Enhancing Rose Bengal penetration in human corneas using iontophoresis.

Rose Bengal photodynamic antimicrobial therapy (RB-PDAT) has poor corneal penetration, limiting its efficacy against acanthamoeba keratitis (AK). Iontophoresis enhances corneal permeation of charged molecules, piquing interest in its effects on RB in human corneas. Five donor whole globes each underwent iontophoresis with RB, soaking in RB, or were soaked in normal saline (controls).

Effect of compound treatments on mouse lens viscoelasticity.

Previous studies have shown that pharmaceutical agents such as lipoic acid have the ability to soften the lens, presenting a promising avenue for treating presbyopia. One obstacle encountered in the preclinical stage of such agents is the need for precise measurements of lens elasticity in experimental models. This study aimed to evaluate the effects of 25-hydroxycholesterol, lipoic acid, and obeticholic acid on the viscoelastic properties of mouse lenses using a custom-built elastometer system.

Validating the use of a stereoscopic robotized teleophthalmic drone slit lamp.

Objective: To validate the use of a mechanized remotely operated stereoscopic drone slit lamp (DSL) in assessing anterior segment pathology in ophthalmology patients compared with conventional slit lamp (CSL).

Methods: Patients were recruited from eye clinics at Hotel Dieu Hospital in Kingston, Ontario, Canada. Each patient was assessed by 2 examiners.

Electroretinogram Recording for Infants and Children under Anesthesia to Achieve Optimal Dark Adaptation and International Standards.

Electroretinogram (ERG) is the only clinical objective test available to assess retinal function. Full-field ERG (ffERG) measures the panretinal rod and cone photoreceptor function as well as inner retinal function and is an important measure in the diagnosis and management of inherited retinal diseases as well as inflammatory, toxic, and nutritional retinopathies. Adhering to international standards and maintaining retinal dark adaptation are critical to acquire valid and reliable dark-adapted (scotopic) and light-adapted (photopic) ffERG responses.

Automated instrument designed to determine visual photosensitivity thresholds.

The Ocular Photosensitivity Analyzer (OPA), a new automated instrument to quantify the visual photosensitivity thresholds (VPT) in healthy and light sensitive subjects, is described. The OPA generates light stimuli of varying intensities utilizing unequal ascending and descending steps to yield the VPT. The performance of the OPA was evaluated in healthy subjects, as well as light sensitive subjects with achromatopsia or traumatic brain injury (TBI).

System for on- and off-axis volumetric OCT imaging and ray tracing aberrometry of the crystalline lens.

We present a new instrument for measuring shape and wavefront aberrations of the primate crystalline lens, both on- and off-axis, while simulating accommodation with a motorized lens stretching system. The instrument merges spectral domain optical coherence tomography (SD-OCT) imaging and ray tracing aberrometry using an approach that senses wavefront aberrations of the lens with the OCT probing beam. Accuracy and repeatability of aberration measurements were quantified.

Robotic Remote Controlled Stereo Slit Lamp.

Purpose: Our purpose was to develop a robotic remotely operated stereo slit lamp system allowing three-dimensional stereo viewing and recording of the patient's examination via local area network, Internet, and satellite.

Methods: A commercial slit lamp was modified to accept motors and servos to permit control of all optical and mechanical components of the device. The custom graphical user interface with dual high-resolution real-time stereoscopic imaging, control/position indicators, overview video, and audio were transmitted via local area network, Internet, and satellite.

A new, specular reflection-based, precorneal tear film stability measurement technique in a rabbit model: viscoelastic increases tear film stability.

Purpose: To develop a safe, noninvasive, noncontact, continuous in vivo method to measure the dehydration rate of the precorneal tear film and to compare the effectiveness of a viscoelastic agent in maintaining the precorneal tear film to that of a balanced salt solution.

Methods: Software was designed to analyze the corneal reflection produced by the operating microscope's coaxial illumination. The software characterized the shape of the reflection, which became distorted as the precorneal tear film evaporated; characterization was accomplished by fitting an ellipse to the reflection and measuring its projected surface area.

Differential flow rate of commercially available triamcinolone with and without preservative through small-gauge needles.

Objective: To compare the flow rate through different gauge needles of triamcinolone acetonide with benzyl alcohol (TABA) versus preservative-free triamcinolone acetonide injectable suspension (TAIS).

Materials And Methods: Experimental injections of 1 mL of TABA or TAIS were performed through a 27-, 30-, or 32-gauge needle. A piezoelectric pressure transducer connected to a personal computer was placed between the syringe and needle to record the force-time relationship and assess the flow rate (mL/s).

A portable, contact animal fundus imaging system based on Rol's GRIN lenses.

Objective: To demonstrate a cost-effective, portable, and simple-to-use fundus imaging system for laboratory animals.

Animals Studied: Albino rats, pigmented mice, albino guinea pigs, and New Zealand white rabbits.

Procedure: A contact fundus imaging system was designed and constructed using standard optical and mechanical components: a digital camera, an otoscope, a fiber optic light source, and standard optical lenses and mounts.