Acute downregulation of emerin alters actomyosin cytoskeleton connectivity and function.

Fetal lung fibroblasts contribute dynamic infrastructure for the developing lung. These cells undergo dynamic mechanical transitions, including cyclic stretch and spreading, which are integral to lung growth in utero. We investigated the role of the nuclear envelope protein emerin in cellular responses to these dynamic mechanical transitions. In contrast to control cells, which briskly realigned their nuclei, actin cytoskeleton, and extracellular matrices in response to cyclic stretch, fibroblasts that were acutely downregulated for emerin showed incomplete reorientation of both nuclei and actin cytoskeleton. Emerin-downregulated fibroblasts were also aberrantly circular in contrast to the spindle-shaped controls and exhibited an altered pattern of filamentous actin organization that was disconnected from the nucleus. Emerin knockdown was also associated with reduced myosin light chain phosphorylation during cell spreading. Interestingly, emerin-downregulated fibroblasts also demonstrated reduced fibronectin fibrillogenesis and production. These findings indicate that nuclear-cytoskeletal coupling serves a role in the dynamic regulation of cytoskeletal structure and function and may also impact the transmission of traction force to the extracellular matrix microenvironment.

The Curvature, Collagen Network Structure, and Their Relationship to the Pressure-Induced Strain Response of the Human Lamina Cribrosa in Normal and Glaucoma Eyes.

The lamina cribrosa (LC) is a connective tissue in the optic nerve head (ONH). The objective of this study was to measure the curvature and collagen microstructure of the human LC, compare the effects of glaucoma and glaucoma optic nerve damage, and investigate the relationship between the structure and pressure-induced strain response of the LC in glaucoma eyes. Previously, the posterior scleral cups of 10 normal eyes and 16 diagnosed glaucoma eyes were subjected to inflation testing with second harmonic generation (SHG) imaging of the LC and digital volume correlation (DVC) to calculate the strain field. In this study, we applied a custom microstructural analysis algorithm to the maximum intensity projection of SHG images to measure features of the LC beam and pore network. We also estimated the LC curvatures from the anterior surface of the DVC-correlated LC volume. Results showed that the LC in glaucoma eyes had larger curvatures p≤0.03), a smaller average pore area (p = 0.001), greater beam tortuosity (p < 0.0001), and more isotropic beam structure (p = 0.01) than in normal eyes. The difference measured between glaucoma and normal eyes may indicate remodeling of the LC with glaucoma or baseline differences that contribute to the development of glaucomatous axonal damage.

Estimations of the effective Young's modulus of specimens prepared by fused filament fabrication.

The elastic response of homogeneous isotropic materials is most commonly represented by their Young's modulus (E), but geometric variability associated with additive manufacturing results in materials that are neither homogeneous nor isotropic. Here we investigated methods to estimate the effective elastic modulus (Eeff) of samples fabricated by fused filament fabrication. We conducted finite element analysis (FEA) on printed samples based on material properties and CT-scanned geometries. The analysis revealed how the layer structure of a specimen altered the internal stress distribution and the resulting Eeff. We also investigated different empirical methods to estimate Eeff as guides. We envision the findings from our study can provide guidelines for modulus estimation of as-printed specimens, with the potential of applying to other extrusion-based additive manufacturing technologies.

Artificial Intelligence Classification of Central Visual Field Patterns in Glaucoma.

PURPOSE: To quantify the central visual field (VF) loss patterns in glaucoma using artificial intelligence. DESIGN: Retrospective study. PARTICIPANTS: VFs of 8712 patients with 13 951 Humphrey 10-2 test results from 13 951 eyes for cross-sectional analyses, and 824 patients with at least 5 reliable 10-2 test results at 6-month intervals or more from 1191 eyes for longitudinal analyses. METHODS: Total deviation values were used to determine the central VF patterns using the most recent 10-2 test results. A 24-2 VF within a 3-month window of the 10-2 tests was used to stage eyes into mild, moderate, or severe functional loss using the Hodapp-Anderson-Parrish scale at baseline. Archetypal analysis was applied to determine the central VF patterns. Cross-validation was performed to determine the optimal number of patterns. Stepwise regression was applied to select the optimal feature combination of global indices, average baseline decomposition coefficients from central VFs archetypes, and other factors to predict central VF mean deviation (MD) slope based on the Bayesian information criterion (BIC). MAIN OUTCOME MEASURES: The central VF patterns stratified by severity stage based on 24-2 test results and a model to predict the central VF MD change over time using baseline test results. RESULTS: From cross-sectional analysis, 17 distinct central VF patterns were determined for the 13 951 eyes across the spectrum of disease severity. These central VF patterns could be divided into isolated superior loss, isolated inferior loss, diffuse loss, and other loss patterns. Notably, 4 of the 5 patterns of diffuse VF loss preserved the less vulnerable inferotemporal zone, whereas they lost most of the remaining more vulnerable zone described by the Hood model. Inclusion of coefficients from central VF archetypical patterns strongly improved the prediction of central VF MD slope (BIC decrease, 35; BIC decrease of >6 indicating strong prediction improvement) than using only the global indices of 2 baseline VF results. Eyes with baseline VF results with more superonasal and inferonasal loss were more likely to show worsening MD over time. CONCLUSIONS: We quantified central VF patterns in glaucoma, which were used to improve the prediction of central VF worsening compared with using only global indices.

