The Experts below are selected from a list of 1893 Experts worldwide ranked by ideXlab platform
Donald E Sweet - One of the best experts on this subject based on the ideXlab platform.
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tendon repair by laser welding a histologic and biomechanical comparison and suture repair with co2 and Argon Lasers
Lasers in Surgery and Medicine, 1996Co-Authors: Maj Francis X Kilkelly, Cpt Theodore J Choma, Neven A Popovic, Maj David W Miller, Donald E SweetAbstract:Background and Objective The purpose of this study was to determine whether welding of tendinous tissue is possible with the application of thermal Lasers. Study Design Materials and Methods: After sharp transection of a unilateral achilles tendon, 40 male outbred Spraque Dawley rats were divided equally between four treatment groups. Ten animals underwent repair using the modified Kessler suture technique. The remaining animals underwent application of laser after the tendon edges were reapproximated and held in place with a vascular clamp. CO2 and Nd:YAG Lasers were applied using 25% human albumin as a solder. Fluorescein dye was added to albumin and used as solder for the Argon laser. Biomechanical and histologic testing were performed immediately and 14 days postoperatively. Results Argon and CO2 Lasers successfully fused the tendon ends together. However, immediately postoperative, the resultant tissue weld was tenuous and conventional tensile strength testing was not possible. At 14 days postoperatively, all modes of tendon repair resulted in tensile failure at consistently lower levels of tension than those required for the normal uninjured tendons. The ultimate tensile strength for the suture-repaired, CO2 laser welded, and Argon laser welded tendons were 74%, 59%, and 64% of the strength of the control tendons respectively. No statistically significant difference was found in the tensile strength among the three repair groups. Histologic evaluation at 14 days revealed the greatest degree of inflammatory response in those tendons repaired with the Argon laser. Those tendons repaired with suture demonstrated the least amount of inflammatory change. Conclusion Our study demonstrates that welding of a tendon is possible with the application of laser energy. However, we were unable to produce a weld sufficient to withstand significant tensile loads in the immediate postoperative period. (This is a U.S. Government work and, as such, is in the public domain in the United States of America.) © 1996 Wiley-Liss, Inc.
Caroline Kl Chee - One of the best experts on this subject based on the ideXlab platform.
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corneal transmissibility of diode versus Argon Lasers and their photothermal effects on the cornea and iris
Clinical and Experimental Ophthalmology, 2000Co-Authors: Paul T K Chew, Jun Shyan Wong, Caroline Kl CheeAbstract:Purpose: Diode laser (810 nm) may possess theoretical advantages over the Argon blue-green laser (488 nm) for iridotomy/iridoplasty in an eye with oedematous cornea, such as the acute angle-closure glaucoma (AACG) patient, because of better diode laser tissue penetration in opaque media. We assessed the transmissibility of diode and Argon Lasers through corneas of varying clarity and evaluated the histopathological features of cornea and iris burns produced by these Lasers. Methods: The transmission of diode and Argon Lasers through human donor corneal buttons of three grades of clarity – clear, intermediate, and hazy – were compared. Corneal buttons of these varying levels of clarity were also treated with Argon and diode Lasers, with the beams deliberately focused onto the mid-stroma to assess their photothermal effects. Exposed pigmented irides from whole human eyes were treated directly with Argon and diode Lasers. The Lasers were delivered via slit-lamp systems and the energy settings used were 1000 mW for Argon and 980 mW for diode; spot sizes for both Lasers were 100 μm, with exposure durations of 0.1 s. Light microscopy studies of these tissues were performed. Results: Transmissibility of diode laser in clear, intermediate, and hazy corneas were 89, 87 and 85% respectively and was significantly superior to Argon laser (78, 73 and 70% respectively; P < 0.001, paired Student’s t-test). Diode laser did not produce morphological changes in all three grades of corneas whereas Argon-laser-treated hazy corneas showed photothermal damage. Both Lasers produced deep iris burns, with the diode laser tending to produce deeper burns. Conclusion: Our findings suggest that diode laser may be the ideal laser for iridotomy/iridoplasty in the AACG patient with hazy cornea.
Maj Francis X Kilkelly - One of the best experts on this subject based on the ideXlab platform.
