Oestrogen, ocular function and low-level vision: a review

Gender inclusivity of ophthalmology journal submission guidelines and associated research metrics

PURPOSE

This cross-sectional study evaluated the prevalence of inclusive author submission guidelines across ophthalmology journals.

METHODS

Journals were identified from the 2021 Journal Citations Report (Clarivate Analytics). Independent reviewers rated each author submission guideline as "inclusive" for satisfying at-least one of six criteria: i) included examples of gender inclusive language; ii) recommended the use of gender-inclusive language; iii) distinguished between sex and gender; iv) provided educational resources on gender-inclusive language; v) provided a policy permitting name changes (e.g., in case of gender and name transition); and/or vi) provided a statement of commitment to inclusivity. The primary objective was to investigate the proportion of journals with "gender-inclusive" author submission guidelines and the elements of the gender-inclusive content within these guidelines. A secondary objective was to review the association between "gender-inclusivity" in author submission guidelines with publisher, origin country, and journal/source/influence metrics (Clarivate Analytics).

RESULTS

Across 94 journals, 29.8% journals were rated as inclusive. Inclusive journals had significantly higher relative impact factor, citations, and article influence scores compared to non-inclusive journals. Of the 29.8% of inclusive journals, the three most common domains were inclusion of an inclusivity statement (71.4% of inclusive journals), distinguishing between sex and gender (67.9%), and provision of additional educational resources on gender reporting for authors (60.7%).

CONCLUSION

A minority of ophthalmology journals have gender-inclusive author submission guidelines. Ophthalmology journals should update their submission guidelines to advance gender equity of both authors and study participants and promote the inclusion of gender-diverse communities.

Decoding and reconstructing disease relations between dry eye and depression: a multimodal investigation comprising meta-analysis, genetic pathways and Mendelian randomization

INTRODUCTION

The clinical presentations of dry eye disease (DED) and depression (DEP) often comanifest. However, the robustness and the mechanisms underlying this association were undetermined.

OBJECTIVES

To this end, we set up a three-segment study that employed multimodality results (meta-analysis, genome-wide association study [GWAS] and Mendelian randomization [MR]) to elucidate the association, common pathways and causality between DED and DEP.

METHODS

A meta-analysis comprising 26 case-control studies was first conducted to confirm the DED-DEP association. Next, we performed a linkage disequilibrium (LD)-adjusted GWAS and targeted phenotype association study (PheWAS) in East Asian TW Biobank (TWB) and European UK Biobank (UKB) populations. Single-nucleotide polymorphisms (SNPs) were further screened for molecular interactions and common pathways at the functional gene level. To further elucidate the activated pathways in DED and DEP, a systemic transcriptome review was conducted on RNA sequencing samples from the Gene Expression Omnibus. Finally, 48 MR experiments were implemented to examine the bidirectional causation between DED and DEP.

RESULTS

Our meta-analysis showed that DED patients are associated with an increased DEP prevalence (OR = 1.83), while DEP patients have a concurrent higher risk of DED (OR = 2.34). Notably, cross-disease GWAS analysis revealed that similar genetic architecture (rG = 0.19) and pleiotropic functional genes contributed to phenotypes in both diseases. Through protein-protein interaction and ontology convergence, we summarized the pleiotropic functional genes under the ontology of immune activation, which was further validated by a transcriptome systemic review. Importantly, the inverse variance-weighted (IVW)-MR experiments in both TWB and UKB populations (p value <0.001) supported the bidirectional exposure-outcome causation for DED-to-DEP and DEP-to-DED. Despite stringent LD-corrected instrumental variable re-selection, the bidirectional causation between DED and DEP remained.

CONCLUSION

With the multi-modal evidence combined, we consolidated the association and causation between DED and DEP.

