The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Peter J Mcdonnell - One of the best experts on this subject based on the ideXlab platform.
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Excimer Laser photorefractive keratectomy.
Ophthalmology clinics of North America, 2001Co-Authors: Charles W. Flowers, Peter J Mcdonnell, Stephen D. McleodAbstract:The Excimer Laser has proved to be a precise and versatile tool for treating refractive errors. Excimer Laser photorefractive keratectomy for myopia is now an established safe and effective alternative to contact lenses and glasses, and should be part of the ophthalmologist's standard armamentarium for treating this condition. This article provides a brief overview of the basic principles underlying Excimer Laser technology, as well as the surgical technique and postoperative management of myopic correction.
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Excimer Laser photorefractive keratectomy
Survey of Ophthalmology, 1995Co-Authors: Theo Seiler, Peter J McdonnellAbstract:Excimer Laser photorefractive keratectomy has been used for the correction of myopia, hyperopia and astigmatism. This Laser removes tissue through a process termed photoablative decomposition, in which incident photon energy is sufficient to break molecular bonds. Selective removal of tissue across the anterior corneal surface results in a change in anterior corneal curvature. The surgical outcome may be influenced also by interindividual variability in wound healing and pharmacologic interventions. The nature of the Excimer Laser-tissue interaction, and clinical outcomes of predictability, stability and complications of surgery for myopia are discussed in detail.
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Phototherapeutic keratectomy with Excimer Laser for Reis-Bückler's corneal dystrophy.
Journal of Refractive Surgery, 1992Co-Authors: Peter J Mcdonnell, Theo SeilerAbstract:: Two patients with decreased visual acuity and recurrent epithelial erosions due to Reis-Buckler's corneal dystrophy underwent phototherapeutic keratectomy with the 193-nanometer Excimer Laser. Because the epithelial surface was relatively smooth prior to surgery, ablations were performed through an intact epithelium. Postoperatively, visual acuity was improved and symptoms of erosion decreased in both patients. Although no refractive shift was intended with the phototherapeutic procedure, both patients were hyperopic following surgery. Superficial keratectomy with the 193-nanometer Excimer Laser thus provides an alternative to conventional surgical keratectomy.
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Unsuccessful Excimer Laser phototherapeutic keratectomy. Clinicopathologic correlation.
Archives of Ophthalmology, 1992Co-Authors: Jan M. Mcdonnell, Jenny J Garbus, Peter J McdonnellAbstract:• A 46-year-old man underwent phototherapeutic keratectomy with a 193-nm Excimer Laser in an attempt to remove a superficial corneal scar that had been present for 36 years. The scar proved to be resistant to ablation with the Laser, while relatively normal stroma was easily ablated. Histopathologic examination of the corneal button removed 3 months after Excimer Laser surgery revealed absence of Bowman's membrane in the area of ablation, superficial stromal disorganization and scarring, raised nodules of collagenous tissue extending into the epithelium, and no calcification within the lesion. Ultrastructural examination was remarkable for irregularly oriented collagen fibers within the scar. The resistance of this lesion to Excimer Laser ablation appears to have been the consequence of marked differences in rates of ablation between normal stroma and the very longstanding scar.
John A. Bittl - One of the best experts on this subject based on the ideXlab platform.
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Excimer Laser ANGIOPLASTY : FOCUS ON TOTAL OCCLUSIONS
The American journal of cardiology, 1996Co-Authors: John A. BittlAbstract:This commentary reviews two studies published in the current issue of The American Journal of Cardiology, which provide important information about the use of Excimer Laser angioplasty for the treatment of chronic total occlusions. The commentary also summarizes fundamental Laser mechanisms to clarify the shortcomings of Excimer Laser angioplasty--modest lumen improvement, prevalent vessel dissection, and troublesome restenosis--and to identify new applications of Excimer Laser technology.
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Excimer Laser coronary angioplasty.
Cardiology clinics, 1994Co-Authors: Waqar H. Ahmed, John A. BittlAbstract:Excimer Laser angioplasty has evolved from a difficult experimental procedure to a more refined intervention with flexible catheters, well-defined indications, and consistent results for certain lesion types such as aortoostial stenoses, total occlusions, and certain saphenous vein graft lesions. This article reviews the current clinical results with Excimer Laser angioplasty, discusses the procedural technique and indications, and emphasizes the need for rigorous comparison of Excimer Laser angioplasty with alternative approaches for patients with coronary artery disease.
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coronary artery perforation during Excimer Laser coronary angioplasty
Journal of the American College of Cardiology, 1993Co-Authors: John A. Bittl, James E. Tcheng, Thomas J Ryan, John F Keaney, Stephen G Ellis, Jeffrey M Isner, Timothy A SanbornAbstract:Abstract Objectives. The aim of this study was to analyze the risk of vessel perforation during Excimer Laser angioplasty. Background. Vessel perforation is a serious complication of angioplasty. Methods. A total of 764 patients had 858 stenoses treated with Excimer Laser angioplasty. Laser catheters had a diameter of 1.4, 1.7 or 2 mm. Laser energy was delivered in pulses of 135 ns, at a frequency of 25 s−1and at a fluence of 30 to 60 mJ/mm2. Follow-up angiography was requested for all patients who did not require emergency bypass surgery. Results. In the 764 consecutive patients treated with Excimer Laser coronary angioplasty, vessel perforation occurred in 23 patients (3%). Nine patients had a major complication resulting directly from vessel perforation (cardiac tamponade, myocardial infarction or need for bypass surgery) and 14 had no clinical complications after successful sealing of the puncture site. No patient with a perforation died. Multivariate analysis showed that bifurcation lesions (odds ratio [OR] = 3.5; p = 0.049), diabetes mellitus (OR = 3.15; p = 0.029) and female gender (OR = 2.86; p = 0.013) were associated with an increased risk of vessel perforation. Lesions >;10 mm in length (OR = 0.45; p = 0.206), calcified stenoses (OR = 0.26; p = 0.088) and saphenous vein graft lesions (OR = 0.50; p = 0.295) were not at increased risk. Vessel perforation was seen in 10 (8.3%) of 120 lesions in which the Laser catheter was equivalent in diameter to the target vessel (≤0.5 mm smaller in size) but in only 8 (1.5%) of 525 lesions in which the Laser catheter was >;1 mm smaller than the target vessel (p = 0.001). Conclusions. Most lesions thought to be suitable for Excimer Laser treatment are not at increased risk of perforation. The complication may be avoided by improved patient and Laser catheter size selection.