The effect of alignment on the rate-dependent behavior of a main-chain liquid crystal elastomer.

This study investigated the effect of alignment on the rate-dependent behavior of a main-chain liquid crystal elastomer (LCE). Polydomain nematic LCE networks were synthesized from a thiol-acrylate Michael addition reaction in the isotropic state. The polydomain networks were stretched to different strain levels to induce alignment then crosslinked in a second stage photopolymerization process. The LCE networks were subjected to dynamic mechanical tests to measure the temperature-dependent storage modulus and uniaxial tension load-unload tests to measure the rate-dependence of the Young's modulus, mechanical dissipation, and characteristics of the soft stress response. Three-dimensional (3D) digital image correlation (DIC) was used to characterize the effect of domain/mesogen relaxation on the strain fields. All LCE networks exhibited a highly rate-dependent stress response with significant inelastic strains after unloading. The Young's modulus of the loading curve and hysteresis of the load-unload curves showed a power-law dependence on the strain rate. The Young's modulus increased with alignment and larger anisotropy and a smaller power-law exponent was measured for the Young's modulus and hysteresis for the highly aligned monodomains. The polydomain and pre-stretched networks loaded perpendicular to the alignment direction exhibited a soft stress response that featured a rate-dependent peak stress, strain-softening, and strain-stiffening. The 3D-DIC strain fields for the polydomain network and programmed networks stretched in the perpendicular direction were highly heterogeneous, showing regions of alternating higher and lower strains. The strain variations increased initially with loading, peaked during the strain softening part of the stress response, then decreased during the strain stiffening part of the stress response. Greater variability was measured for lower strain rates. These observations suggest that local domain/mesogen relaxation led to the development of the heterogeneous strain patterns and strain softening in stress response. These findings improved understanding of the kinetics of mesogen relaxation and its contributions to the rate-dependent stress response and mechanical dissipation.

Biomechanical Evaluations of Ocular Injury Risk for Blast Loading.

Ocular trauma is one of the most common types of combat injuries resulting from the exposure of military personnel with improvised explosive devices. The injury mechanism associated with the primary blast wave is poorly understood. We employed a three-dimensional computational model, which included the main internal ocular structures of the eye, spatially varying thickness of the cornea-scleral shell, and nonlinear tissue properties, to calculate the intraocular pressure and stress state of the eye wall and internal ocular structure caused by the blast. The intraocular pressure and stress magnitudes were applied to estimate the injury risk using existing models for blunt impact and blast loading. The simulation results demonstrated that blast loading can induce significant stresses in the different components of the eyes that correlate with observed primary blast injuries in animal studies. Different injury models produced widely different injury risk predictions, which highlights the need for experimental studies evaluating mechanical and functional damage to the ocular structures caused by the blast loading.

A comparison of 2D and 3D digital image correlation for a membrane under inflation.

