Estrogen-replacement therapy: effects on retrobulbar hemodynamics

Reproductive Factors and the Risk of Open Angle Glaucoma in Women

PRCIS

There was a significant inverse linear relationship between age at menopause and open angle glaucoma (OAG). Late menarche (≥13 y) and a history of 5 or more deliveries were significantly associated with an increased risk of OAG.

PURPOSE

To determine the association between reproductive factors including age at menarche, age at menopause, reproductive period, parity, and the risk of OAG in women.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were searched until February 9, 2022. Studies were included if they assessed the association between reproductive factors and OAG. The adjusted odds ratios (ORs) with relevant 95% CIs were extracted and pooled using fixed-effects models. Besides, we conducted dose-response analyses via the generalized least squares for trend method.

RESULTS

Seven articles including 18,618 women were identified in this review. The pooled results indicated that late age at menarche (≥13 y) was significantly associated with an increased risk of OAG (OR=1.76, 95% CI: 1.28, 2.43). Early menopause (<45 y) also significantly elevated the risk of OAG (OR=1.89, 95% CI: 1.23, 2.90) in categorical meta-analyses, consistent with the inverse linear relationship between menopausal age and the risk of OAG in dose-response analyses ( P =0.002). In addition, women who had delivered at least 5 children were at significantly higher risk of OAG compared with those nulliparous (OR=2.35, 95% CI: 1.02, 5.39), and a J-shape relationship between parity and OAG was observed in dose-response analyses ( P <0.001).

CONCLUSIONS

Late menarche (≥13 y), early menopause (<45 y), and a history of 5 or more parturitions are possible risk factors for OAG. Longitudinal studies are warranted to further examine the relationships between reproductive factors and the risk of OAG.

Characteristics of retinal image associated with premature ovarian insufficiency: a case- control study

PURPOSE

To establish an early clinical diagnosis model based on the retinal vascular features associated with POI, supplying a non-invasive way for accurately and early predicted the risk of POI.

METHODS

A total of 78 women with spontaneous POI and 48 healthy women were recruited from the Affiliated Shenzhen Maternity & Child Healthcare Hospital in the study. Retinal characteristics were analyzed using an automated retinal image analysis system. Binary logistic regression was used to identify POI cases and develop predictive models.

RESULTS

Compared to the normal group, the POI group had larger central retinal artery equivalent (CRAE) (P = 0.006), central retinal vein equivalent (CRVE) (P = 0.001), index of venules asymmetry (Vasym) (P = 0.000); larger bifurcation angles of arterioles (Aangle) (P = 0.001), bifurcation coefficient of venule (BCV) (P = 0.001) and more obvious arteriovenous nipping (Nipping) (P = 0.005), but lower arteriole-to-venule ratio (AVR) (P = 0.012). In the POI group, the odds ratio (OR) of Vasym was 6.72e-32 (95% C.I. 4.62e-49-9.79e-15, P = 0.000), the OR of BCV was 5.66e-20 (95% C.I. 1.93e-34-.0000, P = 5.66e-20) and the OR of Nipping was 6.65e-06 (95% C.I. 6.33e-10-.0698, P = 0.012). Moreover, the area under the ROC curve for the binary logistic regression with retinal characteristics was 0.8582, and the fitting degree of regression models was 60.48% (Prob > chi-square = 0.6048).

CONCLUSION

This study demonstrated that retinal image analysis can provide useful information for POI identification and certain characteristics may help with early clinical diagnosis of POI.

The Association of Female Reproductive Factors with Glaucoma and Related Traits: A Systematic Review

TOPIC

This systematic review summarizes evidence for associations between female reproductive factors (age at menarche, parity, oral contraceptive [OC] use, age at menopause, and postmenopausal hormone [PMH] use) and intraocular pressure (IOP) or open-angle glaucoma (OAG).

CLINICAL RELEVANCE

Understanding the associations between female reproductive factors and glaucoma may shed light on the disease pathogenesis and aid clinical prediction and personalized treatment strategies. Importantly, some factors are modifiable, which may lead to new therapies.

METHODS

Two reviewers independently extracted articles in MEDLINE, Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials databases to identify relevant studies. Eligibility criteria included studies with human subjects aged > 18 years; a measured outcome of either IOP or OAG; a cohort, case-control, cross-sectional, or randomized controlled trial design; a reported measure of association, such as the hazard ratio, relative risk, odds ratio, or mean difference, with an associated confidence interval; and a measured exposure of at least 1 of the following variables: age at menarche, parity, OC use, age at menopause, or PMH use.

RESULTS

We included a total of 27 studies. Substantial differences in study designs, exposure and treatment levels, treatment durations, and variable reporting precluded a meaningful quantitative synthesis of the identified studies. Overall, relatively consistent associations between PMH use and a lower IOP were identified. Estrogen-only PMH use may be associated with lower OAG risk, which may be modified by race. No significant associations were found with combined estrogen-and-progesterone PMH use. No strong associations between parity or age at menarche and glaucoma were found, but a younger age at menopause was associated with an increased glaucoma risk, and adverse associations were identified with a longer duration of OC use, though no overall association with OC use was found.

CONCLUSIONS

The association between PMH use and lower IOP or OAG risk is a potentially clinically relevant and modifiable risk factor and should be investigated further, although this needs to be interpreted in the context of a high risk of bias across included studies. Future research should examine associations with IOP specifically and how the relationship between genetic factors and OAG risks may be influenced by female reproductive factors.

Assessment of choroidal vascularity index during the menstrual cycle

PURPOSE

To explore the effect of menstrual cycle on choroidal vascularity index (CVI).

METHODS

Thirty six eyes of 36 healthy women were included in this prospective study. The menstrual cycles were regular and ranged from 28 to 30 days in length. Optical coherence tomography images were obtained in 3 different phases of the menstrual cycle. The choroidal thickness (CT), total choroidal area, luminal area, stromal area, and CVI were quantified.

RESULTS

Mean subfoveal, nasal and temporal CT were significantly changed in mid-luteal phase in comparison to early follicular (p = 0.018, p = 0.006 and p = 0.001, respectively) and ovulatory phases (p = 0.037, p = 0.037, and p = 0.035, respectively). Mean CVI showed a significant change in mid-luteal phase when compared with early follicular (p = 0.001) and ovulatory phases (p = 0.036).

CONCLUSION

CVI seemed to be affected in mid-luteal phase of menstrual cycle. This should be considered while analyzing choroidal structure in otherwise healthy women.

Functional optical coherence tomography at altitude: retinal microvascular perfusion and retinal thickness at 3,800 meters

Cerebral hypoxia is a serious consequence of several cardiorespiratory illnesses. Measuring the retinal microvasculature at high altitude provides a surrogate for cerebral microvasculature, offering potential insight into cerebral hypoxia in critical illness. Additionally, while sex-specific differences in cardiovascular diseases are strongly supported, few have focused on differences in ocular blood flow. We evaluated the retinal microvasculature in males (n=11) and females (n=7) using functional optical coherence tomography at baseline (1,130m) (Day 0), following rapid ascent (Day 2) and prolonged exposure (Day 9) to high altitude (3,800m). Retinal vascular perfusion density (rVPD; an index of total blood supply), retinal thickness (RT; reflecting vascular and neural tissue volume) and arterial blood were acquired. As a group, rVPD increased on Day 2 vs. Day 0 (p<0.001) and was inversely related to PaO₂ (R²=0.45; p=0.006). By Day 9, rVPD recovered to baseline, but was significantly lower in males vs. females (p=0.007). RT was not different on Day 2 vs. Day 0 (p>0.99) but was reduced by Day 9 relative to Day 0 and Day 2 (p<0.001). RT changes relative to Day 0 were inversely related to changes in PaO₂ on Day 2 (R²=0.6; p=0.001) and Day 9 (R²=0.4; p=0.02). RT did not differ between sexes. These data suggest differential time course and regulation of the retina during rapid ascent and prolonged exposure to high altitude and are the first to demonstrate sex-specific differences in rVPD at high altitude. The ability to assess intact microvasculature contiguous with the brain has widespread research and clinical applications.

