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Topical Gel vs Subconjunctival Lidocaine for Intravitreous Injection: A Randomized Clinical Trial
REFERENCES
1. Treatment of Age-Related Macular Degeneration With Photodynamic Therapy (TAP) Study Group. Verteporfin therapy for subfoveal choroidal neovascularization in age-related macular degeneration: three-year results of an open-label extension of two randomized clinical trials. TAP Report No. 5. Arch Ophthalmol 2002;120:1307–1314. 2. Madreperla SA. Choroidal hemangioma treated with photodynamic therapy using verteporfin. Arch Ophthalmol 2001; 119:1606 –1610. 3. Schmidt-Erfurth UM, Kusserow C, Barbazetto IA, Laqua H. Benefits and complications of photodynamic therapy of papillary capillary hemangiomas. Ophthalmology 2002;109:1256 –1266. 4. Barbazetto IA, Lee TC, Rollins IS. Chang S, Abramson DH. Treatment of choroidal melanoma using photodynamic therapy. Am J Ophthalmol 2003;135:898 – 899. 5. Haubour J. Photodynamic therapy for choroidal metastasis from carcinoid tumor. Am J Ophthalmol 2004;137:1143–1145. 6. Demirci H, Shields CL, Chao AN, Shields JA. Uveal metastasis from breast cancer in 264 patients. Am J Ophthalmol 2003;136:264 –271.
Topical Gel vs Subconjunctival Lidocaine for Intravitreous Injection: A Randomized Clinical Trial Scott M. Friedman, MD, and Curtis E. Margo, MD, MPH To determine if topical gel is superior to subconjunctival injection of lidocaine in relieving pain of intravitreous injection of corticosteroid. DESIGN: Randomized clinical trial. METHODS: PATIENT POPULATION: One hundred patients receiving intravitreous injection of triamcinolone. INTERVENTIONAL PROCEDURE: Topical lidocaine 2% gel and subconjunctival lidocaine 2% injection. OUTCOME MEASURE: Analog pain score assessment, conducted by technician masked to treatment. RESULTS: There was no statistically significant difference in pain scores between the treatment groups (P ⴝ .1). CONCLUSIONS: The effective relief of pain with lidocaine for intravitreous injection is independent of its mode of application (gel vs subconjunctival injection). (Am J Ophthalmol 2006;142:887– 888. © 2006 by Elsevier Inc. All rights reserved.) PURPOSE:
Accepted for publication Jun 8, 2006. From the Central Florida Retina Institute, Lakeland, Florida (S.M.F.); and Department of Ophthalmology, University of South Florida, Tampa, Florida (C.E.M.). Presented at the Retina Society Annual Meeting, September 2005, Coronado, California. Inquiries to Scott M. Friedman, MD, Central Florida Retina Institute, 2202 Lakeland Hills Blvd, Lakeland, FL 33805; e-mail: smfriedman83@ hotmail.com
VOL. 142, NO. 5
T
HE SAFETY AND COMFORT OF AN INTRAVITREOUS IN-
jection depends on the optimal use of local anesthetic. There are several different methods of applying local anesthetic in this situation. From an informal survey, we found the most popular methods are topical gel and subconjunctival injection of lidocaine. In our experience, topical anesthetic drops alone do not provide adequate pain relief for intraocular injection of corticosteroid. A randomized clinical trial was conducted to determine if subconjunctival injection of lidocaine 2% provides superior comfort compared with topical gel. Sample size was based on previous ocular pain studies that used an analog pain scale as an outcome measure.1,2 A sample size of 44 patients/treatment group would provide an 80% probability of detecting an important difference in pain magnitude, if one exists, assuming a ratio of expected treatment effect to standard deviation of 0.6 (two-tailed, ␣ ⫽ 0.05). A total sample size of 100 was selected to take into account a 10% drop out rate. The Internal Review Board of Winter Haven Hospital approved the study. All intravitreous injections were administered according to protocol by one of the authors (S.M.F.). A standardized method was used to prepare the injection site and disinfect the surface of the eye using povidone iodide. One drop of proparacaine hydrochloride 0.5% was placed in the inferior cul-de-sac before positioning the speculum in both treatment groups. For the lidocaine gel group, gel was placed on the eye