Three-dimensional (3D) digital image correlation (DIC) is becoming widely used to characterize the behavior of structures undergoing 3D deformations. However, the use of 3D-DIC can be challenging under certain conditions, such as high magnification, and therefore small depth of field, or a highly controlled environment with limited access for two-angled cameras. The purpose of this study is to compare 2D-DIC and 3D-DIC for the same inflation experiment and evaluate whether 2D-DIC can be used when conditions discourage the use of a stereo-vision system. A latex membrane was inflated vertically to 5.41 kPa (reference pressure), then to 7.87 kPa (deformed pressure). A two-camera stereo-vision system acquired top-down images of the membrane, while a single camera system simultaneously recorded images of the membrane in profile. 2D-DIC and 3D-DIC were used to calculate horizontal (in the membrane plane) and vertical (out of the membrane plane) displacements, and meridional strain. Under static conditions, the baseline uncertainty in horizontal displacement and strain were smaller for 3D-DIC than 2D-DIC. However, the opposite was observed for the vertical displacement, for which 2D-DIC had a smaller baseline uncertainty. The baseline absolute error in vertical displacement and strain were similar for both DIC methods, but it was larger for 2D-DIC than 3D-DIC for the horizontal displacement. Under inflation, the variability in the measurements were larger than under static conditions for both DIC methods. 2D-DIC showed a smaller variability in displacements than 3D-DIC, especially for the vertical displacement, but a similar strain uncertainty. The absolute difference in the average displacements and strain between 3D-DIC and 2D-DIC were in the range of the 3D-DIC variability. Those findings suggest that 2D-DIC might be used as an alternative to 3D-DIC to study the inflation response of materials under certain conditions.

Micromechanical Modeling Study of Mechanical Inhibition of Enzymatic Degradation of Collagen Tissues.

This study investigates how the collagen fiber structure influences the enzymatic degradation of collagen tissues. We developed a micromechanical model of a fibrous collagen tissue undergoing enzymatic degradation based on two central hypotheses. The collagen fibers are crimped in the undeformed configuration. Enzymatic degradation is an energy activated process and the activation energy is increased by the axial strain energy density of the fiber. We determined the intrinsic degradation rate and characteristic energy for mechanical inhibition from fibril-level degradation experiments and applied the parameters to predict the effect of the crimped fiber structure and fiber properties on the degradation of bovine cornea and pericardium tissues under controlled tension. We then applied the model to examine the effect of the tissue stress state on the rate of tissue degradation and the anisotropic fiber structures that developed from enzymatic degradation.

Biomechanical assessment in models of glaucomatous optic neuropathy.

The biomechanical environment within the eye is of interest in both the regulation of intraocular pressure and the loss of retinal ganglion cell axons in glaucomatous optic neuropathy. Unfortunately, this environment is complex and difficult to determine. Here we provide a brief introduction to basic concepts of mechanics (stress, strain, constitutive relationships) as applied to the eye, and then describe a variety of experimental and computational approaches used to study ocular biomechanics. These include finite element modeling, direct experimental measurements of tissue displacements using optical and other techniques, direct experimental measurement of tissue microstructure, and combinations thereof. Thanks to notable technical and conceptual advances in all of these areas, we are slowly gaining a better understanding of how tissue biomechanical properties in both the anterior and posterior segments may influence the development of, and risk for, glaucomatous optic neuropathy. Although many challenging research questions remain unanswered, the potential of this body of work is exciting; projects underway include the coupling of clinical imaging with biomechanical modeling to create new diagnostic tools, development of IOP control strategies based on improved understanding the mechanobiology of the outflow tract, and attempts to develop novel biomechanically-based therapeutic strategies for preservation of vision in glaucoma.

Solvent-driven temperature memory and multiple shape memory effects.

Thermally-activated temperature memory and multiple shape memory effects have been observed in amorphous polymers with a broad glass transition. In this work, we demonstrate that the same shape recovery behaviors can also be achieved through solvent absorption. We investigate the recovery behaviors of programmed Nafion membranes in various solvents and compare the solvent-driven and temperature-driven shape recovery response. The results show that the programming temperature and solvent type have a corresponding strong influence on the shape recovery behavior. Specifically, lower programming temperatures induce faster initial recovery rates and larger recovery, which is known as the temperature memory effect. The temperature memory effect can be used to achieve multi-staged and multiple shape recovery of specimens programmed at different temperatures. Different solvents can also induce different shape recovery, analogous to the temperature memory effect, and can also provide a mechanism for multi-staged and multiple shape memory recovery.

Collagen structure and mechanical properties of the human sclera: analysis for the effects of age.

The objective of this study was to measure the collagen fiber structure and estimate the material properties of 7 human donor scleras, from age 53 to 91. The specimens were subjected to inflation testing, and the full-field displacement maps were measured by digital image correlation. After testing, the collagen fiber structure was mapped using wide-angle X-ray scattering. A specimen-specific inverse finite element method was applied to calculate the material properties of the collagen fibers and interfiber matrix by minimizing the difference between the experimental displacements and model predictions. Age effects on the fiber structure and material properties were estimated using multivariate models accounting for spatial autocorrelation. Older age was associated with a larger matrix stiffness (p = 0.001), a lower degree of fiber alignment in the peripapillary sclera (p = 0.01), and a lower mechanical anisotropy in the peripapillary sclera (p = 0.03).

