Sex hormone levels and risk of primary open-angle glaucoma in postmenopausal women

Estrogen dysregulation, intraocular pressure, and glaucoma risk

Characterized by optic nerve atrophy due to retinal ganglion cell (RGC) death, glaucoma is the leading cause of irreversible blindness worldwide. Of the major risk factors for glaucoma (age, ocular hypertension, and genetics), only elevated intraocular pressure (IOP) is modifiable, which is largely regulated by aqueous humor outflow through the trabecular meshwork. Glucocorticoids such as dexamethasone have long been known to elevate IOP and lead to glaucoma. However, several recent studies have reported that steroid hormone estrogen levels inversely correlate with glaucoma risk, and that variants in estrogen signaling genes have been associated with glaucoma. As a result, estrogen dysregulation may contribute to glaucoma pathogenesis, and estrogen signaling may protect against glaucoma. The mechanism for estrogen-related protection against glaucoma is not completely understood but likely involves both regulation of IOP homeostasis and neuroprotection of RGCs. Based upon its known activities, estrogen signaling may promote IOP homeostasis by affecting extracellular matrix turnover, focal adhesion assembly, actin stress fiber formation, mechanosensation, and nitric oxide production. In addition, estrogen receptors in the RGCs may mediate neuroprotective functions. As a result, the estrogen signaling pathway may offer a therapeutic target for both IOP control and neuroprotection. This review examines the evidence for a relationship between estrogen and IOP and explores the possible mechanisms by which estrogen maintains IOP homeostasis.

Impact of primary glaucoma on health-related quality of life in China: the handan eye study

BACKGROUND

We assessed health-related quality of life (HRQOL) and its determinants among rural glaucoma participants compared to age-matched normal controls in the population-based Handan Eye Study (HES), in rural Yongnian County, northern China.

METHODS

We enrolled 99 adults with glaucoma (mean age 63.0 ± 11.0 years), including primary open-angle glaucoma (POAG, n = 67) and primary angle-closure glaucoma (PACG, n = 32) and 102 controls (mean age 58.5 ± 5.3 years) with normal visual acuity and visual field and no history of glaucoma. Results of ophthalmic examinations and socioeconomic data were recorded. HRQOL was measured using the EQ-5D (converted to utility valves, UVs), and visual function (VF) and vision-related quality of life (VRQOL) were evaluated using the visual function-quality of life (VF-QOL) instrument.

PRIMARY AND SECONDARY OUTCOME MEASURES

EQ-5D and VF-QOL scores.

RESULTS

The mean UVs, VF, and VRQOL scores for glaucoma cases were 0.98 ± 0.04, 87.9 ± 15.2, and 95.5 ± 12.8, respectively, significantly worse than VF (94.4 ± 4.4) and VRQOL (100.0 ± 0.0) among controls, even after adjusting for age, gender, educational level, and family income (P = 0.015, P = 0.033). UVs were significantly lower among glaucoma participants with impaired VRQOL (55.4 ± 11.5) compared to those with normal VRQOL scores (99.1 ± 2.8) (UVs: 0.92 ± 0.08 vs. 0.99 ± 0.03, P = 0.036), also after adjustment for age and family income (P = 0.006). Participants with PACG had significantly lower VF and VRQOL scores compared to POAG (77.8 ± 21.4 vs. 92.9 ± 6.8, P < 0.001; 89.0 ± 18.1 vs. 98.7 ± 7.5, P < 0.001).

CONCLUSION

Participants with glaucoma have worse visual function and related quality of life compared to age-matched normal population controls. Participants with PACG have lower VF and VRQOL compared to those with POAG. UVs can be used for cost-effectiveness research and to support public health strategies for glaucoma in rural China.

Higher testosterone is associated with open-angle glaucoma in women: a genetic predisposition?

BACKGROUND

Testosterone may be a possible modifiable risk factor for open-angle glaucoma (OAG) and intraocular pressure (IOP), but evidence has been scarce and conflicting. In this study we evaluated the association of testosterone and its genetic predisposition with incident (i) OAG, IOP, retinal nerve fiber layer (RNFL), and ganglion cell-inner plexiform layer (GCL +).

