W B Telfair

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Excimer photorefractive keratectomy was performed at three centers on 16 highly myopic eyes (8 diopters [D] or more) and followed up for 6 months. Ablation depths ranged from 137 to 230 microns. The preoperative spherical equivalent of myopia ranged from -8.62 D to -14.50 D (mean +/- SD, -11.57 +/- 1.62 D). Six months after surgery, the mean refraction(More)
The design and development of the instrumentation utilized during the clinical and histopathologic evaluations of the first human eyes treated by argon fluoride excimer laser radiation are described. The laser, optical, alignment, measurement, and control subsystems required for this research were constructed to create a laser beam that has an axially(More)
PURPOSE To use histological techniques to assess and compare the ablation depth, local damage, and surface quality of corneal ablations by a Q-switched Er:YAG laser, an optical parametric oscillator laser at 2.94 microm, a long pulse Er:YAG laser, and a 193-nm excimer laser. METHODS Human cadaver eyes and in vivo cat eyes were treated with a 6.0-mm(More)
The first human trial utilizing the argon fluoride excimer laser at 193 nm to produce a superficial keratectomy in ten human eyes has been described with the histopathological evaluation of four eyes and the longer gross appearance of six eyes at intervals extending to 10 months post-excimer laser treatment. The process of laser superficial keratectomy has(More)
PURPOSE To evaluate the healing characteristics of cat corneas treated with a new scanning mid-infrared laser system. METHODS Six adult cats were treated with 6-mm diameter photorefractive keratectomy (PRK) corrections. One eye in each animal was untreated as a control and the other was treated with either a -3.00 or -6.00 diopter ablation. The laser was(More)
BACKGROUND Photorefractive keratectomy with large diameter ablations using a uniform laser beam has produced central undercorrections, or "steep central islands" in patients, as seen with videokeratography. METHODS Using a custom optical profilometer to measure corneal ablation profiles and a VISX excimer laser system, we measured the effect of ablation(More)
Infrared emission spectra of effluents from the smokestacks of typical small buildings were observed remotely using a Fourier transform infrared (FTIR) spectrometer. The primary purpose of the study was to determine the best method for distinguishing gas from oil as the fuel being burned in a building's furnace. Spectral pattern recognition techniques were(More)
Photospallation is proposed as the primary mechanism behind our recent animal studies involving corneal ablation by nanosecond-pulse mid-IR laser beams. Following a brief summary of earlier work directed to refractive procedures in the mid-IR, a preliminary analysis is presented, based on simple one-dimensional models of thermoelastic expansion developed(More)
PURPOSE A new mechanism for ablating corneal tissue is proposed, based on photospallation with short pulse mid-infrared (IR) laser radiation. METHODS By using a judicious combination of high absorption, short pulses, and low fluences, ablation with this process can potentially remove tissue in a highly localized manner with submicron collateral thermal(More)
PURPOSE To summarize the initial results of excimer laser photorefractive keratectomy (PRK) on 89 eyes of 80 patients with moderate myopia (myopia of -6.00 to -8.00 diopters [D]; mean -6.98 +/- 0.90 D) at nine investigational sites. METHODS All treatments used an argon fluoride excimer laser (VISX, Inc, Santa Clara, Calif) using standard settings. Sixty(More)
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