Proteomics-Based Identification of Retinal Protein Networks Impacted by Elevated Intraocular Pressure in the Hypertonic Saline Injection Model of Experimental Glaucoma

Elevated intraocular pressure is considered a major cause of glaucomatous retinal neurodegeneration. To facilitate a better understanding of the underlying molecular processes and mechanisms, we report a study focusing on alterations of the retina proteome by induced ocular hypertension in a rat model of the disease. Glaucomatous processes were modeled through sclerosing the aqueous outflow routes of the eyes by hypertonic saline injections into an episcleral vein. Mass spectrometry-based quantitative retina proteomics using a label-free shotgun methodology identified over 200 proteins significantly affected by ocular hypertension. Various facets of glaucomatous pathophysiology were revealed through the organization of the findings into protein interaction networks and by pathway analyses. Concentrating on retinal neurodegeneration as a characteristic process of the disease, elevated intraocular pressure-induced alterations in the expression of selected proteins were verified by targeted proteomics based on nanoflow liquid chromatography coupled with nano-electrospray ionization tandem mass spectrometry using the parallel reaction monitoring method of data acquisition. Acquired raw data are shared through deposition to the ProteomeXchange Consortium (PXD042729), making a retina proteomics dataset on the selected animal model of glaucoma available for the first time.

Etiology of Idiopathic Macular Holes in the Light of Estrogen Hormone

The aim of this review was to identify a new potential explanation for the development of macular holes in relation to the female sex and to explain the possible underlying pathways. This approach was based on the evaluation of anatomical, physiological, and morphological analyses currently available in the literature. The findings showed that estrogen exerts a protective effect on the neuroretina and may influence Müller and cone cells. Both cell types are responsible for the building of the fovea structure. However, this protection may be lost due to the sudden decrease in estrogen levels during menopause. In conclusion, the fovea cones, through its sensitivity to estrogen and high energy consumption, may be very vulnerable to damage caused by a sudden changes in the concentration of estrogen in menopausal females. Such changes may result in cone degeneration, and thus a destroyed structure of the fovea, and may lead to the development of a hole in the fovea, as in the case of macular holes. This review revealed that under the decreasing influence of estrogen may cones play a key role with regard to the etiology of the development of macular holes. This aspect may be of strategic importance in prophylactic therapy for the prevention of the development of macular holes in premenopausal females or after ocular trauma.

Evidence for Menopause as a Sex-Specific Risk Factor for Glaucoma

Glaucoma is a leading cause of irreversible blindness worldwide and is characterized by progressive loss of visual function and retinal ganglion cells (RGC). Current epidemiological, clinical, and basic science evidence suggest that estrogen plays a role in the aging of the optic nerve. Menopause, a major biological life event affecting all women, coincides with a decrease in circulating sex hormones, such as estrogen. While 59% of the glaucomatous population are females, sex is not considered a risk factor for developing glaucoma. In this review, we explore whether menopause is a sex-specific risk factor for glaucoma. First, we investigate how menopause is defined as a sex-specific risk factor for other pathologies, including cardiovascular disease, osteoarthritis, and bone health. Next, we discuss clinical evidence that highlights the potential role of menopause in glaucoma. We also highlight preclinical studies that demonstrate larger vision and RGC loss following surgical menopause and how estrogen is protective in models of RGC injury. Lastly, we explore how surgical menopause and estrogen signaling are related to risk factors associated with developing glaucoma (e.g., intraocular pressure, aqueous outflow resistance, and ocular biomechanics). We hypothesize that menopause potentially sets the stage to develop glaucoma and therefore is a sex-specific risk factor for this disease.

