Abstract
Purpose :
The implanting complex electronic microsystems into small animal eyes for feasibility experiments is challenging due to the specific missing of a pars plana. To improve the safety of insertion procedures, we performed anatomical histological studies to describe insertion sites in eyes of mice, rats and rabbits, modeled the anatomy in a 3D simulation platform and described effects of laser and cryoablation to enlarge safe insertion paths.
Methods :
Eyes of C57BL/6J wild-type(wt) mice, rd10 mice, Brown Norway rats and Chinchilla Bastard rabbits were examined histologically. Three-dimensional (3D) models were reconstructed from histological sections and reconstructed in a virtual reality platform where surgical instruments were also simulated. For the laser procedure, ten laser applications were performed in the upper hemisphere of the anterior retina using a transscleral CPC probe with the diode laser. For the cryo procedure, three cryo applications were created. The effect of the ablation was evaluated after three weeks by histological processing of the treated areas.
Results :
3D models of small animal eyes were created by digital image processing. Transformed into virtual reality, the models were used to simulate the surgical environment in experimental animal design. The true size of the models is calculated based on processing-induced shrinkage factors. The ablation effects were visible as an atrophy of all retinal layers. Observations also indicated that photoreceptors have been lost and replaced with a glial scar. No significant side effects such as ruptures, retinal detachments, or lens damage were observed in the treated eyes.
Conclusions :
3D models of small animal eyes allowed visualization of microscopic structures and thus targeted planning of surgical interventions to avoid surgical complications at an early stage of an experiment. Pretreatment of the anterior retina with laser/cryocoagulation may provide larger safe insertion areas in these eyes which do not have a pars plana.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.