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Safety of intracameral phenylephrine
LETTERS
Long-term outcomes of cataract surgery: 15-year results of a prospective study We read with interest the recent paper by Eva M€ onestam1 describing the long-term changes (over a 15-year period) in corrected distance visual acuity, subjective visual function, and neodymium:YAG frequency after cataract surgery. We herein address important and untouched issues, some of which warrant further discussion. First, how many enrolled patients had preexisting age-related macular degeneration or glaucoma, and how many developed these during the follow-up? How many of these patients required intravitreal injections and/or surgeries that might have influenced the 15-year postoperative visual acuity and Visual Function Index-14 (VF-14) scores? Second, even though there were no variations in the surgical technique used by 4 operating surgeons, no mention was made of the intraoperative and postoperative complications encountered by the different surgeons that might have influenced the final visual acuity and the VF-14 questionnaire scores. Last, previous studies2,3 have shown that patients who had bilateral surgery had greater improvement in functional status and were significantly more satisfied with their visual function than patients having first-eye surgery. Did the 23 patients who had singleeye surgery fare poorer on the VF-14 questionnaire than those who were operated on bilaterally? Parul Chawla Gupta, MS Jagat Ram, MS Chandigarh, India REFERENCES €nestam E. Long-term outcomes of cataract surgery: 15-year 1. Mo results of a prospective study. J Cataract Refract Surg 2016; 42: 19–26. Available at: http://www.jcrsjournal.org/article/S0886 -3350(15)01202-X/pdf. Accessed April 5, 2016 2. Tan ACS, Tay WT, Zheng YF, Tan AG, Wang JJ, Mitchell P, Wong TY, Lamoureux EL. The impact of bilateral or unilateral cataract surgery on visual functioning: when does second eye cataract surgery benefit patients? Br J Ophthalmol 2012; 96: 846–851 3. Castells X, Comas M, Alonso J, Espallargues M, Martınez V, Garcıa-Arumı J, Castilla M. In a randomized controlled trial, cataract surgery in both eyes increased benefits compared to surgery in one eye only. J Clin Epidemiol 2006; 59:201–207
Reply : Thank you for your interest and comments regarding my article. I agree that issues such as preexisting age-related macular degeneration (AMD) or glaucoma and how they develop during follow-up are important. A manuscript regarding the glaucoma patients is under preparation and 944
Q 2016 ASCRS and ESCRS Published by Elsevier Inc.
regarding the AMD patients, an extensive analysis was performed at the follow-up 10 years after surgery.1 The intraoperative and postoperative complications are described in references 8 to 10 as mentioned in the paper, especially the reference by M€ onestam et al.2 The frequency of capsular/zonular rupture was within normal limits for the time in a population with a high frequency of pseudoexfoliation and mature cataracts. There was no difference between the surgeons. When this long-time outcome study started in 1997, some patients enrolled had second-eye surgery. During the 15 years that have passed, all first-eye surgery patients with significant cataract in their fellow eye had already had second-eye surgery. The majority of the 23 patients with only 1 eye with cataract surgery have no useful vision in their fellow eye for various reasons and therefore no indication for cataract surgery. A few patients are still without significant cataract, but they will be operated on when there is an indication for surgery. The issue of bilateral surgery is not relevant for this patient cohort.dEva M€onestam, MD, PhD REFERENCES € nestam E, Lundqvist B. Long-term visual outcome after cata1. Mo ract surgery: comparison of healthy eyes and eyes with agerelated macular degeneration. J Cataract Refract Surg 2012; 38:409–414 € nestam E, Kuusik M, Wachtmeister L. Topical anesthesia for 2. Mo cataract surgery: a population-based perspective. J Cataract Refract Surg 2001; 27:445–451
