Abstract
Purpose :
To test the hypothesis that oxidative stress in the outer retina can be detected using antioxidants (AO’s) to correct an impaired light-evoked response as measured by OCT.
Methods :
C57BL/6 mice were maintained in the dark for ~20 hours and studied by OCT before and after 1 hour of light exposure. Outer retina (OR, from outer limiting membrane to the retinal pigment epithelium–choroid boundary) thickness in dark or light were measured, and the light-dark difference (i.e., the photoresponse) was calculated. Subgroups of mice were given either saline or d-cis-diltiazem (an inducer of transient and non-damaging OR oxidative stress) ± AO's (methylene blue given 24 hours prior to examination and α-lipoic acid applied 1 hour prior to examination); one group was given only AO’s but kept in the dark.
Results :
In uninjected or saline injected control mice, the OR showed a similar and reproducible light-induced expansion; AO’s given to dark adapted mice did not increase dark adapted OR thickness. d-cis-diltiazem treated mice had no photoresponse (p > 0.05). Administration of AO’s corrected (p < 0.05) the suppressed OR photoresponse, indicating the presence of oxidative stress in d-cis-diltiazem treated mice.
Conclusions :
QUEnch-assiSTed (QUEST) OCT reproduced results from previous gold-standard assays showing that oxidative stress impairs the OR photoresponse, and that d-cis-diltiazem produces OR oxidative stress. We envision future applications of QUEST OCT in a range of oxidative stress-based retinopathies.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.