To evaluate a femtosecond laser system to create the capsulotomy.Porcine and cadaver eye studies were performed at OptiMedica Corp., Santa Clara, California, USA; human trial was Centro Laser, Santo Domingo, Dominican Republic.Experimental clinical study.Capsulotomies by an optical coherence tomography-guided evaluated in porcine eyes. Subsequently, procedure 39 patients as part of prospective randomized study laser-assisted cataract surgery. The accuracy capsulotomy size, shape, centration...

An image-guided, femtosecond laser can create precisely placed, accurate cuts in the eye to improve cataract surgery.

Loss of photoreceptors in atrophic age-related macular degeneration results severe visual impairment, although some peripheral vision is retained. To restore central without compromising the residual field, we developed a wireless photovoltaic retinal implant (PRIMA; Pixium Vision, Paris, France) which pixels convert images projected from video glasses using near-infrared light into electric current to stimulate nearby inner neurons.We carried out first-in-human clinical trial test safety...

Loss of photoreceptors in atrophic age-related macular degeneration (AMD) results severe visual impairment. Since the low-resolution peripheral vision is retained such conditions, restoration central should not jeopardize surrounding healthy retina and allow for simultaneous use natural prosthetic sight. This interim report, prespecified study protocol, presents first clinical with a photovoltaic substitute providing AMD. In this open-label single group feasibility trial (NCT03333954,...

It has been demonstrated that electrical stimulation of the retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. However, current retinal implants provide very low resolution (just a few electrodes), whereas at least several thousand pixels would be required for functional restoration sight. This paper presents design an optoelectronic prosthetic system with stimulating pixel density up to 2500 pix mm−2 (corresponding...

Nanometer-sized glass-sealed metal ultramicroelectrodes (UMEs) have been prepared using a laser-based micropipet puller. The tip was exposed to solution either by etching away small portion of glass insulator or micropolishing. characterization the UMEs carried out combination steady-state voltammetry, scanning electron microscopy (SEM), and electrochemical (SECM). cyclic voltammograms obtained regular shape with very capacitive resistive background. effective electrode radii from...

In Brief Sequential application of a large number single spots in retinal photocoagulation often results significant physician fatigue and patient discomfort. This article describes semiautomated scanning laser photocoagulator that greatly improves efficiency increases the precision by rapid patterns lesions using pulses as short 10 milliseconds.

Objective: To systematically evaluate the effects of laser beam size, power, and pulse duration 1 to 100 milliseconds on characteristics ophthalmoscopically visible retinal coagulation lesions.Methods: A 532-nm Nd:YAG was used irradiate 36 retinas in Dutch Belt rabbits with sizes 66, 132, 330 µm.Lesions were clinically graded minute after placement, their size measured by digital imaging, depth assessed histologically at different time points.Results: Retinal lesion increased linearly power...

To systematically assess the changes in retinal morphology during healing of photocoagulation lesions various clinical grades.Rabbits were irradiated with a 532-nm Nd:YAG laser beam diameter 330 microm at surface, power 175 mW, and pulse durations between 5 100 ms. Retinal clinically graded 1 minute after placement as invisible, barely visible, light, moderate, intense, very rupture assessed histologically six time points from hour to 4 months.At all durations, width decreased over time. At...

Objective. Intra-retinal placement of stimulating electrodes can provide close and stable proximity to target neurons. We assessed improvement in stimulation thresholds selectivity the direct network-mediated retinal with intraretinal electrodes, compared epiretinal subretinal placements. Approach. Stimulation ganglion cells (RGCs) wild-type rat retina were measured using patch-clamp technique. Direct responses discriminated various synaptic blockers. Main results. Three types RGC...

The objective of this work is to develop and test a photovoltaic retinal prosthesis for restoring sight patients blinded by degenerative diseases. A silicon photodiode array subretinal stimulation has been fabricated silicon-integrated-circuit/MEMS process. Each pixel in the two-dimensional contains three series-connected photodiodes, which photovoltaically convert pulsed near-infrared light into bi-phasic current stimulate nearby neurons without wired power connections. device thickness...

