoreceptor degeneration, diabetic retinopathy, and glaucoma, affect 11.8 million people in the US, resulting in vision loss and blindness. Loss of sight affects patient quality of life and puts an economic burden both on individuals and the greater healthcare system. Despite the urgent need for treatments, few effective options currently exist in the clinic. Here, we review research on promising neuroprotective strategies that promote neuronal survival with the potential to protect against vision loss and retinal cell death. Due to the large number of neuroprotective strategies, we restricted our review to approaches that we had direct experience with in the laboratory. We focus on drugs that target survival pathways, including bile acids like UDCA and TUDCA, steroid hormones like progesterone, therapies that target retinal dopamine, and neurotrophic factors. In addition, we review rehabilitative methods that increase endogenous repair mechanisms, including exercise and electrical stimulation therapies. For each approach, we provide background on the neuroprotective strategy, including history of use in other diseases; describe potential mechanisms of action; review the body of research performed in the retina thus far, both in animals and in humans; and discuss considerations when translating each treatment to the clinic and to the retina, including which therapies show the most promise for each retinal disease. Despite the high incidence of retinal diseases and the complexity of mechanisms involved, several promising neuroprotective treatments provide hope to prevent blindness. We discuss attractive candidates here with the goal of furthering retinal research in critical areas to rapidly translate neuroprotective strategies into the clinic.

Female Hormone 17β-Estradiol Downregulated MMP-2 Expression and Upregulated A1PI Expression in Human Corneal Stromal Cells

Collagens are essential for cornea functions. In non-ocular tissues, it has been demonstrated that sex hormones modulate the collagen remodeling. In this study, we investigated whether the primary female hormone 17β-estradiol plays a role in the expressions of matrix metalloproteinases and proteinase inhibitors in cultured human corneal stromal cells. We found that 17β-estradiol treatment significantly reduced the matrix metalloproteinase-2 mRNA in human corneal stromal cells as well as the matrix metalloproteinase-2 proteins, while the matrix metalloproteinase-9 mRNA level was not significantly altered. 17β-estradiol also upregulated the expression of proteinase inhibitor, alpha1-proteinase inhibitor. The expression of transcription factor specificity protein 1 was reduced by 17β-estradiol. Furthermore, 17β-estradiol did not change the viability and apoptosis of the corneal stromal cells. The downregulation of matrix metalloproteinase-2 and upregulation of alpha1-proteinase inhibitor by 17β-estradiol possibly serve as protective factor for the normal tomography in antagonizing the extracellular matrix degeneration in many cornea diseases.

Estrogen Modulates Corneal Nociception and Maintains Corneal Homeostasis in Rat Eye

PURPOSE

To evaluate the role of estrogen in corneal nociception, its influence on lacrimal secretion, and development of dry eye.

METHODS

Ovariectomy was performed in normal healthy female rats (OVX). Estrogen replacement was performed in a population of these rats (OVX+E). Tests for dry eye and corneal sensitivity were performed and compared with rats in proestrus (PRO) as controls. Gene expression of neuropeptides such as substance P, calcitonin gene receptor-like protein (CGRP), estrogen receptor α, TRPV1, and TRPM8 was evaluated in the cornea and trigeminal ganglion. Expression of substance P and CGRP in the cornea was also examined by immunohistochemistry. The response of the cornea to capsaicin and menthol was evaluated to identify the activity of receptors TRPV1 and TRPM8, respectively.

RESULTS

There was a significant decrease in tear formation (4.2 ± 0.6 mm/min vs. 6.6 ± 0.42 mm/min), corneal sensitivity (2.2 ± 0.17 cm vs. 6 ± 0 cm), and increase in fluorescein staining in corneas after ovariectomy compared with controls. There was a significant decrease in gene expression of CGRP, substance P, TRPV1, and TRPM8 in the ovarioectomized cornea. A significant decrease in tear formation (3.17 ± 0.30 mm/min vs. 7.17 ± 0.87 mm/min) and eye wipe response (10.5 ± 1.99 wipes vs. 18.33 ± 1.05 wipes) after treatment with menthol and capsaicin in OVX rats was observed. Estrogen replacement significantly enhanced tear formation (4.02 ± 0.6 mm/min vs. 6.7 ± 0.80 mm/min), corneal sensitivity (2.2 ± 0.17 cm vs. 3.2 ± 0.17 cm), and response to capsaicin (10.5 ± 1.99 eye wipes vs. 24.5 ± 0.92 wipes) and menthol (3.17 ± 0.30 mm/min vs. 6.5 ± 0.22 mm/min) and increased expression of neuropeptides, TRPV1 and TRPM8.

CONCLUSIONS

This study demonstrates the role of estrogen in corneal nociception and its deficiency as a cause of dry eye.

SEX STEROIDS AND MACULAR TELANGIECTASIA TYPE 2

PURPOSE

To investigate the relationship between macular telangiectasia Type 2 and systemic levels of sex steroids or their antagonization.

METHODS

In a prospective single-center study, 90 patients with macular telangiectasia Type 2 were investigated. Female patients were evaluated for previous surgical (e.g., ovariectomy) and/or pharmacological (e.g., aromatase inhibitors, tamoxifen) therapy resulting in reduced action of sex steroids. In males, free serum testosterone levels were assessed in patients and controls.

RESULTS

Fourteen of 49 (29%) female patients had a history of pharmacological suppression of sex steroids and/or ovariectomy. These patients were younger at disease onset when compared with those without such medical history (mean ± SD: 47.1 ± 7.8, range: 38-59, versus 60.1 ± 7.6, range: 45-76; P < 0.0001). Male patients showed significantly lower free serum testosterone levels compared with controls at younger age (P < 0.0001 and 0.04 in the first and second age quartiles, respectively), as opposed to nonsignificant differences in older patients. In men ≤ 60 years of age, a biochemical hypogonadism (free serum testosterone < 0.05 ng/mL) was present in 53% (8/15) and 4% (2/49) of patients and controls, respectively (P < 0.0001).

