Glaucoma is a leading cause of blindness. Previously, we quantified the deformations in scleral tissue components through a PAM-FEA methodology. This study furthers our examination of perilimbal sclera (PLS) and aqueous veins in intraocular pressure (IOP) regulation using ex vivo porcine eyes. Our results reveal that the cross-sectional area change of the aqueous veins and strain of PLS are strongly and positively correlated with the steady-state IOP (n=8, R2=0.90, R2=0.57, respectively) and the IOP elevation rate at a constantly increasing flow rate (n=8, R2=0.89, R2=0.58, respectively). These findings support our hypothesis that the PLS and aqueous veins with less deformation are correlated with elevated steady state IOP and less adaptive behavior of eyes to increased aqueous outflow.
Glaucoma is a leading cause of blindness. Previously, we quantified the deformations in scleral tissue components through a PAM-FEA methodology. This study furthers our examination of perilimbal sclera (PLS) and aqueous veins in intraocular pressure (IOP) regulation using ex vivo porcine eyes. Our results reveal that the cross-sectional area change of the aqueous veins and strain of PLS are strongly and positively correlated with the steady-state IOP (n=8, R2=0.90, R2=0.57, respectively) and the IOP elevation rate at a constantly increasing flow rate (n=8, R2=0.89, R2=0.58, respectively). These insights bolster our supposition that a stiffer PLS can lead to heightened IOP and reduced ocular adaptability to aqueous outflow, primarily due to restrictions on aqueous vein dilation.
Purposed at validating the hypothesis that overly stiff sclera undermines the passive and adaptive mechanisms of the aqueous outflow pathway in regulating IOP, we combined photoacoustic microscopy (PAM) and finite element analysis (FEA) technologies to resolve and quantify the strains in the aqueous veins and surrounding perilimbal sclera in human and porcine eyes at high resolution in 3D in our previous study. In this study, we introduced large dynamic range of scleral stiffness in intact porcine eyes by crosslinking and observed the correlations between the principal strains in sclera and aqueous veins during IOP elevations, and between the principal strains and the steady state IOP. The results showed strong correlations in both cases.
Purposed at validating the hypothesis that overly stiff sclera undermines the passive and adaptive mechanisms of the aqueous outflow pathway in regulating IOP, we combined photoacoustic microscopy (PAM) and finite element analysis (FEA) technologies to resolve and quantify the strains in the aqueous veins and surrounding perilimbal sclera in human and porcine eyes at high resolution in 3D in our previous study. In this study, we introduced large dynamic range of scleral stiffness in intact porcine eyes by crosslinking and observed the correlations between the principal strains in sclera and aqueous veins during IOP elevations, and between the principal strains and the steady state IOP. The results showed strong correlations in both cases.
We developed a photoacoustic imaging (PAI) and finite element analysis (FEA) approach for characterizing the biomechanical behaviors of the aqueous veins and perilimbal sclera, and their roles in the regulation of intraocular pressure (IOP). In this study, an optical resolution PAI system captures the 3D architectures of the sclera and the aqueous veins perfused with indocyanine green. FEA computes tissue and vein strain fields. The performance of the PAI-FEA has been validated by tensile test in scleral tissue. The methods have also shown the capability of resolving the strain gradients at the vein-sclera interface during the manipulation of IOP.
We developed a photoacoustic imaging (PAI) and finite element analysis (FEA) approach for characterizing the biomechanical behaviors of the aqueous veins and perilimbal sclera, and their roles in the regulation of intraocular pressure (IOP). 3D architectures of the sclera and the aqueous veins perfused with indocyanine green have been resolved by an optical resolution PAI system. The tissue ans strain fields were quantified using FEA. The performance of the proposed method has been validated by tensile test in scleral tissue. The methods have shown the capability of resolving the strain gradients at the vein-sclera interface during the manipulation of IOP.
The current health care approach for chronic care, such as glaucoma, has limitations for access to expert care and to meet the growing needs of a larger population of older adults who will develop glaucoma. The computer aided diagnosis system (CAD) shows great promise to fill this gap. Our purpose is to expand the initial fundus dataset called Retinal fundus Images for Glaucoma Analysis (RIGA) to develop collaborative image processing methods to automate quantitative optic nerve assessments from fundus photos. All the subjects were women and enrolled in an IRBMED protocol. The fundus photographs were taken using Digital Retinography System (DRS), which is dedicated for diabetic retinopathy screening. Among initial 245 photos, there were 166 photos that met quality assurance metrics for analysis and serve as RIGA2 dataset. Three glaucoma fellowship trained ophthalmologists performed various tasks on these photos. In addition, the cup to disc ratio (CDR) and the neuroretinal rim thickness for the subjects were assessed by slit lamp biomicroscopy and served as the gold standard measure. This RIGA2 dataset is additional 2D color disc photos resource, and multiple extracted features that serves the research community as a form of crowd sourcing analytical power in the growing teleglaucoma field.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.