A 61-year-old Caucasian woman, a glaucoma suspect, had a gynecologic history of pre-eclampsia and hysterectomy with bilateral oophorectomy at age 53. She presented with superior visual field loss in the right eye. IOP was 21 mm Hg that decreased to 15 mm Hg with maximal medical therapy. The inferior neural retinal rims are excavated and worse in the right eye. Visual fields were similar to those in the previously described case of PCOAG.
“Estrogen is a big driver of eNOS activity. Retinal ganglion cells have receptors for estrogen,” Dr. Pasquale explained. “Studies in normal menstruating women found that the optic nerve structure varies with the function of the menstrual cycle as does the retinal sensitivity. IOP decreases during pregnancy, despite that the central corneal thickness tends to increase in the third trimester.”
A randomized trial (part of the Women’s Health Initiative study) indicated that postmenopausal hormone use was associated with lower IOP (Vajaranant et al. Am J Ophthalmol. 2016;165:115-124).
While estrogen is important in glaucoma-related traits (Figure 1), studies have shown there is an increased risk of POAG in women with decreased estrogen exposure during their life and conversely, there is a decreased risk for women with increased estrogen exposure.
An animal model of POAG bore that out, i.e., estrogen is neuroprotective and preserved visual function and structure (Prokai-Tatrai et al. Mol Pharm. 2013;1:3253-3261).
The challenge is how to use this information and perform a randomized clinical trial to determine how to stop glaucoma progression, Dr. Pasquale said.