Multimodal imaging of the mouse eye using visible light photoacoustic ophthalmoscopy and near-infrared-II optical coherence tomography

Non-invasive imaging plays a crucial role in diagnosing and studying eye diseases. However, existing photoacoustic ophthalmoscopy (PAOM) techniques in mice have limitations due to handling restrictions, suboptimal optical properties, limited availability of light sources and permissible light fluence at the retina. This study introduces an innovative approach that utilizes Rose Bengal, a contrast agent, to enhance PAOM contrast. This enables visualization of deeper structures like the choroidal microvasculature and sclera in the mouse eye using visible light. The integration of near-infrared-II optical coherence tomography (NIR-II OCT) provides additional tissue contrast and insights into potential NIR-II PAOM capabilities. To optimize imaging, we developed a cost-effective 3D printable mouse eye phantom and a fully 3D printable tip/tilt mouse platform. This solution elevates PAOM to a user-friendly technology, which can be used to address pressing research questions concerning several ocular diseases such as myopia, glaucoma and/or age-related macular degeneration in the future.Comment: 14 pages, 4 figure

Posterior scleral birefringence measured by triple-input polarization-sensitive imaging as a biomarker of myopia progression

In myopic eyes, pathological remodelling of collagen in the posterior sclera has mostly been observed ex vivo. Here we report the development of triple-input polarization-sensitive optical coherence tomography (OCT) for measuring posterior scleral birefringence. In guinea pigs and humans, the technique offers superior imaging sensitivities and accuracies than dual-input polarization-sensitive OCT. In 8-week-long studies with young guinea pigs, scleral birefringence was positively correlated with spherical equivalent refractive errors and predicted the onset of myopia. In a cross-sectional study involving adult individuals, scleral birefringence was associated with myopia status and negatively correlated with refractive errors. Triple-input polarization-sensitive OCT may help establish posterior scleral birefringence as a non-invasive biomarker for assessing the progression of myopia.Agency for Science, Technology and Research (A*STAR)Nanyang Technological UniversityNational Medical Research Council (NMRC)National Research Foundation (NRF)Published versionThis work was funded by grants from the Industry Alignment Fund - Industry Collaboration Projects (IAF-ICP) Grant (I1901E0038, L.S., Q.V.H., A.W.C., R.P.N., V.A.B., M.A. and S.-M.S.) and Johnson & Johnson Vision. We also acknowledge the support of the National Medical Research Council (CG/C010A/2017_SERI, L.S.; OFLCG/004c/2018-00, L.S.; MOH-000249-00, J. Chua; MOH-000647-00, L.S.; MOH-001001-00, L.S.; MOH-001015-00, L.S.; MOH-000500-00, L.S.; MOH-000707-00, L.S.; MOH-001072-06, L.S.; NMRC/CSIRG/MOH-000531/2021, Q.V.H.); the National Research Foundation Singapore (NRF2019-THE002-0006, L.S. and NRF-CRP24-2020-0001, L.S.), A*STAR (A20H4b0141, L.S., J. Chua), the Singapore Eye Research Institute & Nanyang Technological University (SERI-NTU Advanced Ocular Engineering (STANCE) Program, L.S.), the SERI-Lee Foundation (LF1019-1, J. Chua), the US National Institutes of Health (P41EB-015903, M.V. and R01 EY023966, I.A.S.), the EU (H2020-MSCA-IF-2019 program 894325, M.L.) and the Singapore Eye Research Institute & National University of Singapore ASPIRE Program (NUHSRO/2022/038/Startup/08, R.P.N.)