CONCLUSION

The results indicate that steroidal sex hormones might be involved in the presumably multifactorial pathophysiology of macular telangiectasia Type 2.

Association between mode of delivery and astigmatism in preschool children

PURPOSE

To determine whether mode of delivery has any impact on astigmatism.

METHODS

This case-control study was performed in the Department of Ophthalmology in 2015. Exposure was mode of delivery [vaginal delivery (VD) or caesarean section (CS), which here included both elective and emergency CS]. Outcome was astigmatism (≥2.5 D), which was determined by cycloplegic refraction. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were computed to assess the associations between mode of delivery and astigmatism from logistic regression models.

RESULTS

Of the 659 children studied here (341 boys; mean age, 4.37 years), 440 were born by CS and 219 by VD. The incidence of severe astigmatism (≥2.5 D) in the CS and VD groups was 22.06% and 13.24%, respectively. Children delivered by CS had a 77.9% higher risk of severe astigmatism compared with vaginally delivered children (OR = 1.779; 95% CI, 1.121 to 2.824). After dividing CS into elective CS and emergency CS, children delivered by elective CS had an 87.3% increased risk of severe astigmatism (OR = 1.873; 95% CI, 1.157 to 3.032), but children delivered by emergency CS did not differ from vaginally delivered children. In addition, the children whose mothers had histories of breastfeeding had a 44.6% lower risk of severe astigmatism than children whose mother did not breastfeed them (OR = 0.554, 95% CI, 0.335-0.914).

CONCLUSION

Birth by CS, especially elective CS, increases the risk of severe astigmatism (≥2.50 D) in childhood.

Impact of aromatase absence on murine intraocular pressure and retinal ganglion cells

We hypothesize that aromatase, an enzyme that regulates estrogen production, plays a significant role in the control of intraocular pressure (IOP) and retinal ganglion cells (RGCs). To begin to test our hypothesis, we examined the impact of aromatase absence, which completely eliminates estrogen synthesis, in male and female mice. Studies were performed with adult, age-matched wild type (WT) and aromatase knockout (ArKO) mice. IOP was measured in a masked fashion in both eyes of conscious mice at 12 and 24 weeks of age. Retinas were obtained and processed for RGC counting with a confocal microscope. IOP levels in both 12- and 24-week old female ArKO mice were significantly higher than those of age- and sex-matched WT controls. The mean increase in IOP was 7.9% in the 12-week-, and 19.7% in the 24-week-old mice, respectively. These changes were accompanied by significant 9% and 7% decreases in RGC numbers in the ArKO female mice, relative to controls, at 12- and 24-weeks, respectively. In contrast, aromatase deficiency did not lead to an increased IOP in male mice. There was a significant reduction in RGC counts in the 12-, but not 24-, week-old male ArKO mice, as compared to their age- and sex-matched WT controls. Overall, our findings show that aromatase inhibition in females is associated with elevated IOP and reduced RGC counts.

Sex-Dependent Choroidal Thickness Differences in Healthy Adults: A Study Based on Original and Synthesized Data

PURPOSE

The purpose of this study is to determine the influence of sex on choroidal thickness (CT) in healthy adults.

METHODS

Healthy Chinese adults were recruited and complete ophthalmic examinations were performed. The choroid was imaged by swept-source optical coherence tomography and the macular CT in Early Treatment Diabetic Retinopathy Study grids was obtained by the intrinsic automated segmentation software. CT in males and females was compared after controlling other factors. All of the published studies in PubMed were systemically tracked, and a syntheses analysis of the combined data of the present study and previous studies was performed to address this issue further.

RESULTS

A total of 104 healthy adults were included, of whom 38 (37%) were male and 66 (63%) were female. Older age and longer axial length (AL) each were significantly associated with thinner CT. After controlling for age and AL, the foveal CT and average macular CT were 25.5 μm (95% CI: 0.5-50.4 μm) and 22.1 μm (95% CI: 2.7-41.4 μm) thicker in men than in women, respectively. Significant differences in CT between males and females were also observed in inner and outer rings after controlling for age and AL (P < 0.05). After strict screening, 15 previously reported studies were determined to be eligible for inclusion. The combination of data collected from 2821 males and 3389 females provided further evidence that the choroid is thicker in males, with a pooled mean difference of 19.5 μm (95% CI: 11.4 to 27.6) for foveal CT and 14.7 μm (95% CI: 6.8 to 22.6) for average CT.

CONCLUSION

Our study of Chinese subjects, along with the syntheses analysis, strengthens the evidence that CT is greater in males than in females, based on OCT measurements. This observation may be pertinent for the sex disparities in some clinical conditions related to CT.

Effects of 17β-Estradiol on Activity, Gene and Protein Expression of Superoxide Dismutases in Primary Cultured Human Lens Epithelial Cells

PURPOSE

Protective effects of estradiol against H₂O₂-induced oxidative stress have been demonstrated in lens epithelial cells. The purpose of this study was to investigate the effects of 17β-estradiol (E2) on the different superoxide dismutase (SOD) isoenzymes, SOD-1, SOD-2, and SOD-3, as well as estrogen receptors (ERs), ERα and ERβ, in primary cultured human lens epithelial cells (HLECs).

MATERIALS AND METHODS

HLECs were exposed to 0.1 µM or 1 µM E2 for 1.5 h and 24 h after which the effects were studied. Protein expression and immunolocalization of SOD-1, SOD-2, ERα, and ERβ were studied with Western blot and immunocytochemistry. Total SOD activity was measured, and gene expression analyses were performed for SOD1, SOD2, and SOD3.

RESULTS

Increased SOD activity was seen after 1.5 h exposure to both 0.1 µM and 1 µM E2. There were no significant changes in protein or gene expression of the different SODs. Immunolabeling of SOD-1 was evident in the cytosol and nucleus; whereas, SOD-2 was localized in the mitochondria. Both ERα and ERβ were immunolocalized to the nucleus, and mitochondrial localization of ERβ was evident by colocalization with MitoTracker. Both ERα and ERβ showed altered protein expression levels after exposure to E2.

