Abstract
Purpose :
Choroidal neovascularization (CNV) is a common complication resulting in vision loss in wet AMD, pathologic myopia, and multifocal choroiditis. High resolution in vivo imaging of animal models is essential to better elucidate and conduct research on CNV. This study evaluates a novel multimodal imaging platform combining optical coherence tomography (OCT) and photoacoustic microscopy (PAM) to induce and monitor CNV over time in rabbit eyes.
Methods :
Image guidance and monitoring occurred with a modified Thorlabs Ganymede-II-HR OCT integrated with an NT-242 OPO laser for PAM. Subretinal injection was performed in 12 living New Zealand white rabbit eyes. Eight eyes received a mixture of 20uL Matrigel and 7.5uL VEGF (100μg/mL) (M&V), and 4 eyes were injected with 27.5uL sterile water as a control. Eyes were monitored for before injection and 1 day, 4 days, 1 week, 2 weeks, 3 weeks, 4 weeks, and 5 weeks after injection with OCT, PAM, fundus photography, FA, and ICGA.
Results :
Under real-time OCT image guidance, all 12 rabbit eyes had successful subretinal injections. In the M&V group, localized subretinal fluid was observed up to 1 week after injection. Starting at 3 weeks and persisting to 5 weeks after injection, progressive late hyperfluorescence with hazy margins was noted with the FA, indicating the presence of CNV. In the control group, by 1 week after injection, the subretinal fluid had resolved and the overlying retina displaying retinal thinning. PAM allowed high resolution and high contrast visualization of the 3D CNV structure in the M&V group at 4 weeks after injection.
Conclusions :
This novel multimodal imaging system allows for real-time, image-guided CNV formation via subretinal injection under OCT guidance in rabbits. PAM demonstrates high resolution visualization of CNV without exogenous contrast agents. This system has potential for diagnosing and monitoring CNV.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.