Surgical Menopause Impairs Retinal Conductivity and Worsens Prognosis in an Acute Model of Rat Optic Neuropathy

Deficiency of estradiol during the menopausal period is an important risk factor for neurodegenerative diseases, including various optic neuropathies. The aim of this study was to evaluate the impact of surgical menopause on the function and survival ratio of RGCs in the rat model of ONC (optic nerve crush). We used eight-week-old female Long Evans rats, divided into two main groups depending on the time between ovariectomy procedure (OVA) and euthanasia (two weeks vs. seven weeks), and subgroups—OVA, OVA + ONC, or ONC. Retinal function was assessed with electroretinography (ERG). RGC loss ratio was evaluated using immunolabelling and counting of RGCs. Seven weeks after OVA, the menopause morphologically affected interneurons but not RGC; however, when the ONC procedure was applied, RGCs appeared to be more susceptible to damage in case of deprivation of estrogens. In our analysis, PhNR (photopic negative responses) were severely diminished in the OVA + ONC group. A deprivation of estrogens in menopause results in accelerated retinal neurodegeneration that firstly involves retinal interneurons. The lack of estrogens increases the susceptibility of RGCs to insults.

Visual disorders and mal de debarquement syndrome: a potential comorbidity questionnaire-based study

Aim: Mal de debarquement syndrome (MdDS) is a neurological condition characterized by a constant sensation of self-motion; onset may be motion-triggered (MT) or non-motion-triggered/spontaneous (NMT/SO). People with MdDS experience similar symptoms to those with vertical heterophoria, a subset of binocular visual dysfunction. Hence, we aimed to explore potential visual symptom overlaps. Methods: MdDS patients (n = 196) and controls (n = 197) completed a visual health questionnaire. Results: Compared with controls, the MdDS group demonstrated higher visual disorder scores and visual complaints. NMT/SO participants reported unique visual symptoms and a higher prevalence of mild traumatic brain injury. Conclusion: Our findings suggest visual disorders may coexist with MdDS, particularly the NMT/SO subtype. The difference in visual dysfunction frequency and medical histories between subtypes, warrants further investigation into differing pathophysiological mechanisms.

Sex bias and omission exists in Batten disease research: Systematic review of the use of animal disease models

Batten disease, also known as the neuronal ceroid lipofuscinoses (NCL), is a group of inherited neurodegenerative disorders mainly affecting children. NCL are characterised by seizures, loss of vision, and progressive motor and cognitive decline, and are the most common form of childhood dementia. At least one type of Batten disease and three types of mouse disease models show sex differences in their severity and progression. Scientific research has a recognised prevalent omission of female animals when using model organisms for basic and preclinical research. Sex bias and omission in research using animal models of Batten disease may affect understanding and treatment development. We conducted a systematic review of research publications since the first identification of NCL genes in 1995, identifying those using animal models. We found that <10 % of these papers considered sex as a biological variable. There was consistent omission of female model organisms in studies. This varied over the period but is improving; one third of papers considered sex as a biological variable in the last decade, and there is a noticeable increase in the last 5 years. The wide-ranging reasons for this published sex bias are discussed, including misunderstanding regarding oestrogen, impact on sample size, and the underrepresentation of female scientists. Their implications for Batten disease and future research are considered. Recommendations going forward support requirements by funders for consideration of sex in all stages of experimental design and implementation, and a role for publishers, families and others with a particular interest in Batten disease.

Etiopathogenesis of non-exudative age-related macular degeneration (literature review)

The article presents an overview of modern publications on epidemiology, risk factors, and the main links of the etiology and pathogenesis of age-related macular degeneration (AMD). The nonexudative or “dry” form of age-related macular degeneration is a multifactorial progressive pathological process caused by hereditary predisposition, general and local disorders of lipid metabolism, negative changes in  the blood supply to the eye, age-related destruction of the Bruch’s membrane and retinal pigment epithelium, the appearance of signs of local and systemic inflammation, the development of oxidative stress with the impact of toxic lipoperoxidation products on the structures of the posterior segment of the eye. Recent studies have discovered new ways of retinal pigment epithelial cell death in response to oxidative stress in AMD, in particular necroptosis, which, in addition to classical apoptosis, is considered the main mechanism of this process. It is noted that the development of AMD may be associated with an age-related decrease in the level of estrogen in women. The analysis of the data on the etiopathogenesis of age-related macular degeneration presented in the modern literature indicates the need for further research and generalization of local and general pathological processes developing in the dynamics of retinal visual function disorders by specialists of various scientific disciplines. 