CONCLUSIONS

The observed increase in SOD activity after exposure to E2 without accompanying increase in gene or protein expression supports a role for E2 in protection against oxidative stress mediated through non-genomic mechanisms.

Progesterone Administration Fails to Protect Albino Male Rats against Photostress-Induced Retinal Degeneration

PURPOSE

Female patients show better recovery after brain injury and lower incidence of vascular diseases before menopause. The aim of this study was to test the protective effect of female sexual hormones against photostress-induced photoreceptor apoptosis.

METHODS

Five week old male albino Sprague-Dawley rats were injected intraperitoneally with progesterone (60 mg/kg body weight) for 4 days. The control group was injected with the vehicle only (benzyl alcohol). Both groups were halved and one was stressed with light (2700 lux for 24 hours) and the other remained under the original dim cyclic light condition. For functional evaluation, baseline electroretinograms (ERGs) were recorded 7 days before light stress, with follow-up ERGs 5 days after the cessation of light exposure. Animals were sacrificed and their eyes enucleated for histology.

RESULTS

Light exposure caused pronounced decrease in the ERG a- and b-wave amplitudes compared to controls. However, in the light-stressed group, the difference in retinal function between progesterone-treated and nontreated animals was not statistically significant. The thickness of the outer nuclear layer and the length of rod outer and inner segments were significantly reduced in the light-stressed group, indicating loss of rod photoreceptor cells. Progesterone had no neuroprotective effect on rod cell structure.

CONCLUSIONS

The administration of progesterone did not prove to be protective against excessive light-caused retinal degeneration on male albino rats. The role of other sexual steroids and their interaction need to be clarified.

Progesterone treatment shows greater protection in brain vs. retina in a rat model of middle cerebral artery occlusion: Progesterone receptor levels may play an important role

BACKGROUND/OBJECTIVE

To determine whether inflammation increases in retina as it does in brain following middle cerebral artery occlusion (MCAO), and whether the neurosteroid progesterone, shown to have protective effects in both retina and brain after MCAO, reduces inflammation in retina as well as brain.

METHODS

MCAO rats treated systemically with progesterone or vehicle were compared with shams. Protein levels of cytosolic NF-κB, nuclear NF-κB, phosphorylated NF-κB, IL-6, TNF-α, CD11b, progesterone receptor A and B, and pregnane X receptor were assessed in retinas and brains at 24 and 48 h using western blots.

RESULTS

Following MCAO, significant increases were observed in the following inflammatory markers: pNF-κB and CD11b at 24 h in both brain and retina, nuclear NF-κB at 24 h in brain and 48 h in retina, and TNF-α at 24 h in brain.Progesterone treatment in MCAO animals significantly attenuated levels of the following markers in brain: pNF-κB, nuclear NF-κB, IL-6, TNF-α, and CD11b, with significantly increased levels of cytosolic NF-κB. Retinas from progesterone-treated animals showed significantly reduced levels of nuclear NF-κB and IL-6 and increased levels of cytosolic NF-κB, with a trend for reduction in other markers. Post-MCAO, progesterone receptors A and B were upregulated in brain and downregulated in retina.

CONCLUSION

Inflammatory markers increased in both brain and retina after MCAO, with greater increases observed in brain. Progesterone treatment reduced inflammation, with more dramatic reductions observed in brain than retina. This differential effect may be due to differences in the response of progesterone receptors in brain and retina after injury.

Gonadal Hormones and Retinal Disorders: A Review

AIM

Gonadal hormones are essential for reproductive function, but can act on neural and other organ systems, and are probably the cause of the large majority of known sex differences in function and disease. The aim of this review is to provide evidence for this hypothesis in relation to eye disorders and to retinopathies in particular.

METHODS

Epidemiological studies and research articles were reviewed.

RESULTS

Analysis of the biological basis for a relationship between eye diseases and hormones showed that estrogen, androgen, and progesterone receptors are present throughout the eye and that these steroids are locally produced in ocular tissues. Sex hormones can have a neuroprotective action on the retina and modulate ocular blood flow. There are differences between the male and the female retina; moreover, sex hormones can influence the development (or not) of certain disorders. For example, exposure to endogenous estrogens, depending on age at menarche and menopause and number of pregnancies, and exposure to exogenous estrogens, as in hormone replacement therapy and use of oral contraceptives, appear to protect against age-related macular degeneration (both drusenoid and neurovascular types), whereas exogenous testosterone therapy is a risk factor for central serous chorioretinopathy. Macular hole is more common among women than men, particularly in postmenopausal women probably owing to the sudden drop in estrogen production in later middle age. Progestin therapy appears to ameliorate the course of retinitis pigmentosa. Diabetic retinopathy, a complication of diabetes, may be more common among men than women.

CONCLUSION

We observed a correlation between many retinopathies and sex, probably as a result of the protective effect some gonadal hormones may exert against the development of certain disorders. This may have ramifications for the use of hormone therapy in the treatment of eye disease and of retinal disorders in particular.

Pregnancy-induced Changes in Corneal Biomechanics and Topography Are Thyroid Hormone Related

PURPOSE

To identify biomechanical and topographic changes of the cornea during pregnancy and the postpartum period and its association to hormonal changes.

DESIGN

Prospective single-center observational cohort study.

METHODS

Participants were 24 pregnant women (48 eyes), monitored throughout pregnancy and after delivery. Biomechanical and topographic corneal properties were measured using the Ocular Response Analyzer (ORA) and a Scheimpflug imaging system (Pentacam HR) each trimester and 1 month after delivery. At the same consultations blood plasma levels of estradiol (E2) and thyroid hormones (TSH, T3t, T4t) were also determined. A factorial MANCOVA was used to detect interactions between hormonal plasma levels and ocular parameters.