Characteristics of Visual Field Defects in Korean Advanced Glaucoma

Purpose: We investigated the clinical characteristics of visual field (VF) defects in Korean advanced glaucoma patients.Methods: The present study included 109 eyes of 109 advanced glaucoma patients whose mean deviation (MD) is under -12 dB. The subjects were classified into primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) group. Average numeric decibel in each VF points were visualized with color topographic image and dot graph image using python 3.5. VF was divided into four quadrants or two half fields, and the differences in the degree of VF defects in each locations were assessed with raw decibel data. Additionally, mean sensitivity of central 12 points were compared between the two groups.Results: Generally the features of VF defects were severely depressed VF sensitivity at the superonasal quadrant and relatively preserved central area and inferotemporal quadrant in both of the glaucoma groups. But we found the extent of deflection for VF defect in the NTG eyes was higher than that of the POAG eyes (p < 0.05). The POAG eyes tended to show more diffuse and evenly distributed VF defect, whereas NTG eyes tended to have more severely depressed VF at the superonasal quadrant and relatively preserved VF at the inferotemporal quadrant. There was no significant difference in the degree of central VF defects between the two groups.Conclusions: The characteristics of VF defect in Korean advanced glaucoma revealed different features based on the glaucoma diagnosis. The POAG eyes tended to show diffuse VF defects, whereas NTG eyes tended to have more severely depressed VF sensitivity at the superonasal quadrant and relatively preserved VF at the inferotemporal quadrant.

Girl Power in Glaucoma: The Role of Estrogen in Primary Open Angle Glaucoma

Estrogen is essential in maintaining various physiological features in women, and a decline in estrogen levels are known to give rise to numerous unfortunate symptoms associated with menopause. To alleviate these symptoms hormone replacement therapy with estrogen is often used, and has been shown to be fruitful in improving quality of life in women suffering from postmenopausal discomforts. An often forgotten condition associated with menopause is the optic nerve disorder, glaucoma. Thus, estrogen may also have an impact in maintaining the retinal ganglion cells (RGCs), which make up the optic nerve, thereby preventing glaucomatous neurodegeneration. This review aims to provide an overview of possible associations of estrogen and the glaucoma subtype, primary open-angle glaucoma (POAG), by evaluating the current literature through a PubMed-based literature search. Multiple in vitro and in vivo studies of RGC protection, as well as clinical and epidemiological data concerning the well-defined retinal neurodegenerative disorder POAG have been reviewed. Over all, deficiencies in retinal estrogen may potentially instigate RGC loss, visual disability, and eventual blindness. Estrogen replacement therapy may therefore be a beneficial future treatment. However, more studies are needed to confirm the relevance of estrogen in glaucoma prevention.

Gender-related Influences on Superficial Papillary Microcirculation Measured with Optical Coherence Tomography Angiography in Patients with Glaucoma

Purpose: To evaluate the optic nerve head (ONH), macular vessel density, and retinal nerve fiber layer (RNFL) thickness differences between the genders. Material and methods: In this prospective case-control cross-sectional study 111 healthy subjects and 130 primary open-angle glaucoma (OAG) patients were examined with optical coherence tomography angiography (OCT-A (RS-3000 Advance (Nidek, Gamagori, Japan))). The vessel density in the peripapillary and macular area as well as the RNFL thickness was evaluated. Results: Men appeared to have less RNFL thickness compared with women in early glaucomatous group, being significant at the whole circumpapillary retinal nerve fiber layer (cpRNFL) thickness and inferior and nasal quadrants: (cpRNFL) (71.01 ± 9.32 vs 77.64 ± 9.95 μm; P = .001), superior quadrant (89.10 ± 16.63 vs 92.97 ± 17.53 μm; P = .284), inferior quadrant (83.03 ± 19.17 vs 95.07 ± 21.70 μm; P = .006), temporal quadrant (57.11 ± 10.36 vs 61.78 ± 11.37 μm; P = .043), nasal quadrant (54.81 ± 11.42 vs 60.73 ± 11.62 μm; P = .016). Circumpapillary (wcpVD) and macular (wmVD) vessel density values were lower in men than women in the early stage OAG group, being wmVD significantly lower: wcpVD (15.53 ± 2.45% vs 16.81 ± 3.17%, P = .032) and wmVD values (12.51 ± 2.21 vs 13.63 ± 2.28%, P = .019), but not in the moderate OAG group (wcpVD 14.46 ± 2.20% vs 16.61 ± 3.10%, P = .056 and wmVD 12.61 ± 2.40% vs 12.74 ± 2.54%, P = .870). There were no significant differences between men and women for RNFL thickness and the vessel density parameters in normal group. Conclusion: Both, the thickness of the nerve fiber layer and peripapillary and macular vessel density are lower in men than in women with glaucoma, more markedly in early stage glaucomatous patients.

Age-related changes in retrobulbar circulation: a literature review

Introduction

The advances in research methods used in ophthalmology allow for an increasingly accurate examination of the eyes, as well as the morphology and function of the vessels. Colour Doppler imaging is still the first-line method for the analysis of parameters of retrobulbar circulation. Therefore, the aim of this work was to present the current state of knowledge about anatomical and functional age-related changes in retrobulbar arteries.

Methods

A literature search was performed mainly based on the PubMed database.

Results

The anatomy of retrobulbar arteries, histological background of age-related vascular changes, age-related changes in retrobulbar blood flow in the ophthalmic artery, central retinal artery, short posterior ciliary arteries, and the reference values for the age-dependent retrobulbar circulation parameters measured by colour Doppler imaging are discussed in this review.

Conclusion

The age of the subject should always be taken into account when interpreting the parameters of retrobulbar blood flow measured by colour Doppler imaging.

Racial Differences in the Effects of Hormone Therapy on Incident Open-Angle Glaucoma in a Randomized Trial

PURPOSE

We conducted a secondary analysis of a randomized, placebo-controlled trial to test if hormone therapy (HT) altered the risk of open-angle glaucoma (OAG), and if the risk reduction varied by race.

DESIGN

Secondary analysis of randomized controlled trial data.

METHODS

We linked Medicare claims data to 25 535 women in the Women's Health Initiative. Women without a uterus were randomized to receive either oral conjugated equine estrogens (CEE 0.625 mg/day) or placebo, and women with a uterus received oral CEE and medroxyprogesterone acetate (CEE 0.625 mg/day + MPA 2.5 mg/day) or placebo. We used Cox proportional hazards models to calculate hazard ratios (HR) and 95% confidence interval.

RESULTS

After exclusion of women with prevalent glaucoma or without claims for eye care provider visits, the final analysis included 8102 women (mean age = 68.5 ± 4.8 years). The OAG incidence was 7.6% (mean follow-up = 11.5 ± 5.2 years; mean HT duration = 4.4 ± 2.3 years). Increased age (P trend = .01) and African-American race (HR = 2.69, 95% CI = 2.13-3.42; white as a reference) were significant risk factors for incident OAG. We found no overall benefit of HT in reducing incident OAG (HR = 1.01, 95% CI = 0.79-1.29 in the CEE trial, and HR = 1.05, 95% CI = 0.85-1.29 in the CEE + MPA trial). However, race modified the relationship between CEE use and OAG risk (P interaction = .01), and risk was reduced in African-American women treated with CEE (HR = 0.49, 95% CI = 0.27-0.88), compared to placebo. Race did not modify the relation between CEE + MPA use and OAG risk (P interaction = .68).