Safety of intracameral phenylephrine I read with interest the article by Shams et al.1 on systemic complications of phenylephrine used in the preoperative period and agree with their recommendation that patients receiving topical phenylephrine might benefit from cardiac and blood pressure monitoring. It is unclear from their article whether topical preoperative phenylephrine drops were also used. The peak plasma level of phenylephrine after preoperative drops is 15 to 20 minutes,2 which reflects the time course in their patient. Plasma levels after intracameral phenylephrine, unlike with topical administration, have not been measured and must be lower due to the blood–eye barrier and lesser dose. When one reviews the physiologic cardiac responses to phenylephrine, ventricular fibrillation is unlikely to be related to phenylephrine, whether applied topically or intracamerally. Ear, nose, and throat use of large doses of phenylephrine has been reported to cause severe cardiovascular compromise and possibly death.3 Although http://dx.doi.org/10.1016/j.jcrs.2016.04.013 0886-3350
945
LETTERS
phenylephrine is predominantly a selective a-agonist, at very high doses b activation does occur. Patients might demonstrate a marked bradycardia in response to hypertension, suggesting mainly an a-1–mediated vasoconstriction and a baroreceptor-mediated bradycardia. Phenylephrine also increases the energy required to induce ventricular fibrillation in humans. Phenylephrine infusion has differential electrophysiologic effects in atrial and ventricular tissue. Rather than being proarrhythmic, phenylephrine might be protective against arrhythmias because it effectively terminates supraventricular tachycardias and might be protective against ventricular arrhythmias.4 Of greater concern is the anesthesiologist's response to phenylephrine-induced hypertension, especially with bradycardia. Labetalol is readily available and is a drug most anesthesiologists have experience using for intraoperative hypertension. It is a mixed a-antagonist and b-antagonist, although the b effects are about 7 times stronger than the a effects. Beta antagonists might result in the inability of the heart to compensate for the increased after-load, leading to pulmonary edema.5 A New York State report on phenylephrine use in the operating room6 recommended that severe hypertension or associated complications (pulmonary edema or electrocardiogram changes) should be treated with direct vasodilators or a-antagonists, such as phentolamine, rather than b-blockers. I routinely use a compounded solution of phenylephrine 1.5% and lidocaine 1.0% solution as the sole method of pupil dilation as well as for prophylaxis against intraoperative floppy-iris syndrome. I have never had patients with monitored anesthesia care develop new ventricular arrhythmias, while only occasionally do some need management for hypertension. The dose from an intracameral placement of 0.2 mL of phenylephrine 1.5% is exceedingly low, making the risk for systemic complications even lower than that of topical phenylephrine 2.5% drops, a practice deemed safe based on a recent review and metaanalysis.7 William G. Myers, MD Chicago, Illinois, USA Financial Disclosure: Dr. Myers is a consultant to Leiter's Compounding. REFERENCES 1. Shams F, Jafari FA, Mansfield D. Cardiovascular hazard of intracameral phenylephrine. J Cataract Refract Surg 2015; 41:2021–2022 2. Kenawy NB, Jabir M. Phenylephrine 2.5% and 10% in phacoemulsification under topical anaesthesia: is there an effect on systemic blood pressure? [letter] Br J Ophthalmol 2003; 87:505–506. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1771603/ pdf/bjo08700505.pdf. Accessed April 19, 2016
3. Macmillan M, Barker K. Phenylephrine toxicity [letter]. Eur J Anaesthesiol 2008; 25:426–427 4. Tisdale JE, Patel RV, Webb CR, Borzak S, Zarowitz BJ. Proarrhythmic effects of intravenous vasopressors. Ann Pharmacother 1995; 29:269–281 5. Shanks RG. Clinical pharmacology of vasodilatory betablocking drugs. Am Heart J 1991; 121:1006–1011 6. Groudine SB, Hollinger I, Jones J, DeBouno BA. The Phenylephrine Advisory Committee. New York State guidelines on the topical use of phenylephrine in the operating room. Anesthesiology 2000; 92:859–864. Available at: http://anesthesiology. pubs.asahq.org/article.aspx?articleidZ1945724. Accessed April 19, 2016 7. Stavert B, McGuinness MB, Harper CA, Guymer RH, Finger RP. Cardiovascular adverse effects of phenylephrine eyedrops; a systematic review and meta-analysis. JAMA Ophthalmol 2015; 133:647–652
