measurement-carotenoids-perifovea-using-macular-pigment

Measurement of Carotenoids in Perifovea using the Macular Pigment Reflectometer

The macular pigment reflectometer (MPR) objectively measures the overall macular pigment optical density (MPOD) and further provides the lutein optical ...

Western University of Health Sciences

Hematopoietic stem cells recipients remain susceptible to opportunistic viral infections including herpes simplex virus type-1 (HSV-1). The purpose of this investigation was to analyze susceptibility of human mesenchymal stem cells (hMSCs) to HSV-1 infection and identify the major entry receptor. Productive virus infection in hMSCs was confirmed by replication and plaque formation assays using a syncytial HSV-1 KOS (804) virus. To examine the significance of entry receptors, RT-PCR and antibody-blocking assays were performed. RT-PCR data showed the expression of gD receptors: nectin-1, 3-O sulfotransferase-3 (3-OST-3), and HVEM. Antibody-blocking assay together with heparinase treatment suggested an important role for HS and 3-O-sulfated heparan sulfate (3-OS HS), but not nectin-1 or HVEM, in mediating HSV-1 entry and spread in hMSCs. Taken together, our results provide strong evidence demonstrating that HSV-1 is capable of infecting hMSCs and HS and 3-OS HS serve as its entry receptors during this process.

Herpes simplex virus type-1 (HSV-1) entry into human mesenchymal stem cells is heavily dependent on heparan sulfate.

Herpes simplex virus type-1 (HSV-1) entry into target cell is initiated by the ionic interactions between positively charged viral envelop glycoproteins and a negatively charged cell surface heparan sulfate (HS). This first step involves the induction of HS-rich filopodia-like structures on the cell surface that facilitate viral transport during cell entry. Targeting this initial first step in HSV-1 pathogenesis, we generated different zinc oxide (ZnO) micro-nano structures (MNSs) that were capped with multiple nanoscopic spikes mimicking cell induced filopodia. These MNSs were predicted to target the virus to compete for its binding to cellular HS through their partially negatively charged oxygen vacancies on their nanoscopic spikes, to affect viral entry and subsequent spread. Our results demonstrate that the partially negatively charged ZnO-MNSs efficiently trap the virions via a novel virostatic mechanism rendering them unable to enter into human corneal fibroblasts - a natural target cell for HSV-1 infection. The anti-HSV-1 activity of ZnO MNSs was drastically enhanced after creating additional oxygen vacancies under UV-light illumination. Our results provide a novel insight into the significance of ZnO MNSs as the potent HSV-1 inhibitor and rationalize their development as a novel topical agent for the prevention of HSV-1 infection.

Virostatic potential of micro-nano filopodia-like ZnO structures against herpes simplex virus-1.

The peripheral refractive error of the human eye has been hypothesized to be a major stimulus for the development of its central refractive error.

Peripheral refraction and image blur in four meridians in emmetropes and myopes.

This study investigated in-vivo changes of peripheral refraction with commercially available single vision and multifocal soft contact lenses, utilizing different designs and various corrective power values. Starting at the fovea, wave-front aberrations were measured up to 30 nasal retinal eccentricity, in 10 increments, using a commercially available Shack-Hartmann aberrometer. Three different types of contact lenses were fitted in an adult subject's right eye: Acuvue Oasys Single Vision (ASV), Proclear Multifocal D with 2.50 diopters (D) add power (PMD), and ArtMost SoftOK (SOK). Each lens type was fitted in corrective power values of -2.00 D, -4.00 D, and -6.00 D. Refractive errors were computed in power vector notation: The spherical equivalent (M), the Cartesian Jackson-Cross-Cylinder (J), and the oblique Jackson Cross Cylinder (J) from measured second order Zernike terms. Acuvue Oasys Single Vision lenses produced a slight myopic shift at 30 retinal periphery (-0.32 D ± 0.05) without significant differences between the various lens power values. Proclear Multifocal D lenses did not create clinically significant myopic shifts of at least -0.25 D. All SOK lenses produced clinically significant relative myopic shifts at both 20 (-0.61 D ± 0.08) and 30 (-1.42 D ± 0.15) without significant differences between the various lens power values. For all lens types and power values, off-axis astigmatism J was increased peripherally and reached clinical significance beyond 20 retinal eccentricity. The increased amount of off-axis astigmatism J did not show a significant difference for the same type of lenses with different dioptric power. However, at 30 retinal eccentricity, SOK lenses produced significantly higher amounts of off-axis astigmatism J, compared with ASV and PMD lenses (SOK versus ASV versus PMD: -1.67 D ± 0.09, -0.81 D ± 0.07, and -0.72 D ± 0.15). Both ASV and SOK lenses showed no clinically significant differences in the amount of introduced astigmatic retinal image blur, with various lens power values. Proclear Multifocal D lenses showed a systematic increase of astigmatic retinal image blur with an increase of add power. At 30 retinal eccentricity, -6.00 D SOK lenses introduced 0.73 D astigmatic retinal image blur, while PMD and ASV lenses introduced 0.54 D and 0.37 D, respectively. In conclusion, relative peripheral refractions, measured in-vivo, were independent of the contact lenses central corrective power. The SOK contact lenses demonstrated a stronger capability in rendering relative peripheral myopic defocus into far periphery, compared to the other lens designs used in this study. This was accompanied by higher amounts of introduced astigmatic retinal image blur.

In-Vivo Evaluation of Peripheral Refraction Changes with Single Vision and Multifocal Soft Contact Lenses.

Keratoconus is a progressive corneal disease characterized by bilateral yet usually asymmetric thinning of the cornea with an onset typically in teenage years. While it often presents as an isolated condition, keratoconus may also be associated with many systemic and/or ocular diseases, such as connective tissue and chromosomal disorders. Its association with nystagmus has been described in Leber's congenital amaurosis, where patients also exhibit abnormal pupillary responses, early-onset retinal dystrophy, mental developmental delays, and eventual blindness. The case described here, however, was a high-functioning teenager with keratoconus and infantile nystagmus, and oscillopsia on left gaze and a compensatory head turn to the patient's left. The initial distance visual acuities of 20/60 and 20/150 in the right and left eye, respectively improved to 20/25 and 20/40 by the use of corneal rigid gas permeable contact lenses. In addition, the patient's neck strain and overall gait were eased by yoked prism spectacles.

Frank Spors

College of Optometry

Western University of Health Sciences

Measurement of Carotenoids in Perifovea using the Macular Pigment Reflectometer