PURPOSE To study the relationship between intraocular pressure (IOP) and the IOP-related stress (force/cross-sectional area) it generates within the load-bearing connective tissues of the optic nerve head. METHODS Thirteen digital, three-dimensional geometries were created representing the posterior scleral shell of 13 idealized human eyes. Each three-dimensional geometry was then discretized...

The sclera is the protective outer layer of the eye. In fishes, birds, and reptiles, the sclera may be reinforced with additional bony elements called scleral ossicles. Teleost fish vary in the number and size of scleral ossicles; however, the genetic mechanisms responsible for this variation remain poorly understood. In this study, we examine the inheritance of scleral ossicles in the Mexican ...

PURPOSE The development of high myopia is associated with scleral thinning and changes in the diameter of scleral collagen fibrils in humans. In the present study, the association between these scleral changes and the losses in scleral tissue that have previously been reported in animal models were investigated to determine the relationship between changes in collagen fibril architecture and th...

In this paper a new electromechanically actuated punch (EAP) is presented. This punch can apply forces up to 10 kN and has a stroke up to 4mm. Due to the high dynamics drive-concept, the ram’s kinematics is changeable during the punch process and backlashes are non-existent. Therefore, the punch is especially qualified for manufacturing micro-components demanding high accuracy and high stroke r...

PURPOSE Manometric studies have found that intraocular pressure (IOP) rises 116-350 mmHg during scleral depression in surgical settings. No information is available regarding the effect of scleral depression on IOP in routine clinical settings. The aim of this study is to quantify the change in IOP that occurs when scleral depression is performed on normal eyes in a routine clinical setting. ...

OBJECTIVES To investigate the influence of full scleral lenses on corneal curvature and pachymetry in keratoconus patients. METHODS In this intervention study, 20 eyes of 14 patients were measured by Scheimpflug imaging (Pentacam HR, Oculus) at two time points: directly and ≥1 week after scleral lens removal. Steep, flat and maximal keratometry (K(steep), K(flat) and K(max)) and optical pachy...

Scleral contact lenses (ScCL) have gained renewed interest during the last decade. Originally, they were primarily used for severely compromised eyes. Corneal ectasia and exposure conditions were the primary indications. However, the indication range of ScCL in contact lens practices seems to be expanding, and it now increasingly includes less severe and even non-compromised eyes, too. All lens...

PURPOSE To identify an effective method to prevent myopia progression by characterizing the regulation of matrix metalloproteinase- (MMP-) 2 expression and its secretion from scleral fibroblasts and retinal pigment epithelium (RPE) cells by miR-29a. METHODS The effects of miR-29a on the growth of scleral fibroblasts and RPE cells were assessed using the cell counting kit-8. The changes in MMP...

Deep drawing process is one of the most applicable methods in producing industrial parts. In this process, the initial blank deforms to final product using a rigid punch and die. In this investigation, the effect of deep drawing process parameters of brass/steel laminated sheet composites on required forming force has been investigated. The process simulated using finite element method (FEM) an...

In this paper, torsion extrusion (TE) process on 1050 aluminum alloy was investigated by simulation as a severe plastic deformation (SPD) method and the effects of friction coefficient, angular velocity of the rotating die and punch speed on maximum punch force were studied. A finite element (FE) model was developed to simulate the TE process via DEFORM software. The FE results were validated co...