Effects of age and diabetes on scleral stiffness.

The effects of diabetes on the collagen structure and material properties of the sclera are unknown but may be important to elucidate whether diabetes is a risk factor for major ocular diseases such as glaucoma. This study provides a quantitative assessment of the changes in scleral stiffness and collagen fiber alignment associated with diabetes. Posterior scleral shells from five diabetic donors and seven non-diabetic donors were pressurized to 30 mm Hg. Three-dimensional surface displacements were calculated during inflation testing using digital image correlation (DIC). After testing, each specimen was subjected to wide-angle X-ray scattering (WAXS) measurements of its collagen organization. Specimen-specific finite element models of the posterior scleras were generated from the experimentally measured geometry. An inverse finite element analysis was developed to determine the material properties of the specimens, i.e., matrix and fiber stiffness, by matching DIC-measured and finite element predicted displacement fields. Effects of age and diabetes on the degree of fiber alignment, matrix and collagen fiber stiffness, and mechanical anisotropy were estimated using mixed effects models accounting for spatial autocorrelation. Older age was associated with a lower degree of fiber alignment and larger matrix stiffness for both diabetic and non-diabetic scleras. However, the age-related increase in matrix stiffness was 87% larger in diabetic specimens compared to non-diabetic controls and diabetic scleras had a significantly larger matrix stiffness (p = 0.01). Older age was associated with a nearly significant increase in collagen fiber stiffness for diabetic specimens only (p = 0.06), as well as a decrease in mechanical anisotropy for non-diabetic scleras only (p = 0.04). The interaction between age and diabetes was not significant for all outcomes. This study suggests that the age-related increase in scleral stiffness is accelerated in eyes with diabetes, which may have important implications in glaucoma.

Experimental scleral cross-linking increases glaucoma damage in a mouse model.

The purpose of this study was to assess the effect of a scleral cross-linking agent on susceptibility to glaucoma damage in a mouse model.CD1 mice underwent 3 subconjunctival injections of 0.5 M glyceraldehyde (GA) in 1 week, then had elevated intraocular pressure (IOP) induced by bead injection. Degree of cross-linking was measured by enzyme-linked immunosorbent assay (ELISA), scleral permeability was measured by fluorescence recovery after photobleaching (FRAP), and the mechanical effects of GA exposure were measured by inflation testing. Control mice had buffer injection or no injection in 2 separate glaucoma experiments. IOP was monitored by Tonolab and retinal ganglion cell (RGC) loss was measured by histological axon counting. To rule out undesirable effects of GA, we performed electroretinography and detailed histology of the retina. GA exposure had no detectable effects on RGC number, retinal structure or function either histologically or electrophysiologically. GA increased cross-linking of sclera by 37% in an ELISA assay, decreased scleral permeability (FRAP, p = 0.001), and produced a steeper pressure-strain behavior by in vitro inflation testing. In two experimental glaucoma experiments, GA-treated eyes had greater RGC axon loss from elevated IOP than either buffer-injected or control eyes, controlling for level of IOP exposure over time (p = 0.01, and 0.049, multivariable regression analyses). This is the first report that experimental alteration of the sclera, by cross-linking, increases susceptibility to RGC damage in mice.

Susceptibility to glaucoma damage related to age and connective tissue mutations in mice.

The purpose of this research was to study the effects of age and genetic alterations in key connective tissue proteins on susceptibility to experimental glaucoma in mice. We used mice haploinsufficient in the elastin gene (EH) and mice without both alleles of the fibromodulin gene (FM KO) and their wild type (WT) littermates of B6 and CD1 strains, respectively. FM KO mice were tested at two ages: 2 months and 12 months. Intraocular pressure (IOP) was measured by Tonolab tonometer, axial lengths and widths measured by digital caliper post-enucleation, and chronic glaucoma damage was measured using a bead injection model and optic nerve axon counts. IOP in EH mice was not significantly different from WT, but FM KO were slightly lower than their controls (p = 0.04). Loss of retinal ganglion cell (RGC) axons was somewhat, but not significantly greater in young EH and younger or older FM KO strains than in age-matched controls (p = 0.48, 0.34, 0.20, respectively, multivariable regression adjusting for IOP exposure). Older CD1 mice lost significantly more RGC axons than younger CD1 (p = 0.01, multivariable regression). The CD1 mouse strain showed age-dependence of experimental glaucoma damage to RGC in the opposite, and more expected, direction than in B6 mice in which older mice are more resistant to damage. Genetic alteration in two genes that are constituents of sclera, fibromodulin and elastin do not significantly affect RGC loss.