METHODS

Participants aged 45-100 years were derived from the prospective, population-based Rotterdam Study. Ophthalmic examinations and serum testosterone measurements (including bioavailable and free testosterone) were performed from 1991 onwards. Follow-up took place every 4-5 years. A total of 187 out of 7898 participants were diagnosed with incident (i) OAG during follow-up. Genotyping was performed in 165 glaucoma cases and 6708 controls. We calculated sex-specific weighted genetic risk scores (GRS) for total and bioavailable testosterone. Associations with iOAG were analyzed using multivariable logistic regression. Associations with IOP, RNFL, and GCL + were analyzed with multivariable linear regression. Analyses were stratified on sex and adjusted for at least age, body mass index, and follow-up duration.

RESULTS

In men, testosterone was not associated with iOAG. However, the GRS for higher total testosterone was associated with an increased iOAG risk (odds ratio [OR] with 95% confidence interval [95% CI]: 2.48 [1.18; 5.22], per unit). In women, higher values of bioavailable testosterone (2.05 [1.00; 4.18] per nmol/L) and free testosterone (1.79 [1.00; 3.20] per ng/dL) were significantly associated with increased risk of iOAG. Moreover, the GRS for higher bioavailable testosterone was associated with an increased iOAG risk (2.48 [1.09; 5.65], per unit). Higher bioavailable and free testosterone were adversely associated with IOP (0.58 [0.05; 1.10] per nmol/L and 0.47 [0.04; 0.90] per ng/dL). Higher total testosterone was inversely associated with peripapillary RNFL and GCL + (Beta [95% CI]: - 3.54 [- 7.02; - 0.06] per nmol/L and - 2.18 [- 4.11; - 0.25] per nmol/L, respectively).

CONCLUSIONS

In women, higher testosterone levels increased the risk of iOAG. Both IOP-dependent and IOP-independent mechanisms may underlie this association. Managing testosterone levels may be particularly relevant for the prevention of neurodegeneration in the eye. Future research should confirm these findings.

Relationship between Androgen Deprivation Therapy and Normal-Tension Glaucoma in Patients with Prostate Cancer: A Nationwide Cohort Study

PURPOSE

This study assessed the relationship between newly developed normal-tension glaucoma (NTG) and androgen deprivation therapy (ADT) in patients with prostate cancer.

MATERIALS AND METHODS

A retrospective population-based cohort study was performed. During the period between 2008 and 2017, a total of 218203 prostate cancer patients were identified in a nationwide claims database in the Republic of Korea. The final analysis included 170874 patients (42909 in the ADT group, 127965 in the control group) after applying the inclusion and exclusion criteria. The incidences of NTG according to ADT duration were compared with controls. Exact matching was conducted to adjust comorbidities between cohorts. Cox proportional hazard regression models were performed after controlling for latent confounding factors, and adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the incidence of NTG according to ADT were obtained.

RESULTS

In the matched cohort, the ADT group was associated with a significantly reduced risk of NTG in multivariable analysis compared to the control group. The risk of NTG decreased in patients who underwent ADT for less than 2 years (HR=0.824; 95% CI, 0.682-0.995; p=0.0440) and in those using ADT over 2 years (HR=0.796; 95% CI, 0.678-0.934; p=0.0051), compared to the controls.

CONCLUSION

Medical castrations for patients with prostate cancer results in a lower incidence of newly diagnosed NTG compared to no ADT. These findings suggest that testosterone may be involved in the pathogenesis of NTG.

Association Between Sex Hormones and Visual Field Progression in Women With Primary Open Angle Glaucoma: A Cross-Sectional and Prospective Cohort Study

Purpose: We evaluated the level of sex hormones in female patients with primary open angle glaucoma (POAG) to determine whether they are associated with the onset and/or progression of POAG.

Methods: The cross-sectional study enrolled 63 women with POAG and 56 healthy women as normal control subjects. Furthermore, 57 women with POAG were included and followed-up for at least 2 years in the cohort study. All subjects were evaluated for serum concentration of sex hormones [prolactin (PRL), luteinizing hormone (LH), testosterone (TESTO), follicle-stimulating hormone (FSH), progesterone (PROG), and estrogen (E2)] and underwent visual field (VF) examination. In the cross-sectional study, Spearman analysis, linear regression analysis, and logistic regression analysis were performed to assess risk factors for POAG in women. In the cohort study, Cox regression analyses and Kaplan–Meier survival analysis were performed to identify factors associated with VF progression in women with POAG.