before injection. For the subconjunctival group, a 30-gauge needle was used to deliver 0.2 to 0.4 ml of lidocaine 2% adjacent to the limbus. All intravitreous injections were given within 30 seconds of anesthetic application. The method of intravitreous injection of triamcinolone acetonide using a 27gauge needle was identical in the two groups. Fifteen minutes after the injection, patients were asked to rate their pain experience on a 10-point analog scale. Scores of zero and 10 corresponded to no pain and maximum conceivable pain, respectively. A technician, who was masked to the treatment, conducted the interview. The mean score for the topical gel group was 2.6 (n ⫽ 52; SD ⫽ 1.7) and for the subconjunctival group was 3.3 (n ⫽ 48; SD ⫽ 1.9). Although there was a trend to less pain in the gel group, the difference was not statistically significant (P ⫽ .1 [Mann-Whitney test, for nonparametric statistics]). Simple linear regression analysis showed that pain scores were not correlated with age, gender, or laterality of eye. There were no significant differences in the two treatment groups by gender, age, or laterality. There was a comparable distribution of underlying disease in both groups (macular degeneration, diabetic macular edema, retinal vascular occlusive disease, and uveitis). Kozak and associates3 performed two studies comparing the effectiveness of topical gel and subconjunctival injection of lidocaine for intravitreous injection, and found no differences in patient comfort between the two groups in either study. Their study designs consisted of a crossover
BRIEF REPORTS
887
trial involving 12 patients and a series of 16 patients (eight assigned to each group). Both studies were underpowered to detect a small but possibly important difference in outcome. The results of our study support their conclusions, and had a final probability of 88% of detecting a difference in outcome between groups if one truly existed. Though the generalizability of the results of our study may be limited because the procedure was performed by a single ophthalmologist, the technique of intravitreous injection is relatively standardized and tends to vary minimally among ophthalmologists. We found that the effective relief of pain with lidocaine for intravitreous injection is independent of its mode of application. Physicians and patients may prefer topical lidocaine gel because of easy of
888
AMERICAN JOURNAL
administration and because of the lower incidence of subconjunctival hemorrhage, given that the level of comfort is equivalent to subconjunctival injection. REFERENCES
1. Jacobi PC, Dietlein TS, Bacobi FK. A comparative study of topical vs retrobulbar anesthesia in complicated cataract surgery. Arch Ophthalmol 2000;118:1037–1043. 2. Crandall AS, Zabriskie NA, Patel BC, Burns TA, et al. A comparison of patient comfort during cataract surgery with topical anesthesia and intracameral lidocaine. Ophthalmology 1999;106:60 – 66. 3. Kozak I, Cheng L, Freeman WR. Lidocaine gel anesthesia for intravitreal drug administration. Retina 2005;25:994 –998.
OF
OPHTHALMOLOGY
NOVEMBER 2006
1. Treatment of Age-Related Macular Degeneration With Photodynamic Therapy (TAP) Study Group. Verteporfin therapy for subfoveal choroidal neovascularization in age-related macular degeneration: three-year results of an open-label extension of two randomized clinical trials. TAP Report No. 5. Arch Ophthalmol 2002;120:1307–1314. 2. Madreperla SA. Choroidal hemangioma treated with photodynamic therapy using verteporfin. Arch Ophthalmol 2001; 119:1606 –1610. 3. Schmidt-Erfurth UM, Kusserow C, Barbazetto IA, Laqua H. Benefits and complications of photodynamic therapy of papillary capillary hemangiomas. Ophthalmology 2002;109:1256 –1266. 4. Barbazetto IA, Lee TC, Rollins IS. Chang S, Abramson DH. Treatment of choroidal melanoma using photodynamic therapy. Am J Ophthalmol 2003;135:898 – 899. 5. Haubour J. Photodynamic therapy for choroidal metastasis from carcinoid tumor. Am J Ophthalmol 2004;137:1143–1145. 6. Demirci H, Shields CL, Chao AN, Shields JA. Uveal metastasis from breast cancer in 264 patients. Am J Ophthalmol 2003;136:264 –271.
