Non-invasive Detection of Unique Molecular Signatures in Laser-Induced Retinal Injuries.

Unintentional laser exposure is an increasing concern in many operational environments. Determining whether a laser exposure event caused a retinal injury currently requires medical expertise and specialized equipment that are not always readily available. The purpose of this study is to test the feasibility of using dynamic light scattering (DLS) to non-invasively detect laser retinal injuries through interrogation of the vitreous humor (VH).

Longitudinal Study of Age-Related Cataract Using Dynamic Light Scattering: Loss of α-Crystallin Leads to Nuclear Cataract Development.

Purpose: To conduct a longitudinal study on age-related nuclear cataracts using dynamic light scattering (DLS) to determine if cataract progression is associated with loss of the unbound form of the lens molecular chaperone protein, α-crystallin.

Design: Natural history and cohort study.

Participants: Patients 30 years of age or older of either gender seeking treatment at the Wilmer Eye Institute Cornea-Cataract Department.

A hypothesis on biological protection from space radiation through the use of new therapeutic gases as medical counter measures.

Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is biological damage that is associated with increased oxidative stress.

Isoelectric focusing in a drop.

A novel approach to molecular separations is investigated using a technique termed droplet-based isoelectric focusing. Drops are manipulated discretely on a superhydrophobic surface, subjected to low voltages for isoelectric focusing, and split-resulting in a preparative separation. A universal indicator dye demonstrates the generation of stable, reversible pH gradients (3-10) in ampholyte buffers, and these gradients lead to protein focusing within the drop length.

Hydrogen therapy may reduce the risks related to radiation-induced oxidative stress in space flight.

Cosmic radiation is known to induce DNA and lipid damage associated with increased oxidative stress and remains a major concern in space travel. Hydrogen, recently discovered as a novel therapeutic medical gas in a variety of biomedical fields, has potent antioxidant and anti-inflammatory activities. It is expected that space mission activities will increase in coming years both in numbers and duration.

Clinical detection of precataractous lens protein changes using dynamic light scattering.

Objective: To use dynamic light scattering to clinically assess early precataractous lens protein changes.

Methods: We performed a cross-sectional study in 380 eyes of 235 patients aged 7 to 86 years with Age-Related Eye Disease Study clinical nuclear lens opacity grades 0 to 3.8.

Measurement of lens protein aggregation in vivo using dynamic light scattering in a guinea pig/UVA model for nuclear cataract.

The role of UVA radiation in the formation of human nuclear cataract is not well understood. We have previously shown that exposing guinea pigs for 5 months to a chronic low level of UVA light produces increased lens nuclear light scattering and elevated levels of protein disulfide. Here we have used the technique of dynamic light scattering (DLS) to investigate lens protein aggregation in vivo in the guinea pig/UVA model.

Pharmacologic vitreolysis with microplasmin increases vitreous diffusion coefficients.

Background: Pharmacologic vitreolysis is a new approach to improve vitreo-retinal surgery and ultimately to liquefy and detach the vitreous from the retina to eliminate the contribution of the vitreous to retinopathy. The mechanism of action of the agents being developed for pharmacologic vitreolysis remains unclear. The effect of microplasmin on vitreous diffusion coefficients was investigated using the non-invasive technique of dynamic light scattering (DLS).

Particle-size and velocity measurements in flowing conditions using dynamic light scattering.

The noninvasive optical technique of dynamic light scattering (DLS) is routinely used to characterize dilute and transparent submicrometer particle dispersions in laboratory environments. A variety of industrial and biological applications would, however, greatly benefit from on-line monitoring of dispersions under flowing conditions. We present a model experiment to study flowing dispersions of polystyrene latex particles of varying sizes under varying flow conditions by using a newly developed fiber-optic DLS probe.

Aggregation of lens crystallins in an in vivo hyperbaric oxygen guinea pig model of nuclear cataract: dynamic light-scattering and HPLC analysis.

Purpose: The role of oxygen in the formation of lens high-molecular-weight (HMW) protein aggregates during the development of human nuclear cataract is not well understood. The purpose of this study was to investigate lens crystallin aggregate formation in hyperbaric oxygen (HBO)-treated guinea pigs by using in vivo and in vitro

Methods: methods. Guinea pigs were treated three times weekly for 7 months with HBO, and lens crystallin aggregation was investigated in vivo with the use of dynamic light-scattering (DLS) and in vitro by HPLC analysis of water-insoluble (WI) proteins.

New optical scheme for a polarimetric-based glucose sensor.

A new optical scheme to detect glucose concentration in the aqueous humor of the eye is presented. The ultimate aim is to apply this technique in designing a new instrument for, routinely and frequently, noninvasively monitoring blood glucose levels in diabetic patients without contact (no index matching) between the eye and the instrument. The optical scheme exploits the Brewster reflection of circularly polarized light off of the lens of the eye.

Ocular static and dynamic light scattering: a noninvasive diagnostic tool for eye research and clinical practice.

The noninvasive techniques of static and dynamic light scattering are emerging as valuable diagnostic tools for the early detection of ocular and systemic diseases. These include corneal abnormalities, pigmentary dispersion syndrome, glaucoma, cataract, diabetic vitreopathy, and possibly macular degeneration. Systemic conditions such as diabetes and possibly Alzheimer's disease can potentially be detected early via ocular tissues.

In vivo assessment of diabetic lenses using dynamic light scattering.

One of the most threatening aspects of diabetes mellitus is the development of visual impairment. For example, cataracts are 1.6 times more common in people with diabetes than in those without diabetes.

A clinical study of the human lens with a dynamic light scattering device.

A study was conducted to determine the potential usefulness and repeatability of a new dynamic light scattering (DLS) device for clinical studies of the human lens and early cataract. Studies using the cold cataract model showed this new device to be more sensitive than the Scheimpflug cataract imaging system in detecting the earliest cataractous changes. A miniaturized clinical DLS device developed by NASA using fiber optic probes was mounted on a Keratoscope (Optikon 2000), which has a 3-dimensional aiming system for accurate repeated sampling of the same area of the lens.