CONCLUSIONS

Analysis suggests that HT containing estrogen, but not a combination of estrogen and progesterone, reduces the risk of incident OAG among African-American women. Further investigation is needed.

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.

Comparison of Visual Function and Ocular Hemodynamics between Pre- and Post-Menopausal Women

Purpose

The incidence of eye disease increases with age and can often be linked to worsening cardiovascular function and increasing intraocular pressure. Estrogen is known to have vasodilatory effects in the systemic circulation. Decreased estrogen levels during menopause may therefore complicate or contribute to ocular pathologies as estrogen receptors are found in both retinal and choroidal tissue. The purpose of this investigation was to determine the effects of menopause on visual function and cardiovascular and ocular hemodynamics.

Methods

Twelve premenopausal and 24 postmenopausal women were evaluated at the Indiana University School of Medicine during a single study visit. Vision screening and ocular blood flow evaluations were performed, including blood pressure, heart rate, visual acuity, contrast sensitivity, intraocular pressure, and retinal capillary and retrobulbar blood flow imaging. Vision and ocular hemodynamics were compared using unpaired Student t-tests with pp<0.05 regarded as statistically significant.

Results

The premenopausal group had significantly lower heart rate (-16.1 b/m, p=0.0001) and systolic blood pressure (-17.7 mmHg, p=0.003) than postmenopausal subjects. Contrast sensitivity was significantly higher (measured in log units) in premenopausal women in both the right (0.25, p=0.039; 0.16, p=0.039) and left (0.45, p=0.001; 0.27, p=0.032) eyes at 9 and 18 cycles per degree, respectively. Premenopausal women also had significantly lower intraocular pressure in both the right (-2.19 mmHg, p=0.024) and left (-1.74 mmHg, p=0.035) eyes. Total ocular perfusion was not significantly different between groups.

Conclusions

This pilot work suggests that postmenopausal women have lower contrast sensitivity detection and elevated intraocular pressures compared to premenopausal women. Premenopausal women have lower cardiovascular risk factors, while total ocular circulation was similar to post-menopausal women.

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.

Investigation of causes of sex-related differences in ocular blood flow in healthy eyes determined by laser speckle flowgraphy

Sex-related differences are present in the systemic and ocular blood flow. However, the cause of the sex-related differences has not been determined. We investigated the ocular blood flow, represented by the mean blur rate (MBR), on the optic nerve head (ONH) determined by laser speckle flowgraphy in 138 males (63.9 ± 8.9 years) and 194 females (63.5 ± 9.4 years). The correlations between the MBR on the ONH and the clinical data were determined. The overall ONH-MBR was significantly higher in females than males (P < 0.001). In addition, the levels of the hemoglobin and hematocrit were significantly lower in females than in males (P < 0.001). The ONH-MBR was negatively and significantly correlated with the levels of the hemoglobin and hematocrit (both, P < 0.001). Multiple regression analyses showed that the sex (β = 0.248, P < 0.001) was an independent factor correlated with the ONH-MBR when the clinical examination data were not included in the analyses. However, when the clinical examination data were included, the hemoglobin level (β = −0.295, P < 0.001) was an independent factor that contributed to the ONH-MBR but the sex was not. We conclude that the sex-related differences in the hemoglobin level and the negative correlation between hemoglobin and the ONH-MBR are the causes of the sex-related differences in the ONH-MBR.

Transient Monocular Vision Loss on Awakening: A Benign Amaurotic Phenomenon

BACKGROUND

Transient monocular vision loss (TMVL) is an alarming symptom owing to potentially serious etiologies such as thromboembolism or giant cell arteritis. Our objective is to describe the phenomenon of TMVL present on awakening, which may represent a distinct and benign entity.

METHODS

We performed a retrospective observational case series of 29 patients who experienced TMVL on awakening. Patients who described monocular dimming or blackout of vision were included, and those with blurred vision, concurrent eye pain, and binocular vision loss were excluded. Descriptive statistics were used to summarize the study population.

RESULTS

Of the 29 patients we studied, 90% (n = 26) were female and 48% had crowded discs (cup-to-disc ratio ≤0.2). The mean age was 45.4 years, although women were significantly younger than men (mean ages 43.4 and 62.7 years, respectively, P = 0.017). Brain magnetic resonance imaging and vascular imaging (magnetic resonance angiography, computed tomographic angiography, or carotid Doppler) were performed in 69% and 55% of cases, respectively, and were uniformly negative. In 14 patients for whom clear follow-up data could be obtained, no medically or visually significant sequelae of this syndrome were found, and 50% experienced resolution of symptoms.

CONCLUSIONS

Evaluation was uniformly negative when patients described waking with isolated vision loss in 1 eye with subsequent resolution, usually in less than 15 minutes. The natural history seems benign with symptoms frequently remitting spontaneously. This visual phenomenon may represent an autoregulatory failure resulting in a supply/demand mismatch during low-light conditions.

Relationship between progression of visual field defect and intraocular pressure in primary open-angle glaucoma

Purpose

To analyze the relationship between intraocular pressure (IOP) and the progression of visual field defects in Japanese primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG) patients.

Patients and methods

The subjects of the study were patients undergoing treatment for POAG or NTG who had performed visual field tests at least ten times with a Humphrey field analyzer (Swedish interactive thresholding algorithm standard, C30-2 program). The progression of visual field defects was defined by a significantly negative value of the mean deviation slope at the final visual field test during the follow-up period. The relationships between the progression of visual field defects and IOP, as well as other clinical factors, were retrospectively analyzed.

Results

A total of 156 eyes of 156 patients were included in the analysis. Significant progression of visual field defects was observed in 70 eyes of 70 patients (44.9%), while no significant progression was evident in 86 eyes of 86 patients (55.1%). The eyes with visual field defect progression had significantly lower baseline IOP (P<0.05), as well as significantly lower IOP reduction rate (P<0.01). The standard deviation of IOP values during follow-up was significantly greater in the eyes with visual field defect progression than in eyes without (P<0.05).

Conclusion

Reducing IOP is thought to be useful for Japanese POAG or NTG patients to suppress the progression of visual field defects. In NTG, IOP management should take into account not only achieving the target IOP, but also minimizing the fluctuation of IOP during follow-up period.

Ocular blood flow in polycystic ovary syndrome

AIM

The aim of this study was to evaluate whether the presence of polycystic ovary syndrome (PCOS) alters ocular blood flow parameters.

MATERIAL AND METHODS

Color Doppler imaging of the orbital vessels was performed in 41 eyes of 41 patients with PCOS. Forty-eight eyes of 48 age-matched volunteers served as controls. The ophthalmic artery (OA), the central retinal artery and the posterior ciliary artery were examined. Ocular blood flow indices of the peak systolic velocity, diastolic velocity, end-diastolic velocity, systolic/diastolic ratio, resistive index and pulsatility index were computed.

RESULTS

The peak systolic velocity, diastolic velocity and end-diastolic velocity of the OA, central retinal artery and posterior ciliary artery were significantly increased in PCOS patients in comparison to the controls (all P < 0.001). The mean systolic/diastolic ratio, resistive index and pulsatility index of the OA in PCOS patients were significantly decreased (all P < 0.05). Ocular blood flow velocity was positively correlated with serum luteinizing hormone, follicle-stimulating hormone and total cholesterol levels. There was a significant negative correlation between serum glucose and insulin levels and ocular blood flow velocity.

CONCLUSION

Ocular blood flow velocity is increased in PCOS patients and vascular resistance seems to decrease only in the OA.

