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sub-Tenon's Injection (sub-tenon + injection)
Selected AbstractsAn audit of peribulbar blockade using 15 mm, 25 mm and 37.5 mm needles, and sub-Tenon's injection,ANAESTHESIA, Issue 8 2004A. A. Van Den Berg Summary The efficacy of peribulbar anaesthesia performed with short, medium and long needles, with sub-Tenon's injection as a control, was audited. Two hundred patients undergoing cataract surgery underwent peribulbar injection using 25G needles of the following lengths: 15 mm, 25 mm or 37.5 mm. Sub-Tenon's injections were performed with a curved 25-mm sub-Tenon anaesthesia cannula. The injection technique, ocular akinesia and analgesia scoring system, and supplementary injection protocols were standardised. After initial injections of local anaesthetic via the sub-Tenon's cannula or with 37.5 mm, 25 mm and 15 mm needles, supplementation was required in one (2%), 13 (26%), 22 (44%) and 32 (64%) of patients, respectively; the total number of supplementary injections required were 1, 16, 35 and 47, respectively. It is concluded that the efficacy of peribulbar anaesthesia depends upon the proximity of the deposition of local anaesthetic solution either to the globe or orbital apex. These data justify the classification of peribulbar anaesthesia into: circum-ocular (sub-Tenon's, episcleral), peri-ocular (anterior, superficial); peri-conal (posterior, deep) and apical (ultra-deep) for teaching purposes. [source] Long-term biomechanical properties after collagen crosslinking of sclera using glyceraldehydeACTA OPHTHALMOLOGICA, Issue 8 2008Gregor Wollensak Abstract. Purpose:, Chemical crosslinking by glyceraldehyde has been shown to increase significantly the biomechanical rigidity of sclera. It might therefore become an option for a sclera-based treatment of progressive myopia. The present pilot study was designed to test the long-term biomechanical efficiency of the new crosslinking method. Methods:, Six Chinchilla rabbits were treated with sequential sub-Tenon's injections of 0.15 ml 0.5 m glyceraldehyde, which were given in the supero-nasal quadrant of the right eye (OD) five times over 14 days. The rabbits were killed 4 months and 8 months after crosslinking treatment, respectively. Biomechanical stress,strain measurements of scleral strips from the treatment area were performed and compared to non-treated contralateral control sclera using a microcomputer-controlled biomaterial testing device. In addition, the eyes were examined histologically by light microscopy to evaluate possible side-effects. Results:, Following the crosslinking treatment, the ultimate stress was 10.2 ± 2.3 MPa after 4 months and 8.5 ± 2.2 MPa after 8 months versus 2.4 ± 0.3 MPa in the controls (increases of 325% and 254.17%, respectively); Young's modulus was 104.6 ± 13.7 MPa after 4 months and 53.2 ± 5.2 MPa after 8 months versus 9.6 ± 1.3 MPa in the controls (increases of 989.6% and 554.17%, respectively); and ultimate strain was 15.8 ± 1.5% after 4 months and 24.1 ± 0.7% after 8 months versus 38.4 ± 4.6% in the controls (decreases of 58.84% and 37.24%, respectively). Histologically, no side-effects were found. Conclusion:, Our new method of scleral collagen crosslinking proved very efficient in increasing scleral biomechanical strength over a period of up to 8 months. Glyceraldehyde can be applied easily by sequential parabulbar injections. Before clinical application in myopic patients, a study in an animal myopia model is recommended. [source] | ||||||||||