Abstract
Purpose :
Choroidal neovascularization (CNV) is a leading cause of visual impairment and vision loss in humans. Therefore, it is important to establish an accurate, rapid, and durable animal model to perform CNV research. This study introduces a novel model involving laser induced CNV in pigmented rabbits in vivo. The model is longitudinally monitored using photoacoustic microscopy (PAM) and OCT to track development and maintenance of CNV.
Methods :
CNV models were generated in 6 Dutch Belted Rabbits ages 2-4 months and weighing 1.9 to 3.0 kg. A laser contact lens was coated in Gonak Hypromellose Ophthalmic Demulcent Solution (2.5%) and placed directly on the eye. The eyes were then irradiated at a power of 450 mW with 532 nm laser light Vitra photocoadulator connected to a Zeiss SL 130 slit lamp. The rabbit eyes received 16 laser spots in a 4 x 3 rectangle with a spot size of 300 µm in aerial diameter and a pulse duration of 500 ms/spot. The models were monitored for 28 days, allowing time for CNV to generate and persist at the locations of laser irradiation. Longitudinal visualization of the models was acquired using multimodal PAM and OCT, fundus photography, FA, and ICGA. The rabbits were then euthanized, and histological analysis was performed to determine CNV or ocular damage.
Results :
Using the multimodal imaging system, it was demonstrated that all 6 rabbit eyes had successful development and persistence of CNV in some of the laser irradiation sites. CNV developed approximately on day 14. This was deduced from leakage present on FA and ICGA images and 3D PAM and OCT data. In the FA images, the late leakage and hyperfluorescence observed was consistent with CNV. Histological analysis verified focal areas of laser damage. No rabbits had unexpected complications during the procedure or imaging.
Conclusions :
The imaging data demonstrates that laser photocoagulation can effectively produce a stable model of CNV in pigmented rabbits. PAM and OCT imaging provide high resolution imaging of the growth of CNV without exogenous contrast agents. FA and ICGA confirmed the presence of CNV leakage.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.