Risk of glaucoma after early bilateral oophorectomy

OBJECTIVE

Because early estrogen deficiency may increase the susceptibility of the optic nerve to glaucoma, we studied the association of early bilateral oophorectomy with glaucoma.

METHODS

In the Mayo Clinic Cohort Study of Oophorectomy and Aging, we studied the risk of glaucoma by comparing women who underwent bilateral oophorectomy from 1950 to 1987 with age-matched referent women who did not undergo unilateral or bilateral oophorectomy. Glaucoma diagnostic codes were identified in the records linkage system of the Rochester Epidemiology Project. Hazard ratios (HRs) were calculated during a median follow-up of 25.5 years. Analyses were stratified by age at the time of bilateral oophorectomy (in tertiles).

RESULTS

Of 1,044 women who underwent bilateral oophorectomy before menopause, 147 developed glaucoma. Of 1,070 referent women, 133 developed glaucoma. Women who underwent bilateral oophorectomy showed no increased risk of glaucoma in the overall group (HR, 1.12; 95% CI, 0.89-1.42). However, women who underwent oophorectomy before the age of 43 years (n = 344; first tertile) had a significantly increased risk of glaucoma (HR, 1.60; 95% CI, 1.15-2.23). The results did not change after adjustment for hypertension, obesity, diabetes, or disorders of lipid metabolism at baseline. Approximately 11% of women who had undergone bilateral oophorectomy before the age of 43 years were treated with estrogen up to the age of 50 years; however, treatment did not reduce the association (HR, 1.59; 95% CI, 0.81-3.13).

CONCLUSIONS

Bilateral oophorectomy before the age of 43 years may increase the risk of glaucoma, and estrogen treatment does not seem to attenuate the risk.

Gender differences in ocular blood flow

Gender medicine has been a major focus of research in recent years. The present review focuses on gender differences in the epidemiology of the most frequent ocular diseases that have been found to be associated with impaired ocular blood flow, such as age-related macular degeneration, glaucoma and diabetic retinopathy. Data have accumulated indicating that hormones have an important role in these diseases, since there are major differences in the prevalence and incidence between men and pre- and post-menopausal women. Whether this is related to vascular factors is, however, not entirely clear. Interestingly, the current knowledge about differences in ocular vascular parameters between men and women is sparse. Although little data is available, estrogen, progesterone and testosterone are most likely important regulators of blood flow in the retina and choroid, because they are key regulators of vascular tone in other organs. Estrogen seems to play a protective role since it decreases vascular resistance in large ocular vessels. Some studies indicate that hormone therapy is beneficial for ocular vascular disease in post-menopausal women. This evidence is, however, not sufficient to give any recommendation. Generally, remarkably few data are available on the role of sex hormones on ocular blood flow regulation, a topic that requires more attention in the future.

Female reproductive factors and major eye diseases in Asian women -the Singapore Malay Eye Study

PURPOSE

To examine the association of reproductive factors and major eye diseases, including glaucoma, age-related macular degeneration (AMD), diabetic retinopathy and cataract, in Asian women.

METHODS

The Singapore Malay Eye Study is a population-based cross-sectional epidemiological study which examined 3280 persons (78.7% response) of Malay ethnicity aged 40-80 years; 1704 were female. Information on reproductive factors and use of hormone replacement therapy (HRT) was collected using an interviewer-administered questionnaire. Glaucoma was defined according to the International Society for Geographical and Epidemiological Ophthalmology criteria. Retinal photographs were graded for AMD following the Wisconsin grading system, and diabetic retinopathy according to the modified Airlie House classification system. Cataract was graded according to the Lens Opacity Classification System III.

RESULTS

A total of 1176 women reported having experienced menopause by the time of the study with 1073 (91%) having a natural menopause, 88 (7.5%) a hysterectomy and 9 (0.8%) due to other reasons; HRT was used by 70 (6%) women. Women whose age at menopause was ≤52 years were 3.5 times more likely to have glaucoma (95% confidence interval, CI, 1.23-9.98, p value = 0.02) than those whose age at menopause was ≥53 years. Age of menopause was not associated with AMD (age-adjusted odds ratio, OR, 1.22, 95% CI 0.65-2.31), diabetic retinopathy (age-adjusted OR 1.01, 95% CI 0.66-1.54) or cataract (age-adjusted OR 1.38, 95% CI 0.95-2.00). Use of HRT was not associated with any of these eye diseases.

CONCLUSION

Women who had menopause at a younger age were more likely to have glaucoma. This association needs to be confirmed in other studies.

Ophthalmic artery vasodilation after intranasal estradiol use in postmenopausal women

AIM

The study aim was to evaluate the acute hemodynamic effects of intranasal 17-beta-estradiol on ophthalmic arterial circulation in postmenopausal women.

METHODS

Twenty-one healthy women in natural menopause for at least 6 months (mean age: 53.2± 2.9 years) were investigated. Each patient received 300 µg intranasal 17-beta-estradiol. We evaluated the heart rate, systolic and diastolic blood pressure, ophthalmic artery velocity at systolic and diastolic peak and its flow curve integral (FCI) before and 30, 60 and 180 minutes after the administration of the drug.

RESULTS

At all time points, the ophthalmic artery FCI showed statistically significant variations (p<0.001) of velocity (cm/sec) compared to T0 (speed recorded at baseline before drug administration). Moreover, systolic blood pressure, diastolic blood pressure and heart rate did not significantly differ each other after drug administration.

CONCLUSIONS

Administration of a single dose of intranasal 17-beta-estradiol to healthy postmenopausal women increases ophthalmic artery perfusion.

Estrogen deficiency accelerates aging of the optic nerve

The aim of this study was to provide a comprehensive review on hormone-based pathophysiology of aging of the optic nerve and glaucoma, including a literature review and expert opinions. Glaucoma, a group of intraocular pressure-related optic neuropathies, is characterized by the slow progressive neurodegeneration of retinal ganglion cells and their axons, resulting in irreversible visual sensitivity loss and blindness. Increasing evidence suggests that glaucoma represents the accelerated aging of the optic nerve and is a neurodegenerative disease of the central nervous system. This review highlights the high burden of glaucoma in older women and the importance of understanding the hormone-related pathophysiology of optic nerve aging and glaucoma in women. Strong epidemiological, clinical, and experimental evidence supports the proposed hypothesis that early loss of estrogen leads to premature aging and increased susceptibility of the optic nerve to glaucomatous damage. Future investigations into the hormone-related mechanisms of aging and glaucoma will support the development of novel sex-specific preventive and therapeutic strategies in glaucoma.

Contrast sensitivity, ocular blood flow and their potential role in assessing ischaemic retinal disease

PURPOSE

To examine the definition, evaluation methodology, association to ocular blood flow and potential clinical value of contrast sensitivity (CS) testing in clinical and research settings, focusing in patients with ischemic retinal disease.

METHODS

A review of the medical literature focusing on CS and ocular blood flow in ischemic retinal disease.

RESULTS

CS may be more sensitive than other methods at detecting subtle defects or improvements in primarily central retinal ganglion cell function early on in a disease process. CS testing attempts to provide spatial detection differences which are not directly assessed with standard visual acuity chart testing. Analyzing all studies that have assessed both CS change and ocular blood flow, it is apparent that both choroidal circulation and retinal circulation may have an important role in influencing CS.

CONCLUSION

The concept that CS is directly influenced by ocular blood flow is supported by reviewing the studies involving both. Although the studies in the literature have not established a direct cause and effect relationship per se, the literature review makes it logical to assume that changes in retinal and choroidal blood flow influence CS. This raises the possibility that a subjective visual characteristic, specifically CS, may be able to be evaluated more objectively by studying blood flow. It appears appropriate to study the relationship between blood flow and CS more extensively to develop improved ways of measuring various aspects of blood flow to the eye and to best quantify early changes in visual function.