Theo Seiler - One of the best experts on this subject based on the ideXlab platform.
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Excimer Laser photorefractive keratectomy
Survey of Ophthalmology, 1995Co-Authors: Theo Seiler, Peter J McdonnellAbstract:Excimer Laser photorefractive keratectomy has been used for the correction of myopia, hyperopia and astigmatism. This Laser removes tissue through a process termed photoablative decomposition, in which incident photon energy is sufficient to break molecular bonds. Selective removal of tissue across the anterior corneal surface results in a change in anterior corneal curvature. The surgical outcome may be influenced also by interindividual variability in wound healing and pharmacologic interventions. The nature of the Excimer Laser-tissue interaction, and clinical outcomes of predictability, stability and complications of surgery for myopia are discussed in detail.
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Phototherapeutic keratectomy with Excimer Laser for Reis-Bückler's corneal dystrophy.
Journal of Refractive Surgery, 1992Co-Authors: Peter J Mcdonnell, Theo SeilerAbstract:: Two patients with decreased visual acuity and recurrent epithelial erosions due to Reis-Buckler's corneal dystrophy underwent phototherapeutic keratectomy with the 193-nanometer Excimer Laser. Because the epithelial surface was relatively smooth prior to surgery, ablations were performed through an intact epithelium. Postoperatively, visual acuity was improved and symptoms of erosion decreased in both patients. Although no refractive shift was intended with the phototherapeutic procedure, both patients were hyperopic following surgery. Superficial keratectomy with the 193-nanometer Excimer Laser thus provides an alternative to conventional surgical keratectomy.
Timothy A Sanborn - One of the best experts on this subject based on the ideXlab platform.
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coronary artery perforation during Excimer Laser coronary angioplasty
Journal of the American College of Cardiology, 1993Co-Authors: John A. Bittl, James E. Tcheng, Thomas J Ryan, John F Keaney, Stephen G Ellis, Jeffrey M Isner, Timothy A SanbornAbstract:Abstract Objectives. The aim of this study was to analyze the risk of vessel perforation during Excimer Laser angioplasty. Background. Vessel perforation is a serious complication of angioplasty. Methods. A total of 764 patients had 858 stenoses treated with Excimer Laser angioplasty. Laser catheters had a diameter of 1.4, 1.7 or 2 mm. Laser energy was delivered in pulses of 135 ns, at a frequency of 25 s−1and at a fluence of 30 to 60 mJ/mm2. Follow-up angiography was requested for all patients who did not require emergency bypass surgery. Results. In the 764 consecutive patients treated with Excimer Laser coronary angioplasty, vessel perforation occurred in 23 patients (3%). Nine patients had a major complication resulting directly from vessel perforation (cardiac tamponade, myocardial infarction or need for bypass surgery) and 14 had no clinical complications after successful sealing of the puncture site. No patient with a perforation died. Multivariate analysis showed that bifurcation lesions (odds ratio [OR] = 3.5; p = 0.049), diabetes mellitus (OR = 3.15; p = 0.029) and female gender (OR = 2.86; p = 0.013) were associated with an increased risk of vessel perforation. Lesions >;10 mm in length (OR = 0.45; p = 0.206), calcified stenoses (OR = 0.26; p = 0.088) and saphenous vein graft lesions (OR = 0.50; p = 0.295) were not at increased risk. Vessel perforation was seen in 10 (8.3%) of 120 lesions in which the Laser catheter was equivalent in diameter to the target vessel (≤0.5 mm smaller in size) but in only 8 (1.5%) of 525 lesions in which the Laser catheter was >;1 mm smaller than the target vessel (p = 0.001). Conclusions. Most lesions thought to be suitable for Excimer Laser treatment are not at increased risk of perforation. The complication may be avoided by improved patient and Laser catheter size selection.
F Tayfour - One of the best experts on this subject based on the ideXlab platform.
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Excimer Laser in situ keratomileusis in 124 myopic eyes
Journal of Refractive Surgery, 1995Co-Authors: D C Fiander, F TayfourAbstract:The development of corneal haze in some patients treated with Excimer Laser photorefractive keratectomy (PRK) and the variable predictability of the refractive cut in microkeratome keratomileusis in situ prompted us to evaluate Excimer Laser in situ keratomileusis (LASIK) for myopia. The Automated Corneal Shaper (Steinway-Chiron) was used to create a hinged corneal flap of 130 to 160 microns thick. PRK was performed on the lamellar bed with a Summit OmniMed Laser. Minimum follow up was 3 months. Postoperative results and complications in the first 124 eyes are presented. LASIK is an effective method to correct myopia.