Purpose.: Subthreshold retinal phototherapy demonstrated clinical efficacy for the treatment of diabetic macular edema without visible signs damage. To assess range cellular responses to sublethal hyperthermia, expression gene encoding a 70 kDa heat shock protein (HSP70) was evaluated after laser irradiation using transgenic reporter mouse. Methods.: One hundred millisecond, 532 nm exposures with 400 μm beam diameter were applied retina surrounding optic nerve in 32 mice. Transcription from...

To determine the long-term safety of high-density subvisible diode micropulse photocoagulation (810 nm), compare clinical findings with computational modeling tissue hyperthermia and to report results for a subset eyes treated diabetic macular edema (ME) documented pre- postoperatively by spectral-domain optical coherence tomography.All ME from retinopathy (diabetic ME) branch retinal vein occlusion between April 2000 January 2010 were reviewed laser-induced damage. Therapeutic outcomes...

Laser therapy for diabetic macular edema and other retinal diseases has been used within a wide range of laser settings: from intense burns to nondamaging exposures. However, there no algorithm dosimetry that could determine parameters yielding predictable extent tissue damage. This multimodal imaging structural correlation study aimed verify calibrate computational model-based titration ranging coagulative effects.Endpoint Management, an based on model photothermal damage, was set various...

Photoreceptors initiate vision by converting photons to electrical activity. The onset of the phototransduction cascade is marked isomerization photopigments upon light capture. We revealed that accompanied a rapid (<5 ms), nanometer-scale electromechanical deformation in individual human cone photoreceptors. Characterizing this biophysical phenomenon associated with vivo was enabled high-speed phase-resolved optical coherence tomography line-field configuration allowed sufficient...

To compare 2 optical patient interface designs used for femtosecond laser-assisted cataract surgery.Optimedica Corp., Santa Clara, California, USA, and Centro Laser, Santo Domingo, Dominican Republic.Experimental clinical studies.Laser capsulotomy was performed during surgery with a curved contact lens (CCL) or liquid immersion (LOI). The presence of corneal folds, incomplete capsulotomy, subconjunctival hemorrhage, eye movement laser treatment were analyzed using video coherence tomography....

Purpose: Retinal photocoagulation and nondamaging laser therapy are used for treatment of macular disorders, without understanding the response mechanism with no rationale dosimetry. To establish a proper titration algorithm, we measured range tissue damage threshold. We then evaluated safety efficacy retinal (NRT) based on this algorithm chronic central serous chorioretinopathy (CSCR) telangiectasia (MacTel). Methods: to below threshold was assessed in pigmented rabbits by expression heat...

Neurons undergo nanometer-scale deformations during action potentials, and the underlying mechanism has been actively debated for decades. Previous observations were limited to a single spot or cell boundary, while movement across entire neuron potential remained unclear. Here we report full-field imaging of cellular accompanying in mammalian somas (−1.8 1.4 nm) neurites (−0.7 0.9 nm), using high-speed quantitative phase with temporal resolution 0.1 ms an optical path length sensitivity...

Abstract Localized stimulation of the inner retinal neurons for high-acuity prosthetic vision requires small pixels and minimal crosstalk from neighboring electrodes. Local return electrodes within each pixel limit crosstalk, but they over-constrain electric field, thus precluding efficient with subretinal smaller than 55 μm. Here we demonstrate a high-resolution based on novel design photovoltaic array, where field confinement is achieved dynamically, leveraging adjustable conductivity...

Modeling of Multi-Electrode Arrays used in neural stimulation can be computationally challenging since it may involve incredibly dense circuits with millions interconnected resistors, representing current pathways an electrolyte (resistance matrix), coupled to nonlinear the stimulating pixels themselves. Here, we present a method for accelerating modeling such minimal error by using sparse plus low-rank approximation resistance matrix. We prove that thresholding matrix elements enables its...

The design of high-resolution retinal prostheses presents many unique engineering and biological challenges. Ever smaller electrodes must inject enough charge to stimulate nerve cells, within electrochemically safe voltage limits. Stimulation sites should be placed an electrode diameter from the target cells prevent 'blurring' minimize current. Signals delivered wirelessly external source a large number electrodes, visual information should, ideally, maintain its natural link eye movements....