Gender Differences in Ocular Blood Flow

Abstract

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.

The estrogenic retina: The potential contribution to healthy aging and age-related neurodegenerative diseases of the retina

“…Intraretinal vascular endothelium constitutes the main component of the inner retinal-blood-barrier (iBRB; Fig.1). The lack of retinal autonomic innervation suggests that factors released locally from endothelial cells and surrounding retinal tissues are relevant for the regulation of blood flow [24,25]. Avascular areas located at the extreme retinal periphery and the outer retinal layer (ONL) containing the photoreceptors, also receive metabolic energy through the choroid, which is richly supplied from autonomic vasoactive nerves.…”

“…E2 treatment increases retinal blood flow, protects the retinal nerve fiber layer in ovariectomized rats, and prevents from swelling of rat retinal glial cells [25]. However, E2 effects on pathological neovascularization in retinal diseases appear controversial.…”

Ocular perfusion pressure variation in relation to gender and body mass index in healthy young adults

“…[22] These findings were statistically significant only in the younger age group (<40 years). A study investigating choroidal blood flow in men and women also found significant differences.…”

Low serum testosterone and increased diastolic ocular perfusion pressure: a risk for retinal microvasculature

“…Th e fact that low compliance to hypertension treatment is evident might prove to be detrimental in the control of blood pressure and microvascular risk. It is known that serum T is inversely associated with BP and positively associated with microvascular blood fl ow [28,29]. Th is raises the possibility that reduced serum T may be a complicating factor in pathologies associated with reduced perfusion in the retinal and, maybe, also other microvascular beds.…”

“…Th is raises the possibility that reduced serum T may be a complicating factor in pathologies associated with reduced perfusion in the retinal and, maybe, also other microvascular beds. However, very little data are available concerning the role of sex hormones in ocular blood fl ow [28]. A number of the role players determining retinal blood fl ow (PP, IOP and CRVE) were signifi cantly higher in the black than in the white group.…”