RESULTS

Significant differences in corneal biomechanical and topographic parameters were found during pregnancy in relation to T3t (p = .01), T4t (p < .001), T3t/T4t (P = .001), and TSH (p = .001) plasma levels. E2 plasma levels (p = .092) and time period of measurement (p = .975) did not significantly affect corneal parameters. TSH levels significantly affected the maximal keratometry reading (p = .036), the vertical keratometry reading (p = .04), and the index of height asymmetry (p = .014). Those results persist after excluding hypothyroidism patients from the statistical analysis.

CONCLUSIONS

Hormonal changes affecting corneal biomechanics and topography during pregnancy could be thyroid related. Dysthyroidism may directly influence corneal biomechanics and represents a clinically relevant factor that needs further investigation.

ZENK induction in the zebra finch brain by song: Relationship to hemisphere, rhythm, oestradiol and sex

Oestradiol is abundant in the zebra finch auditory forebrain and has the capacity to modulate neural responses to auditory stimuli with specificity as a result of both hemisphere and sex. Arrhythmic song induces greater ZENK expression than rhythmic song in the caudomedial nidopallium (NCM), caudomedial mesopallium (CMM) and nucleus taeniae (Tn) of adult zebra finches. The increases in the auditory regions (i.e. NCM and CMM) may result from detection of errors in the arrhythmic song relative to the learned template. In the present study, zebra finches were treated with oestradiol, the aromatase inhibitor fadrozole or a control and then exposed to rhythmic or arrhythmic song to assess the effect of oestradiol availability on neural responses to auditory rhythms. ZENK mRNA was significantly greater in the left hemisphere within the NCM, CMM and Tn. Main effects of sex were detected in both auditory regions, with increased ZENK in males in the NCM and in females in the CMM. In the CMM, an effect of hormone treatment also existed. Although no pairwise comparison was statistically significant, the pattern suggested greater ZENK expression in control compared to both fadrozole- and oestradiol-treated birds. In the NCM, an interaction between sex and hormone treatment suggested that the sex effect was restricted to control animals. An additional interaction in the NCM among sex, stimulus rhythmicity and hemisphere indicated that the strongest effect of laterality was present in males exposed to arrhythmic song. The hormone effects suggest that an optimal level of oestradiol may exist for processing rhythmicity of auditory stimuli. The overall pattern for left lateralisation parallels the left lateralisation of language processing in humans and may suggest that this hemisphere is specialised for processing conspecific vocalisations. The reversed sex differences in the NCM and CMM suggest that males and females differentially rely on components of the auditory forebrain for processing conspecific song.

Effect of mistletoe combined with carboxymethyl cellulose on dry eye in postmenopausal women

AIM

To investigate the protective effect of mistletoe combined with carboxymethyl cellulose eye drops on dry eye in postmenopausal women.

METHODS

Sixty postmenopause female patients diagnosed of dry eye were assigned randomly to mistletoe combined with carboxymethyl cellulose eye drops treatment group (n=30) and control group treated with normal saline eye drops (n=30). The subjective symptoms of ocular surface, Ocular Surface Disease Index (OSDI), tear film function tests, tear protein and corneal morphology by confocal scanning microscopy were analyzed before treatment and at 1, 2, 4 and 8wk after treatment respectively. To ensure the safety of the trial, all patients were examined with systolic pressure, diastolic pressure, glutamic-pyruvic transaminase, glutamic oxaloacetic transaminase, urine creatinine, and blood urea nitrogen at 8wk after treatment.

RESULTS

There were no obvious differences between two groups before the treatment (P>0.05). In two months after the treatment, the symptoms of ocular surface, OSDI, tear protein, and tear film function were only slightly changed in normal saline eye drops group. However, all indices were improved after the treatment of mistletoe combined with carboxymethyl cellulose eye drops group (P<0.05). In addition, the average amount of corneal epithelium basal cells and inflammatory cells of mistletoe treated group were 3174±379 and 38±25 cells/mm², significantly decreased as compared to the control group with 4309±612 and 158± 61 cells/mm², respectively. In the control group, although nerves still maintained straight under corneal epithelium, the number of nerves were significantly decreased, as compared with normal female. In the mistletoe treated group, the number of nerves was only slightly reduced, compared with normal female.

CONCLUSION

Mistletoe combined with carboxymethyl cellulose eye drops can alleviate the symptoms and signs of dry eye symptoms.

Local synthesis of sex hormones: are there consequences for the ocular surface and dry eye?

Sex hormones are associated with the physiology and pathophysiology of almost all organs in the body, as well as most diseases. Interest in the associations between sex hormones and ocular tissues has increased in recent years. Androgens may have a positive effect on dry eye, whereas the effects of oestrogen on ocular conditions remain unclear. Intracrinology, the local synthesis and metabolism of hormones that is unique to humans, is of relevance to the eye and may help to explain why studies of the relationship between oestrogens and dry eye signs and symptoms are inconclusive. Knowledge of the pathways of hormone formation and metabolism is crucial to understanding the pathogenesis of ocular disease including dry eye. This review examines the mechanisms of steroidal sex hormone biosynthesis and reviews the significance of locally produced sex hormones, with a focus on ocular surface tissues. Much of the current literature is based on animal studies, which may not be transferable to humans due to the absence of intracrine production in animals. A large proportion of the human studies investigate systemic hormone levels rather than local levels. There is subsequently a need for additional studies to provide a better understanding of the local production of sex hormones within the human eye and ocular surface and to clarify the relationships between ocular levels of sex hormones and conditions including dry eye.

Anterior, posterior and biomechanical parameters of cornea during pregnancy in healthy eyes: a cohort study

BACKGROUND

To investigate the effect of pregnancy on anterior, posterior and biomechanical corneal parameters of healthy eyes.

METHOD

In this prospective cohort study, 70 pregnant participants with clinically healthy eyes underwent corneal topographic imaging evaluation by Pentacam and biomechanical assessment by Ocular Response Analyzer (ORA) before pregnancy, at the third trimester of pregnancy (34th week of pregnancy) and 12 months after delivery. The same number of age-matched non-pregnant females was evaluated at the corresponding appointments as the control group.