Influence of gender and menopausal status on peripheral and choroidal circulation

PURPOSE

To evaluate the influence of menopausal status and age on peripheral and ocular circulation assessed by means of continuous laser Doppler flowmetry (LDF).

METHODS

Fifty-three healthy participants were recruited randomly. Twenty-six men and 27 women were divided into two age groups. Choroidal blood flow was measured by LDF and peripheral circulation was measured at the fingertips (digit IV) using the Perimed PeriFlux (Järfälla, Sweden) laser Doppler System 5000. Independent t-test and two-way analysis of variance (anova) were performed.

RESULTS

Group distribution was: male/female = 14/16 for the younger group and 12/11 for the older group. Average age across groups was 31.3 ± 6.8/28.4 ± 7.0 years and 66.3 ± 8.3/61.5 ± 3.6 years, respectively. Finger and choroidal LDF flow values were significantly different between the two female age groups (p < 0.001 and p = 0.03, respectively). In men this was not the case (p = 0.85 and p = 0.56, respectively). anova interaction p-value for the factors 'age group' and 'gender' for finger LDF flow was p = 0.012, and for choroidal LDF flow p = 0.049, demonstrating significant gender differences with ageing.

CONCLUSION

  Menopausal status in women has significant influence on both choroidal and peripheral blood flow; the opposite behaviour occurs with ageing.

Gender and glaucoma: what we know and what we need to know

PURPOSE OF REVIEW

With growing aging populations and an increase in cases of glaucoma and glaucoma blindness worldwide, aging populations are particularly at higher risk of glaucoma and glaucoma blindness. Awareness of the gender differences might increase attention toward populations at risk.

RECENT FINDINGS

Women not only outlive men, but also outnumber men in glaucoma cases worldwide. Women are at higher risks for angle closure glaucoma, but there is no clear gender predilection for open angle glaucoma. Of interest, there is some evidence suggesting that female sex hormones might be protective of the optic nerve. In addition, it is hypothesized that decreased estrogen exposure is associated with increased risk for open angle glaucoma, yet population-based studies present inconsistent results. Presently, there is insufficient evidence to support hormonal replacement therapy use in glaucoma prevention. In addition, it appears that women carry a larger burden of glaucoma blindness due to longevity and disadvantages in socioeconomic/health beliefs.

SUMMARY

Current evidence suggests that older women are at risk for glaucoma and glaucoma blindness. Further interdisciplinary research involving investigators, specialized in glaucoma, women's health and health disparities, will lead to better understanding of gender health disparities in glaucoma and better targeting populations at risk.

Menstrual phase-related differences in the pulsatility index on the central retinal artery suggest an oestrogen vasodilatation effect that antagonizes with progesterone

PURPOSE

The actual effect of steroid hormones on cerebral microcirculation is still controversial. Therefore, the aim of our study was to investigate vascular flow variations in the central retinal artery that may exist during the ovulatory menstrual cycle.

METHODS

A total of 34 healthy women were included in this observational, longitudinal, and prospective study. All participants were submitted to dopplerfluxometric evaluation of the eyes in order to study the pulsatility index (PI) of the central retinal arteries, during four phases of the menstrual cycle: early follicular, mid follicular, periovulatory, and mid luteal phases.

RESULTS

Subjects' ages ranged from 14 to 47 years old (mean: 29.7 ± 10.1) and PI did not differ among age groups. The PI of the central retinal artery was different among the four phases of the menstrual cycle. PI showed a significant decrease from early follicular phase (1.72) to mid follicular phase (1.57) (p = 0.037), and was similar during periovulatory phase (1.56) and significantly increased in mid luteal phase (1.70). After that it returned to the values observed in the early follicular phase.

CONCLUSION

Our results suggest the existence of an oestrogen vasodilatation effect on the central retinal artery that is menstrual phase-related and antagonized by progesterone.

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

PURPOSE

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

METHODS

Review of current indexed literature was conducted.

RESULTS

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

CONCLUSIONS

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

Endothelial nitric oxide synthase gene variants and primary open-angle glaucoma: interactions with sex and postmenopausal hormone use

PURPOSE

To evaluate the association between the nitric oxide synthase gene (NOS3) variants and primary open-angle glaucoma (POAG).

METHODS

Two functional single-nucleotide polymorphisms (SNPs) (T-786C: rs2070744; Glu298Asp: rs1799983) and three tagging SNPs (rs7830, rs3918188, and rs1800779) were evaluated in a nested case-control study from the Nurses' Health Study (1980-2002) and the Health Professionals' Follow-up Study (1986-2002). Participants were aged >or=40 years and Caucasian. Included were 527 incident cases and 1543 controls, matched by cohort, age, and eye examination at the matched cases' diagnosis dates. Cohort-specific relative risks (RR) were estimated by using multivariable conditional logistic regression and were pooled with meta-analysis.

RESULTS

No NOS3 polymorphism was significantly associated with overall POAG. For high-tension POAG (HTPOAG), rs3918188 was significantly inversely associated among the women (AA versus CC genotype: RR = 0.48; 95% CI, 0.28-0.82) but not among the men (P-heterogeneity by sex = 0.02). The minor alleles of T -786C and rs1800779 showed positive association with high-tension POAG (P-trend < 0.02) in the women only, but P-heterogeneity was not significant. In the women, four of the five NOS3 SNPs showed significant interactions with postmenopausal hormone (PMH) use in relation to HTPOAG: for example, among the women with the TT genotype in T -786C, PMH use was inversely associated (RR = 0.41; 95% CI, 0.22-0.76), but among carriers of the minor allele, use of PMH was not associated.

CONCLUSIONS

Interactions were observed between NOS3 SNPs and female sex and postmenopausal hormone use in the women in relation to HTPOAG. These findings should be confirmed in different racial/ethnic groups.

Lifestyle, nutrition, and glaucoma

The only proven strategy to prevent primary open-angle glaucoma (POAG) is the use of ocular hypotensive therapy among people diagnosed with ocular hypertension. In this review, various modifiable lifestyle factors, such as exercise, diet, and cigarette smoking, that may influence intraocular pressure and that have been studied in relation to the risk of developing POAG are discussed. Epidemiologic studies on lifestyle factors are few, and the current evidence suggests that there are no environmental factors that are clearly associated with POAG; however, a few factors merit further study. This review also outlines future directions for research into the primary prevention of POAG.

Effect of aging on retinal circulation in normotensive healthy subjects

Although it is important to investigate the effects of normal aging on the ocular circulation, few studies have examined the effects of aging on the retinal microcirculation in healthy subjects. The purpose of this study was to evaluate the effects of aging on the retinal microcirculation in healthy men. Forty-five healthy men were divided into three groups based on age (young, middle-aged, elderly). We measured vessel diameter and blood velocity and calculated the retinal blood flow (RBF) and wall shear rate (WSR) in the retinal arteries. We performed pulse wave analysis obtained from the retinal blood velocity measurements. We also divided the subjects into two groups based on the presence or absence of prehypertension defined as 120-139/80-89 mmHg. No significant differences in vessel diameter, blood velocity, RBF, and WSR were seen among the groups. Pulse wave analysis showed significant increases in upstroke time (UT) in elderly men compared with young men (P < 0.05). Multiple regression analysis showed that the UT was correlated with age in all subjects. A significant difference was seen only in the UT between subjects with and without prehypertension. The UT calculated from the retinal blood velocity profile is associated significantly with aging, suggesting that measurement of the UT may detect the changes in the retinal and the systemic vessels with increasing age. The UT is the only parameter that increased significantly in subjects with prehypertension compared with those without prehypertension, suggesting that the UT may indicate the effects of prehypertension on the retinal arterioles.