Results: In the cross-sectional study, the level of E2 was significantly lower in the POAG group than in the normal group (p < 0.05). Multiple logistic regression showed that the decreased level of E2 was a risk factor of POAG (OR = 0.27, 95% CI = 0.09–0.78, p < 0.05), especially in premenopausal subjects. In the cohort study, there were 29 non-progression subjects and 28 progression subjects. Patients in the progression group had significantly lower levels of E2 than those in the no progression group (p < 0.01). The decreased level of E2 at baseline was associated with POAG progression (HR = 0.08, 95% CI = 0.02–0.46, p < 0.05), especially in premenopausal subjects. Patients with POAG and with lower baseline E2 levels had significantly lower VF non-progression rates than patients with higher E2 levels (log-rank test p < 0.001), especially premenopausal subjects (log-rank test p < 0.05). Additionally, logistic regression analyses, Cox regression analyses, and Kaplan–Meier survival analysis showed that PROG, LH, FSH, and TESTO were risk factors of POAG and/or significantly associated with POAG progression.

Conclusion: A decreased E2 level is a POAG risk factor and is associated with VF progression in women with POAG, especially in premenopausal subjects. Additionally, other sex hormones (PROG, LH, FSH, and TESTO) might also play a role in POAG pathogenesis.

Genetic variation reveals the influence of steroid hormones on the risk of retinal neurodegenerative diseases

It is difficult to get evidence from randomized trials of a causal relationship between steroid hormones produced by the adrenal gland and gonad and retinal neurodegenerative disorders (RND). In this study, genetic variations of aldosterone (Aldo), androstenedione (A4), progesterone (P4), hydroxyprogesterone (17-OHP), and testosterone/17β-estradiol (T/E2) were obtained from genome-wide association studies as instrumental variables. Mendelian randomization (MR) analysis was used to assess the impact on the risk of RND, including glaucoma (8,591 cases and 210,201 controls), diabetic retinopathy (DR, 14,584 cases and 202,082 controls) and age-related macular degeneration (AMD, 14,034 cases and 91,214 controls). As the main method, inverse variance weighted results suggest that the increased glaucoma risk was affected by T/E2 (OR = 1.11, 95% CI, 1.01-1.22, P = 0.03), which was further validated by other methods (P_WM = 0.03, P_MLE = 0.03, P_{MR-RAPS =} 0.03). In the replicated stage, the causal relationship between T/E2 and glaucoma was verified based on the MRC-IEU consortium (P = 0.04). No impact of Aldo, A4, P4, 17-OHP, and T/E2 was observed for the risk of DR (P > 0.05) and AMD (P > 0.05). The heterogeneity test (P > 0.05) and pleiotropy test (P > 0.05) verified the robustness of the results. Our results suggest that T/E2 has a suggestive effect on the glaucoma risk. However, the genetic evidence based on a large sample does not support the effect of steroid hormones on DR and AMD risk. Further studies are vital to assess the possibility of steroid hormones as targets for prevention and treatment.

Androgen deprivation therapy may reduce the risk of primary open-angle glaucoma in patients with prostate cancer: a nationwide population-based cohort study

Background

We evaluated the risk of developing primary open-angle glaucoma (POAG) according to androgen deprivation therapy (ADT) status in patients with prostate cancer.

Materials and methods

From the nationwide claims database in South Korea, 218,203 men with prostate cancer were identified between 2008 and 2017. After applying the inclusion and exclusion criteria, a total of 170,701 patients (42,877 in the ADT and non-ADT groups and 127,824 in the non-ADT group) were included in the analysis. To adjust for comorbidities between cohorts, exact matching was performed. Cox proportional hazard regression models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of POAG associated with ADT after controlling for potential confounding factors.

Results

In the matched cohort, the ADT group had a lower proportion of newly developed POAG than the non-ADT group (2.10% vs. 2.88%, respectively; P < 0.0001). Multivariable analysis revealed that the ADT group had a significantly lower risk of POAG than the non-ADT group (HR, 0.808; 95% CI, 0.739–0.884; P < 0.0001). The risk of POAG was lower in patients who underwent ADT for less than 2 years (HR, 0.782; 95% CI, 0.690–0.886; P = 0.0001) and in those receiving ADT for over 2 years (HR, 0.825; 95% CI, 0.744–0.916; P = 0.0003) compared with the non-ADT group.

Conclusions

The use of ADT was associated with a decreased risk of POAG in Korean patients with prostate cancer. Our findings suggest that testosterone may be involved in the pathophysiology of POAG, and this should be confirmed through further studies.