RESULTS

Assessment of the tomographic, topographic and ORA measurements before pregnancy, at the third trimester of pregnancy and 12 months post partum revealed no statistically significant changes in anterior and posterior corneal flat, steep and mean keratometry, anterior and posterior elevation measurements, central and thinnest corneal thickness, corneal hysteresis, corneal resistance factor and intraocular pressure measurements (p>0.05, repeated measures analysis of variance (ANOVA)). All of the study parameters returned to their baseline levels 1 year after delivery. The ophthalmic parameters of the non-pregnant group remained significantly unchanged during the study period (p>0.05, all comparisons, repeated measures ANOVA). Moreover, no statistically significant differences were found between pregnant and non-pregnant groups in the second (34th week of pregnancy) and third (post partum) appointments (p>0.05, all comparisons, one-way ANOVA).

CONCLUSION

Our findings may suggest a physiological nature for ocular changes during pregnancy that these changes return to baseline values after delivery. The differences between tomographic, topographic and biomechanical corneal parameters before pregnancy, during pregnancy and post partum were not statistically or clinically significant.

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.

Meibomian glands, meibum, and meibogenesis

Meibum is a lipid-rich secretion that is produced by fully differentiated meibocytes in the holocrine Meibomian glands (MG) of humans and most mammals. The secretion is a part of a defense mechanism that protects the ocular surface from hazardous environmental factors, and from desiccation. Meibomian lipids that have been identified in meibum are very diverse and unique in nature. The lipid composition of meibum is different from virtually any other lipid pool found in the human body. In fact, meibum is quite different from sebum, which is the closest secretion that is produced by anatomically, physiologically, and biochemically related sebaceous glands. However, meibum of mice have been shown to closely resemble that of humans, implying similar biosynthetic mechanisms in MG of both species. By analyzing available genomic, immunohistochemical, and lipidomic data, we have envisioned a unifying network of enzymatic reactions that are responsible for biosynthesis of meibum, which we call meibogenesis. Our current theory is based on an assumption that most of the biosynthetic reactions of meibogenesis are catalyzed by known enzymes. However, the main features that make meibum unique - the ratio of identified classes of lipids, the extreme length of its components, extensive ω-hydroxylation of fatty acids and alcohols, iso- and anteiso-branching of meibomian lipids (e.g. waxes), and the presence of rather unique complex lipids with several ester bonds - make it possible that either the activity of known enzymes is altered in MG, or some unknown enzymes contribute to the processes of meibogenesis, or both. Studies are in progress to elucidate meibogenesis on molecular level.

Differential Effects of Hormones on Cellular Metabolism in Keratoconus In Vitro

Keratoconus (KC) is a corneal thinning disease with an onset commonly immediately post-puberty and stabilization by 40 to 50 years of age. The role of hormones in regulating corneal tissue structure in homeostatic and pathological conditions is unknown. Our group recently linked altered hormone levels to KC. Our current study sought to investigate and delineate the effects of exogenous hormones, such as androgen, luteotropin, and estrogen, on corneal stroma bioenergetics. We utilized our established 3D in vitro model to characterize the effects of DHEA, prolactin, 17β-estradiol on insulin-growth factor-1 and -2 (IGF-1, -2) signaling and metabolic function in primary corneal fibroblasts from healthy controls (HCFs) and KC patients (HKCs). Our data showed that exogenous DHEA significantly downregulated IGF-1 and its receptor in both HCFs and HKCs with HKCs showing consistently lower basal pentose phosphate flux. Prolactin caused no significant change in IGF-1 levels and an increase in IGF-2 in HKCs correlating with an increase in ATP and NADH levels. 17β-estradiol led to a significant upregulation in pentose phosphate flux and glycolytic intermediates in HCFs. Our results identified hormone-specific responses regulated in HKCs compared to HCFs revealing a novel role for hormones on bioenergetics in KC.

Anterior Segment Findings in Women with Polycystic Ovary Syndrome

Objectives:

This study aimed to investigate the anterior segment in women with polycystic ovary syndrome (PCOS) and to compare them with those of healthy reproductive-age female volunteers.

Materials and Methods:

The study included 50 right eyes of 50 women with PCOS (group 1) and 50 right eyes of 50 healthy women (group 2). Intraocular pressure, Schirmer’s test, tear film break-up time and central corneal thickness were evaluated in all subjects. Correlations between serum hormone (estradiol and testosterone) levels and observed findings were also investigated.

Results:

Mean central corneal thickness values were significantly higher in the PCOS group (p=0.001). The mean intraocular pressures values were similar between the two groups (p=0.560). Schirmer’s test results and tear film break-up time values were significantly lower in the PCOS group (p=0.001 and p=0.001 respectively). Serum estradiol levels were moderately positively correlated with mean central corneal thickness (r=0.552), weakly positively correlated with intraocular pressure (r=0.351) and weakly negatively correlated with tear film break-up time (r=-0.393). Serum free testosterone levels were weakly correlated with intraocular pressure (r=0.342) and central corneal thickness (r=0.303), and showed weak negative correlations with Schirmer’s test results (r=-0.562) and tear film break-up time (r=-0.502).

Conclusion:

PCOS leads to physiological and structural changes in the eye. Dry eye symptoms were more severe and central corneal thickness measurements were greater in patients with PCOS. Those are correlated serum testosterone and estradiol levels.

