Dose-dependent effect of 11-cis-6mr-retinal on retinal health in Abca4−/−Rdh8−/−mice
The thickness of the ONL and the number of AF spots were evaluated in OCT or SLO images, respectively, obtained from Abca4−/−Rdh8−/− mouse eyes under different treatments. Mice were kept in the dark, treated with DMSO, or with different doses (4, 8, 12, or 20 mg/kg) of 11-cis-6mr-retinal 30 minutes before bright-light illumination. Morphologic changes induced by bright light were largely prevented by pretreatment with 11-cis-6mr-retinal at 20 mg/kg; the ONL thickness and AF spot counts closely resembled those of mice not exposed to bright light. Partial protection was achieved with 11-cis-6mr-retinal at 12 mg/kg. Statistical significance was calculated with the Student’s t test, unpaired two-tailed for two-group comparison, and one-way ANOVA test (SigmaPlot 11.0 software) for multiple group comparison.
| Treatment | OCT ONL Thickness | Statistical Significance (P) | SLO AF, Spot Counts | Statistical Significance (P) |
|---|---|---|---|---|
| µm | P value | Spot counts | P value | |
| No light | 58 ± 3 | NA | 4 ± 2 | NA |
| DMSO | 4 ± 2 | NA | 1200 ± 100 | NA |
| 11-cis-6mr-retinal (4 mg/kg b.wt.) | 5 ± 3 | NS | 1100 ± 200 | NS |
| 11-cis-6mr-retinal (8 mg/kg b.wt.) | 15 ± 10 | <0.05 | 1000 ± 200 | <0.05 |
| 11-cis-6mr-retinal (12 mg/kg b.wt.) | 27 ± 18 | <0.001 | 400 ± 100 | <0.001 |
| 11-cis-6mr-retinal (20 mg/kg b.wt.) | 58 ± 3 | <0.001 | 4 ± 3 | <0.001 |
AF, autofluorescence; ANOVA, analysis of variance; DMSO, dimethylsulfoxide; NA, not applicable; NS, not statistically significant; OCT, optical coherence tomography; ONL, outer nuclear layer; SLO, scanning laser ophthalmoscopy.