Long-term effects of tibolone on ocular functions in postmenopausal women

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.

Eye diseases in women

Although eye diseases are considered to be relatively less affected by patient sex, it is noteworthy that the presence of hormone receptors have been confirmed in various ocular tissues, which were considered to have few sex-based differences. Female hormone levels are known to change because of menstruation, pregnancy, and menopause. When female hormone levels markedly fluctuate in such situations, the disease state may change.The fluctuations in the levels of sex hormones affect the corneal thickness conditions of uveitis.Estrogen may be a possible therapeutic option for glaucoma because it protects the eyes from damage caused by glaucoma and reduces intraocular pressure;it is particularly promising in the treatment of postmenopausal women with glaucoma.Estrogen is considered to have a prophylactic effect against eye diseases. However, there is a report that female sex is an independent risk factor for the progression of diabetic retinopathy, so it may not always exert a prophylactic effect. Thus, caution should be exercised.Based on recent progression of studies on this field, the importance of treatment according to gender has been recognized in the treatment of eye diseases.

Sex hormones and the dry eye

The greater prevalence of dry eye in women compared to men suggests that sex hormones may have a role in this condition. This review aims to present evidence for how sex hormones may affect the ocular structures involved in the production, regulation and maintenance of the normal tear film. It is hypothesised that hormone changes alter the homeostasis of the ocular surface and contribute to dry eye. Androgens impact on the structure and function of the meibomian and lacrimal glands and therefore androgen deficiency is, at least in part, associated with the aetiology of dry eye. In contrast, reports of the effects of oestrogen and progesterone on these ocular structures and on the conjunctiva are contradictory and the mechanisms of action of these female-specific sex hormones in the eye are not well understood. The uncertainty of the effects of oestrogen and progesterone on dry eye symptoms is reflected in the controversial relationship between hormone replacement therapy and the signs and symptoms of dry eye. Current understanding of sex hormone influences on the immune system suggests that oestrogen may modulate a cascade of inflammatory events, which underlie dry eye.

Breast cancer medications and vision: effects of treatments for early-stage disease

This review concerns the effects on vision and the eye of medications prescribed at three phases of treatment for women with early-stage breast cancer (BC): (1) adjuvant cytotoxic chemotherapy, (2) adjuvant endocrine therapy, and (3) symptomatic relief. The most common side effects of cytotoxic chemotherapy are epiphora and ocular surface irritation, which can be caused by any of several different regimens. Most notably, the taxane docetaxel can lead to epiphora by inducing canalicular stenosis. The selective-estrogen-receptor-modulator (SERM) tamoxifen, long the gold-standard adjuvant-endocrine-therapy for women with hormone-receptor-positive BC, increases the risk of posterior subcapsular cataract. Tamoxifen also affects the optic nerve head more often than previously thought, apparently by causing subclinical swelling within the first 2 years of use for women older than ∼50 years. Tamoxifen retinopathy is rare, but it can cause foveal cystoid spaces that are revealed with spectral-domain optical coherence tomography (OCT) and that may increase the risk for macular holes. Tamoxifen often alters the perceived color of flashed lights detected via short-wavelength-sensitive (SWS) cone response isolated psychophysically; these altered perceptions may reflect a neural-response sluggishness that becomes evident at ∼2 years of use. The aromatase inhibitor (AI) anastrozole affects perception similarly, but in an age-dependent manner suggesting that the change of estrogen activity towards lower levels is more important than the low estrogen activity itself. Based on analysis of OCT retinal thickness data, it is likely that anastrozole increases the tractional force between the vitreous and retina. Consequently, AI users, myopic AI users particularly, might be at increased risk for traction-related vision loss. Because bisphosphonates are sometimes prescribed to redress AI-induced bone loss, clinicians should be aware of their potential to cause scleritis and uveitis occasionally. We conclude by suggesting some avenues for future research into the visual and ocular effects of AIs, particularly as relates to assessment of cognitive function.

Variability in short-wavelength automated perimetry among peri- or postmenopausal women: a dependence on phyto-oestrogen consumption?

PURPOSE

To determine whether the hill of vision for Short-Wavelength Automated Perimetry (SWAP) is shallower for women who consume phyto-oestrogen-rich foods than for women who do not.

METHODS

Visual field data were compared for two groups of healthy amenorrhoeic women 48-69 years-old with normal vision and not using hormone replacement: (1) 24 subjects who reported consuming soy and/or flax products and (2) 20 subjects who reported not consuming these products. Two types of 24-2 visual fields were measured: (1) Full Threshold SWAP and (2) a white-on-white (W/W) field obtained using a Swedish Interactive Threshold Algorithm (SITA Standard).

RESULTS

The reduction of SWAP sensitivity from the centre of the field (4 loci, mean eccentricity = 4.2°) to the periphery (20 loci, mean eccentricity = 21.9°) was less for soy/flax consumers than for nonconsumers, both with age-referencing (mean difference = 1.7 dB, p = 0.018) and without (p = 0.012). Corresponding distinctions existed for the SWAP - W/W difference, and there was minimal effect for W/W fields alone. The peripheral age-referenced SWAP sensitivities averaged 2.5 dB higher for consumers than nonconsumers (p = 0.022).

CONCLUSION

The between-group distinctions are consistent with the possibility (derived from the women's health literature) that phyto-oestrogens may counteract a decline of short-wavelength-sensitive cone-mediated response among postmenopausal women. These results suggest another potential application for SWAP outside its original intended purpose as a glaucoma test. Future studies should assess whether phyto-oestrogen consumption is most beneficial for women who are sufficiently young and/or not too far beyond menopause.