Topical Gel vs Subconjunctival Lidocaine for Intravitreous Injection: A Randomized Clinical Trial Scott M. Friedman, MD, and Curtis E. Margo, MD, MPH To determine if topical gel is superior to subconjunctival injection of lidocaine in relieving pain of intravitreous injection of corticosteroid. DESIGN: Randomized clinical trial. METHODS: PATIENT POPULATION: One hundred patients receiving intravitreous injection of triamcinolone. INTERVENTIONAL PROCEDURE: Topical lidocaine 2% gel and subconjunctival lidocaine 2% injection. OUTCOME MEASURE: Analog pain score assessment, conducted by technician masked to treatment. RESULTS: There was no statistically significant difference in pain scores between the treatment groups (P ⴝ .1). CONCLUSIONS: The effective relief of pain with lidocaine for intravitreous injection is independent of its mode of application (gel vs subconjunctival injection). (Am J Ophthalmol 2006;142:887– 888. © 2006 by Elsevier Inc. All rights reserved.) PURPOSE:
Accepted for publication Jun 8, 2006. From the Central Florida Retina Institute, Lakeland, Florida (S.M.F.); and Department of Ophthalmology, University of South Florida, Tampa, Florida (C.E.M.). Presented at the Retina Society Annual Meeting, September 2005, Coronado, California. Inquiries to Scott M. Friedman, MD, Central Florida Retina Institute, 2202 Lakeland Hills Blvd, Lakeland, FL 33805; e-mail: smfriedman83@ hotmail.com
VOL. 142, NO. 5
T
HE SAFETY AND COMFORT OF AN INTRAVITREOUS IN-
jection depends on the optimal use of local anesthetic. There are several different methods of applying local anesthetic in this situation. From an informal survey, we found the most popular methods are topical gel and subconjunctival injection of lidocaine. In our experience, topical anesthetic drops alone do not provide adequate pain relief for intraocular injection of corticosteroid. A randomized clinical trial was conducted to determine if subconjunctival injection of lidocaine 2% provides superior comfort compared with topical gel. Sample size was based on previous ocular pain studies that used an analog pain scale as an outcome measure.1,2 A sample size of 44 patients/treatment group would provide an 80% probability of detecting an important difference in pain magnitude, if one exists, assuming a ratio of expected treatment effect to standard deviation of 0.6 (two-tailed, ␣ ⫽ 0.05). A total sample size of 100 was selected to take into account a 10% drop out rate. The Internal Review Board of Winter Haven Hospital approved the study. All intravitreous injections were administered according to protocol by one of the authors (S.M.F.). A standardized method was used to prepare the injection site and disinfect the surface of the eye using povidone iodide. One drop of proparacaine hydrochloride 0.5% was placed in the inferior cul-de-sac before positioning the speculum in both treatment groups. For the lidocaine gel group, gel was placed on the eye before injection. For the subconjunctival group, a 30-gauge needle was used to deliver 0.2 to 0.4 ml of lidocaine 2% adjacent to the limbus. All intravitreous injections were given within 30 seconds of anesthetic application. The method of intravitreous injection of triamcinolone acetonide using a 27gauge needle was identical in the two groups. Fifteen minutes after the injection, patients were asked to rate their pain experience on a 10-point analog scale. Scores of zero and 10 corresponded to no pain and maximum conceivable pain, respectively. A technician, who was masked to the treatment, conducted the interview. The mean score for the topical gel group was 2.6 (n ⫽ 52; SD ⫽ 1.7) and for the subconjunctival group was 3.3 (n ⫽ 48; SD ⫽ 1.9). Although there was a trend to less pain in the gel group, the difference was not statistically significant (P ⫽ .1 [Mann-Whitney test, for nonparametric statistics]). Simple linear regression analysis showed that pain scores were not correlated with age, gender, or laterality of eye. There were no significant differences in the two treatment groups by gender, age, or laterality. There was a comparable distribution of underlying disease in both groups (macular degeneration, diabetic macular edema, retinal vascular occlusive disease, and uveitis). Kozak and associates3 performed two studies comparing the effectiveness of topical gel and subconjunctival injection of lidocaine for intravitreous injection, and found no differences in patient comfort between the two groups in either study. Their study designs consisted of a crossover
BRIEF REPORTS
887
trial involving 12 patients and a series of 16 patients (eight assigned to each group). Both studies were underpowered to detect a small but possibly important difference in outcome. The results of our study support their conclusions, and had a final probability of 88% of detecting a difference in outcome between groups if one truly existed. Though the generalizability of the results of our study may be limited because the procedure was performed by a single ophthalmologist, the technique of intravitreous injection is relatively standardized and tends to vary minimally among ophthalmologists. We found that the effective relief of pain with lidocaine for intravitreous injection is independent of its mode of application. Physicians and patients may prefer topical lidocaine gel because of easy of
888
AMERICAN JOURNAL
administration and because of the lower incidence of subconjunctival hemorrhage, given that the level of comfort is equivalent to subconjunctival injection. REFERENCES
1. Jacobi PC, Dietlein TS, Bacobi FK. A comparative study of topical vs retrobulbar anesthesia in complicated cataract surgery. Arch Ophthalmol 2000;118:1037–1043. 2. Crandall AS, Zabriskie NA, Patel BC, Burns TA, et al. A comparison of patient comfort during cataract surgery with topical anesthesia and intracameral lidocaine. Ophthalmology 1999;106:60 – 66. 3. Kozak I, Cheng L, Freeman WR. Lidocaine gel anesthesia for intravitreal drug administration. Retina 2005;25:994 –998.
OF
OPHTHALMOLOGY
NOVEMBER 2006