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

Gender differences in retinal diseases: A review

Gender medicine is a medical specialty that addresses gender differences in health and disease. Traditionally, medical research and clinical practice have often been focused on male subjects and patients. As a result, gender differences in medicine have been overlooked. Gender medicine considers the biological, psychological, and social differences between the genders and how these differences affect the development, diagnosis, treatment, and prevention of disease. For ophthalmological diseases epidemiological differences are known. However, there are not yet any gender-based ophthalmic treatment approaches for women and men. This review provides an overview of gender differences in retinal diseases. It is intended to make ophthalmologists, especially retinologists, more sensitive to the topic of gender medicine. The goal is to enhance comprehension of these aspects by highlighting fundamental gender differences. Integrating gender medicine into ophthalmological practice helps promote personalized and gender-responsive health care and makes medical research more accurate and relevant to the entire population.

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.

Age and Sex-Related Changes in Retinal Function in the Vervet Monkey

Among the deficits in visual processing that accompany healthy aging, the earliest originate in the retina. Moreover, sex-related differences in retinal function have been increasingly recognized. To better understand the dynamics of the retinal aging trajectory, we used the light-adapted flicker electroretinogram (ERG) to functionally assess the state of the neuroretina in a large cohort of age- and sex-matched vervet monkeys (N = 35), aged 9 to 28 years old, with no signs of obvious ocular pathology. We primarily isolated the cone–bipolar axis by stimulating the retina with a standard intensity light flash (2.57 cd/s/m²) at eight different frequencies, ranging from 5 to 40 Hz. Sex-specific changes in the voltage and temporal characteristics of the flicker waveform were found in older individuals (21–28 years-old, N = 16), when compared to younger monkeys (9–20 years-old, N = 19), across all stimulus frequencies tested. Specifically, significantly prolonged implicit times were observed in older monkeys (p < 0.05), but a significant reduction of the amplitude of the response was only found in old male monkeys (p < 0.05). These changes might reflect ongoing degenerative processes targeting the retinal circuitry and the cone subsystem in particular. Altogether, our findings corroborate the existing literature in humans and other species, where aging detrimentally affects photopic retinal responses, and draw attention to the potential contribution of different hormonal environments.

Sex and Age-Related Differences in Complement Factors Among Patients With Intermediate Age-Related Macular Degeneration

Purpose

Age-related macular degeneration (AMD) is an acquired degenerative disease of the retina classified into early, intermediate, and advanced AMD. A key factor in the pathogenesis of AMD is the complement system. The interaction of age and sex with the complement system may affect the risk of developing AMD. The purpose of this study was to determine if there were sex-specific differences in levels of complement factors among patients with the intermediate phenotype of AMD (iAMD) and explore the correlation between age and complement proteins.

Methods

We studied complement factors in patients with iAMD and controls without AMD. Nonparametric, rank-based linear regressions including a sex by AMD interaction were used to compare levels for each analyte. Correlations between age and complement proteins were evaluated using the Spearman rank correlation coefficient.

Results

We found significantly higher levels of factor B and factor I in females compared with males with iAMD, whereas no differences were seen in complement levels in male and female controls. The ratios of Ba/factor B, C3a/C3, C4b/C4, and C5a/C5 were not different in males and females with iAMD.

Conclusions

We demonstrate disparities in a subset of systemic complement factors between females and males with iAMD, but apparent complement turnover as measured by ratios of activation fragments to intact molecules was not different between these groups. The results suggest that complement system levels, including complement regulator factor I, exhibits sex-related differences in patients with iAMD and highlights that stratification by sex might be helpful in the interpretation of clinical trials of anticomplement therapy.

Menopause and the Risk of Developing Age-Related Macular Degeneration in Korean Women

Previous studies have shown that menopausal hormone therapy in postmenopausal women results in a higher prevalence of age-related macular degeneration. This study aimed to evaluate the effects of menopause and patient factors on the development of age-related macular degeneration in Korean women. Data between 2011 and 2014 were collected from the Korean National Health Insurance database. In this retrospective cohort study, 97,651 participants were premenopausal and 33,598 were menopausal. Participants were divided into menopausal and premenopausal groups to analyze the risk factors associated with the development of age-related macular degeneration. The prevalence of age-related macular degeneration was compared between the two groups. Other patient factors were also analyzed. Using a 1:1 propensity score matching method and adjusting for variables, the incidence of age-related macular degeneration was not significantly different between the two groups. Age and diabetes mellitus were associated with an increased risk of developing age-related macular degeneration, regardless of menopause. Menopause was not a risk factor for age-related macular degeneration. These findings may help physicians identify women with diabetes who are at a greater risk of developing age-related macular degeneration.

Progression of cRORA (Complete RPE and Outer Retinal Atrophy) in Dry Age-Related Macular Degeneration Measured Using SD-OCT

Purpose

The purpose of this study was to evaluate the long-term rate of progression and baseline predictors of geographic atrophy (GA) using complete retinal pigment epithelium and outer retinal atrophy (cRORA) annotation criteria.