The effects of raloxifene hydrochloride on ocular hemodynamics and visual function

OBJECTIVE

To assess the comprehensive effects of raloxifene hydrochloride on retinal, choroidal and retrobulbar hemodynamics and on visual function in post-menopausal women.

DESIGN

Twenty-four post-menopausal women (age 55 +/- 3.8 years) were recruited for this cross-sectional study: 12 received placebo and 12 received raloxifene hydrochloride 60 mg once a day for 3 months. Baseline measurements of both groups included heart rate (HR), blood pressure (BP), visual acuity, contrast sensitivity and intraocular pressure (IOP) for both eyes. A comprehensive ocular blood flow (OBF) assessment was obtained for each patient in a randomly chosen study eye. Retinal blood flow data was obtained using confocal scanning laser Doppler flowmetry [Heidelberg Retinal Flowmeter (HRF)]. Color Doppler imaging (CDI) was used to assess retrobulbar hemodynamics in the ophthalmic, central retinal, short nasal and temporal posterior ciliary arteries. Baseline vision and hemodynamics in post-menopausal subjects were compared using paired Student's t tests, and the percentage change in baseline versus 3-month parameters was analyzed.

RESULTS

There were no statistically significant differences between 3 months of raloxifene therapy and placebo in terms of age, HR, arterial or mean BP, visual acuity, contrast sensitivity, IOP or retinal or retrobulbar blood flow.

CONCLUSION

Raloxifene therapy at 60 mg/day had no clinically significant impact on BP, IOP or OBF in post-menopausal women.

Effect of Aerodiol administration on ocular arteries in postmenopausal women

OBJECTIVE

The aim of the present study was to evaluate the alteration of ocular blood hemodynamics after intranasal administration of 17beta-estradiol, through measurement of the ophthalmic artery (OA) and the central retinal artery (CRA) using color duplex sonography.

METHODS

Thirty healthy women who had been naturally postmenopausal for at least 1 year were enrolled in the study. A randomized, placebo-controlled, crossover, double-blinded study was conducted of the acute effect of 17beta-estradiol (Aerodiol; Servier, Chambrayles-Tours, France) on OA and CRA blood flow using color duplex sonography.

RESULTS

The peak systolic and end diastolic velocities of the CRA were increased significantly after 17beta-estradiol administration compared with placebo. A significant decrease was also found in the pulsatility and resistive indices of the CRA. However, there were no statistically significant differences in OA flow velocities or pulsatility and resistive indices.

CONCLUSIONS

Nasal 17beta-estradiol administration in postmenopausal women causes an improvement in the ocular vascular Doppler indices. These results suggest that there could be a positive effect of Aerodiol on middle-sized arteries and arterioles.

Ocular manifestations of Fabry's disease: data from the Fabry Outcome Survey

BACKGROUND

Fabry's disease is an X-linked lysosomal storage disorder characterised by deficient activity of the enzyme alpha-galactosidase A.

AIM

To study eye abnormalities in patients with Fabry's disease in the Fabry Outcome Survey (FOS).

METHODS

This is the largest study of ocular manifestations in patients with Fabry's disease. In all, 173 of the 688 patients enrolled in FOS underwent a detailed ophthalmic examination, with a special focus on abnormalities of the cornea, lens, conjunctival and retinal vessels.

RESULTS

Cornea verticillata was reported in 76.9% of females and 73.1% of males; vessel tortuosity was observed in 21.9% of females and in 48.7% of males. Fabry cataract was recorded in 9.8% of females and in 23.1% of males. Cornea verticillata was therefore the most frequently reported ophthalmic abnormality in Fabry's disease in both hemizygotic males and heterozygotic females. Tortuous conjunctival and retinal vessels and Fabry cataract were more frequently found in males than in females. Vessel tortuosity was more frequently observed in patients with a higher severity score and greater impairment of renal and cardiac function, suggesting that it may be associated with a more severe disease. The youngest patient with ocular changes was 3 years old. The prevalence of tortuous vessels in males increased with age.

CONCLUSION

The presence of cornea verticillata is a useful aid in the diagnosis of Fabry's disease, as it is often present at the time of diagnosis. Vessel tortuosity may have some predictive value for systemic involvement.

The effects of different hormone replacement therapy regimens on tear function, intraocular pressure and lens opacity

OBJECTIVE

Estrogen may have adverse effects on the ocular surface, intraocular pressure (IOP), lens opacity and tear function. The aim of the present study was to elucidate the effects of different hormone replacement therapy (HRT) protocols on tear function, IOP and lens opacity.

DESIGN AND SETTING

This was a prospective, uncontrolled study carried out at the Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Faculty of Medicine, Uludağ University, Turkey.

PATIENTS AND INTERVENTIONS

Thirty postmenopausal patients who had spontaneous or surgical menopause for at least 1 year and were not taking any medications were assigned to one of three groups. Group 1 comprised 19 patients (n = 38 observations) given conjugated equine estrogen 0.625 mg plus medroxyprogesterone acetate 2.5 mg (Premelle 2.5) daily; Group 2 contained six patients (n = 12 observations) given tibolone 2.5 mg (Livial) daily; and Group 3 comprised five patients (n = 10 observations) treated with estradiol patch, 3.9 mg/12 cm2 (Climara). Tear function, evaluated with Schirmer's test, IOP and lens opacity were determined before treatment and at 6 and 12 months of treatment.

RESULTS

Mean Schirmer's test score in each group and all eyes (n = 60) did not change significantly after 6 months of treatment but decreased significantly at 12 months. The percentage decrease in tear function was greatest in the estrogen-only group (Group 3). Mean IOP did not change significantly in Groups 1 and 2; however, in Group 3, IOP showed a statistically significant decrease from 14.63 +/- 0.84 mmHg before treatment to 12.60 +/- 0.68 mmHg (mean +/- standard error) at the end of treatment. Lens opacity in women of all groups did not change during treatment.

CONCLUSIONS

HRT decreased tear production, the decrease being greater in the estrogen- only group. Woman who are taking or considering HRT should be informed of the potential increased risk of dry eye syndrome with this therapy. In addition, estrogen-only treatment decreased IOP while estrogen plus progesterone and tibolone had no effect. HRT did not affect lens opacity after 12 months of treatment.

Does Postmenopausal Hormone Replacement Therapy Affect Intraocular Pressure?

PURPOSE

To assess the effects of postmenopausal hormone replacement therapy (HRT) on intraocular pressure (IOP).

PATIENTS AND METHODS

This was a cross-sectional controlled study, including 107 women aged 60 to 80 years receiving HRT and 107 controls who have never received HRT. All subjects underwent IOP assessment and funduscopic photography for cup-to-disc (C/D) ratios, and completed questionnaires regarding personal and family history of glaucoma, hormone replacement therapy, lifetime estrogen and progesterone exposure, and cardiovascular risk factors. Main Outcome Measures included IOP, prevalence of increased IOP, and C/D ratios.

RESULTS

The groups did not differ in mean IOP (15.3 versus 15.3 mm Hg), mean vertical (0.18 versus 0.21) and horizontal (0.17 versus 0.14) C/D ratios, and in prevalence of increased IOP (15% versus 14%), C/D ratio (7% versus 7%), or glaucoma (9% versus 11%). A personal history of ischemic heart disease was the only risk factor associated with increased IOP (O.R. = 4.63, P = 0.003). Lifetime estrogen and progesterone exposure, including pregnancies, deliveries, menstruation years, and the use of oral contraceptives did not significantly affect the risk for increased IOP.

