EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/194331
40 EW CATARACT October 2013 Parabulbar continued from page 39 nated sedation from the comparison, "Topical Versus Sub-Tenon Anesthesia Without Sedation in Cataract Surgery"7 revealed significantly improved pain scores in the group of cataract surgery patients receiving sub-Tenon's anesthesia. "Seventy-two percent of patients in the topical anesthesia group and 86% in the sub-Tenon anesthesia group reported no pain or slight discomfort during surgery (mean score 1.13± 1.57 and 0.57±1.28, respectively) (p<0.001): ninety percent of topical anesthesia patients and 100% of sub-Tenon anesthesia patients reported no pain or slight discomfort for 30 minutes postoperatively (mean score 0.80±0.93 and 0.12± 036, respectively) (p<0.001)." If parabulbar anesthesia was a technically challenging procedure to perform, one might understand better the reluctance to adopt it over the somewhat less effective topical block. My standard anesthetic of choice is a 50/50 mixture of 4% lidocaine, 0.75% bupivacaine, and 150 u Hylenex (Halozyme, San Diego). I find that since I began adding Hylenex to my block, the akinetic effect has been significantly improved. Since the Greenbaum Anesthesia Cannula is no longer available, I now use a Beaver Visitec (Waltham, Mass.) sub-Tenon's cannula, taking strict care to only introduce it halfway in. Fechtner Fechtner Fechtner ech e htne EXEX-PRESS® EX-PRESS Marker Marker K3-8977 r r r r r king perimeter rate sertion ed r e for sibility Watch Watch it! While the 2001 study I cited eliminated sedation from the comparison of topical and sub-Tenon's anesthesia, most cases using either technique also employ sedation. My impression is that sub-Tenon's requires less. That is supported by the comparison study above, which demonstrates less need for sedation in sub-Tenon's than in topical. As with everything else in medicine, eventually the government bean counters will tell us. If the improved anesthesia of anterior sub-Tenon's or parabulbar anesthesia does show a reduced cost of accompanying IV sedation, Leaming's survey will show increased use. Subcutaneous administration of drugs parallels nicely sub-Tenon's delivery of anesthesia. The principal is the same—get the drug in the right plane and let it diffuse. In the same way that improved anesthesia allows for reduced sedation, the elimination of the need for an IV for delivering medicine allows for reduced services and home use. Surely, quality and reduced costs are driving subcutaneous delivery. Sub-Tenon's may follow. EW References 1. Stevens JD. A new local anaesthesia technique for cataract extraction by one quadrant sub-Tenon's infiltration. Br J Ophthalmol 1992;76:670. 2. Greenbaum S. Parabulbar anesthesia. Am J Ophthalmol 1992;114:776. 3. Merino P, Mnoz-Sanz N. Diplopia after subTenon's anesthesia for cataract surgery. Arch Soc Esp Oftalmol 2006; 81: 141-146. 4. Kumar CM, Eid H, Dodds C. SubTenon's anaesthesia complications and their prevention. Eye (Lond). 2011 June; 25(6): 694–703. 5. El-Hindy N, Johnston RL, Jaycock P, et al. The Cataract National Dataset Electronic Multicentre Audit of 55,567 Operations: Anaesthetic Techniques and Complications. Eye (Lond). 2009;23(1):50-55. 6. Katz J, Feldman MA, MD, Bass EB, et al. Injectable versus Topical Anesthesia for Cataract Surgery Patient Perceptions of Pain and Side Effects. Ophthalmology 2000;107:2054–2060. 7. Zafirakis P, Voudouri A, Rowe S, et al. Topical versus sub-Tenon's anesthesia without sedation in cataract surgery. J Cataract Refract Surg 2001;27:873-879 Editors' note: Dr. Greenbaum is in practice at Greenbaum Eye Associates, and clinical assistant professor of ophthalmology, New York University Medical Center, New York. He has financial interests with Halozyme. Alcon® Contact information ® 973-989-1600 r800-225-1195 r www.katena.com r80 Greenbaum: 718-897-2020, thecannula@aol.com