Effects of testosterone on intraocular pressure, thicknesses of retinal nerve fiber layer, ganglion cell complex, macula and on ocular blood flow in female-to-male transgender persons

PURPOSE

To compare the effects of testosterone on intraocular pressure (IOP), thicknesses of retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), macula and on ocular blood flow between female-to-male transgender (FMT) persons who use testosterone and healthy women and healthy men.

METHOD

The study included 39 eyes of 20 FMT(Group 1), 40 eyes of 20 healthy women (Group 2), and 42 eyes of 21 healthy men (Group 3). In all subjects, RNFL, GCC and, macular thicknesses (MT) were measured by optical coherence tomography (OCT). Ocular blood flow was measured by Color Doppler Ultrasonography in all subjects.

RESULTS

IOP levels in FMT were significantly higher than men (p = 0.025). Superior (Sup), inferior (Inf) thicknesses of parafovea, and nasal thickness of perifovea in FMT were significantly higher than the Group 2 (p = 0.024, p = 0.037, p = 0.018). Sup thickness of perifovea in FMT was significantly higher than Group 3 (p = 0.011). Inf thickness of perifovea in FMT was significantly higher than Group 2 and 3 (p = 0.038, p = 0.002). Mean thickness of RNFL Inf in FMT was significantly higher than the Group 2 and 3 (p = 0.039, p = 0.032). Avg and Inf thicknesses of GCC in FMT were significantly higher than group 2 (p = 0.02, p = 0.005). In correlation test, systole/diastole ratio(S/D) in ophthalmic artery (OA) (r = 0.504, p = 0.028) and Inf thickness of perifovea (r = 0.485, p = 0.035) were positively correlated with the serum levels of testosterone in FMT.

CONCLUSIONS

We found that the use of supraphysiologic testosterone dose increased IOP and the thicknesses of macula, RNFL, and GCC in FMT. Serum testosterone level was positively correlated with S/D ratio in the OA.

Cross Sectional Study among Intraocular Pressure, Mean Arterial Blood Pressure, and Serum Testosterone according to the Anthropometric Obesity Indices in Korean Men

Purpose

To investigate the association between intraocular pressure (IOP) and serum testosterone according to the severity of obesity.

Materials and Methods

We investigated the correlation of IOP-testosterone according to the anthropometric obesity indices, such as obesity index (OI), body mass index (BMI), and waist circumference to height ratio (WtHR). Each of the obesity indices was classified into three groups: normal, overweight, and obesity. In additional, the association of IOP-testosterone was compared between testosterone 3.0 ng/mL below and above.

Results

Total of 3,949 participants, the mean age was 58.86±10.06 years, mean IOP was 14.40±2.61 mmHg, mean arterial blood pressure (MAP) was 93.67±11.47 mmHg, and mean serum testosterone was 4.21±1.83 ng/mL. The association of MAP and IOP was significantly positively correlated according to the severity of obesity, but testosterone showed a significant negative relationship (p<0.05). IOP was significantly correlated with OI and BMI, but MAP and testosterone were correlated with all anthropometric obesity indices (p<0.05). The relationship of IOP and testosterone was significantly associated with only normal groups according to the degree of obesity (p<0.05). The IOP in patients with testosterone above 3.0 ng/mL was significantly higher than testosterone below 3.0 ng/mL (p<0.05).

Conclusions

The correlation of IOP-testosterone has a significantly positive relationship, in case of healthy men with normal weight by OI or BMI.

Association Between 17-β-Estradiol and Interleukin-8 and Visual Field Progression in Postmenopausal Women with Primary Angle Closure Glaucoma

PURPOSE

To investigate an association between sex hormones and inflammatory cytokines, and to determine whether baseline 17-β-estradiol (E2) and interleukin-8 (IL-8) are associated with visual field (VF) progression in postmenopausal women with primary angle closure glaucoma (PACG).

DESIGN

A prospective cross-sectional and cohort study.

PARTICIPANTS

The cross-sectional study enrolled 200 postmenopausal women with PACG and 151 healthy postmenopausal women as normal control subjects. A total of 105 postmenopausal women with PACG were included and followed up for ≥2 years in the cohort study.