Synergism effect of swimming exercise and genistein on the inflammation, oxidative stress, and VEGF expression in the retina of diabetic-ovariectomized rats

AIMS

Retinal neovascularization is one of the visual disorders during the postmenopausal period or types two diabetes. Physical activities and also phytoestrogens with powerful antioxidant features have been widely considered to improve nervous system diseases. Therefore, this study investigated the effects of genistein, swimming exercise, and their co-treatment on retina angiogenesis, oxidative stress, and inflammation in diabetic-ovariectomized rats.

MAIN METHODS

Wistar rats were randomly divided into six groups (n = 8 per group): sham, ovariectomized group (OVX), OVX + diabetes (OVX.D), OVX.D+ genistein (1 mg/kg, eight weeks; daily SC), OVX.D + exercise (eight weeks), and OVX.D+ genistein+exercise (eight weeks). At the end of 8 weeks, the retina was removed under anesthesia. The assessed effects of treatment were by measuring MiR-146a and miR-132 expression via RT-PCR, the protein levels of ERK, MMP-2, VEGF, and NF-κB via western blotting, inflammation, and oxidative stress markers levels via the Eliza.

KEY FINDINGS

The results showed miR-132, miR-146b, and MMP-2, NF-κB, ERK, VEGF, TNF-α, IL-1β proteins, and MDA factor in the OVX.D group were increased, but glutathione (GSH) was decreased in comparison with the sham and OVX groups. Both exercise and genistein treatment has reversed the disorder caused by diabetes. However, the combination of exercise and genistein was more effective than each treatment alone.

SIGNIFICANCE

It can be concluded that the interaction of exercise and genistein on microRNAs and their target protein was affected in the inflammation, stress oxidative, and extracellular matrix metalloproteinase pathways, can leading to a decrease in impairment of retinal neovascularization of the ovariectomized diabetic rats.

The Association Between Genetic Polymorphisms in Estrogen Receptor Genes and the Risk of Ocular Disease: A Meta-Analysis

Objectives:

To evaluate the association between estrogen receptor (ER) genes polymorphisms and the risk of ocular disease.

Materials and Methods:

A meta-analysis was performed of all available studies that investigated the association between ER gene polymorphisms and the risk of ocular disease.

Results:

Studies that were selected based on inclusion criteria reported 5 and 4 single-nucleotide polymorphisms (SNPs) identified in the ESR1 (ERα) (rs2234093, rs12154178, rs1884054, rs1801132, and rs9340799) and ESR2 (ERβ) (rs1268656, rs7159462, rs1256031, and rs4986938) genes, respectively. The pooled result showed a significant association between ESR2 rs1256031 gene polymorphism and ocular disease (odds ratio: 0.55, 95% confidence interval: 0.41-0.74, p<0.0001).

Conclusion:

The recessive genotype of ESR2 rs1256031 gene polymorphism had a protective effect against ocular disease, which supports the hypothesis that the estrogen-signaling pathway through ERβ plays a pivotal role in the pathogenesis of ophthalmic disorders.

Successful induction of diabetes in mice demonstrates no gender difference in development of early diabetic retinopathy

Purpose

Female mice have been found to be resistant to streptozotocin (STZ)-induced diabetes, and pre-clinical research related to diabetic complications commonly omits females. The purpose of this study was to develop a method to induce diabetes in female mice, and to determine if retinas of diabetic female mice develop molecular changes and histopathological abnormalities comparable to those which develop in male diabetic mice.

Methods

To induce diabetes, animals of both sexes received daily intraperitoneal (i.p.) injection of STZ for 5 consecutive days at 55 mg/kg BW (a dose that is known to induce diabetes in male mice) or for females, 75 mg/kg BW of STZ. Retinal abnormalities that have been implicated in the development of the retinopathy (superoxide generation and expression of inflammatory proteins, iNOS and ICAM-1) were evaluated at 2 months of diabetes, and retinal capillary degeneration was evaluated at 8 months of diabetes.

