Low-hemorrhage-risk surgical approach to expose the optic nerve in rabbits without bony removal and rectus resection

Objective  A low-hemorrhage-risk surgical approach to expose the optic nerve (ON) in rabbits through the orbital process of the frontal bone without removal of the bony orbit and resection of the rectus muscle was explored and assessed in this study. This approach will be used to investigate a new visual prosthesis that requires intraorbital ON stimulation with penetrating electrodes.
Animals  Chinese Albino rabbits ( n  = 10).
Methods  Rabbits were classified into a surgery and a control group (five in each). In the surgery group, the ON exposure was explored by the newly proposed surgical approach. Surgical time, blood loss, visually evoked potentials (VEP) at four different scheduled time points, and H&E-stained histology of the ON at one month after surgery were recorded and analyzed to assess the ease and safety of the approach.
Results  The average surgical time for the ON exposure was 16.40 ± 1.14 min with average blood loss of 0.52 ± 0.08 mL. Within the one-month follow-up, the ON exhibited a naturally reversible conduction change in terms of VEP amplitude. Histological examination of the ON was unremarkable. A postoperative mild ptosis of the surgical eye resolved within one month after surgery.
Conclusion  The ease and safety of this new surgical approach allowed it to be easily used by non-expert operators and widely applied in rabbit experiments for various research purposes requiring exposure of the ON.