Intraocular pressure and prolactin measures in seasonal affective disorder

To test further an original hypothesis of possible dampening of the hemodynamics of the eye in Seasonal Affective Disorder (SAD), the authors determined temporal organisation of both the intraocular pressure (IOP) and serum prolactin (PRL) values for ten seasonally depressed women and twelve sex- and age-matched controls during the late luteal phase of the menstrual cycle in winter (February through December). Recent studies suggest that low prolactin secretion may be a trait characteristic in SAD and this hormone is known to influence on transport mechanism of water and electrolytes from blood to aqueous humor. The SAD women had significantly lower IOP and PRL values than the control subjects at all four time points measured starting from 4.00 p.m. The authors discuss the implications of the finding of lowered IOP in relation to opposing roles of dopamine and serotonin in prolactin secretion in SAD.