Results

Daily i.p. injection of STZ for 5 consecutive days at a concentration of 55 mg/kg BW was sufficient to induce diabetes in 100% of male mice, but only 33% of female mice. However, females did become hyperglycemic when the dose of STZ administered was increased to 75 mg/kg BW. The resulting STZ-induced hyperglycemia in female and male mice was sustained for at least 8 months. After induction of the diabetes, both sexes responded similarly with respect to the oxidative stress, expression of iNOS, and degeneration of retinal capillaries, but differed in the limited population evaluated with respect to expression of ICAM-1.

Conclusions

The resistance of female mice to STZ-induced diabetes can be overcome by increasing the dose of STZ used. Female mice can, and should, be included in pre-clinical studies of diabetes and its complications.

The effect of hormone therapy on the ocular surface and intraocular pressure for postmenopausal women: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The aim of the study was to investigate the impact of hormone therapy (HT) on the ocular surface and intraocular pressure in postmenopausal women.

METHODS

This systematic review and meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement. PubMed, EMBASE, Cochrane Library of Systematic Reviews, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure were searched from inception to November 2019 without language restrictions. Only randomized controlled trials that evaluated the impact of HT on the ocular surface and intraocular pressure in postmenopausal women were eligible. The trials had to report at least one of the following outcomes: break-up time, Schirmer test, corneal staining, ocular surface symptom score, and intraocular pressure. Two investigators independently extracted the information, assessed the risk of bias, and evaluated the publication bias. All data were analyzed by Review Manager V.5.3. Sensitivity analysis and subgroup analysis were performed to find the source of heterogeneity and evaluate the different effects among subgroups.

RESULTS

Nine randomized controlled trials (N = 612) were included. The HT group showed significant improvements compared with the control group in break-up time (mean difference [MD] = 2.09, 95% confidence interval [CI] 1.00-3.19, P = 0.0002), Schirmer test without anesthesia (MD = 4.17, 95% CI 1.55-6.80, P = 0.002), Schirmer test with anesthesia (MD = 1.44, 95% CI 0.71-2.18, P = 0.0001), and corneal staining scores (standardized mean difference [SMD] = -0.85, 95% CI -1.39 to -0.30, P = 0.002). Moreover, significant beneficial effects were observed on all four symptoms, including dryness (SMD = -1.21, 95% CI -1.99 to -0.44, P = 0.002), foreign body sensation (SMD = -1.02, 95% CI -1.29 to -0.76, P < 0.00001), ocular fatigue (SMD = -1.74, 95% CI -2.12 to -1.36, P < 0.00001), and burning (SMD = -0.53, 95% CI -0.78 to -0.29, P < 0.0001) after HT. Subgroup analysis revealed that, in terms of break-up time, postmenopausal women younger than 55 years achieved more improvements (MD = 0.88, 95% CI 0.16-1.59, P = 0.02) than women older than 55 years old (MD = 2.60, 95% CI -1.34 to 6.55, P = 0.20), and the estrogen subgroup received more benefits (MD = 3.11, 95% CI 0.93-5.30, P = 0.005) than the estrogen plus progestogen subgroup (MD = 0.42, 95% CI -0.02 to 0.85, P = 0.06). Sensitivity analysis and subgroup analysis suggested that the heterogeneity might derive from the methodological quality, the age of participants, and the intervention of the control group. Intraocular pressure (MD = -1.54, 95% CI -3.39 to 0.32, P = 0.10) was not evidently decreased after HT. No more specific adverse events (relative risk  = 1.66, 95% CI 0.41-6.77, P = 0.48) were found in the HT group.