METHODS

All participants were evaluated for levels of baseline sex hormones (follicle-stimulating hormone, prolactin, progesterone, testosterone, luteinizing hormone, and E2) and inflammatory cytokines (IL-1, IL-2, IL-6, IL-8, IL-10, and C-reactive protein) and underwent VF examinations. The cross-sectional study was conducted to establish risk factors for postmenopausal women with PACG using logistic regression analysis. The cohort study was designed to identify factors that could be used to predict VF progression in postmenopausal women with PACG using multivariate Cox regression analyses. The main outcome measures included factors associated with VF progression over time.

RESULTS

Decreased E2 (odds ratio 0.88 [95% confidence interval {CI} 0.78-0.99], P = .007) and increased IL-8 (odds ratio 1.12 [95% CI 1.01-1.23], P < .001) levels were risk factors in postmenopausal women with PACG. A significant negative correlation was observed between IL-8 levels and E2 (r = -0.21, P = .02). Multivariable regression analyses revealed a significant correlation between E2 levels and visual field mean deviation (MD) (B = -0.16, P = .04 [95% CI -.09 to -.003) and between IL-8 levels and MD (B = 0.36, P < .001 [95% CI 0.01-0.02]). During follow-up, 48 (45.71%) patients showed VF progression. Lower baseline E2 (hazard ratio 0.85 [95% CI 0.82-0.88], P = .04) and higher baseline IL-8 levels (hazard ratio 1.01 [95% CI 1.00-1.02], P = .004) were associated with progression of glaucoma. Patients with lower E2 levels had a significantly higher rate of PACG progression (log-rank test P < .001), similar to those with higher IL-8 levels (log-rank test P = .04).

CONCLUSIONS

Decreased E2 and increased IL-8 levels at baseline are significant predictors of VF progression in postmenopausal women with PACG.

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.

Discovery and Validation of Circulating Hsa-miR-210-3p as a Potential Biomarker for Primary Open-Angle Glaucoma

Purpose

Blood-based examination tools for glaucoma diagnosis in clinical practice, which can be useful for screening patients when traditional ophthalmic examinations cannot be utilized, are not available thus far. This study aimed to identify circulating microRNAs (miRNAs) associated with primary open-angle glaucoma (POAG) and explore their utility as diagnostic markers.

Methods

A total of 136 POAG patients and controls were enrolled. Next-generation RNA sequencing was used to explore the expression profile of circulating miRNAs in the sequencing set, and potential miRNAs from independent samples in both the screening and validation sets were validated by quantitative real-time polymerase chain reaction (qRT-PCR). Receiver operating characteristic (ROC) analysis was used to evaluate the ability of certain miRNAs to distinguish POAG patients from control subjects.

Results

Using sequencing and qRT-PCR, hsa-miR-210-3p was found to be elevated in POAG patients in all sets. ROC analysis of the screening and validation sets revealed that hsa-miR-210-3p differentiated between POAG patients and matched controls with an area under the curve (AUC) of 0.846 (sensitivity: 84.6%; specificity: 80.8%) and 0.813 (sensitivity: 84.8%; specificity: 69.7%), respectively. In case of all nonsequencing participants, analysis revealed that hsa-miR-210-3p differentiated between severe POAG patients and controls with an AUC of 0.880 (sensitivity: 85.4%; specificity: 85.7%). In addition, the expression of hsa-miR-210-3p was associated with visual field defects of |mean deviation| (β = 0.237; P = 0.022) and average retinal nerve fiber layer thickness (β = -5.792; P = 0.014).

Conclusions

Circulating hsa-miR-210-3p may serve as a potential diagnostic marker for POAG (especially for severe POAG patients).

Effects of Sex Hormones on Ocular Blood Flow and Intraocular Pressure in Primary Open-angle Glaucoma: A Review

Primary open-angle glaucoma (POAG) is a multifactorial optic neuropathy characterized by progressive retinal ganglion cell death and visual field loss. Some speculate that sex plays a role in the risk of developing POAG and that the physiological differences between men and women may be attributed to the variable effects of sex hormones on intraocular pressure, ocular blood flow, and/or neuroprotection. Estrogen, in the form of premenopausal status, pregnancy, and postmenopausal hormone therapy is associated with an increase in ocular blood flow, decrease in intraocular pressure and neuroprotective properties. The vasodilation caused by estrogen and its effects on aqueous humor outflow may contribute. In contrast, although testosterone may have known effects in the cardiovascular and cerebrovascular systems, there is no consensus as to its effects in ocular health or POAG. With a better understanding of sex hormones in POAG, sex hormone-derived preventative and therapeutic considerations in disease management may provide for improved sex-specific patient care.