CONCLUSION

Hormone replacement therapy and lifetime estrogen and progesterone exposure do not seem to affect IOP or the risk for increased IOP. A personal history of ischemic heart disease may be associated with a higher risk for this disorder.

Early impact of hormone replacement therapy on vascular hemodynamics detected via ocular colour Doppler analysis

OBJECTIVE

To determine the effects of hormone replacement therapy (HRT) on ocular blood flow.

STUDY DESIGN

In a prospective controlled study, 40 healthy women who presented to the menopause clinic between December 2000 and December 2001 were randomly assigned into the study. The HRT-receiving group was administered estradiol 17-valerate 2 mg the first 11 days, and estradiol 17-valerate 2 mg plus ciproterone acetate 1 mg the next 10 days of the monthly cycle for 6 months. The control group did not receive any HRT for 6 months. The ocular colour Doppler analysis were performed at baseline and after 3 and 6 months. The ocular Doppler analysis was performed in the first half of the cycle in the HRT-receiving group.

RESULTS

Central retinal artery and ophthalmic artery basal Doppler index (peak systolic velocity, end-diastolic velocity, resistive index and pulsatility index) values of the two groups at the beginning of the study did not show any statistically significant difference. Both the right and the left central retinal artery pulsatility index (PI) values of the study group, who received HRT at the end of the third and sixth months, showed a statistically significant decline (paired-samples test, P < 0.05), while the decrease in the resistive indexes was not significant.

CONCLUSION

These results suggest that 6 months of combined hormone replacement therapy with estradiol 17-valerate 2 mg plus ciproterone acetate 1 mg improves ocular vascular Doppler indices which may be a reflection of cerebral vascular status.

Normal reference intervals and ranges of side-to-side and day-to-day variability of ocular blood flow Doppler parameters

The study presents normal reference intervals and ranges of "normal" side-to-side and day-to-day variability of ocular blood flow Doppler parameters. Peak-systolic (PSV), end-diastolic velocity (EDV) and impedance indices in the ophthalmic artery (OA), the central retinal artery (CRA) and the short posterior ciliary artery (SPCA) of both orbits were determined with color-coded duplex sonography in 140 healthy volunteers (range 18 to 83 y; 68 men and 72 women). Decreases in flow velocities and concomitant increases in impedance indices were found in all arteries with advancing age. The PSV and the EDV values for the OA, the CRA and the SPCA in the age group less than 40 yr-old were 40.6 +/- 8.9 and 11.2 +/- 3.7, 9.9 +/- 1.8 and 3.7 +/- 0.9, 13.8 +/- 2.6 and 5.7 +/- 1.5 cm/s (mean +/- SD), respectively. In the 40 to 60 yr-old age group, the values were 35 +/- 7.9 and 10.7 +/- 4.3, 9.7 +/- 2 and 3.5 +/- 0.8, 13.5 +/- 2.9 and 5.3 +/- 1.5 cm/s. In the age group over 60 yr-old, the values were 34 +/- 8 and 8.4 +/- 3.3, 9.3 +/- 2 and 3 +/- 0.9, 12.8 +/- 2.4 and 4.3 +/- 1.2 cm/s. In the youngest age group, the EDV in the CRA and the SPCA was higher in women, while in the OA the PSV and the EDV were higher in men. Ranges of side-to-side variability in the OA, the CRA and the SPCA, determined with repeatability coefficient for the PSV and the EDV, were 24, 5.4, 7.5 cm/s and 11, 2.5, 4.2 cm/s, respectively, whereas the values for day-to-day variability were 16.8, 4.3, 6.7 cm/s and 5.6, 1.7 and 3.9 cm/s. Ocular blood flow Doppler parameters range widely and are significantly age and sex dependent. Ranges of "normal" side-to-side and day-to-day variability of the parameters can help to determine abnormal flow pattern.

Does hormone replacement therapy influence retinal microvascular caliber?

Previous population-based data suggest that retinal arteriolar diameter is wider in women than in men. Estrogen exposures could account for this difference. To evaluate the effects of HRT on small blood vessels, we assessed the relationship between use of hormone replacement therapy (HRT) and retinal microvascular diameter in older women in the Blue Mountains Eye Study baseline population (n = 1993, age >/= 49 years). Information on HRT use was recorded by trained interviewers. A computer-assisted program measured retinal vessel diameters from digitized photographs. Average arteriolar diameter was calculated as the central retinal arteriolar equivalent (CRAE); the lowest quintile of CRAE was considered generalized arteriolar narrowing. Of the 1897 women with complete data, 79 (4%) were premenopausal and 315 (17%), 224 (12%), and 1279 (67%) were current, past, and never HRT users, respectively. Among women aged < 65 years, multivariate-adjusted mean CRAE for the four groups was 196, 198, 201, and 200 microm (P < 0.0001), respectively. Among postmenopausal women >/= 65 years, multivariate-adjusted mean CRAE was 187, 188, 191 microm (P < 0.0001), respectively, for current, past, and never users. Current HRT users were 40% more likely than never users to have generalized arteriolar narrowing (95% confidence interval 1.0-2.1). It appears that the use of HRT in older women may not have any long-term vasodilatory effects on retinal arterioles. These data do not support our hypothesis that exogenous estrogen exposures account for observed wider retinal arteriolar diameters in women.

Hormone therapy and ophthalmic artery blood flow changes in women with primary open-angle glaucoma

OBJECTIVE

To compare the effects of hormone therapy (HT) on plasma viscosity and Doppler flow parameters in normal, healthy, postmenopausal women and in women with normal-tension and chronic, open-angle glaucoma.

DESIGN

Eight postmenopausal women with glaucoma (group I) and 15 controls (group II) were given HT. The duration of the study was 6 months, and the women were examined in basal condition and at the end of the treatment. All women underwent ultrasonographic evaluation of pelvic organs and color Doppler analysis of uterine, internal carotid, and ophthalmic arteries. Also, plasma viscosity was assayed.

RESULTS

The ultrasonographic analysis showed that none of the women presented with irregular endometrial echoes, polyps, or intracavitary fluid. In addition, endometrial thickness never exceeded the normal range (5 mm). Plasma viscosity and Doppler parameters significantly improved during therapy. However, the ophthalmic artery mean improvements of pulsatility index (-43% v -28%; P = 0.001), peak systolic blood flow velocity (+35% v +24%; P = 0.026), and time-averaged maximum velocity (+44% v +32%; P = 0.031) were significantly more evident in the control group than in the glaucoma group.

CONCLUSIONS

Although, in people with glaucoma, vasospasm can increase the risk of visual loss by inducing a retrobulbar blood flow reduction, HT seems to beneficially affect the ocular vascularization.

The influence of sex hormones on ocular blood flow in women

PURPOSE

To investigate the influence of sex hormones on ocular haemodynamics, blood flow velocities in the ophthalmic and central retinal arteries and serum levels of sex hormones were measured in pre- and postmenopausal women.

METHODS

Colour Doppler imaging (CDI) was used to determine the flow velocities (peak systolic velocity [PSV] and end-diastolic velocity [EDV]) and the resistive index (RI) in the ophthalmic and central retinal arteries in 22 premenopausal and 32 postmenopausal women, who had never received hormone replacement therapy. Serum levels were measured for oestradiol, free testosterone and follicle-stimulating hormone. The CDI parameters were compared between the two groups and the influence of serum levels of oestradiol and testosterone on blood flow velocities and the resistive indices were analysed.