Intraocular lens placement with inadequate capsule support We read with interest the recent paper by Sorenson et al.1 determining practice patterns with regard to intraocular lens (IOL) placement during cataract surgery when there is inadequate capsule support for intracapsular or sulcus IOL placement. We herein address important and untouched issues, some of which warrant further discussion. First, faced with inadequate capsule support, 58.6% of surgeons would place a primary anterior chamber (AC) IOL, 29.3% would place a primary scleral-fixated posterior chamber (PC) IOL, and 5.3% would leave the patient aphakic for secondary scleral-fixated PC IOL placement. What would the rest of the surgeons (ie, 6.8%) do? Second, the number of surgeons completing fellowship was different in the manuscript (n Z 43) and in the table (n Z 42). Third, what percentage of patients had phacoemulsification, and how many had extracapsular cataract extraction; this is important because the type of surgery might also influence the type of IOL placement. Was scleral fixation performed using glue or sutures? Which type of IOL was used, a 3-piece poly(methyl methacrylate) or a 3-piece acrylic? Secondary implantation of a scleral-fixated IOL was performed how long after the primary surgery? Fourth, how many surgeons were equally comfortable placing scleral-fixated PC IOLs or AC IOLs independently at the time of primary surgery? Out of them, how many chose to implant AC IOLs based on possibly shorter surgery times with AC IOLs than with scleral-fixated IOLs? Last, the postoperative safety and visual outcomes of AC IOL implantation versus scleral-fixated IOL implantation in the study patients could also have been documented. This would have allowed the readers to decide about the choice of IOL implantation in a more comprehensive manner.
J CATARACT REFRACT SURG - VOL 42, JUNE 2016
Long-term outcomes of cataract surgery: 15-year results of a prospective study We read with interest the recent paper by Eva M€ onestam1 describing the long-term changes (over a 15-year period) in corrected distance visual acuity, subjective visual function, and neodymium:YAG frequency after cataract surgery. We herein address important and untouched issues, some of which warrant further discussion. First, how many enrolled patients had preexisting age-related macular degeneration or glaucoma, and how many developed these during the follow-up? How many of these patients required intravitreal injections and/or surgeries that might have influenced the 15-year postoperative visual acuity and Visual Function Index-14 (VF-14) scores? Second, even though there were no variations in the surgical technique used by 4 operating surgeons, no mention was made of the intraoperative and postoperative complications encountered by the different surgeons that might have influenced the final visual acuity and the VF-14 questionnaire scores. Last, previous studies2,3 have shown that patients who had bilateral surgery had greater improvement in functional status and were significantly more satisfied with their visual function than patients having first-eye surgery. Did the 23 patients who had singleeye surgery fare poorer on the VF-14 questionnaire than those who were operated on bilaterally? Parul Chawla Gupta, MS Jagat Ram, MS Chandigarh, India REFERENCES €nestam E. Long-term outcomes of cataract surgery: 15-year 1. Mo results of a prospective study. J Cataract Refract Surg 2016; 42: 19–26. Available at: http://www.jcrsjournal.org/article/S0886 -3350(15)01202-X/pdf. Accessed April 5, 2016 2. Tan ACS, Tay WT, Zheng YF, Tan AG, Wang JJ, Mitchell P, Wong TY, Lamoureux EL. The impact of bilateral or unilateral cataract surgery on visual functioning: when does second eye cataract surgery benefit patients? Br J Ophthalmol 2012; 96: 846–851 3. Castells X, Comas M, Alonso J, Espallargues M, Martınez V, Garcıa-Arumı J, Castilla M. In a randomized controlled trial, cataract surgery in both eyes increased benefits compared to surgery in one eye only. J Clin Epidemiol 2006; 59:201–207
Reply : Thank you for your interest and comments regarding my article. I agree that issues such as preexisting age-related macular degeneration (AMD) or glaucoma and how they develop during follow-up are important. A manuscript regarding the glaucoma patients is under preparation and 944
Q 2016 ASCRS and ESCRS Published by Elsevier Inc.