CONCLUSIONS

Our study revealed that HT could improve ocular surface function in postmenopausal women effectively and safely, especially for those who were younger than 55 years, and estrogen only showed more improvements than estrogen plus progestogen. The effectiveness of HT in treating dry eye in postmenopausal women is, however, still a controversial topic. In addition, we did not find HT led to a significant reduction of intraocular pressure.

Leveraging Nuclear Receptors as Targets for Pathological Ocular Vascular Diseases

Vasculogenesis and angiogenesis are physiological mechanisms occurring throughout the body. Any disruption to the precise balance of blood vessel growth necessary to support healthy tissue, and the inhibition of abnormal vessel sprouting has the potential to negatively impact stages of development and/or healing. Therefore, the identification of key regulators of these vascular processes is critical to identifying therapeutic means by which to target vascular-associated compromises and complications. Nuclear receptors are a family of transcription factors that have been shown to be involved in modulating different aspects of vascular biology in many tissues systems. Most recently, the role of nuclear receptors in ocular biology and vasculopathies has garnered interest. Herein, we review studies that have used in vitro assays and in vivo models to investigate nuclear receptor-driven pathways in two ocular vascular diseases associated with blindness, wet or exudative age-related macular degeneration, and proliferative diabetic retinopathy. The potential therapeutic targeting of nuclear receptors for ocular diseases is also discussed.

Hormone Therapy as a Protective Factor for Age-Related Macular Degeneration

Purpose: The purpose of this study was to determine if the use of menopausal hormone therapy (HT) is related to the development of neovascular (NV) age-related macular degeneration (AMD), geographic atrophy (GA) and/or early/intermediate AMD.Methods: A case-control study was conducted from patients prospectively recruited from July 2014 to June 2019. Cases were females with AMD recruited into a registry and controls were females with age-related cataract and no AMD. Age-related macular degeneration was categorized into NV-AMD, GA, and early/intermediate. Hormone therapy (historic and current) was self-reported by the patient and categorized as ever/never use. Adjusted odds ratios (ORs) from multinomial logistic regressions are presented for each AMD group.Results: Female AMD case patients (n = 409) and controls (n = 132) were included in the analytic database. Almost half (45.5%) of the female AMD patients had NV-AMD, 14.9% had GA, and 39.6% had early/intermediate AMD. Among all study participants, 285 (52.7%) reported historic and/or current use of HT. Controls were significantly more likely to have any HT use (71.2%), compared to 43.0% (p ≤ 0.001) of NV-AMD patients, 47.5% (p = .002) of GA patients, and 50.6% (p ≤ 0.001) of early/intermediate AMD patients. Adjusted for potential confounders of age and Caucasian race, cases were significantly more likely to have lower HT use compared to controls: NV-AMD, OR = 0.31 (95%CI: 0.18-0.54), GA, OR = 0.40 (95%CI: 0.20-0.80), and early/intermediate AMD, OR = 0.36 (95%CI: 0.22-0.61).Conclusion: Our case-control study found that the use of HT was associated with a lower odds of all AMD stages studied: NV-AMD, GA and early/intermediate.

Integrated assessment of visual perception abnormalities in psychotic disorders and relationship with clinical characteristics

BACKGROUND

The visual system is recognized as an important site of pathology and dysfunction in schizophrenia. In this study, we evaluated different visual perceptual functions in patients with psychotic disorders using a potentially clinically applicable task battery and assessed their relationship with symptom severity in patients, and with schizotypal features in healthy participants.

METHODS

Five different areas of visual functioning were evaluated in patients with schizophrenia and schizoaffective disorder (n = 28) and healthy control subjects (n = 31) using a battery that included visuospatial working memory (VSWM), velocity discrimination (VD), contour integration, visual context processing, and backward masking tasks.

RESULTS

The patient group demonstrated significantly lower performance in VD, contour integration, and VSWM tasks. Performance did not differ between the two groups on the visual context processing task and did not differ across levels of interstimulus intervals in the backward masking task. Performances on VSWM, VD, and contour integration tasks were correlated with negative symptom severity but not with other symptom dimensions in the patient group. VSWM and VD performances were also correlated with negative sychizotypal features in healthy controls.

