Mapping Pulsatile Optic Nerve Head Deformation Using OCT

Solano, Marissé Masís; Richer, Emmanuelle; Cheriet, Foued; Lesk, Mark R.; Costantino, Santiago

doi:10.1016/j.xops.2022.100205

Cited by 6 publications

(7 citation statements)

References 43 publications

(47 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One recent study of three monkeys found that premortem strains due to an increase in IOP were somewhat greater than postmortem strains using OCT imaging, specifically the median effective and the maximum shear strains. 39 There are displacements measurable by OCT in human eyes due to vascular pulsation, 40 and these may influence regions of the human ONH or the mouse AL nearer to large vessels. In the human eye, the regional maximum principal strain due to ex vivo inflation test of the posterior scleral cups was greater in upper and lower polar areas of the ONH.…”

Section: Discussionmentioning

confidence: 99%

Comparison of the Biomechanics of the Mouse Astrocytic Lamina Cribrosa Between Glaucoma and Optic Nerve Crush Models

Korneva,

Kimball,

Johnson

et al. 2023

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

Purpose The strain response of the mouse astrocytic lamina (AL) to an ex vivo mechanical test was compared between two protocols: eyes that underwent sustained intraocular pressure (IOP) increase and eyes after optic nerve crush. Methods Chronic IOP elevation was induced by microbead injection or the optic nerve was crushed in mice with widespread green fluorescence. After 3 days or 6 weeks, eyes were inflation tested by a published method of two-photon fluorescence to image the AL. Digital volume correlation was used to calculate strains. Optic nerve axon damage was also evaluated. Results In the central AL but not the peripheral AL, four strains were greater in eyes at the 3-day glaucoma time point than control ( P from 0.029 to 0.049, n = 8 eyes per group). Also, at this time point, five strains were greater in the central AL compared to the peripheral AL ( P from 0.041 to 0.00003). At the 6-week glaucoma time point, the strains averaged across the specimen, in the central AL, and the peripheral AL were indistinguishable from the respective controls. Strains were not significantly different between controls and eyes 3 days or 6 weeks after crush ( n = 8 and 16). Conclusions We found alterations in the ex vivo mechanical behavior in eyes from mice with experimental glaucoma but not in those with crushed optic nerves. The results of this study demonstrate that significant axon injury does not directly affect mechanical behavior of the astrocytic lamina.

show abstract

Section: Discussionmentioning

confidence: 99%

Comparison of the Biomechanics of the Mouse Astrocytic Lamina Cribrosa Between Glaucoma and Optic Nerve Crush Models

Korneva,

Kimball,

Johnson

et al. 2023

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

show abstract

“…The OCT resolution is of 6.3 µm axially and 20 µm transversally. A more detailed description of the data acquisition protocol was previously published 12 .…”

Section: Methodsmentioning

confidence: 99%

“…We followed a methodology we have used in the past 12 : a known displacement field simulating the expansion of the choroid was created. 100 pairs of consecutive scans in the original and the one-cycle videos were identified, after which the second scan of each pair was warped with the known deformation field (for the one-cycle videos, those hundred scans were simply the one-cycle video itself).…”

Section: Methodsmentioning

confidence: 99%

“…The characterization of ocular biomechanics, and particularly the calculation of stress and strain in retinal tissues driven by several stimuli was characterized in numerical simulations based on finite element modeling 4 – 6 , or in non-human primates subjected to acutely elevated IOP 7 – 9 . Human subjects with high and normal-tension glaucoma were studied using a digital volume correlation technique to map deformations 10 , a 3D tracking algorithm based on optimizing numerical transformations of OCT volumes was used to quantify strains in optic nerves of glaucoma subjects after IOP reduction by trabeculectomy 11 , and displacement maps were obtained to characterize the behavior of the retina and optic nerve head in normal and myopia cohorts subjected to optic nerve physiological traction due to eye movement 12 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Denoising OCT videos based on temporal redundancy

Richer,

Solano,

Cheriet

et al. 2024

Sci Rep

Self Cite

View full text Add to dashboard Cite

The identification of eye diseases and their progression often relies on a clear visualization of the anatomy and on different metrics extracted from Optical Coherence Tomography (OCT) B-scans. However, speckle noise hinders the quality of rapid OCT imaging, hampering the extraction and reliability of biomarkers that require time series. By synchronizing the acquisition of OCT images with the timing of the cardiac pulse, we transform a low-quality OCT video into a clear version by phase-wrapping each frame to the heart pulsation and averaging frames that correspond to the same instant in the cardiac cycle. Here, we compare the performance of our one-cycle denoising strategy with a deep-learning architecture, Noise2Noise, as well as classical denoising methods such as BM3D and Non-Local Means (NLM). We systematically analyze different image quality descriptors as well as region-specific metrics to assess the denoising performance based on the anatomy of the eye. The one-cycle method achieves the highest denoising performance, increases image quality and preserves the high-resolution structures within the eye tissues. The proposed workflow can be readily implemented in a clinical setting.

show abstract

“…We developed a method to measure ONH changes during the peripheral pulse which on its own may have important implications [28][29][30]. It is possible that what we learn from these pulsatile measurements may lead to a better understanding of the pathophysiology of glaucoma and help with diagnosis and management.…”

Section: Introductionmentioning

confidence: 99%

Optic Nerve Head Pulsatile Displacement in Open-Angle Glaucoma after Intraocular Pressure Reduction Measured by Optical Coherence Tomography: A Pilot Study

Masís Solano,

Richer,

Costantino

et al. 2024

Bioengineering

Self Cite

View full text Add to dashboard Cite

This study investigated the effect of intraocular pressure (IOP) reduction on pulsatile displacement within the optic nerve head (ONH) in primary open-angle glaucoma (POAG) patients with and without axial myopia. Forty-one POAG patients (19 without myopia, 9 with axial myopia and 13 glaucoma with no intervention) participated. Swept-source optical coherence tomography (OCT) videos of the ONH were obtained before and after IOP-lowering treatment (medical or surgical) achieving a minimum IOP drop of 3 mmHg. A demons registration-based algorithm measured local pulsatile displacement maps within the ONH. Results demonstrated a significant 14% decrease in pulsatile tissue displacement in the non-myopic glaucoma cohort after intervention (p = 0.03). However, glaucoma patients with axial myopia exhibited no statistically significant change. There were no significant changes in the pulsatile ONH deformation in the control group. These findings suggest a potential link between IOP reduction and reduced pulsatile displacement within the ONH in POAG patients without myopia, offering new insights into the disease’s pathophysiology and warranting further investigation into underlying mechanisms and clinical implications.

show abstract

Mapping Pulsatile Optic Nerve Head Deformation Using OCT

Cited by 6 publications

References 43 publications

Comparison of the Biomechanics of the Mouse Astrocytic Lamina Cribrosa Between Glaucoma and Optic Nerve Crush Models

Comparison of the Biomechanics of the Mouse Astrocytic Lamina Cribrosa Between Glaucoma and Optic Nerve Crush Models

Denoising OCT videos based on temporal redundancy

Optic Nerve Head Pulsatile Displacement in Open-Angle Glaucoma after Intraocular Pressure Reduction Measured by Optical Coherence Tomography: A Pilot Study

Contact Info

Product

Resources

About