Methods

This is a retrospective study. Columns of GA were manually annotated by two graders using a self-developed software on optical coherence tomography (OCT) B-scans and projected onto the infrared images. The primary outcomes were: (1) rate of area progression, (2) rate of square root area progression, and (3) rate of radial progression towards the fovea. The effects of 11 additional baseline predictors on the primary outcomes were analyzed: total area, focality (defined as the number of lesions whose area is >0.05 mm2), circularity, total lesion perimeter, minimum diameter, maximum diameter, minimum distance from the center, sex, age, presence/absence of hypertension, and lens status.

Results

GA was annotated in 33 pairs of baseline and follow-up OCT scans from 33 eyes of 18 patients with dry age-related macular degeneration (AMD) followed for at least 6 months. The mean rate of area progression was 1.49 ± 0.86 mm2/year (P < 0.0001 vs. baseline), and the mean rate of square root area progression was 0.33 ± 0.15 mm/year (P < 0.0001 vs. baseline). The mean rate of radial progression toward the fovea was 0.07 ± 0.11 mm/year. A multiple variable linear regression model (adjusted r2 = 0.522) revealed that baseline focality and female sex were significantly correlated with the rate of GA area progression.

Conclusions

GA area progression was quantified using OCT as an alternative to conventional measurements performed on fundus autofluorescence images. Baseline focality correlated with GA area progression rate and lesion's minimal distance from the center correlated with GA radial progression rate toward the center. These may be important markers for the assessment of GA activity.

Translational Relevance

Advanced method linking specific retinal micro-anatomy to GA area progression analysis.

The impact of advanced age-related macular degeneration on the National Eye Institute's Visual Function Questionnaire-25

PURPOSE

To assess visual function among patients diagnosed with age-related macular degeneration (AMD) by stage of disease and laterality.

METHODS

This is a cross-sectional cohort study of 739 AMD patients and their responses to the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) at time of study enrolment. Patients with AMD were categorized into Early/Intermediate AMD and three groups of advanced AMD: (i) neovascular AMD (NV), (ii) geographic atrophy (GA) and (iii) Both Advanced forms. These three advanced stages were further stratified into unilateral or bilateral advanced disease. Mean composite scores and subscale scores for 12 different areas were based on a 100-point scale with the lowest and highest possible scores set at 0 and 100, respectively. Scores for the advanced AMD groups were compared with Early/Intermediate AMD using general linear modelling.

RESULTS

A total of 739 AMD patients (294 Early/Intermediate, 115 GA, 168 NVAMD and 162 Both Advanced) were included in the analysis. Mean composite scores were highest among Early/Intermediate patients (89.9), followed by patients diagnosed with unilateral disease in the Both Advanced (88.0) and NV (86.1) groups. Mean composite scores were similar for bilateral NV (82.9) and unilateral GA (81.7), and mean scores were lowest for the bilateral GA (71.3) and bilateral Both Advanced (68.5) groups. In general, this pattern persisted across the twelve subscales as well. Subscale scores ranged from a low of 35.1 for driving among bilateral Both Advanced patients to a high of 99.2 for colour vision among patients with unilateral Both Advanced. Overall, patients with unilateral advanced disease consistently had higher mean scores than their bilateral counterparts. The largest difference was 19.5 composite score points between the unilateral and bilateral Both Advanced groups, there was a difference of 10.4 points between the GA groups, and a relatively small difference of 3.2 points between the NV groups.

CONCLUSIONS

We found large differences in visual function as reported from the VFQ-25 across the different types of advanced stage AMD groups and number of eyes affected with advanced AMD. These findings demonstrate the importance of accounting for the type and number of eyes affected by advanced stage AMD.

FEMALE REPRODUCTIVE FACTORS AND THE RISK OF EXUDATIVE AGE-RELATED MACULAR DEGENERATION: A Nationwide Cohort Study

PURPOSE

To evaluate the association between female reproductive factors and the incidence of exudative age-related macular degeneration (AMD).

METHODS

A total of 1,297,388 postmenopausal women over 50 years of age who participated in both national health screening and cancer screening in 2009 were identified using the Korea National Health Insurance System database. Data on female reproductive factors were collected using a self-administered questionnaire. Patients were followed up until 2018, and the incident cases of exudative AMD were identified. The hazard ratios and 95% confidence intervals for exudative AMD were estimated using the multivariable-adjusted Cox proportional hazard model.

RESULTS

During a mean follow-up of 7.27 years, 4,086 patients were newly diagnosed with exudative AMD. The hazard ratio (95% confidence intervals) for exudative AMD was 1.14 (1.01-1.31) for a reproductive period ≥40 years compared with a reproductive period <30 years, 1.72 (1.48-2.00) for patients with ≥5 years of hormone replacement therapy, and 1.29 (1.09-1.52) for those with 2 to 5 years of hormone replacement therapy compared with those who never underwent hormone replacement therapy.

CONCLUSION

Female reproductive factors were associated with the risk of exudative AMD. Greater lifetime exposure to endogenous and exogenous estrogen was associated with a higher incidence of exudative AMD.