The Influence of Donor and Recipient Gender Incompatibility on Corneal Transplant Rejection and Failure

In vascularized organ transplants, gender mismatches have higher rates of immunological rejection. We investigated the influence of gender incompatibility, including H-Y incompatibility, on corneal transplant graft rejection and failure. Patients were included who had undergone a first corneal transplant for keratoconus (KC), Fuchs endothelial dystrophy (FED), pseudophakic bullous keratopathy (PBK), infection and other indications. A Cox regression model was fitted for each indication to determine factors affecting graft failure and rejection at 5 years. The impact of gender, including H-Y, matching was analyzed after accounting for other factors, including known risk factors. Of 18 171 patients, 4314 had undergone a transplant for FED, 4783 for KC, 3669 for PBK, 1903 for infection and 3502 for other disorders. H-Y mismatched (male [M]→female [F]) corneas were at greater risk of graft failure or rejection. For FED, F→F were 40% less likely to fail (p < 0.0001) and 30% less likely to reject (p = 0.01); M→M were 20% less likely to fail (p = 0.04) and 30% less likely to reject (p = 0.01). For KC, M→M matched corneas were 30% less likely to fail (p = 0.05) and 20% less likely to reject (p = 0.01) compared with H-Y mismatches. H-Y antigen mismatched (M→F) patients were at greater risk of rejection or graft failure.

Evaluation of corneal thickness alterations during menstrual cycle in productive age women

PURPOSE

To determine the change in corneal thickness through different phases of menstrual cycle in women who are in their productive age.

MATERIALS AND METHODS

Fifty healthy women with normal past medical history were enrolled in this prospective study. Central corneal thickness was measured with ultrasound pachymeter three times during a menstrual cycle: Beginning of the cycle (days 1-3), ovulation time, and at the end of cycle (days 27-32). We confirmed ovulation time with determining a peak in luteinizing hormone in urine. To avoid the diurnal variation of the corneal thickness which is well recognized, we checked all our subjects at 10 in the morning.

RESULTS

In days 1 to 3 of menstruation, mean corneal thickness was 541.40 ± 11.36 and 540.82 ± 11.70 microns for left and right eyes respectively. At ovulation time the mean thickness changed to 556.50 ± 7.11 and 555.98 ± 7.26 microns for left and right eyes respectively, and at the end of the cycle, the corneal thickness turned in to 536.38 ± 12.83 and 535.48 ± 13.08 microns for left and right eyes respectively. The difference of corneal thickness was statistically significant relating to the different stages of menstrual cycle.

CONCLUSION

The thickest cornea during the menstruation cycle is achieved at the ovulation time and the thinnest at the end of the cycle and this should be taken in to account whilst plan to do a corneal refractive surgery.

The effect of assisted reproductive technology on ocular assessments

PURPOSE

The aim was to study the various ocular assessments in women undergoing assisted reproductive techniques (ART).

METHODS

A total of 117 women with infertility were enrolled for study and the ART protocol was followed. The outcome measures were intraocular pressure (IOP), central corneal thickness, corneal endothelial cell counts, Schirmer I test done at baseline (V0), post-oral contraceptive (V1), post-GnRH agonist induction phase (V2), post-conception (V3), third trimester of pregnancy (V4) and three months post-partum (V5). Schirmer I test (without topical anaesthesia) less than 10 mm in at least one eye was considered a criterion for dry eye.

RESULTS

Out of 117 women enrolled for in vitro fertilisation (IVF), only 48 patients conceived. Sixteen women had abortions and remaining 32 women, who had childbirth were followed until three months post-partum. Baseline mean IOP showed a slight decrement and corneal pachymetry and corneal endothelial cell counts showed slight increment from phases V1 to V4 of ART but statistically they were not significant (p > 0.05). At three months post-partum (V5) mean IOP, corneal pachymetry, corneal endothelial cell counts become closer to baseline in both eyes. The number of patients with at least one eye with dryness (Schirmer I less than 10 mm) significantly increased at the third trimester (p = 0.02) and three months post-partum (p = 0.035), whereas in the rest of the phases, it was comparable to baseline (p > 0.05).

CONCLUSION

The ocular physiological changes (IOP, corneal pachymetry and corneal endothelial cell counts) seen in various phases of ART were non-specific. The ART appears to reduce tear secretions as measured by Schirmer I; however, further research would be required to determine the impact of ART on the tear film and whether ART is associated with symptoms and signs of dry eye.

Endocrine and Metabolic Pathways Linked to Keratoconus: Implications for the Role of Hormones in the Stromal Microenvironment

Hormones play a critical role in regulating tissue function by promoting cell survival, proliferation, and differentiation. Our study explores the influence of endocrine function in regulating metabolism and inflammatory pathways in Keratoconus (KC), which is a corneal thinning disease associated with reduced stromal deposition. KC is known to be a multifactorial disease with an elusive pathogenesis. We utilized a cross-sectional study analyzing clinical features and saliva samples from sixty-four KC patients and fourteen healthy controls. In order to determine if endocrine function varied between healthy controls and KC, we measured hormone levels in saliva and found significantly increased dehydroepiandrosterone sulfate (DHEA-S) and reduced estrone levels in KC patients compared to healthy controls. We measured significant variations in metabolites associated with pro-inflammatory processes, including myoinositol and 1-methyl-histidine, by targeted mass spectrometry. We also measured significantly increased IL-16 and stem cell factor in KC saliva samples compared to healthy controls, with higher expression of these pro-inflammatory proteins correlating with increased KC clinical grade, corneal curvature, and stromal thinning. Our results identify a novel mechanism linking KC and pro-inflammatory markers and suggest that altered hormone levels modulate metabolism, cytokine, and growth factor expression leading to increased severity of the KC condition.

Low Serum 25-Hydroxyvitamin D Levels Are Associated with Dry Eye Syndrome

Background

Dry eye syndrome (DES) is a common tear film and ocular surface disease that results in discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. Systemic diseases associated with DES include diabetes mellitus, rheumatoid arthritis, depression, anxiety, thyroid disease, allergic diseases, irritable bowel syndrome, chronic pain syndrome, and hyperlipidemia. Interestingly, it has been found that most of these are associated with low levels of serum 25-hydroxyvitamin D (25(OH)D) or inadequate sunlight exposure.