regarding the AMD patients, an extensive analysis was performed at the follow-up 10 years after surgery.1 The intraoperative and postoperative complications are described in references 8 to 10 as mentioned in the paper, especially the reference by M€ onestam et al.2 The frequency of capsular/zonular rupture was within normal limits for the time in a population with a high frequency of pseudoexfoliation and mature cataracts. There was no difference between the surgeons. When this long-time outcome study started in 1997, some patients enrolled had second-eye surgery. During the 15 years that have passed, all first-eye surgery patients with significant cataract in their fellow eye had already had second-eye surgery. The majority of the 23 patients with only 1 eye with cataract surgery have no useful vision in their fellow eye for various reasons and therefore no indication for cataract surgery. A few patients are still without significant cataract, but they will be operated on when there is an indication for surgery. The issue of bilateral surgery is not relevant for this patient cohort.dEva M€onestam, MD, PhD REFERENCES € nestam E, Lundqvist B. Long-term visual outcome after cata1. Mo ract surgery: comparison of healthy eyes and eyes with agerelated macular degeneration. J Cataract Refract Surg 2012; 38:409–414 € nestam E, Kuusik M, Wachtmeister L. Topical anesthesia for 2. Mo cataract surgery: a population-based perspective. J Cataract Refract Surg 2001; 27:445–451
Safety of intracameral phenylephrine I read with interest the article by Shams et al.1 on systemic complications of phenylephrine used in the preoperative period and agree with their recommendation that patients receiving topical phenylephrine might benefit from cardiac and blood pressure monitoring. It is unclear from their article whether topical preoperative phenylephrine drops were also used. The peak plasma level of phenylephrine after preoperative drops is 15 to 20 minutes,2 which reflects the time course in their patient. Plasma levels after intracameral phenylephrine, unlike with topical administration, have not been measured and must be lower due to the blood–eye barrier and lesser dose. When one reviews the physiologic cardiac responses to phenylephrine, ventricular fibrillation is unlikely to be related to phenylephrine, whether applied topically or intracamerally. Ear, nose, and throat use of large doses of phenylephrine has been reported to cause severe cardiovascular compromise and possibly death.3 Although http://dx.doi.org/10.1016/j.jcrs.2016.04.013 0886-3350
945
LETTERS
phenylephrine is predominantly a selective a-agonist, at very high doses b activation does occur. Patients might demonstrate a marked bradycardia in response to hypertension, suggesting mainly an a-1–mediated vasoconstriction and a baroreceptor-mediated bradycardia. Phenylephrine also increases the energy required to induce ventricular fibrillation in humans. Phenylephrine infusion has differential electrophysiologic effects in atrial and ventricular tissue. Rather than being proarrhythmic, phenylephrine might be protective against arrhythmias because it effectively terminates supraventricular tachycardias and might be protective against ventricular arrhythmias.4 Of greater concern is the anesthesiologist's response to phenylephrine-induced hypertension, especially with bradycardia. Labetalol is readily available and is a drug most anesthesiologists have experience using for intraoperative hypertension. It is a mixed a-antagonist and b-antagonist, although the b effects are about 7 times stronger than the a effects. Beta antagonists might result in the inability of the heart to compensate for the increased after-load, leading to pulmonary edema.5 A New York State report on phenylephrine use in the operating room6 recommended that severe hypertension or associated complications (pulmonary edema or electrocardiogram changes) should be treated with direct vasodilators