Abstract
Purpose :
Evidence suggests neurotransmitters targeted by antidepressants are involved in retinal cellular metabolism with serotonin receptors found in multiple layers of mammalian retina including the outer plexiform layer of humans. Work on mammal retinas found that serotonin modulated activity of rods but not cones. Yet no work has examined if visual function is altered by antidepressant use. This analysis sought to determine if antidepressant use was associated with worse cone-, cone and rod-, and rod-mediated visual functions in older adults.
Methods :
Visual function testing was done in 1 eye at the baseline visit of ALSTAR2 (NCT04112667) and included best-corrected visual acuity (BCVA), contrast sensitivity (CS), light sensitivity, and rod-mediated dark adaptation (RMDA) at 5° and 12° quantified by rod-intercept time (RIT). Light sensitivity was tested under photopic, mesopic and scotopic conditions; photopic and mesopic BCVA and CS were also assessed. Worse function was defined by prior work or, when unestablished, derived from the sample. Antidepressant use was determined from self-reported medications, excluding those without known serotoninergic mechanisms, i.e., bupropion. AMD was classified using the AREDS 9-step system. For each function, an odds ratio for worse visual function among antidepressant users versus non-users was calculated using logistic regression, adjusting for age and AMD severity.
Results :
Of 500 participants, 106 reported taking an antidepressant with serotoninergic mechanisms. Those taking antidepressants were 2 times as likely to have worse RMDA at 5° and 2.3 times as likely to have worse scotopic light sensitivity compared to those not taking antidepressants (Table). Antidepressant use was not associated with worse function on other tests.
Conclusions :
Among older adults in normal macular health and with early or intermediate AMD, antidepressant use was associated with worse rod-mediated visual functions but not those based on cones only or both rods and cones. Worse RMDA at 12° was not associated with antidepressant use, which could be due to the reduced power for the effect of delayed RMDA at this eccentricity. The findings suggest rods are impacted by neurotransmitters altered by antidepressants, e.g. serotonin, while cones are not. Future work should further investigate this pharmacological difference.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.