CONCLUSION

Taken together, these results demonstrate significant abnormalities in multiple visual processing tasks in patients with psychotic disorders, adding to the literature implicating visual abnormalities in these conditions. Furthermore, our results show that visual processing impairments are associated with the negative symptom dimension in patients as well as healthy individuals.

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.

Preliminary data for performance in hue ordering tests during pregnancy

The visual system of women changes during pregnancy. Few reports have addressed the effects of pregnancy on color vision. We aimed to compare the color vision of women in the first, second, and third trimesters of pregnancy. Fifty women were divided into first (n=10), second (n=10), third trimester pregnancy groups (n=10), and non-pregnant group (n=20). We used the Farnsworth D15 and Lanthony desaturated D15 (D15d) tests. The hue ordering quantified the amount of error (C-index) and the chromatic selectivity of the errors (S-index). Bland-Altman analysis was applied to the hue ordering data. No difference was found for Farnsworth D15 test results obtained from the pregnant groups and the non-pregnant group (P<0.0083). For the Lanthony D15 desaturated test, the third trimester pregnant group had higher C-index and S-index than non-pregnant women and first-trimester pregnant women (P<0.0083). The Bland-Altman analysis showed that the limits of agreement increased as pregnancy advanced, and the errors were biased to the D15d test. In this study, color vision was impaired during pregnancy. Color vision evaluation could be used as an indicator of the functional status of the central vision during pregnancy.

Rapid changes in auditory processing in songbirds following acute aromatase inhibition as assessed by fMRI

Contribution to Special Issue on Fast effects of steroids. This review introduces functional MRI (fMRI) as an outstanding tool to assess rapid effects of sex steroids on auditory processing in seasonal songbirds. We emphasize specific advantages of this method as compared to other more conventional and invasive methods used for this purpose and summarize an exemplary auditory fMRI study performed on male starlings exposed to different types of starling song before and immediately after the inhibition of aromatase activity by an i.p. injection of Vorozole™. We describe how most challenges that relate to the necessity to anesthetize subjects and minimize image- and sound-artifacts can be overcome in order to obtain a voxel-based 3D-representation of changes in auditory brain activity to various sound stimuli before and immediately after a pharmacologically-induced depletion of endogenous estrogens. Analysis of the fMRI data by assumption-free statistical methods identified fast specific changes in activity in the auditory brain regions that were stimulus-specific, varying over different seasons, and in several instances lateralized to the left side of the brain. This set of results illustrates the unique features of fMRI that provides opportunities to localize and quantify the brain responses to rapid changes in hormonal status. fMRI offers a new image-guided research strategy in which the spatio-temporal profile of fast neuromodulations can be identified and linked to specific behavioral inputs or outputs. This approach can also be combined with more localized invasive methods to investigate the mechanisms underlying the observed neural changes.

Lifestyles guide and glaucoma (II). Diet, supplements, drugs, sleep, pregnancy, and systemic hypertension

PURPOSE

To establish evidence based guidelines to advise patients on the relationship between habits, diet, certain circumstances, diseases and glaucoma.

METHODS

Review of all published articles on glaucoma and sports or other activities. The papers were classified according to the level of scientific evidence based on the Oxford Centre for Evidence-based Medicine classification.

RESULTS

The evidence on the relationship between diet or supplements and the incidence or progression of glaucoma is insufficient to make a general recommendation for glaucoma patients. Although some studies on normal tension glaucoma suggest that Gingko biloba could reduce glaucoma progression, the results do not allow a general recommendation for all these patients. Similarly, the evidence on the usefulness of vitamin supplements is not conclusive. The studies on smoking do not clearly demonstrate the relationship between this habit and incidence of glaucoma. Marihuana is not a useful treatment for glaucoma. Although the results on the relationship between sleep apnoea and glaucoma are heterogeneous, it is recommended that patients with moderate to intense apnoea are tested for glaucoma. Pregnancy does not influence the course of the disease, but several hypotensive drugs may be harmful for the foetus. Nocturnal systemic hypotension is a risk factor for glaucoma progression.