or a-antagonists, such as phentolamine, rather than b-blockers. I routinely use a compounded solution of phenylephrine 1.5% and lidocaine 1.0% solution as the sole method of pupil dilation as well as for prophylaxis against intraoperative floppy-iris syndrome. I have never had patients with monitored anesthesia care develop new ventricular arrhythmias, while only occasionally do some need management for hypertension. The dose from an intracameral placement of 0.2 mL of phenylephrine 1.5% is exceedingly low, making the risk for systemic complications even lower than that of topical phenylephrine 2.5% drops, a practice deemed safe based on a recent review and metaanalysis.7 William G. Myers, MD Chicago, Illinois, USA Financial Disclosure: Dr. Myers is a consultant to Leiter's Compounding. REFERENCES 1. Shams F, Jafari FA, Mansfield D. Cardiovascular hazard of intracameral phenylephrine. J Cataract Refract Surg 2015; 41:2021–2022 2. Kenawy NB, Jabir M. Phenylephrine 2.5% and 10% in phacoemulsification under topical anaesthesia: is there an effect on systemic blood pressure? [letter] Br J Ophthalmol 2003; 87:505–506. Available at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1771603/ pdf/bjo08700505.pdf. Accessed April 19, 2016
3. Macmillan M, Barker K. Phenylephrine toxicity [letter]. Eur J Anaesthesiol 2008; 25:426–427 4. Tisdale JE, Patel RV, Webb CR, Borzak S, Zarowitz BJ. Proarrhythmic effects of intravenous vasopressors. Ann Pharmacother 1995; 29:269–281 5. Shanks RG. Clinical pharmacology of vasodilatory betablocking drugs. Am Heart J 1991; 121:1006–1011 6. Groudine SB, Hollinger I, Jones J, DeBouno BA. The Phenylephrine Advisory Committee. New York State guidelines on the topical use of phenylephrine in the operating room. Anesthesiology 2000; 92:859–864. Available at: http://anesthesiology. pubs.asahq.org/article.aspx?articleidZ1945724. Accessed April 19, 2016 7. Stavert B, McGuinness MB, Harper CA, Guymer RH, Finger RP. Cardiovascular adverse effects of phenylephrine eyedrops; a systematic review and meta-analysis. JAMA Ophthalmol 2015; 133:647–652
Intraocular lens placement with inadequate capsule support We read with interest the recent paper by Sorenson et al.1 determining practice patterns with regard to intraocular lens (IOL) placement during cataract surgery when there is inadequate capsule support for intracapsular or sulcus IOL placement. We herein address important and untouched issues, some of which warrant further discussion. First, faced with inadequate capsule support, 58.6% of surgeons would place a primary anterior chamber (AC) IOL, 29.3% would place a primary scleral-fixated posterior chamber (PC) IOL, and 5.3% would leave the patient aphakic for secondary scleral-fixated PC IOL placement. What would the rest of the surgeons (ie, 6.8%) do? Second, the number of surgeons completing fellowship was different in the manuscript (n Z 43) and in the table (n Z 42). Third, what percentage of patients had phacoemulsification, and how many had extracapsular cataract extraction; this is important because the type of surgery might also influence the type of IOL placement. Was scleral fixation performed using glue or sutures? Which type of IOL was used, a 3-piece poly(methyl methacrylate) or a 3-piece acrylic? Secondary implantation of a scleral-fixated IOL was performed how long after the primary surgery? Fourth, how many surgeons were equally comfortable placing scleral-fixated PC IOLs or AC IOLs independently at the time of primary surgery? Out of them, how many chose to implant AC IOLs based on possibly shorter surgery times with AC IOLs than with scleral-fixated IOLs? Last, the postoperative safety and visual outcomes of AC IOL implantation versus scleral-fixated IOL implantation in the study patients could also have been documented. This would have allowed the readers to decide about the choice of IOL implantation in a more comprehensive manner.
J CATARACT REFRACT SURG - VOL 42, JUNE 2016