Intracameral Injection in Rats with Low Risk of Adverse Effects

Intracameral injections allow to bypass the outer ocular barrier and directly deliver compounds to the aqueous humor. However, conducting intracameral injection in rodent present technical challenges that may result in adverse effect and impact the experimental outcome. We, therefore, design the protocol considering the red-eye anatomy to allow intracameral injection with minimal risk of adverse effects.

Intracameral injections in rodents involve the risk of tissue damage due to the small eye dimensions, limited aqueous humor of volume, and lens position. Tissue damage during manipulation can lead to complication, like anterior chamber shallowing, lens injury, endothelial cell damage, and inflammation. All of this cause experimental variability and influence findings.

The length and angle of the incision are critical. We make the incision in the central corneal area where the anterior chamber is the deepest at an angle close to flat. This generates a long tunnel, which helps in reducing the loss of aqueous humor.

Injecting through the tunnel improves precision and reduces the likelihood of touching the lens. The described intracameral injection method can be utilized in various experimental settings to generate disease models or assess different treatments. We expect that the precision and reproducibility of this injection technique will be a valuable tool in experimental ophthalmology.