RESULTS

After correcting for age and mean arterial blood pressure, an analysis of covariance disclosed a significantly lower EDV (p=0.02) and a significantly higher RI (p=0.01) in the central retinal artery of postmenopausal women compared with premenopausal women. Partial correlation analysis, controlling for age, revealed significant correlations between the CDI parameters and serum levels of oestradiol and testosterone. For premenopausal women, PSV (r=0.58, p=0.04) and EDV (r=0.73, p=0.006) in the ophthalmic artery correlated positively with serum oestradiol levels. The RI in the central retinal artery decreased with increasing oestradiol levels in both groups (premenopausal r= -0.40, p=0.04; postmenopausal r= -0.32, p=0.05). Peak systolic velocity in the central retinal artery correlated negatively (r= -0.49, p=0.04), whereas the RI correlated positively (r=0.53, p=0.02) with testosterone levels in the premenopausal group. Postmenopausal women with higher testosterone levels had lower EDV (r= -0.53, p=0.007) in the central retinal artery and higher RI in both vessels (ophthalmic artery r=0.48, p=0.01; central retinal artery r=0.61, p=0.002).

CONCLUSION

Our data provide evidence of a relationship between serum sex hormone levels and blood flow velocities and resistive indices in retrobulbar arteries. Oestradiol appears to have beneficial effects on ocular haemodynamics, whereas testosterone may act as an antagonistic to the effects of oestrogen.

Female reproductive factors and open angle glaucoma: the Blue Mountains Eye Study

AIMS

To determine whether endogenous oestrogen exposures are associated with open angle glaucoma (OAG).

METHODS

The Blue Mountains Eye Study examined 2072 women aged 49-97 years during 1992-4. Questions about female reproductive factors included age at menarche and menopause, parity, and use of hormone replacement therapy. Applanation tonometry, visual field tests, and stereo-optic disc photographs were performed. OAG was diagnosed when glaucomatous visual fields matched optic disc changes. Ocular hypertension (OH) was defined in the absence of glaucoma, but with intraocular pressure >or=22 mm Hg.

RESULTS

A significantly increased OAG risk with later (>13 years) compared with earlier (<or=12 years) age of menarche was found, odds ratio (OR) = 2.0; 95% confidence interval (CI) 1.0 to 3.9, p for trend = 0.01, after adjustment for multiple confounders. Non-significant increased odds for OAG were found for early natural menopause (<45 years) compared with the reference group (>or=50 years), adjusted OR = 1.7; CI: 0.7 to 3.8, and for shorter duration of endogenous oestrogen exposure (<30 years), adjusted OR = 1.8; CI: 0.6 to 5.3. Increasing parity was associated with an increased risk of OAG (p = 0.03) and decreased risk of OH (p = 0.03).

CONCLUSION

The modest associations found in relation to late menarche and increased parity do not allow the exclusion of a possible role for endogenous female hormones in the pathogenesis of OAG.

The effect of hormone therapy on the risk for age-related maculopathy in postmenopausal women

OBJECTIVE

To evaluate the effect of postmenopausal hormone therapy (HT) as well as the use of oral contraceptives and lifetime endogenous hormone exposure on the risk for age-related maculopathy (ARM) in postmenopausal women.

DESIGN

This was a cross-sectional, controlled study. A total of 102 women from 60 to 80 years of age who were receiving HT and 100 controls underwent a detailed clinical funduscopic evaluation and stereoscopic fundus photography for the presence and grading of ARM. All participants completed a standardized questionnaire regarding vascular risk factors, HT, and lifetime exogenous and endogenous estrogen and progesterone exposure. Statistical analysis was performed using Student's t test, chi2 test, and a multivariate logistic regression model.

RESULTS

The HT and the non-HT groups did not differ in terms of early (11% v 15%), late (6% v 6%), or wet (2% v 2%) ARM prevalence rates. Women with ARM were significantly older than controls (69 v 66 years; P = 0.001, 95% CI = 0.008 - 0.027) and were more likely to have ischemic heart disease (21% v 9%; OR = 2.86, P = 0.03, 95% CI = 0.020 - 0.360). Lifetime exogenous and endogenous hormone exposures and other cardiovascular risk factors were not significantly different among women with ARM as compared with controls.

CONCLUSION

Postmenopausal HT may not affect the risk for either early or late ARM in women aged 60 to 80 years. The risk for both entities is not necessarily affected by either exogenous or endogenous lifetime hormone exposure. A history of ischemic heart disease may be associated with an increased risk for ARM.

Ocular changes in pregnancy

Visual changes in pregnancy are common, and many are specifically associated with the pregnancy itself. Serous retinal detachments and blindness occur more frequently during preeclampsia and often subside postpartum. Pregnant women are at increased risk for the progression of preexisting proliferative diabetic retinopathy, and diabetic women should see an ophthalmologist before pregnancy or early in the first trimester. The results of refractive eye surgery before, during, or immediately after pregnancy are unpredictable, and refractive surgery should be postponed until there is a stable postpartum refraction. A decreased tolerance to contact lenses also is common during pregnancy; therefore, it is advisable to fit contact lenses postpartum. Furthermore, pregnancy is associated with a decreased intraocular pressure in healthy eyes, and the effects of glaucoma medications on the fetus and breast-fed infant are largely unknown.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to list the various ocular changes that occur during pregnancy, summarize the ocular disturbances that occur with preeclampsia and diabetes, and describe the management of some ocular problems during pregnancy.

Pulsatile ocular blood flow during pregnancy

PURPOSE

To study pulsatile ocular blood flow (POBF) throughout pregnancy.

METHODS

We enrolled twenty-seven healthy women in the first trimester of gestation, only ten of which were followed through the second trimester, and fourteen non pregnant healthy women. In each subject we measured POBF with the POBF pneumotonometer (OBF Ltd. UK), IOP, blood pressure (BP) and heart rate (HR). An unpaired Student t-test was used to compare pregnant women with non-pregnant women, and a two-tailed paired Student t-test was used to compare the same women in the first and second trimester of pregnancy. p <0.05 is considered statistically significant.

RESULTS

Results are presented as means +/- SD. In the first trimester of pregnancy the age was 32 +/- 6, POBF 1516.4 +/- 382 ml/min, IOP 13 +/- 3 mmHg, BP 92 +/- 6 mmHg, and HR 86 +/- 14 beats/min. In the second trimester POBF was 1629.11 +/- 352.4 ml/min, intraocular pressure (IOP) 12 +/- 3 mmHg, BP 96 +/- 3 mmHg, and HR 93 +/- 10 beats/min. In the control group the age was 27 +/- 9, POBF 972.23 +/- 329.3 ml/min, BP 88 +/- 4.3 mmHg, and HR 80 +/- 14 beats/min. POBF increases during the first trimester (p = 0.00008). In the second trimester POBF was higher compared to the first trimester (p = 0.0008). Non significant differences were observed for the other parameters.

CONCLUSIONS

The POBF increases throughout gestation. During pregnancy there is an increase in estrogen which induces endothelial-dependent vasodilatation in several tissues. The estrogen changes may influence POBF.

Change in retrobulbar circulation during menstrual cycle assessed by Doppler ultrasound

Our purpose was to study the hemodynamic changes in the ophthalmic, central retinal and posterior ciliary arteries during the normal menstrual cycle and to relate the vascular changes to menstrual cycle. A total of 23 healthy women underwent serial color Doppler ultrasonography at least six times during a normal menstrual cycle, twice each in follicular, ovulatory and luteal phases. Pulsatility and resistance index and peak systolic velocity of the each arteries were assessed with color Doppler imaging. There was no statistical difference in any of the parameters during the menstrual cycle. This was supposed to be because generalized hormonal effects on heart rate, blood pressure, blood volume, cardiac output and on the diameter of the vessel cancel each other and this effect maintains the same ocular blood flow and perfusion during the menstrual cycle.