IOP and glaucoma damage: The essential role of optic nerve head and retinal mechanosensors.

There are many unanswered questions on the relation of intraocular pressure to glaucoma development and progression. IOP itself cannot be distilled to a single, unifying value, because IOP level varies over time, differs depending on ocular location, and can be affected by method of measurement. Ultimately, IOP level creates mechanical strain that affects axonal function at the optic nerve head which causes local extracellular matrix remodeling and retinal ganglion cell death - hallmarks of glaucoma and the cause of glaucomatous vision loss. Extracellular tissue strain at the ONH and lamina cribrosa is regionally variable and differs in magnitude and location between healthy and glaucomatous eyes. The ultimate targets of IOP-induced tissue strain in glaucoma are retinal ganglion cell axons at the optic nerve head and the cells that support axonal function (astrocytes, the neurovascular unit, microglia, and fibroblasts). These cells sense tissue strain through a series of signals that originate at the cell membrane and alter cytoskeletal organization, migration, differentiation, gene transcription, and proliferation. The proteins that translate mechanical stimuli into molecular signals act as band-pass filters - sensing some stimuli while ignoring others - and cellular responses to stimuli can differ based on cell type and differentiation state. Therefore, to fully understand the IOP signals that are relevant to glaucoma, it is necessary to understand the ultimate cellular targets of IOP-induced mechanical stimuli and their ability to sense, ignore, and translate these signals into cellular actions.

Long-term Remodeling Response in the Lamina Cribrosa Years after Intraocular Pressure Lowering by Suturelysis after Trabeculectomy.

OBJECTIVE: To measure the remodeling of the lamina cribrosa (LC) years after intraocular pressure (IOP) lowering by suturelysis. DESIGN: Cohort study. PARTICIPANTS: Glaucoma patients were imaged 20 minutes after laser suturelysis after trabeculectomy surgery and at their follow-up appointment 1 to 4 years later (16 image pairs; 15 persons). INTERVENTION: Noninvasive OCT imaging of the eye. MAIN OUTCOME MEASURES: Deformation calculated by correlating OCT scans of the LC immediately after IOP lowering by suturelysis and those acquired years later (defined as remodeling strain). RESULTS: The LC anterior border moved 60.9 ± 54.6 µm into the eye (P = 0.0007), and the LC exhibited regions of large local stretch in the anterior-posterior direction on long-term, maintained IOP lowering, resulting in a mean anterior-posterior remodeling strain of 14.0% ± 21.3% (P = 0.02). This strain and the LC border movement was 14 times and 124 times larger, respectively, than the direct response to IOP lowering by suturelysis. A larger anterior LC border movement was associated with greater mean anterior-posterior remodeling strain (P = 0.004). A thinner retinal nerve fiber layer at suturelysis was also associated with greater mean anterior-posterior remodeling strain at follow-up (P = 0.05). Worsening visual field indexes during follow-up were associated with a greater mean circumferential remodeling strain (P = 0.02), due to regions of large local circumferential stretch of the LC. Eyes with a more compliant LC torsional shear strain response at lysis were associated with worse mean deviation at follow-up (P = 0.03). CONCLUSIONS: Strains and LC border position changes measured years after IOP lowering are far larger than the immediate response to IOP lowering and indicate dramatic remodeling of the LC anatomical structure caused by IOP lowering and glaucoma progression. The remodeling strains indicate substantial local stretch in the anterior-posterior direction and are associated with movement of the LC anterior border into the eye. Eyes with greater direct strain response to IOP lowering, greater glaucoma damage at suturelysis, and greater worsening of visual field at follow-up experienced greater remodeling. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03267849. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

A Noninvasive Clinical Method to Measure in Vivo Mechanical Strains of the Lamina Cribrosa by OCT.