Methods

In this cross-sectional data analysis, noninstitutionalized adults aged ≥19 years (N = 17,542) who participated in Korean National Health and Nutrition Examination Survey 2010–2012 were included. Information regarding duration of sunlight exposure was collected from the survey participants. Serum 25(OH)D and zinc levels were measured. The confounding variables were age, gender, sunlight exposure time, region of residence, obesity, serum 25(OH)D level, diabetes mellitus, rheumatoid arthritis, depression, thyroid disorder, atopic dermatitis, history of ocular surgery, regular exercise, and walking exercise.

Results

Mean serum 25(OH)D levels of subjects with and without DES were 16.90 ± 6.0 and 17.52 ± 6.07 (p<0.001). Inadequate sunlight exposure time (odds ratio [OR], 1.554; 95% confidence interval [CI], 1.307–1.848), urban residence (OR, 1.669; 95% CI, 1.456–1.913), indoor occupation (OR, 1.578; 95% CI, 1.389–1.814), and low serum 25(OH)D level (OR, 1.158; 95% CI, 1.026–1.308) were the risk factors for DES. After adjusting for age, sex, obesity, diabetes mellitus, rheumatoid arthritis, depression, thyroid disorder, atopic dermatitis, history of ocular surgery, regular exercise, and occupation, low serum 25(OH)D level (OR, 1.178; 95% CI, 1.010–1.372) and deficient sunlight exposure time (OR, 1.383; 95% CI, 1.094–1.749) were the risk factors for diagnosed DES.

Conclusion

Low serum 25(OH)D levels and inadequate sunlight exposure are associated with DES in Korean adults. These results suggest that sufficient sunlight exposure or vitamin D supplementation may be useful in DES treatment.

High Levels of 17β-Estradiol Are Associated with Increased Matrix Metalloproteinase-2 and Metalloproteinase-9 Activity in Tears of Postmenopausal Women with Dry Eye

Purpose. To determine the serum levels of sex steroids and tear matrix metalloproteinases (MMP) 2 and 9 concentrations in postmenopausal women with dry eye. Methods. Forty-four postmenopausal women with dry eye and 22 asymptomatic controls were enrolled. Blood was drawn and analyzed for serum levels of sex steroids and lipids. Then, the following tests were performed: tear collection, Ocular Surface Disease Index (OSDI) questionnaire, fluorescein tear film break-up time (TBUT), corneal fluorescein staining, Schirmer test, and conjunctival impression cytology. The conjunctival mRNA expression and tear concentrations of MMP-2 and MMP-9 were measured. Results. Serum 17β-estradiol levels were significantly higher in the dry eye subjects than in the controls (P = 0.03), whereas there were no significant differences in levels of testosterone, dehydroepiandrosterone sulfate (DHEA-S), and progesterone. Tear MMP-2 and MMP-9 concentrations (P < 0.001), as well as the MMP-9 mRNA expression in conjunctival samples (P = 0.02), were significantly higher in dry eye subjects than in controls. Serum 17β-estradiol levels were positively correlated with tear MMP-2 and MMP-9 concentrations and negatively correlated with Schirmer test values. Conclusions. High levels of 17β-estradiol are associated with increased matrix metalloproteinase-2 and metalloproteinase-9 activity in tears of postmenopausal women with dry eye.

Is Estrogen a Therapeutic Target for Glaucoma?

This article's objective is to provide an overview of the association between estrogen and glaucoma. A literature synthesis was conducted of articles published in peer-reviewed journals screened through May 5, 2015, using the PubMed database. Keywords used were "estrogen and glaucoma," "reproductive factors and glaucoma," and "estrogen, nitric oxide and eye." Forty-three journal articles were included. Results indicated that markers for lifetime estrogen exposure have been measured by several studies and show that the age of menarche onset, oral contraceptive (OC) use, bilateral oophorectomy, age of menopause onset and duration between menarche to menopause are associated with primary open-angle glaucoma (POAG) risk. The Blue Mountain Eye Study found a significantly increased POAG risk with later (>13 years) compared with earlier (≤12 years) age of menarche. Nurses' Health Study (NHS) investigators found that OC use of greater than 5 years was associated with a 25% increased risk of POAG. The Mayo Clinic Cohort Study of Oophorectomy and Aging found that women who underwent bilateral oophorectomy before age 43 years had an increased risk of glaucoma. The Rotterdam Study found that women who went through menopause before reaching the age of 45 years had a higher risk of open-angle glaucoma (2.6-fold increased risk), while the NHS showed a reduced risk of POAG among women older than 65 who entered menopause after age ≥ 54 years. Increased estrogen states may confer a reduced risk of glaucoma or glaucoma-related traits such as reduced intraocular pressure (IOP). Pregnancy, a hyperestrogenemic state, is associated with decreased IOP during the third trimester. Though the role of postmenopausal hormone (PMH) use in the reduction of IOP is not fully conclusive, PMH use may reduce the risk of POAG. From a genetic epidemiologic perspective, estrogen metabolic pathway single nucleotide polymorphisms (SNPs) were associated with POAG in women and polymorphisms in endothelial nitric oxide synthase, a gene receptive to estrogen regulation, are associated with glaucoma. The study concluded that increasing evidence suggests that lifetime exposure to estrogen may alter the pathogenesis of glaucoma. Estrogen exposure may have a neuroprotective effect on the progression of POAG but further studies need to confirm this finding. The role of sex-specific preventive and therapeutic treatment may be on the horizon.

Effects of Sex Hormones on Ocular Surface Epithelia: Lessons Learned From Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine abnormality in women of reproductive age. Although its clinical consequences have been known for a long time to extend beyond the reproductive system, with type-2 diabetes and obesity being the most common, the involvement of the ocular surface in PCOS has been described only more recently. The ocular surface is a morphofunctional unit comprising eyelid margin, tear film, cornea, and conjunctiva. Increasing evidence indicates that these structures are under a sex hormone control and relevant diseases such as ocular allergy and dry eye are often caused by alterations in circulating or local steroid hormones levels. Novel treatments targeting sex hormone receptors on ocular surface epithelial cells are also being developed. In this review we aim to describe the current knowledge on the effects of sex hormones at the ocular surface, with a special focus on the effects of androgen imbalance in PCOS.

