Abstract
Purpose :
Studies have shown that humans and chickens with myopia have reduced electroretinogram (ERG) amplitudes. Jiang et al. found that mice with lens-induced myopia showed no changes in ERG amplitudes after three weeks of defocus (Sci Rep, 2018). Here, we examined the influence of long-term form deprivation myopia on ERGs in mice.
Methods :
Male and female C57BL/6J mice (n=5) were measured for refractive errors and retinal function using dark- and light-adapted ERGs up to 16 weeks postnatal. Mice underwent form deprivation (FD) in the right eye (OD) using head-mounted diffuser goggles at 4 weeks of age. Refractive errors using photorefraction were measured biweekly. Retinal function was assessed after 1, 2, and 3 months of FD. A 2-way, repeated measures ANOVA was used to determine statistical significance.
Results :
Myopic shifts developed within 2 weeks of FD (myopic OD - control OS: -3.87 ± 1.84 D) and remained myopic through 3 months of FD (-6.45 ± 1.73 D). Under dark-adapted conditions, myopic eyes were statistically similar in a- and b-wave amplitudes up to 3 months of FD (2.5 log cd s/m2 flash: a-wave OD: -204.51 ± 43.36 µV, OS: -275.43 ± 27.82 µV; b-wave OD: 332.14 ± 84.67 µV, OS: 444.93 ± 40.40 µV). After light-adaptation, myopic and control eyes had a trend for decreased b-wave amplitudes after 3 months of FD, but did not reach significance (2.0 log cd s/m2 flash; b-wave OD: 117.95 ± 26.46 µV, OS: 166.37 ± 19.67 µV). Oscillatory potential parameters and implicit times for all waves showed no significant differences between eyes.
Conclusions :
These results suggest myopia may have no noticeable adverse effects on retinal function in mice. In other species, myopic effects on ERG amplitudes have been attributed to axial length elongation. Due to the small ocular size in mice, changes in axial length may not influence the ERG recordings.
This is a 2020 ARVO Annual Meeting abstract.