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tendon repair by laser welding a histologic and biomechanical comparison and suture repair with co2 and Argon Lasers
Lasers in Surgery and Medicine, 1996Co-Authors: Maj Francis X Kilkelly, Cpt Theodore J Choma, Neven A Popovic, Maj David W Miller, Donald E SweetAbstract:Background and Objective The purpose of this study was to determine whether welding of tendinous tissue is possible with the application of thermal Lasers. Study Design Materials and Methods: After sharp transection of a unilateral achilles tendon, 40 male outbred Spraque Dawley rats were divided equally between four treatment groups. Ten animals underwent repair using the modified Kessler suture technique. The remaining animals underwent application of laser after the tendon edges were reapproximated and held in place with a vascular clamp. CO2 and Nd:YAG Lasers were applied using 25% human albumin as a solder. Fluorescein dye was added to albumin and used as solder for the Argon laser. Biomechanical and histologic testing were performed immediately and 14 days postoperatively. Results Argon and CO2 Lasers successfully fused the tendon ends together. However, immediately postoperative, the resultant tissue weld was tenuous and conventional tensile strength testing was not possible. At 14 days postoperatively, all modes of tendon repair resulted in tensile failure at consistently lower levels of tension than those required for the normal uninjured tendons. The ultimate tensile strength for the suture-repaired, CO2 laser welded, and Argon laser welded tendons were 74%, 59%, and 64% of the strength of the control tendons respectively. No statistically significant difference was found in the tensile strength among the three repair groups. Histologic evaluation at 14 days revealed the greatest degree of inflammatory response in those tendons repaired with the Argon laser. Those tendons repaired with suture demonstrated the least amount of inflammatory change. Conclusion Our study demonstrates that welding of a tendon is possible with the application of laser energy. However, we were unable to produce a weld sufficient to withstand significant tensile loads in the immediate postoperative period. (This is a U.S. Government work and, as such, is in the public domain in the United States of America.) © 1996 Wiley-Liss, Inc.
Shereen Ezzelregal Alashry - One of the best experts on this subject based on the ideXlab platform.
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Argon laser versus erbium yag laser in the treatment of xanthelasma palpebrarum
Saudi Journal of Ophthalmology, 2015Co-Authors: Mona Abdelkader, Shereen Ezzelregal AlashryAbstract:Abstract Background Xanthelasma palpebrarum is the most common of the xanthomas with asymptomatic, symmetrical, bilateral, soft, yellow, polygonal papules around the eyelids. Though it is a benign lesion causing no functional disturbance, it is esthetically annoying. The surgical laser offers an extremely elegant and powerful solution to this problem. Objective To evaluate the effectiveness of erbium:YAG and Argon Lasers in the treatment of xanthelasma lesions. Patients and methods Forty patients were included in the study. Twenty patients (15 patients were bilateral with 30 eyes either in the upper or lower lid and 5 patients were unilateral) were treated with erbium:YAG laser. Another 20 patients (10 patients were bilateral with 20 eyes and 10 patients were unilateral) were treated with Argon laser. Results In the majority of treated patients (either treated with erbium:YAG or Argon laser), xanthelasma lesions were completely disappeared or significantly decreased in size. Two patients showed pigmentary changes in the form of hypopigmentation with erbium:YAG laser (one case), another case showed hyperpigmentation. No intraoperative complication was observed. No significant scar or recurrence was observed. Conclusion Argon laser in xanthelasma is an easy, effective, and safe method of treatment for small lesions and YAG laser is more better for large lesions than Argon laser.
Paul T K Chew - One of the best experts on this subject based on the ideXlab platform.
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corneal transmissibility of diode versus Argon Lasers and their photothermal effects on the cornea and iris
Clinical and Experimental Ophthalmology, 2000Co-Authors: Paul T K Chew, Jun Shyan Wong, Caroline Kl CheeAbstract:Purpose: Diode laser (810 nm) may possess theoretical advantages over the Argon blue-green laser (488 nm) for iridotomy/iridoplasty in an eye with oedematous cornea, such as the acute angle-closure glaucoma (AACG) patient, because of better diode laser tissue penetration in opaque media. We assessed the transmissibility of diode and Argon Lasers through corneas of varying clarity and evaluated the histopathological features of cornea and iris burns produced by these Lasers. Methods: The transmission of diode and Argon Lasers through human donor corneal buttons of three grades of clarity – clear, intermediate, and hazy – were compared. Corneal buttons of these varying levels of clarity were also treated with Argon and diode Lasers, with the beams deliberately focused onto the mid-stroma to assess their photothermal effects. Exposed pigmented irides from whole human eyes were treated directly with Argon and diode Lasers. The Lasers were delivered via slit-lamp systems and the energy settings used were 1000 mW for Argon and 980 mW for diode; spot sizes for both Lasers were 100 μm, with exposure durations of 0.1 s. Light microscopy studies of these tissues were performed. Results: Transmissibility of diode laser in clear, intermediate, and hazy corneas were 89, 87 and 85% respectively and was significantly superior to Argon laser (78, 73 and 70% respectively; P < 0.001, paired Student’s t-test). Diode laser did not produce morphological changes in all three grades of corneas whereas Argon-laser-treated hazy corneas showed photothermal damage. Both Lasers produced deep iris burns, with the diode laser tending to produce deeper burns. Conclusion: Our findings suggest that diode laser may be the ideal laser for iridotomy/iridoplasty in the AACG patient with hazy cornea.