In two small randomized trials, diode (810 nm) and double-frequency Nd : YAG (532 nm) lasers gave results similar to those of the argon green laser. No differences were found in the effectiveness of argon versus krypton treatment, although retrobulbar anesthesia was used more frequently with krypton treatment. 51.15 was observed in almost identical proportions of the two groups (41.4% and 41.8%, respectively, at 3 months and 55.0% and 52.8%, respectively, at 1 year). Regression of NVD to less than that shown in Fig. Worsening NVD was the reason for the retreatment in ~40% of retreated eyes in each group. Retreatment was carried out in 36% and 33%, respectively, of the argon and krypton groups. 141 If, after the initial treatment, NVD increased by more than 0.5 disc area, retreatment was recommended (and could also be applied for other reasons, such as increasing NVE or vitreous hemorrhage). 51.15 to scatter photocoagulation (1600–2000 moderate-intensity 500-mm burns) with either blue–green argon or red krypton wavelengths. The Krypton-Argon Regression of Neovascularization Study (KARNS) randomly assigned 907 eyes (of 696 patients) that had NVD equaling or exceeding those in Fig. Schachat MD, in Ryan's Retina, 2018 Wavelength
Krypton color skin#
Patients must be informed of the possibility of prolonged pigmentation at an incidence similar to that seen with sclerotherapy as well as temporary blistering and hypopigmentation that is predominantly caused by epidermal damage in pigmented skin (type III or above).Īndrew P. Efficacy is technique dependent, with the potential for achieving excellent results. Although individual physicians report considerable variation in results, usually more than one treatment is necessary for maximum vessel improvement, with only rare reports of 100% resolution of the leg vein. Some overlying epidermal scabbing is noted, and hypopigmentation is not uncommon in dark-skinned patients. When used with a 4☌ chilled tip, a fluence of 12 to 15 J/cm 2 is delivered as a train of pulses in a spot size 3 to 4 mm in diameter to trace the vessel until spasm or thrombosis occurs. We and others have found the long-pulse 532-nm laser (frequency-doubled Nd:YAG) to be effective in treating leg veins less than 1 mm in diameter that are not directly connected to a feeding reticular vein. Lengthening of the pulse duration to match the diameter of the vessel is attempted to optimize treatment.
Immediately after laser exposure, the epidermis is blanched.
Typically the laser is moved between adjacent 1-mm spots following the vessels at 5 to 10 mm/s. 42.2).Įffective results have been achieved by tracing vessels with a 1-mm projected spot. Although this wavelength does not penetrate deeply into the dermis (about 0.75 mm), relatively specific damage (compared with argon laser) can occur in the vascular target by selecting an optimal pulse duration, enlarging the spot size, and adding epidermal cooling ( Fig. The 532-nm wavelength is one of the hemoglobin absorption peaks. Modulated krypton triphosphate lasers have been reported to be effective at removing leg telangiectases using pulse durations between 1 and 50 ms. Fowler MD, in Pfenninger and Fowler's Procedures for Primary Care, 2020 Krypton Triphosphate and Frequency-Doubled Nd:YAG (532 nm)
0 kommentar(er)
