Finite element model of the temperature increase in excised porcine cadaver iris during direct illumination by femtosecond laser pulses.

In order to model the thermal effect of laser exposure of the iris during laser corneal surgery, we simulated the temperature increase in porcine cadaver iris. The simulation data for the 60 kHz FS60 Laser showed that the temperature increased up to 1.23°C and 2.

Temperature increase in porcine cadaver iris during direct illumination by femtosecond laser pulses.

Purpose: To measure the temperature rise in porcine cadaver iris during direct illumination by the femtosecond laser as a model for laser exposure of the iris during femtosecond laser corneal surgery.

Setting: Department of Ophthalmology, University of California-Irvine, Irvine, California, USA.

Design: Experimental study.

Temperature increase in human cadaver retina during direct illumination by femtosecond laser pulses.

Purpose: Femtosecond lasers have been approved by the US Food and Drug Administration for ophthalmic surgery, including use in creating corneal flaps in LASIK surgery. During normal operation, approximately 50% to 60% of laser energy may pass beyond the cornea, with potential effects on the retina. As a model for retinal laser exposure during femtosecond corneal surgery, we measured the temperature rise in human cadaver retinas during direct illumination by the laser.

Imaging pulsatile retinal blood flow in human eye.

A functional Fourier domain optical coherence tomography instrument offering spectral Doppler imaging of in vivo pulsatile human retinal blood flow was constructed. An improved phase-resolved algorithm was developed to correct bulk motion artifacts. Spectral Doppler imaging provides complementary temporal flow information to the spatially distributed flow information of the color Doppler image by providing direct visualization of the Doppler spectrum of the flow whose pattern can be further quantified with various velocity envelope curves and their corresponding flow indices.

Corneal response to femtosecond laser photodisruption in the rabbit.

In this report we evaluated the effect of femtosecond laser energy on the development of corneal haze and keratocyte activation in rabbits following intra-stromal photodisruption to create LASIK flaps using a modified commercial femtosecond surgical laser. Three groups of flap parameters were studied: 1.5 microJ/pulse with 10 microm spot separation and complete side cut (Group 1); 3.

Finite-element modeling of posterior lamellar keratoplasty: construction of theoretical nomograms for induced refractive errors.

Purpose: To estimate the theoretical corneal refractive error induced by mechanical weakening effects from posterior lamellar keratoplasty (PLKP) in the human cornea.

Methods: The refractive effects of PLKP are simulated by finite-element modeling (FEM) as a mathematical function of the thickness of the excised posterior lamellar corneal button, with a nonlinear formulation of stress-strain relation for the corneal material. A theoretical nomogram was developed to correlate the refractive changes to button thickness.

Top hat wound configuration for penetrating keratoplasty using the femtosecond laser: a laboratory model.

Purpose: To evaluate the mechanical stability and induced astigmatism of a modified multiplanar "top hat" wound configuration for full-thickness penetrating keratoplasty (PK) using the femtosecond laser as compared with PK in a laboratory model.

Methods: Eight human corneoscleral rims were mounted on an artificial anterior chamber. Four samples were assigned to the traditional PK group.

Femtosecond laser-assisted intracorneal keratoprosthesis implantation: a laboratory model.

Purpose: To demonstrate femtosecond laser-assisted intracorneal keratoprosthesis implantation and determine the mechanical stability as a function of intraocular pressure.

Methods: Eight human corneoscleral rims were mounted on an artificial anterior chamber. The femtosecond laser microkeratome was used to create a 2.

Femtosecond laser posterior lamellar keratoplasty: a laboratory model.

Purpose: To evaluate feasibility of femtosecond laser application in posterior lamellar keratoplasty.

Methods: To evaluate the laser's effectiveness through opaque corneas, anterior corneal caps were resected from opaque corneas induced with 80% acetone solution. To evaluate the femtosecond laser posterior lamellar keratoplasty surgical procedure, human corneoscleral rims were mounted on an artificial anterior chamber.

Subsurface photodisruption in human sclera: wavelength dependence.

Background And Objective: Approximately 105 million people worldwide have glaucoma, and approximately 5 million are blind from its complications. Current surgical techniques often fail because of scarring of the conjunctival tissue, Tenon's tissue, or both. Femtosecond lasers can create highly precise incisions beneath the surface of a tissue, as previously demonstrated in the transparent cornea.