Objective: To measure mechanical strain of the lamina cribrosa (LC) after intraocular pressure (IOP) change produced 1 week after a change in glaucoma medication. Design: Cohort study. Participants: Adult glaucoma patients (23 eyes, 15 patients) prescribed a change in IOP-lowering medication. Intervention: Noninvasive OCT imaging of the eye. Main Outcome Measures: Deformation calculated by digital volume correlation of OCT scans of the LC before and after IOP lowering by medication. Results: Among 23 eyes, 17 eyes of 12 persons had IOP lowering ≥ 3 mmHg (reduced IOP group) with tensile anterior-posterior Ezz strain = 1.0% ± 1.1% (P = 0.003) and compressive radial strain (Err) = -0.3% ± 0.5% (P = 0.012; random effects models accounting inclusion of both eyes in some persons). Maximum in-plane principal (tensile) strain and maximum shear strain in the reduced-IOP group were as follows: Emax = 1.7% ± 1.0% and Γmax = 1.4% ± 0.7%, respectively (both P < 0.0001 vs. zero). Reduced-IOP group strains Emax and Γmax were significantly larger with greater % IOP decrease (P < 0.0001 and P < 0.0001, respectively). The compliances of the Ezz, Emax, and Γmax strain responses, defined as strain normalized by the IOP decrease, were larger with more abnormal perimetric mean deviation or visual field index values (all P ≤ 0.02). Strains were unrelated to age (all P ≥ 0.088). In reduced-IOP eyes, mean LC anterior border posterior movement was only 2.05 µm posteriorly (P = 0.052) and not related to % IOP change (P = 0.94, random effects models). Only Err was significantly related to anterior lamina depth change, becoming more negative with greater posterior LC border change (P = 0.015). Conclusions: Lamina cribrosa mechanical strains can be effectively measured by changes in eye drop medication using OCT and are related to degree of visual function loss in glaucoma. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Minimal preconditioning effects observed for inflation tests of planar tissues.

The purpose of this study is to investigate the effects of preconditioning on the deformation response of planar tissues measured by inflation tests. The inflation response of test specimens, including the bovine cornea, bovine and porcine sclera, and human skin, exhibited a negligible evolving deformation response when subjected to repeated pressure loading with recovery periods between cycles. Tissues obtained complete recovery to the reference state, and strain contours across the entire specimen were nearly identical at the maximum pressure of each load cycle. This repeatability was obtained regardless of strain history. These results suggest that negligible permanent change was induced in the microstructure by inflation testing. Additionally, we present data illustrating that a lack of a recovery period can result in an evolving deformation response to repeated loading that is commonly attributed to preconditioning. These results suggest that the commonly observed effects of preconditioning may be avoided by experimental design for planar tissues characterized by long collagen fibers arranged in the plane of the tissue. Specifically, if the test is designed to fully fix the specimen boundary during loading, adequate recovery periods are allowed after each load cycle, and loads are limited to avoid damage, preconditioning effects may be avoided for planar tissues.

A noninvasive clinical method to measure in vivo mechanical strains of the lamina cribrosa by optical coherence tomography.

Objective: To measure mechanical strain of the lamina cribrosa (LC) after intraocular pressure (IOP) change produced one week after a change in glaucoma medication. Design: Cohort study. Participants: Adult glaucoma patients (23 eyes, 15 patients) prescribed a change in IOP-lowering medication. Intervention: Non-invasive optical coherence tomography (OCT) imaging of the eye. Main Outcomes: Deformation calculated by digital volume correlation of OCT scans of the LC before and after IOP lowering by medication. Results: Among 23 eyes, 17 eyes of 12 persons had IOP lowering ≥ 3 mmHg (reduced IOP group) with tensile anterior-posterior E zz strain = 1.0% ± 1.1% (p = 0.003) and compressive radial strain ( E rr ) = -0.3% ± 0.5% (p=0.012; random effects models accounting inclusion of both eyes in some persons). Maximum in-plane principal (tensile) strain and maximum shear strain in the reduced IOP group were: E max = 1.7% ± 1.0% and Γ max = 1.4% ± 0.7%, respectively (both p<0.0001 versus zero). Reduced IOP group strains E max and Γ max were significantly larger with greater %IOP decrease (<0.0001, <0.0001). The compliance of the E zz , E max , and Γ max strain response, defined as strain normalized by the IOP decrease, were larger with more abnormal perimetric mean deviation or visual field index values (all p≥0.02). Strains were unrelated to age (all p≥0.088). In reduced IOP eyes, mean LC anterior border posterior movement was only 2.05 µm posteriorly (p=0.052) and not related to % IOP change (p=0.94, random effects models). Only E rr was significantly related to ALD change, becoming more negative with greater posterior LC border change (p=0.015). Conclusion: LC mechanical strains can be effectively measured by changes in eye drop medication using OCT and are related to degree of visual function loss in glaucoma. Trial Registration: ClinicalTrials.gov Identifier: NCT03267849.