Progesterone receptor signalling in retinal photoreceptor neuroprotection

'Norgestrel', a synthetic form of the female hormone progesterone has been identified as potential drug candidate for the treatment of the degenerative eye disease retinitis pigmentosa. However, to date, no work has looked at the compound's specific cellular target. Therefore, this study aimed to identify the receptor target of Norgestrel and begin to examine its potential mechanism of action in the retina. In this work, we identify and characterize the expression of progesterone receptors present in the C57 wild type and rd10 mouse model of retinitis pigmentosa. Classical progesterone receptors A and B (PR A/B), progesterone receptor membrane components 1 and 2 (PGRMC1, PGRMC2) and membrane progesterone receptors α, β and γ were found to be expressed. All receptors excluding PR A/B were also found in the 661W photoreceptor cell line. PGRMC1 is a key regulator of apoptosis and its expression is up-regulated in the degenerating rd10 mouse retina. Activated by Norgestrel through nuclear trafficking, siRNA knock down of PGRMC1 abrogated the protective properties of Norgestrel on damaged photoreceptors. Furthermore, specific inhibition of PGRMC1 by AG205 blocked Norgestrel-induced protection in stressed retinal explants. Therefore, we conclude that PGRMC1 is crucial to the neuroprotective effects of Norgestrel on stressed photoreceptors. The synthetic progestin 'Norgestrel' has been identified as a potential therapeutic for the treatment of Retinitis Pigmentosa, a degenerative eye disease. However, the mechanism behind this neuroprotection is currently unknown. In this work, we identify 'Progesterone Receptor Membrane Component 1' as the major progesterone receptor eliciting the protective effects of Norgestrel, both in vitro and ex vivo. This furthers our understanding of Norgestrel's molecular mechanism, which we hope will help bring Norgestrel one step closer to the clinic.

Relevant factors of estrogen changes of myopia in adolescent females

Background:

Gender is one of the risk factors accounting for the high prevalence of adolescent myopia. Considerable research results have shown that myopia incidence of female is higher than that of male. This study aimed to analyze the correlation between ocular parameters and serum estrogen level and to investigate the vision changes along with estrogen change in menstrual cycle of adolescent females.

Methods:

A total of 120 young females aged between 15 and 16 years, diagnosed with myopia were recruited. Spherical lens, cylindrical lens, axis, interpupillary distance (IPD), and vision in each tested eye of the same subject were measured by automatic optometry and comprehensive optometry, with repetition of all measurements in the menstrual cycle of the 2^nd or 3^rd days, 14^th days, and 28^th days, respectively. Serum estradiol (E₂) levels were assayed by chemiluminescence immunoassay at the same three times points of the menstrual cycle mentioned above.

Results:

In young females with myopia, the spherical lens showed a statistically significant difference among all different time in menstrual cycle (all P < 0.0001). The cylindrical lens, axis, and IPD were changed significantly during the menstrual cycle (P < 0.05). The vision of the three different time points in menstrual cycle had a significant difference (χ² = 6.35, P = 0.042). The vision during the 14^th and 28^th day was higher compared to that on the 2^nd or 3^rd days (P = 0.021). Serum E₂ levels were significantly different at different time points in menstrual cycle (P < 0.05). E₂ levels reached its maximum value on the 14^th day and the minimum value on the 2^nd or 3^rd day.

Conclusions:

In adolescent females, the spherical lens and other related ocular parameters vary sensitively with different levels of E₂ in menstrual cycle. Vision in late menstrual stage is significantly higher than that in premenstrual stage.

Progesterone treatment in two rat models of ocular ischemia

PURPOSE

To determine whether the neurosteroid progesterone, shown to have protective effects in animal models of traumatic brain injury, stroke, and spinal cord injury, is also protective in ocular ischemia animal models.

METHODS

Progesterone treatment was tested in two ocular ischemia models in rats: a rodent anterior ischemic optic neuropathy (rAION) model, which induces permanent monocular optic nerve stroke, and the middle cerebral artery occlusion (MCAO) model, which causes transient ischemia in both the retina and brain due to an intraluminal filament that blocks the ophthalmic and middle cerebral arteries. Visual function and retinal histology were assessed to determine whether progesterone attenuated retinal injury in these models. Additionally, behavioral testing and 2% 2,3,5-triphenyltetrazolium chloride (TTC) staining in brains were used to compare progesterone's neuroprotective effects in both retina and brain using the MCAO model.

RESULTS

Progesterone treatment showed no effect on visual evoked potential (VEP) reduction and retinal ganglion cell loss in the permanent rAION model. In the transient MCAO model, progesterone treatment reduced (1) electroretinogram (ERG) deficits, (2) MCAO-induced upregulation of glutamine synthetase (GS) and glial fibrillary acidic protein (GFAP), and (3) retinal ganglion cell loss. As expected, progesterone treatment also had significant protective effects in behavioral tests and a reduction in infarct size in the brain.

CONCLUSIONS

Progesterone treatment showed protective effects in the retina following MCAO but not rAION injury, which may result from mechanistic differences with injury type and the therapeutic action of progesterone.

Central serous chorioretinopathy in patients receiving exogenous testosterone therapy

PURPOSE

To report an association between central serous chorioretinopathy (CSCR) and exogenous testosterone therapy.

METHODS

This is a retrospective case series from two institutions. Patients who presented with fluorescein angiography and optical coherence tomography findings consistent with CSCR were included. All patients were concurrently being treated with exogenous testosterone therapy and lacked other known risk factors for CSCR.

RESULTS

Nine patients presented with CSCR after beginning exogenous testosterone therapy. Two patients stopped therapy with resolution of symptoms and subretinal fluid.

CONCLUSION

Exogenous testosterone may be an independent risk factor for the development of CSCR.