CONCLUSIONS

Certain habits, circumstances, or diseases may have an influence on the onset or progression of glaucoma. It is important to have adequate information about the scientific evidence in the publications in order to properly advise patients.

Natural variation in female reproductive hormones does not affect contrast sensitivity

Evidence suggests that females experience adaptive shifts in facial preferences across the menstrual cycle. However, recent discussions and meta-analyses suggest that these findings are equivocal. A previously unexplored question is the extent to which shifts in female preferences are modulated by hormone-dependent changes occurring in low-level vision, such as visual sensitivity. This mechanistic approach has been a novel method for investigating the extent to which complex perceptual phenomena are driven by low-level versus higher-level perceptual processes. We investigated whether the contrast sensitivity function-an early dimension of vision-is also influenced by variation in female reproductive hormones. Visual contrast thresholds were measured for 1, 4 and 16 cycles/degree gratings during the ovulatory, luteal and menstrual phases of the menstrual cycle in naturally cycling women, and women using oral contraceptives. Male participants were tested at similar time intervals. Results showed that visual contrast sensitivity does not differ according to sex, or use of oral contraception, nor does it vary relative to hormonal shifts across the menstrual cycle. These findings suggest that shifts in female preferences are not driven by changes in visual sensitivity, and are therefore likely attributable to changes in higher-level perception or cognition.

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.

New insights into the role of motion and form vision in neurodevelopmental disorders

A selective deficit in processing the global (overall) motion, but not form, of spatially extensive objects in the visual scene is frequently associated with several neurodevelopmental disorders, including preterm birth. Existing theories that proposed to explain the origin of this visual impairment are, however, challenged by recent research. In this review, we explore alternative hypotheses for why deficits in the processing of global motion, relative to global form, might arise. We describe recent evidence that has utilised novel tasks of global motion and global form to elucidate the underlying nature of the visual deficit reported in different neurodevelopmental disorders. We also examine the role of IQ and how the sex of an individual can influence performance on these tasks, as these are factors that are associated with performance on global motion tasks, but have not been systematically controlled for in previous studies exploring visual processing in clinical populations. Finally, we suggest that a new theoretical framework is needed for visual processing in neurodevelopmental disorders and present recommendations for future research.

Visual impairment at baseline is associated with future poor physical functioning among middle-aged women: The Study of Women's Health Across the Nation, Michigan Site

OBJECTIVES

Emerging evidence suggests that the prevalence rates of poor functioning and of disability are increasing among middle-aged individuals. Visual impairment is associated with poor functioning among older adults but little is known about the impact of vision on functioning during midlife. The objective of this study was to assess the impact of visual impairment on future physical functioning among middle-aged women.

STUDY DESIGN

In this longitudinal study, the sample consisted of 483 women aged 42 to 56 years, from the Michigan site of the Study of Women's Health Across the Nation.

MAIN OUTCOME MEASURES

At baseline, distance and near vision were measured using a Titmus vision screener. Visual impairment was defined as visual acuity worse than 20/40. Physical functioning was measured up to 10 years later using performance-based measures, including a 40-foot timed walk, timed stair climb and forward reach.

RESULTS

Women with impaired distance vision at baseline had 2.81 centimeters less forward reach distance (95% confidence interval (CI): -4.19, -1.42) and 4.26s longer stair climb time (95% CI: 2.73, 5.79) at follow-up than women without impaired distance vision. Women with impaired near vision also had less forward reach distance (2.26 centimeters, 95% CI: -3.30, -1.21) than those without impaired near vision.

CONCLUSION

Among middle-aged women, visual impairment is a marker of poor physical functioning. Routine eye testing and vision correction may help improve physical functioning among midlife individuals.