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

Authors


Alvin Eisner, PhD
Casey Eye Institute
Oregon Health & Science University
3375 SW Terwilliger Blvd.
Portland, Oregon 97239
USA
Tel: +1 503 418 2590
Fax: +1 503 418 2701
Email: eisnera@ohsu.edu

Abstract.

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.

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