Abstract
The promise of vision restoration in human remains challenging due to the absence of a retinal degeneration model in non-human primates. There has been tremendous progress in vision restoration using stem cell therapy and optogenetics in rodents which are not ideal models for human-like vision. Here we report a noninvasive and axially targeted retinal degeneration model in macaque using an ultrafast laser and adaptive optics. A femtosecond laser (720 nm, 55 fs, 80 MHz) was directed through the anesthetized macaque’s pupil using an adaptive optics scanning light ophthalmoscope (AOSLO). The focal plane of laser was adjusted close to the outer nuclear layer with the help of adaptive optics. Laser pulse energy and irradiance duration were varied keeping the scanning area fixed. The lesions were monitored over 6 months using optical coherence tomography, confocal SLO, and AOSLO imaging to assess the extent of the damage.
Laser pulse energy between 1 μJ- 2 μJ for a duration of 1.5 μs selectively ablates photoreceptors within the scanning area leaving retinal layers above and below and vasculature structure relatively intact whereas laser pulse energy < 1 μJ did not show any visible damage and laser pulse energy >2 μJ produced severe collateral injury. These results show that ultrafast exposures can produce highly localized, selective damage to photoreceptors, providing a useful primate model for restoring vision.