Table 2.

Effects of sex hormones on ocular disorders.

Ocular Disorder	Effects of Sex Hormones
Dry eye disease (DED)	Androgens promote the activity of the meibomian glands, stimulating lipogenesis and maturation of acinar cells. Androgens have an anti-inflammatory role, favoring the synthesis of TGF-β and inhibiting the synthesis of interleukin-1β and TNF-α. Estrogens inhibit cell proliferation in the meibomian glands by downregulation of the cyclic AMP signal pathway and decreasing the secretion of the sebaceous glands, inhibiting lipogenesis. Estrogens promote inflammation on the ocular surface.
Corneal disorders	Estrogens stimulate the activation of proteinases of the stromal matrix and collagenolytic enzymes, responsible for the biomechanical and structural alteration of the cornea. Estrogens promote hyaluronic acid deposition and hydration, leading to an increase in central corneal thickness. Estrogens may promote keratoconus progression (no significant current data). Estrogens promote corneal wound healing by stimulating the migration and proliferation of corneal epithelial cells and the production of epidermal growth factor (EGF).
Cataract	Estrogens have a protective role against lens opacification, reducing cataractogenesis. Estrogens have an antioxidant function, inhibiting the formation of TGFβ. Estrogens regulate the hydration and ionic composition of the lens, maintaining its transparency.
Glaucoma	Estrogens have a neuroprotective action. Estrogens promote the survival of RGCs, preserve the thinning of the RNFL, and contribute to the IOP lowering. Estrogens have an anti-inflammatory action, downregulating the cytokine production.
Leber’s hereditary optic neuropathy (LHON)	Estrogens have an antioxidant role, activating the superoxide dismutase enzyme. Estrogens reduce apoptosis of RGCs by activation of the ERβ receptor in mitochondria.
Demyelinating optic neuritis	Estrogens have an immunomodulatory effect and promote remyelination by activation of the ERβ receptor, both on CD11c+ brain immune cells and on oligodendrocytes. Progesterone and derivatives reduce the myelin loss and promote its regeneration. Androgens stimulate myelin repair and have an anti-inflammatory action.
Age-related macular degeneration (AMD)	Estrogens may decrease the risk of developing AMD in old age (no significant current data).
Central serous chorioretinopathy (CSCR)	Exogenous androgens may increase the risk of developing CSCR (no significant current data).
Retinitis pigmentosa	Progesterone and derivatives have an antioxidant and neuroprotective action on photoreceptors and nerve cells. Progesterone and derivatives promote cell survival and inhibit photoreceptor apoptosis.