Abstract
P 066
Effect of transcorneal electrical stimulation on rat retinal function after bright light exposure
Gabriel Willmann, Hua Zhang, Andre Messias, Andreas Schatz, Eberhart Zrenner, Karl Bartz-Schmidt, Florian Gekeler
Universitäts-Augenklinik Tübingen
Objective
To investigate whether transcorneal electrical stimulation (TES) using a gold-ring contact lens electrode has effects on retinal function recovery in rats after strong light exposure.
Methods
Eight Sprague-Dawley rats (age 4 weeks, weight 80-100g) were dark adapted for >12 hrs before 6 hours intense light exposure (20000 lux). Extended ISCEV protocol electroretinograms (ERGs) were recorded one and two weeks after light exposure. Animals were assigned into two groups: control (n=5) and TES (n=3). TES was applied once via a custom made contact lens electrode with a gold ring on the right eye, immediately before 6 hours light exposure. A neuro-stimulator (TWISTER) was used with the following settings: 1 ms-biphasic current pulses; 30 min duration; frequency 20 Hz; current 0.1 mA.
Results
After two weeks dark adapted ERG values of a saturating rod flash (3 cd*s/m²) differed significantly in the right eyes of the two groups (control vs. TES; mean±SEM): a-wave amplitude (µV): 77.02±24.64 vs. 149.66±17.00; a-wave implicit time (ms): 12.00±3.05 vs. 16.33±0.33; b-wave amplitude (µV): 273.90±75.47 vs. 598.59±75.29; b-wave implicit time (ms): 50.00±8.07 vs. 73.00±1.53; oscillatory potentials (µV x ms): 575.88±156.67 vs. 1184.99±154.80. Values of a Naka-Rushton fit also differed significantly: Vmax (µV): 327.11±28.33 vs. 565.86±65.31; k (log cd*s/m²): -2.86±0.09 vs. -2.57±0.00.
There was no statistically significant difference in a-wave, b-wave or OP in the left eyes of the two groups after scotopic and photopic ERG measurement.
Conclusions
Our data show that transcorneal electrical stimulation improves retinal recovery after strong light exposure, which indicates a potential neuroprotective effect, improving the tolerance of retinal function to light damage.
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